Journal articles: 'Acid and bile tolerance'

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Masaaki Minami, Shin-nosuke Hashikawa, Takafumi Ando, Hidemi Goto, and Michio Ohta. "AcrB is essential for bile acid tolerance in Helicobacter pylori." GSC Advanced Research and Reviews 10, no. 2 (February 28, 2022): 099–106. http://dx.doi.org/10.30574/gscarr.2022.10.2.0055.

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Resistance to bile acids is a necessary ability for bacteria that live in the gastrointestinal tract, such as Helicobacter pylori. The role of the bacterial drug efflux system is important for bile acid tolerance. Using the H. pylori JP26 strain and the JP26AcrB strain deficient in AcrB the relationship between the drug efflux system AcrB and the bile acid tolerance of H. pylori was investigated. Bacterial susceptibility to bile acids was measured by the agar dilution method. To examine the ability to efflux bile acids, the intracellular accumulation of radiolabeled chenodeoxycholic acid was measured with a liquid scintillation counter. To investigate the effect of bile acid on the cell adhesion ability of bacteria, bacteria were attached to AGS cells supplemented with chenodeoxycholic acid, and the number of bacteria was counted. Bile acid resistance was significantly lower in the AcrB mutant than in the wild-type strain. The AcrB mutant strains showed a significant increase in the accumulation of 14C - labeled chenodeoxycholic acid in the bacteria. In terms of attachment to AGS cells, the AcrB mutant was significantly lower than the wild-type strain. Furthermore, the AcrB mutant with chenodeoxycholic acid could not be identified. Our results reveal that H. pylori AcrB plays an important role in bile acid resistance. We also suggest that drugs targeting the AcrB efflux system may be a new treatment for H. pylori.

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Kimoto-Nira, Hiromi, Shigenori Suzuki, Takafumi Yakabe, and Chise Suzuki. "Relationships between fatty acid composition and bile tolerance in lactobacillus isolates from plants and from non-plant materials." Canadian Journal of Microbiology 58, no. 12 (December 2012): 1396–404. http://dx.doi.org/10.1139/cjm-2012-0442.

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Twenty plant-derived and 18 non-plant-derived strains of Lactobacillus casei were compared for their growth in tryptone – yeast extract – glucose broth containing 0.3% bile by measuring absorbance at a wavelength of 620 nm after 24 h of incubation at 37 °C. Bile tolerance — a fundamental probiotic property — was calculated by dividing the experimental data by control values (growth without bile). We found that bile tolerance was strain specific but that the average bile tolerance of the plant-derived strains was significantly (P < 0.05) lower than that of the non-plant-derived strains tested. All tested strains could not deconjugate sodium taurocholate, indicating that the difference in bile tolerance was not due to the ability to deconjugate bile. The fatty acid compositions of the test strains with and without exposure to 0.3% bile were investigated, and a statistical correlation analysis between these compositions and their bile tolerance was conducted. The fatty acids correlated with bile tolerance differed between plant and non-plant lactobacilli. This is the first report to show that the origin (i.e., growth environment) of lactobacilli affects their fatty acid composition, which in turn, appears to be related to their bile tolerance.

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HE, XINLONG, YUNYUN ZOU, YOUNGJAE CHO, and JUHEE AHN. "Effects of Bile Salt Deconjugation by Probiotic Strains on the Survival of Antibiotic-Resistant Foodborne Pathogens under Simulated Gastric Conditions." Journal of Food Protection 75, no. 6 (June 1, 2012): 1090–98. http://dx.doi.org/10.4315/0362-028x.jfp-11-456.

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This study was designed to evaluate the effects of bile acid deconjugation by probiotic strains on the antibiotic susceptibility of antibiotic-sensitive and multiple antibiotic–resistant Salmonella Typhimurium and Staphylococcus aureus. Eight probiotic strains, Bifidobacterium longum B6, Lactobacillus acidophilus ADH, Lactobacillus brevis KACC 10553, Lactobacillus casei KACC 12413, Lactobacillus paracasei ATCC 25598, Lactobacillus rhamnosus GG, Leuconostoc mesenteroides KACC 12312, and Pediococcus acidilactici KACC 12307, were used to examine bile acid tolerance. The ability to deconjugate bile acids was evaluated using both thin-layer chromatography and high-performance liquid chromatography. The antibiotic susceptibility testing was carried out to determine the synergistic inhibitory activity of deconjugated bile acids. L. acidophilus, L. brevis, and P. acidilactici showed the most tolerance to the conjugated bile acids. P. acidilactici deconjugated glycocholic acid and glycodeoxycholate from 3.18 and 3.09 mM to the detection limits, respectively. The antibiotic susceptibility of selected foodborne pathogens was increased by increasing the concentration of deconjugated bile acids. The study results are useful for understanding the relationship between bile acid deconjugation by probiotic strains and antibiotic susceptibility in the presence of deconjugated bile acids, and they may be useful for designing new probiotic-antibiotic combination therapy based on bile acid deconjugation.

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Kohli, Rohit, Kenneth DR Setchell, Michelle Kirby, Andriy Myronovych, Karen K. Ryan, Samar H. Ibrahim, Jose Berger, et al. "A Surgical Model in Male Obese Rats Uncovers Protective Effects of Bile Acids Post-Bariatric Surgery." Endocrinology 154, no. 7 (April 16, 2013): 2341–51. http://dx.doi.org/10.1210/en.2012-2069.

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Abstract Bariatric surgery elevates serum bile acids. Conjugated bile acid administration, such as tauroursodeoxycholic acid (TUDCA), improves insulin sensitivity, whereas short-circuiting bile acid circulation through ileal interposition surgery in rats raises TUDCA levels. We hypothesized that bariatric surgery outcomes could be recapitulated by short circuiting the normal enterohepatic bile circulation. We established a model wherein male obese rats underwent either bile diversion (BD) or Sham (SH) surgery. The BD group had a catheter inserted into the common bile duct and its distal end anchored into the middistal jejunum for 4–5 weeks. Glucose tolerance, insulin and glucagon-like peptide-1 (GLP-1) response, hepatic steatosis, and endoplasmic reticulum (ER) stress were measured. Rats post-BD lost significantly more weight than the SH rats. BD rats gained less fat mass after surgery. BD rats had improved glucose tolerance, increased higher postprandial glucagon-like peptide-1 response and serum bile acids but less liver steatosis. Serum bile acid levels including TUDCA concentrations were higher in BD compared to SH pair-fed rats. Fecal bile acid levels were not different. Liver ER stress (C/EBP homologous protein mRNA and pJNK protein) was decreased in BD rats. Bile acid gavage (TUDCA/ursodeoxycholic acid [UDCA]) in diet-induced obese rats, elevated serum TUDCA and concomitantly reduced hepatic steatosis and ER stress (C/EBP homologous protein mRNA). These data demonstrate the ability of alterations in bile acids to recapitulate important metabolic improvements seen after bariatric surgery. Further, our work establishes a model for focused study of bile acids in the context of bariatric surgery that may lead to the identification of therapeutics for metabolic disease.

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Paz, David, Ricardo S. Aleman, Roberto Cedillos, Douglas W. Olson, Kayanush Aryana, Jhunior Marcia, and Charles Boeneke. "Probiotic Characteristics of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus as Influenced by Carao (Cassia grandis)." Fermentation 8, no. 10 (September 29, 2022): 499. http://dx.doi.org/10.3390/fermentation8100499.

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Carao is considered a functional ingredient since its bioactive compounds are meaningful in nutritional, pharmacological, and medicinal applications. The objective of this study was to determine the effects of carao pulp powder on the bacterial viability, acid tolerance, bile tolerance, and protease activity of S. thermophilus STI-06 and L. bulgaricus LB-12. M17 broth with 0.5% lactose and MRS broth were used for S. thermophilus and L. bulgaricus, respectively, for determining bacterial viability, acid tolerance, and bile tolerance. Skim milk was used to study the protease activity of both bacteria. The carao was added at 0 (control), 1.3, 2.6, and 5.3 (g/L) into the broths and skim milk. The broths were enumerated for bacterial viability (every 2 h), bile tolerance (every 4 h), and acid tolerance (every 30 min), and the skim milk was analyzed for protease activity (every 12 h). The General Linear Model (PROC GLM) was used to analyze the data. The 2.6 g/L and 5.3 g/L usage level of carao improved the acid tolerance of S. thermophilus. Carao did not affect the acid tolerance of L. bulgaricus. The usage of 5.3 g/L of carao significantly improved the bile tolerance and protease activity of both bacteria. However, carao did not affect the viability of either bacteria. Overall, 5.3 g/L of carao with these probiotics could be recommended in fermentation processes.

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Suzuki, Shigenori, Hiromi Kimoto-Nira, Hiroyuki Suganuma, Chise Suzuki, Tadao Saito, and Nobuhiro Yajima. "Cellular fatty acid composition and exopolysaccharide contribute to bile tolerance in Lactobacillus brevis strains isolated from fermented Japanese pickles." Canadian Journal of Microbiology 60, no. 4 (April 2014): 183–91. http://dx.doi.org/10.1139/cjm-2014-0043.

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Bile tolerance is a fundamental ability of probiotic bacteria. We examined this property in 56 Lactobacillus brevis strains isolated from Japanese pickles and also evaluated cellular fatty acid composition and cell-bound exopolysaccharide (EPS-b) production. The bile tolerance of these strains was significantly lower in modified de Man – Rogosa – Sharpe (MRS) medium (without Tween 80 or sodium acetate) than in standard MRS medium. Aggregating strains showed significantly higher bile tolerance than nonaggregating strains in MRS medium, but there was no significant difference in the modified MRS media. The relative octadecenoic acid (C18:1) content of the 3 most tolerant aggregating and nonaggregating strains was significantly higher when bile was added to MRS. In MRS without Tween 80, the relative C18:1 content was only marginally affected by addition of bile. In MRS without sodium acetate, only the 3 most tolerant nonaggregating strains increased their relative C18:1 content in the presence of bile. Meanwhile, culture in MRS without sodium acetate reduced EPS-b production in aggregating strains. In conclusion, both EPS-b and cellular fatty acid composition play important roles in bile tolerance of pickle-derived L. brevis.

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Hagi, Tatsuro, Sharon Y. Geerlings, Bart Nijsse, and Clara Belzer. "The effect of bile acids on the growth and global gene expression profiles in Akkermansia muciniphila." Applied Microbiology and Biotechnology 104, no. 24 (November 7, 2020): 10641–53. http://dx.doi.org/10.1007/s00253-020-10976-3.

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Abstract Akkermansia muciniphila is a prominent member of the gut microbiota and the organism gets exposed to bile acids within this niche. Several gut bacteria have bile response genes to metabolize bile acids or an ability to change their membrane structure to prevent membrane damage from bile acids. To understand the response to bile acids and how A. muciniphila can persist in the gut, we studied the effect of bile acids and individual bile salts on growth. In addition, the change in gene expression under ox-bile condition was studied. The growth of A. muciniphila was inhibited by ox-bile and the bile salts mixture. Individual bile salts have differential effects on the growth. Although most bile salts inhibited the growth of A. muciniphila, an increased growth was observed under culture conditions with sodium deoxycholate. Zaragozic acid A, which is a squalene synthase inhibitor leading to changes in the membrane structure, increased the susceptibility of A. muciniphila to bile acids. Transcriptome analysis showed that gene clusters associated with an ABC transporter and RND transporter were upregulated in the presence of ox-bile. In contrast, a gene cluster containing a potassium transporter was downregulated. Membrane transporter inhibitors also decreased the tolerance to bile acids of A. muciniphila. Our results indicated that membrane transporters and the squalene-associated membrane structure could be major bile response systems required for bile tolerance in A. muciniphila. Key points • The growth of Akkermansia muciniphila was inhibited by most bile salts. • Sodium deoxycholate increased the growth of A. muciniphila. • The genes encoding transporters and hopanoid synthesis were upregulated by ox-bile. • The inhibitors of transporters and hopanoid synthesis reduced ox-bile tolerance.

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Gathercole, Laura L., Nikolaos Nikolaou, Shelley E. Harris, Anastasia Arvaniti, Toryn M. Poolman, Jonathan M. Hazlehurst, Denise V. Kratschmar, et al. "AKR1D1 knockout mice develop a sex-dependent metabolic phenotype." Journal of Endocrinology 253, no. 3 (June 1, 2022): 97–113. http://dx.doi.org/10.1530/joe-21-0280.

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Steroid 5β-reductase (AKR1D1) plays important role in hepatic bile acid synthesis and glucocorticoid clearance. Bile acids and glucocorticoids are potent metabolic regulators, but whether AKR1D1 controls metabolic phenotype in vivo is unknown. Akr1d1–/– mice were generated on a C57BL/6 background. Liquid chromatography/mass spectrometry, metabolomic and transcriptomic approaches were used to determine effects on glucocorticoid and bile acid homeostasis. Metabolic phenotypes including body weight and composition, lipid homeostasis, glucose tolerance and insulin tolerance were evaluated. Molecular changes were assessed by RNA-Seq and Western blotting. Male Akr1d1–/– mice were challenged with a high fat diet (60% kcal from fat) for 20 weeks. Akr1d1–/– mice had a sex-specific metabolic phenotype. At 30 weeks of age, male, but not female, Akr1d1–/– mice were more insulin tolerant and had reduced lipid accumulation in the liver and adipose tissue yet had hypertriglyceridemia and increased intramuscular triacylglycerol. This phenotype was associated with sexually dimorphic changes in bile acid metabolism and composition but without overt effects on circulating glucocorticoid levels or glucocorticoid-regulated gene expression in the liver. Male Akr1d1–/– mice were not protected against diet-induced obesity and insulin resistance. In conclusion, this study shows that AKR1D1 controls bile acid homeostasis in vivo and that altering its activity can affect insulin tolerance and lipid homeostasis in a sex-dependent manner.

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Hyronimus, B., C. Le Marrec, A. Hadj Sassi, and A. Deschamps. "Acid and bile tolerance of spore-forming lactic acid bacteria." International Journal of Food Microbiology 61, no. 2-3 (November 2000): 193–97. http://dx.doi.org/10.1016/s0168-1605(00)00366-4.

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Bustamante, Jessica-Miranda, Tyson Dawson, Caitlin Loeffler, Zara Marfori, Julian R. Marchesi, Benjamin H. Mullish, Christopher C. Thompson, et al. "Impact of Fecal Microbiota Transplantation on Gut Bacterial Bile Acid Metabolism in Humans." Nutrients 14, no. 24 (December 7, 2022): 5200. http://dx.doi.org/10.3390/nu14245200.

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Fecal microbiota transplantation (FMT) is a promising therapeutic modality for the treatment and prevention of metabolic disease. We previously conducted a double-blind, randomized, placebo-controlled pilot trial of FMT in obese metabolically healthy patients in which we found that FMT enhanced gut bacterial bile acid metabolism and delayed the development of impaired glucose tolerance relative to the placebo control group. Therefore, we conducted a secondary analysis of fecal samples collected from these patients to assess the potential gut microbial species contributing to the effect of FMT to improve metabolic health and increase gut bacterial bile acid metabolism. Fecal samples collected at baseline and after 4 weeks of FMT or placebo treatment underwent shotgun metagenomic analysis. Ultra-high-performance liquid chromatography-mass spectrometry was used to profile fecal bile acids. FMT-enriched bacteria that have been implicated in gut bile acid metabolism included Desulfovibrio fairfieldensis and Clostridium hylemonae. To identify candidate bacteria involved in gut microbial bile acid metabolism, we assessed correlations between bacterial species abundance and bile acid profile, with a focus on bile acid products of gut bacterial metabolism. Bacteroides ovatus and Phocaeicola dorei were positively correlated with unconjugated bile acids. Bifidobacterium adolescentis, Collinsella aerofaciens, and Faecalibacterium prausnitzii were positively correlated with secondary bile acids. Together, these data identify several candidate bacteria that may contribute to the metabolic benefits of FMT and gut bacterial bile acid metabolism that requires further functional validation.

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Das, Nilanjana, and Mangala Lakshmi Ragavan. "ISOLATION AND CHARACTERIZATION OF POTENTIAL PROBIOTIC YEASTS FROM DIFFERENT SOURCES." Asian Journal of Pharmaceutical and Clinical Research 10, no. 4 (April 1, 2017): 451. http://dx.doi.org/10.22159/ajpcr.2017.v10i4.17067.

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objective The main objective of the present study is to isolate yeasts from different environmental sources to investigate their potential probiotic characteristics.Methods Appropriate in vitro assays has been conducted to examine their probiotic potentiality, such as acid and bile salt tolerance, temperature resistance, stimulated GIT tolerance, cell adhesion and cholesterol removal. All the yeast isolates were tested under in vitro conditions.Results In the present study, 20 yeast species have been isolated from different sources, screened and their desirable probiotic properties viz. pH tolerance, bile salt tolerance and thermo-tolerance have been evaluated. Screened yeast isolates treated with gastric juices showed increased survival rate above 60%. A further in vitro study investigates cholesterol removal and it showed increased cholesterol removal rate up to 92%. Exopolysaccharide production was estimated for selected yeast isolates and applications are under investigation.Conclusion Among 20 yeast isolates, 5 isolates showed increased growth under stress tolerance. It can be concluded that the screened yeast isolates LM, MR, GOI, GII2 and WI can serve as promising probiotics in various fields of food industry.Key words: Acid tolerance; bile tolerance, cholesterol removal, probiotics, yeast.

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Vernazza, Claire L., Glenn R. Gibson, and Robert A. Rastall. "Carbohydrate preference, acid tolerance and bile tolerance in five strains of Bifidobacterium." Journal of Applied Microbiology 100, no. 4 (April 2006): 846–53. http://dx.doi.org/10.1111/j.1365-2672.2006.02832.x.

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Boke, Hatice, Belma Aslim, and Gulcin Alp. "The role of resistance to bile salts and acid tolerance of exopolysaccharides (EPSS) produced by yogurt starter bacteria." Archives of Biological Sciences 62, no. 2 (2010): 323–28. http://dx.doi.org/10.2298/abs1002323b.

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The aim of this study was to investigate a possible relation between EPS production and resistance to bile salts and tolerance to low pH. Eight strains which produced the highest and lowest amount of EPS (16- 211mg/l) were selected among 54 bacteria isolated from yogurt. Additionally, they were tested for resistance to bile salts (0.15, 0.3 %) and tolerance to low pH (2.0-3.0). After treatment with bile salts and acid, viable bacteria (log cfu ml-1) were determined by surface plating. The high EPS producing strains (B3, G12, W22) showed a significant (P<0.05) protective effect against low pH (pH 2.0). All Streptococcus thermophilus strains showed a higher tolerance to bile salts than the Lactobacillus delbrueckii subsp. bulgaricus strains. The high EPS-producing S. thermophilus (W22, T12) and L. bulgaricus (B3, G2) strains showed a significant (P<0.01) protective effect against bile salts (0.3 %).

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Wu, Yingjie, An Zhou, Li Tang, Yuanyuan Lei, Bo Tang, and Linjing Zhang. "Bile Acids: Key Regulators and Novel Treatment Targets for Type 2 Diabetes." Journal of Diabetes Research 2020 (July 18, 2020): 1–11. http://dx.doi.org/10.1155/2020/6138438.

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Type 2 diabetes mellitus (T2DM), characterized by insulin resistance and unclear pathogenesis, is a serious menace to human health. Bile acids are the end products of cholesterol catabolism and play an important role in maintaining cholesterol homeostasis. Furthermore, increasing studies suggest that bile acids may regulate glucose tolerance, insulin sensitivity, and energy metabolism, suggesting that bile acids may represent a potential therapeutic target for T2DM. This study summarizes the metabolism of bile acids and, more importantly, changes in their concentrations, constitution, and receptors in diabetes. Furthermore, we provide an overview of the mechanisms underlying the role of bile acids in glucose and lipid metabolism, as well as the occurrence and development of T2DM. Bile acid-targeted therapy may represent a valid approach for T2DM treatment.

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Knop, Filip K. "Bile-induced secretion of glucagon-like peptide-1: pathophysiological implications in type 2 diabetes?" American Journal of Physiology-Endocrinology and Metabolism 299, no. 1 (July 2010): E10—E13. http://dx.doi.org/10.1152/ajpendo.00137.2010.

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During the last decades it has become clear that bile acids not only act as simple fat solubilizers, but additionally represent complex hormonal metabolic integrators. Bile acids activate both nuclear receptors (controlling transcription of genes involved in for example bile acid, cholesterol, and glucose metabolism) and the cell surface G protein-coupled receptor TGR5 (modulating energy expenditure in brown fat and muscle cells). It has been shown that TGR5 is expressed in enteroendocrine L cells, which secrete the potent glucose-lowering incretin hormone glucagon-like peptide-1 (GLP-1). Recently it was shown that bile acid-induced activation of TGR5 results in intestinal secretion of GLP-1 and that enhanced TGR5 signaling improves postprandial glucose tolerance in diet-induced obese mice. This Perspectives article presents these novel findings in the context of prior studies on nutrient-induced GLP-1 secretion and outlines the potential implications of bile acid-induced GLP-1 secretion in physiological, pathophysiological, and pharmacological perspectives.

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Saveleva, E. E., E. S. Tyutrina, T. Nakanishi, I. Tamai, and A. B. Salmina. "The inhibitors of the apical sodium-dependent bile acid transporter (ASBT) as promising drugs." Biomeditsinskaya Khimiya 66, no. 3 (2020): 185–95. http://dx.doi.org/10.18097/pbmc20206603185.

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Inhibition of the apical sodium-dependent bile acid transporter (ASBT, also known as IBAT — ileal bile acid transporter, SLC10A2) leads to disruption of the enterohepatic circulation of bile acids and their excretion with fecal masses. This is accompanied by cholesterol utilization for synthesis of new bile acids. ASBT inhibitors are promising drugs for the treatment of such diseases as non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, type 2 diabetes mellitus, necrotic enterocolitis, chronic constipation, atherosclerosis. To date the most known chemically synthesized inhibitors are: A3309, SHP626, A4250, 264W94, GSK2330672, SC-435. All of them are at different stages of clinical trials, which confirm the high efficacy and good tolerance of these inhibitors. Current trends in this field also include directed chemical synthesis of ASBT inhibitors, as well as their search among substances of plant origin.

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Lefebvre, Philippe, Bertrand Cariou, Fleur Lien, Folkert Kuipers, and Bart Staels. "Role of Bile Acids and Bile Acid Receptors in Metabolic Regulation." Physiological Reviews 89, no. 1 (January 2009): 147–91. http://dx.doi.org/10.1152/physrev.00010.2008.

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The incidence of the metabolic syndrome has taken epidemic proportions in the past decades, contributing to an increased risk of cardiovascular disease and diabetes. The metabolic syndrome can be defined as a cluster of cardiovascular disease risk factors including visceral obesity, insulin resistance, dyslipidemia, increased blood pressure, and hypercoagulability. The farnesoid X receptor (FXR) belongs to the superfamily of ligand-activated nuclear receptor transcription factors. FXR is activated by bile acids, and FXR-deficient ( FXR−/−) mice display elevated serum levels of triglycerides and high-density lipoprotein cholesterol, demonstrating a critical role of FXR in lipid metabolism. In an opposite manner, activation of FXR by bile acids (BAs) or nonsteroidal synthetic FXR agonists lowers plasma triglycerides by a mechanism that may involve the repression of hepatic SREBP-1c expression and/or the modulation of glucose-induced lipogenic genes. A cross-talk between BA and glucose metabolism was recently identified, implicating both FXR-dependent and FXR-independent pathways. The first indication for a potential role of FXR in diabetes came from the observation that hepatic FXR expression is reduced in animal models of diabetes. While FXR−/−mice display both impaired glucose tolerance and decreased insulin sensitivity, activation of FXR improves hyperglycemia and dyslipidemia in vivo in diabetic mice. Finally, a recent report also indicates that BA may regulate energy expenditure in a FXR-independent manner in mice, via activation of the G protein-coupled receptor TGR5. Taken together, these findings suggest that modulation of FXR activity and BA metabolism may open new attractive pharmacological approaches for the treatment of the metabolic syndrome and type 2 diabetes.

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Matysik, Silke, Josefine Martin, Margarita Bala, Max Scherer, Andreas Schäffler, and Gerd Schmitz. "Bile acid signaling after an oral glucose tolerance test." Chemistry and Physics of Lipids 164, no. 6 (September 2011): 525–29. http://dx.doi.org/10.1016/j.chemphyslip.2011.05.003.

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Süle, Judit, László Varga, Zoltán Hatvan, and Zoltán Kerényi. "Application of an in vitro test system for the selection of probiotic bacterial strains." Élelmiszervizsgálati Közlemények 68, no. 2 (2022): 3916–27. http://dx.doi.org/10.52091/evik-2022/2-4-eng.

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The aim of our studies was to evaluate in vitro methods for the simple and efficient selection of putative probiotic bacterial strains. Of the possible methods, the following were tested: culturing on selective media, Gram staining, catalase assay, hemolytic, clonality and aggregation ability, gastric acid tolerance and bile acid tolerance. A total of 217 bacterial strains isolated from raw sheep’s milk, curdled milk and sheep’s cheese samples produced in Transylvania were included in our experiments. Isolates with hemolytic activity, as well as those exhibiting Gram-negative or catalase-positive phenotypes not characteristic of probiotics were excluded from our studies. Based on the results of RAPD-PCR studies suitable for the detection of individual-level polymorphisms, a total of 34 clone classes and 57 strains with unique RAPD patterns were identified. From each of the 34 clone classes thus narrowed, one strain was selected and tested for its aggregation ability, as well as its gastric acid and bile acid tolerance. High aggregation values above 70%, typical of probiotic strains, were measured in the case of a total of six isolates. In the course of the presence-absence studies conducted on the surface of solid media supplemented with acid or bile acid, it was possible to select several strains specifically tolerant to acid or bile acid. Based on our results, isolates to be included in further tests, e.g., in antibiotic resistance and antimicrobial activity assays, were selected.

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Adekunle, Olutoyin Catherine. "Effect of Bile on Campylobacter species isolated from stool samples in Osogbo." Pan African Journal of Life Sciences 6, no. 2 (August 31, 2022): 453–59. http://dx.doi.org/10.36108/pajols/2202/60.0230.

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Background: Campylobacter jejuni is a prevalent human pathogen and a major cause of bacterial gastroenteritis worldwide. In humans, C. jejuni colonises the intestinal tract, and its tolerance to bile is crucial for bacteria to survive and establish infection. Campylobacter jejuni and C. coli have the highest rate of foodborne-related clinical Campylobacteriosis. The study aims to determine the effect of bile salts, acid, and bacteriocin on campylobacter isolates obtained from stool samples. Methods: Campylobacters were identified phenotypically in this study using biochemical tests and genotypically using 16S rRNA species-specific gene amplification by PCR. The confirmed twenty-five Campylobacter isolates comprising18 C. jejuni and 7 C. coli were tested for physiological factors such as bile tolerance, bacteriocin tolerance and ability to synthesise proteolytic enzymes on a solid medium. Results: Campylobacter isolates survived at different concentrations of bile (2.1 -6.8%), low pH (7.1- 3.2) and in the presence of bacteriocin (3.8-6.8 AU/mL) with the production of proteolytic enzymes in the range of 16.2-15.2 mm. Conclusion: The ability of Campylobacter spp to survive in the presence of bacteriocin and different concentrations of acid and bile salt indicates the strains’ virulence

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ALVAREZ, GENOVEVA, NORMA HEREDIA, and SANTOS GARCÍA. "Relationship between the Effects of Stress Induced by Human Bile Juice and Acid Treatment in Vibrio cholerae." Journal of Food Protection 66, no. 12 (December 1, 2003): 2283–88. http://dx.doi.org/10.4315/0362-028x-66.12.2283.

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The effects of low pH and human bile juice on Vibrio cholerae were investigated. A mild stress condition (exposure to acid shock at pH 5.5 or exposure to 3 mg of bile per ml for 20 min) slightly decreased (by ≤1 log unit) V. cholerae cell viability. However, these treatments induced tolerance to subsequent exposures to more severe stress. In the O1 strain, four proteins were induced in response to acid shock (ca. 101, 94, 90, and 75 kDa), whereas only one protein (ca. 101 kDa) was induced in response to acid shock in the O139 strain. Eleven proteins were induced in response to bile shock in the O1 strain (ca. 106, 103, 101, 96, 88, 86, 84, 80, 66, 56, and 46 kDa), whereas only one protein was induced in response to bile shock in the O139 strain (ca. 88 kDa). V. cholerae O1 and O139 cells that had been preexposed to mild acid shock were twofold more resistant to pH 4.5 (with times required to inactivate 90% of the cell population [D-values] of 59 to 73 min) than were control cells (with D-values of 24 to 27 min). Likewise, cells that were preexposed to mild bile shock (3 mg/ml) were almost twofold more tolerant of severe bile shock (30 mg/ml; D-values, 68 to 87 min) than were control cells (with D-values of 37 to 43 min). These protective effects persisted for at least 1 h after the initial shock but were abolished when chloramphenicol was added to the culture during the shock. Cells preexposed to acid shock exhibited cross-protection against subsequent bile shock. However, cells preexposed to bile shock exhibited no changes in acid tolerance. Bile shock induced a modest reduction (0 to 20%) in enterotoxin production in V. cholerae, whereas acid shock had no effect on enterotoxin levels. Adaptation to acid and bile juice and protection against bile shock in response to preexposure to acid shock would be predicted to enhance the survival of V. cholerae in hosts and in foods. Thus, these adaptations may play an important role in the development of cholera disease.

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Leverrier, Pauline, Diliana Dimova, Vianney Pichereau, Yanick Auffray, Patrick Boyaval, and Gwénaël Jan. "Susceptibility and Adaptive Response to Bile Salts in Propionibacterium freudenreichii: Physiological and Proteomic Analysis." Applied and Environmental Microbiology 69, no. 7 (July 2003): 3809–18. http://dx.doi.org/10.1128/aem.69.7.3809-3818.2003.

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ABSTRACT Tolerance to digestive stresses is one of the main factors limiting the use of microorganisms as live probiotic agents. Susceptibility to bile salts and tolerance acquisition in the probiotic strain Propionibacterium freudenreichii SI41 were characterized. We showed that pretreatment with a moderate concentration of bile salts (0.2 g/liter) greatly increased its survival during a subsequent lethal challenge (1.0 g/liter, 60 s). Bile salts challenge led to drastic morphological changes, consistent with intracellular material leakage, for nonadapted cells but not for preexposed ones. Moreover, the physiological state of the cells during lethal treatment played an important role in the response to bile salts, as stationary-phase bacteria appeared much less sensitive than exponentially growing cells. Either thermal or detergent pretreatment conferred significantly increased protection toward bile salts challenge. In contrast, some other heterologous pretreatments (hypothermic and hyperosmotic) had no effect on tolerance to bile salts, while acid pretreatment even might have sensitized the cells. Two-dimensional electrophoresis experiments revealed that at least 24 proteins were induced during bile salts adaptation. Identification of these polypeptides suggested that the bile salts stress response involves signal sensing and transduction, a general stress response (also triggered by thermal denaturation, oxidative toxicity, and DNA damage), and an alternative sigma factor. Taken together, our results provide new insights into the tolerance of P. freudenreichii to bile salts, which must be taken into consideration for the use of probiotic strains and the improvement of technological processes.

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Jin, L. Z., Y. W. Ho, N. Abdullah, and S. Jalaludin. "Acid and bile tolerance of Lactobacillus isolated from chicken intestine." Letters in Applied Microbiology 27, no. 3 (September 1998): 183–85. http://dx.doi.org/10.1046/j.1472-765x.1998.00405.x.

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Andriantsoanirina, Valérie, Solène Allano, Marie José Butel, and Julio Aires. "Tolerance of Bifidobacterium human isolates to bile, acid and oxygen." Anaerobe 21 (June 2013): 39–42. http://dx.doi.org/10.1016/j.anaerobe.2013.04.005.

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Guo, Chun Feng, Lan Wei Zhang, Jing Yan Li, Ying Chun Zhang, Chao Hui Xue, Hua Xi Yi, Ming Du, and Xue Han. "Screening of Bile Salt Hydrolase-Active Lactic Acid Bacteria for Potential Cholesterol-Lowering Probiotic Use." Advanced Materials Research 345 (September 2011): 139–46. http://dx.doi.org/10.4028/www.scientific.net/amr.345.139.

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.Cholesterol-lowering effect of lactic acid bacteria (LAB) with bile salt hydrolase activity is well known. In this study, 150 LAB were screened for bile salt deconjugation ability and probiotic characters. Fourteen isolates with higher bile salt deconjugation ability were initially screened out using deconjugation rate above 50% as standard. These isolates were further screened for adhesion to HT-29 cells, bile tolerance and acid resistance. Four isolates, namely Lactobacillus casei F0822, Lactobacillus casei F0422, Enterococcus faecium F0511 and Enterococcus faecium IN7.12, was finally screened out. The 4 isolates may be able to reduce serum cholesterol levels in human and thus have a potential to apply in the biomedicine field.

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Gajbhiye, Milind H. "Probiotic traits of lactic acid bacteria isolated from aerial surfaces of pomegranate." International Journal of Bioassays 5, no. 08 (July 31, 2016): 4733. http://dx.doi.org/10.21746/ijbio.2016.08.002.

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Lactic acid bacteria isolated from aerial plant surfaces of pomegranate viz., Lactococcus lactis subsp. cremoris PB6, Lactobacillus brevis PFR77, L. lactis subsp. cremoris PFL9, Enterococcus faecium PB119 and L. lactis subsp. lactis PFL4 were tested for hemolysis, antibiotic susceptibility, gelatinase activity, tolerance to low pH and bile, resistance to digestive enzymes and antibacterial activity against human pathogens. All the isolates were non-hemolytic and non-gelatinolytic. These isolates were sensitive to clinically important antibiotics (amoxyclav, ampicillin, chloramphenicol, doxycycline, erythromycin, gentamycin, methicillin, penicillin G, Rifampicin and tetracycline), whereas resistance was recorded in case of norfloxacin and vancomycin. They could survive for more than 2h at pH 3 and the survival period of PB6, PFR77 and PFL9 was 3 h. Thus, the tolerance level of these LAB isolates was higher than the suggested values which indicate their good tolerance to stomach pH. In case of PB6, PFR77 and PFL9, around 80% of population survived in presence of 0.3% bile for 6 h. Also, they could survive at 1% concentration for 6 h. Thus, these isolates had good bile salt tolerance. All the isolates inhibited the growth of Gram positive and Gram negative bacterial pathogens with greater inhibition zones. PB6, PFR77 and PFL9 showed 60-70% survival in presence of trypsin whereas in presence of pepsin the survival decreased in between 50 and 60%. These isolates also showed good resistance to amylase and lipase. Thus, these LAB may be good candidates in formulation of probiotic preparations.

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Soomro, Aijaz Hussain, Sana Subhopoto, Saghir Ahmed Sheikh, Muhammad Khaskheli, Shahzor Gul Khaskheli, Asadullah Marri, and Allah Bux Baloch. "Probiotic Properties of Lactic Acid Bacteria Isolated from Traditional Yoghurt (Dahi) in Sindh Pakistan." Biological Sciences - PJSIR 65, no. 1 (February 24, 2022): 67–76. http://dx.doi.org/10.52763/pjsir.biol.sci.65.1.2022.67.76.

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The probiotic properties of Lactobacillus isolates of traditional yoghurt were investigated during the study. For that seven species of Lactobacillus were identified phenotypically. Out of 84 isolates, 23 acidophilus, 21 L. casei, 11 L. helveticus, 09 each L. delbrueckii sub sp. bulgaricus and L. delbrueckii sub sp. lactis, 03 L. viridescense and 02 L. plantarum were identified. All of these identified species were screened for antibacterial activity against foodborne pathogens, acid and bile tolerance and antibiotic resistance pattern. The results indicated that L. casei S66, L. delbrueckii sub sp. bulgaricus S65, L. acidophilus S26 and L. plantarum S19 produced antimicrobial substances against the indicator organisms and showed tolerance against acidic pH of 2.5 and survival against the bile salt concentration of 0.1 and 0.2. The L. acidophilus S26 survived the 0.3% bile salt concentration and was resistant to antibiotics ciprofloxacin, kanamycin, penicillin and vancomycin.

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Higgins, Victoria, Shervin Asgari, Jill K. Hamilton, Anna Wolska, Alan T. Remaley, Bolette Hartmann, Jens J. Holst, and Khosrow Adeli. "Postprandial Dyslipidemia, Hyperinsulinemia, and Impaired Gut Peptides/Bile Acids in Adolescents with Obesity." Journal of Clinical Endocrinology & Metabolism 105, no. 4 (December 11, 2019): 1228–41. http://dx.doi.org/10.1210/clinem/dgz261.

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Abstract Background With increased rates of obesity and insulin resistance in youth, development of postprandial dyslipidemia, an important cardiovascular disease risk factor, is a concern. Glucagon-like peptides (ie, GLP-1 and GLP-2) and bile acids have been shown to regulate dietary fat absorption and postprandial lipids in animal models and humans. We hypothesize that the physiological response of GLPs and bile acids to dietary fat ingestion is impaired in adolescents with obesity and this associates with marked postprandial dyslipidemia and insulin resistance. Methods In this cross-sectional study, normal weight adolescents and adolescents with obesity underwent a 6-hour oral fat tolerance test. The postprandial lipoprotein phenotype profile was determined using various assays, including nuclear magnetic resonance spectroscopy, to characterize lipoprotein particle number, size, lipid content, and apolipoproteins. GLP-1 and GLP-2 were quantified by electrochemiluminescent immunoassays. Total bile acids were measured by an automated enzymatic cycling colorimetric method and the bile acid profile by mass spectrometry. Results Adolescents with obesity exhibited fasting and postprandial dyslipidemia, particularly augmented postprandial excursion of large triglyceride-rich lipoproteins. Postprandial GLPs were reduced and inversely correlated with postprandial dyslipidemia and insulin resistance. Postprandial bile acids were also diminished, particularly lithocholic acid, a potent stimulator of GLP-1 secretion. Conclusion Blunted postprandial GLP and bile acid response to dietary fat ingestion strongly associates with marked postprandial dyslipidemia. Further investigation is needed to assess their potential utility as early biomarkers for postprandial dyslipidemia in adolescents with obesity.

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CHENG, HSIN-YI, HSIN-YI YANG, and CHENG-CHUN CHOU. "Influence of Acid Adaptation on the Tolerance of Escherichia coli O157:H7 to Some Subsequent Stresses." Journal of Food Protection 65, no. 2 (February 1, 2002): 260–65. http://dx.doi.org/10.4315/0362-028x-65.2.260.

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Three stains of Escherichia coli O157:H7, including ATCC 43889, ATCC 43895, and 933, were first subjected to acid adaptation at a pH of 5.0 for 4 h. Thermal tolerance at 52°C and survival of the acid-adapted as well as the nonadapted cells of E. coli O157:H7 in the presence of 10% sodium chloride, 0.85% bile salt, or 15.0% ethanol were investigated. Results showed that the effect of acid adaptation on the survival of E. coli O157:H7 varied with the strains and types of subsequent stress. Acid adaptation caused an increase in the thermal tolerance of E. coli O157:H7 ATCC 43889 and ATCC 43895, but no significant difference in the thermal tolerance was noted between acid-adapted and nonadapted cells of E. coli O157:H7 933. Although the magnitude of increase varied with strains of test organisms, acid adaptation generally led to an increase in the tolerance of E. coli O157:H7 to sodium chloride. On the other hand, the susceptibility of acid-adapted cells of the three strains of E. coli O157:H7 tested did not show a significant difference from that of their nonadapted counterparts when stressed with bile salt. The acid-adapted cells of E. coli O157:H7 ATCC 43889 and ATCC 43895 were less tolerant than the nonadapted cells to ethanol, whereas the tolerance of adapted and nonadapted cells of E. coli O157:H7 933 showed no significant differences.

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Li, Jing Yan, Lan Wei Zhang, Chun Feng Guo, Hua Xi Yi, Ying Chun Zhang, and Qi Li. "Probiotic Characteristics of Conjugated Linoleic Acid Producing Bacteria." Advanced Materials Research 345 (September 2011): 147–53. http://dx.doi.org/10.4028/www.scientific.net/amr.345.147.

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The aim of this study was to select CLA producing bacteria from fermented diary products and human faeces, then evaluate their resistance to simulated gastrointestinal stress and adhesiveness to human intestinal epithelial cells according typically assess methods. Additionally, hydrophobicity, resistance to opportunistic pathogens and phenol ability were analysed. Results showed that three L. paracasei subp. Paracasei (F0721, IN 5.22 and Q9), two Lactobacillus acidophilus (F0221 and M6) and one Lactobacillus plantarum (G14) exert the ability to product conjugated linoleic aicd ranging from 77.21 to 111.59 μg/ml in the presence of 0.5 mg/ml linoleic acid (LA) in MRSc broth under anaerobic conditions at 37°C for 40 h. Strain F0721, IN5.22 and G14 showed higher resistance to gastric acid than other strains at pH 2.0, F0721 and IN5.22 showed higher tolerance ability at pH 3.0. F0221 showed the highest bile salt tolerance than other strains at 0.15%, 0.3% and 0.5% bile concentrations, whereas highest sensitivity to the bile stress was found for IN5.22. F0221, IN5.22 and G14 strains showed the highest levels of adherences (range from 106 to 129 cfu/100 cells), and intestine origin bacteria (F0221, F0721 and IN5.22) exhibited higher hydrophobicity values and resistant to phenol ability as compared to the dairy products.

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ABRAHAM, LA, JA CHARLES, and SA HOLLOWAY. "Effect of oral ursodeoxycholic acid on bile acids tolerance tests in healthy dogs." Australian Veterinary Journal 82, no. 3 (March 2004): 157–60. http://dx.doi.org/10.1111/j.1751-0813.2004.tb12646.x.

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Chen, Lihong, Xiaozhou Yao, Andrew Young, Judi McNulty, Don Anderson, Yaping Liu, Christopher Nystrom, et al. "Inhibition of apical sodium-dependent bile acid transporter as a novel treatment for diabetes." American Journal of Physiology-Endocrinology and Metabolism 302, no. 1 (January 1, 2012): E68—E76. http://dx.doi.org/10.1152/ajpendo.00323.2011.

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Bile acids are recognized as metabolic modulators. The present study was aimed at evaluating the effects of a potent Asbt inhibitor (264W94), which blocks intestinal absorption of bile acids, on glucose homeostasis in Zucker Diabetic Fatty (ZDF) rats. Oral administration of 264W94 for two wk increased fecal bile acid concentrations and elevated non-fasting plasma total Glp-1. Treatment of 264W94 significantly decreased HbA1c and glucose, and prevented the drop of insulin levels typical of ZDF rats in a dose-dependent manner. An oral glucose tolerance test revealed up to two-fold increase in plasma total Glp-1 and three-fold increase in insulin in 264W94 treated ZDF rats at doses sufficient to achieve glycemic control. Tissue mRNA analysis indicated a decrease in farnesoid X receptor (Fxr) activation in small intestines and the liver but co-administration of a Fxr agonist (GW4064) did not attenuate 264W94 induced glucose lowering effects. In summary, our results demonstrate that inhibition of Asbt increases bile acids in the distal intestine, promotes Glp-1 release and may offer a new therapeutic strategy for type 2 diabetes mellitus.

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Fiamoncini, Jarlei, Andrianos M. Yiorkas, Kurt Gedrich, Milena Rundle, Sanne I. Alsters, Guus Roeselers, Tim J. van den Broek, et al. "Determinants of postprandial plasma bile acid kinetics in human volunteers." American Journal of Physiology-Gastrointestinal and Liver Physiology 313, no. 4 (October 1, 2017): G300—G312. http://dx.doi.org/10.1152/ajpgi.00157.2017.

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Bile acids (BA) are signaling molecules with a wide range of biological effects, also identified among the most responsive plasma metabolites in the postprandial state. We here describe this response to different dietary challenges and report on key determinants linked to its interindividual variability. Healthy men and women ( n = 72, 62 ± 8 yr, mean ± SE) were enrolled into a 12-wk weight loss intervention. All subjects underwent an oral glucose tolerance test and a mixed-meal tolerance test before and after the intervention. BA were quantified in plasma by liquid chromatography-tandem mass spectrometry combined with whole genome exome sequencing and fecal microbiota profiling. Considering the average response of all 72 subjects, no effect of the successful weight loss intervention was found on plasma BA profiles. Fasting and postprandial BA profiles revealed high interindividual variability, and three main patterns in postprandial BA response were identified using multivariate analysis. Although the women enrolled were postmenopausal, effects of sex difference in BA response were evident. Exome data revealed the contribution of preselected genes to the observed interindividual variability. In particular, a variant in the SLCO1A2 gene, encoding the small intestinal BA transporter organic anion-transporting polypeptide-1A2 (OATP1A2), was associated with delayed postprandial BA increases. Fecal microbiota analysis did not reveal evidence for a significant influence of bacterial diversity and/or composition on plasma BA profiles. The analysis of plasma BA profiles in response to two different dietary challenges revealed a high interindividual variability, which was mainly determined by genetics and sex difference of host with minimal effects of the microbiota. NEW & NOTEWORTHY Considering the average response of all 72 subjects, no effect of the successful weight loss intervention was found on plasma bile acid (BA) profiles. Despite high interindividual variability, three main patterns in postprandial BA response were identified using multivariate analysis. A variant in the SLCO1A2 gene, encoding the small intestinal BA transporter organic anion-transporting polypeptide-1A2 (OATP1A2), was associated with delayed postprandial BA increases in response to both the oral glucose tolerance test and the mixed-meal tolerance test.

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Begley, Máire, Cormac G. M. Gahan, and Colin Hill. "Bile Stress Response in Listeria monocytogenes LO28: Adaptation, Cross-Protection, and Identification of Genetic Loci Involved in Bile Resistance." Applied and Environmental Microbiology 68, no. 12 (December 2002): 6005–12. http://dx.doi.org/10.1128/aem.68.12.6005-6012.2002.

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ABSTRACT Bile is one of many barriers that Listeria monocytogenes must overcome in the human gastrointestinal tract in order to infect and cause disease. We demonstrated that stationary-phase cultures of L. monocytogenes LO28 were able to tolerate concentrations of bovine, porcine, and human bile and bile acids well in excess of those encountered in vivo. Strain LO28 was relatively bile resistant compared with other clinical isolates of L. monocytogenes, as well as with Listeria innocua, Salmonella enterica serovar Typhimurium LT2, and Lactobacillus sakei. While exponential-phase L. monocytogenes LO28 cells were exquisitely sensitive to unconjugated bile acids, prior adaptation to sublethal levels of bile acids or heterologous stresses, such as acid, heat, salt, or sodium dodecyl sulfate (SDS), significantly enhanced bile resistance. This adaptive response was independent of protein synthesis, and in the cases of bile and SDS adaptation, occurred in seconds. In order to identify genetic loci involved in the bile tolerance phenotype of L. monocytogenes LO28, transposon (Tn917) and plasmid (pORI19) integration banks were screened for bile-sensitive mutants. The disrupted genes included a homologue of the capA locus required for capsule formation in Bacillus anthracis; a gene encoding the transcriptional regulator ZurR; a homologue of an Escherichia coli gene, lytB, involved in isoprenoid biosynthesis; a gene encoding a homologue of the Bacillus subtilis membrane protein YxiO; and a gene encoding an amino acid transporter with a putative role in pH homeostasis, gadE. Interestingly, all of the identified loci play putative roles in maintenance of the cell envelope or in stress responses.

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Cummings, Bethany P., Ahmed Bettaieb, James L. Graham, Kimber L. Stanhope, Mark Kowala, Fawaz G. Haj, Michael L. Chouinard, and Peter J. Havel. "Vertical Sleeve Gastrectomy Improves Glucose and Lipid Metabolism and Delays Diabetes Onset in UCD-T2DM Rats." Endocrinology 153, no. 8 (June 19, 2012): 3620–32. http://dx.doi.org/10.1210/en.2012-1131.

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Vertical sleeve gastrectomy (VSG) has gained interest as a low morbidity bariatric surgery, which is effective in producing weight loss and causing type 2 diabetes resolution. However, the efficacy of VSG to prevent the onset of type 2 diabetes has not been previously investigated. VSG or sham surgery was performed on 2-month-old prediabetic male University of California Davis-type 2 diabetes mellitus rats. Sham-operated animals were either sham-operated ad libitum fed (S-AL) or were weight-matched to VSG-operated animals (S-WM). Diabetes onset was determined by weekly nonfasting blood glucose measurements. Animals underwent oral glucose tolerance tests at 1 and 4 months after surgery and indirect calorimetry at 1.5 months after surgery. VSG surgery significantly delayed diabetes onset compared with both S-AL and S-WM animals. VSG-operated animals ate 23% less and weighed 20% less than S-AL. Energy expenditure did not differ between VSG-operated animals and controls. Results from the oral glucose tolerance tests demonstrate improved glucose tolerance and islet function in VSG-operated animals compared with S-AL and S-WM. Nutrient-stimulated glucagon-like peptide (GLP)-1, GLP-2, and peptide YY excursions were greater in VSG-operated animals. VSG surgery resulted in decreased fasting plasma insulin, ghrelin and lipid concentrations, and markedly higher fasting plasma adiponectin and bile acid concentrations, independent of body weight. Increases of circulating bile acid concentrations were due to selective increases of taurine-conjugated bile acids. Thus, VSG delays type 2 diabetes onset in the University of California Davis-type 2 diabetes mellitus rat, independent of body weight. This is potentially mediated by increases of circulating bile acids, adiponectin, and nutrient-stimulated GLP-1 secretion and decreased circulating ghrelin concentrations.

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Pereira, Dora I. A., and Glenn R. Gibson. "Cholesterol Assimilation by Lactic Acid Bacteria and Bifidobacteria Isolated from the Human Gut." Applied and Environmental Microbiology 68, no. 9 (September 2002): 4689–93. http://dx.doi.org/10.1128/aem.68.9.4689-4693.2002.

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ABSTRACT The objective of this study was to evaluate the effect of human gut-derived lactic acid bacteria and bifidobacteria on cholesterol levels in vitro. Continuous cultures inoculated with fecal material from healthy human volunteers with media supplemented with cholesterol and bile acids were used to enrich for potential cholesterol assimilators among the indigenous bacterial populations. Seven potential probiotics were found: Lactobacillus fermentum strains F53 and KC5b, Bifidobacterium infantis ATCC 15697, Streptococcus bovis ATCC 43143, Enterococcus durans DSM 20633, Enterococcus gallinarum, and Enterococcus faecalis. A comparative evaluation regarding the in vitro cholesterol reduction abilities of these strains along with commercial probiotics was undertaken. The degree of acid and bile tolerance of strains was also evaluated. The human isolate L. fermentum KC5b was able to maintain viability for 2 h at pH 2 and to grow in a medium with 4,000 mg of bile acids per liter. This strain was also able to remove a maximum of 14.8 mg of cholesterol per g (dry weight) of cells from the culture medium and therefore was regarded as a candidate probiotic.

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Yi, Ruokun, Fang Tan, and Xin Zhao. "Probiotic properties of Lactobacillus strains from traditional fermented yogurt in Xinjiang." E3S Web of Conferences 131 (2019): 01121. http://dx.doi.org/10.1051/e3sconf/201913101121.

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In this study, 3 Lactobacillus strains isolated from 5 kinds of traditional fermented yogurt in Xinjiang were identified as Lactobacillus plantarum (LP1, LP2), and Lactobacillus delbrueckii subsp. Bulgaricus (LD). Probiotic properties of Lactobacillus strains have been evaluated by testing the tolerance to artificial gastric juice and bile salt, cell surface hydrophobicity, hydroxyl radicals and DPPH free radicals scavenging rates. As the results, LP1 showed better tolerance to acid, cell surface hydrophobicity and antioxidant ability, LP2 showed better tolerance to bile salt comparing with the other two LAB strains. LP1 showed the best probiotic properties in general. These results provide reference value for the probiotic research in vivo and the development of new functional probiotic products in the future.

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Liong, M. T., and N. P. Shah. "Acid and Bile Tolerance and Cholesterol Removal Ability of Lactobacilli Strains." Journal of Dairy Science 88, no. 1 (January 2005): 55–66. http://dx.doi.org/10.3168/jds.s0022-0302(05)72662-x.

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Ding, W. K., and N. P. Shah. "Acid, Bile, and Heat Tolerance of Free and Microencapsulated Probiotic Bacteria." Journal of Food Science 72, no. 9 (November 2007): M446—M450. http://dx.doi.org/10.1111/j.1750-3841.2007.00565.x.

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Pan, Xiaodong, Fenqin Chen, Tianxing Wu, Honggang Tang, and Zhanyu Zhao. "The acid, bile tolerance and antimicrobial property of Lactobacillus acidophilus NIT." Food Control 20, no. 6 (June 2009): 598–602. http://dx.doi.org/10.1016/j.foodcont.2008.08.019.

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Uugantsetseg, E., and B. Batjargal. "Antioxidant activity of probiotic lactic acid bacteria isolated from Mongolian airag." Mongolian Journal of Chemistry 15 (December 12, 2014): 73–78. http://dx.doi.org/10.5564/mjc.v15i0.327.

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This research aimed to determine the antioxidant activity of probiotic lactic acid bacteria isolated from airag. In this study, 42 lactic acid bacteria were isolated from Mongolian airag. All isolates were identified by using morphological, biochemical and physiological methods. The isolated bacteria were studied for antagonistic effects on Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, 22 strains showed antibacterial activity. When we examined their probiotic properties such as bile acid tolerance and gastric acid tolerance, it is shown that only 6 bacterial strains can survive up to 3 hours in a pH 3.0 acid environment and up to 8 hours in 0.3% bile acid environment. Selected probiotic strains were further identified to species by API 50CHL system. Antioxidant activity of probiotic strains were determined by 1,1-diphenyl-2 picrylhydrazyl (DPPH) assay. While the antioxidant activity in cell free supernatant fluctuated between the range of 26.1-38.4%, the antioxidant activity after 72 hours of fermentation in the whey fraction was between 17.23-55.12%. DOI: http://doi.dx.org/10.5564/mjc.v15i0.327 Mongolian Journal of Chemistry 15 (41), 2014, p73-78

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Coué, Marine, Angela Tesse, Juliette Falewée, Audrey Aguesse, Mikaël Croyal, Lionel Fizanne, Julien Chaigneau, Jérôme Boursier, and Khadija Ouguerram. "Spirulina Liquid Extract Protects against Fibrosis Related to Non-Alcoholic Steatohepatitis and Increases Ursodeoxycholic Acid." Nutrients 11, no. 1 (January 18, 2019): 194. http://dx.doi.org/10.3390/nu11010194.

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Non-alcoholic steatohepatitis (NASH) is characterized by an excess of lipids and oxidative stress in the liver. Spirulina was reported to possess hypolipemic and antioxidative effects and might counteract NASH development. C57Bl/6J mice were fed a western diet (WD) during 25 weeks with or without spirulina liquid extract (SLE) at 2 different doses (WDS1 and WDS2 groups) in drinking water. Liver histology, inflammation, and oxidative stress were assessed as well as glucose tolerance status, lipid metabolism, and gallbladder bile acid profile. WDS2 gained significantly less weight than WD. Liver weight-to-body weight ratio and plasma alanine aminotransferase were significantly lower in WDS2 mice. A reduced liver fibrosis and NFκBp65 protein expression were measured in the supplemented group as a lower accumulation of superoxide anion, nitric oxide, and thiobarbituric reactive substances. WDS2 mice showed also a preserved glucose tolerance, a strong decrease of plasma cholesterol, and a significant increase of gallbladder ursodeoxycholic acid and β-muricholic acid. Our findings demonstrate a protective effect of SLE against WD induced NASH that is related to less inflammation and oxidative stress, a preserved glucose tolerance, and less hepatotoxic bile acid profile.

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Tulumoğlu, Şener, Belgin Erdem, and Ömer Şimşek. "The effects of inulin and fructo-oligosaccharide on the probiotic properties of Lactobacillus spp. isolated from human milk." Zeitschrift für Naturforschung C 73, no. 9-10 (September 25, 2018): 367–73. http://dx.doi.org/10.1515/znc-2018-0001.

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Abstract This study aims to determine the effects of inulin and fructo-oligosaccharide (FOS) on the probiotic properties of five Lactobacillus spp. isolated from human milk. Lactobacillus spp. were isolated and identified, and the growth characteristics, acid and bile salt tolerance, antagonistic effects, and cholesterol assimilation of Lactobacillus strains were investigated in the presence of inulin and FOS. Lactobacillus casei L1 was able to utilize inulin and FOS as carbon source as well as glucose even other strains were able to use, including Lactobacillus rhamnosus GG. This strain also showed high tolerance to acid and bile salt, even at pH 2.5 and 0.5% bile salt levels, respectively. Inulin and FOS promoted the antimicrobial activity of L. casei L1 against pathogenic bacteria. Cholesterol assimilation was higher than in the other and control probiotic strains in the presence inulin and FOS, which were measured as 14 and 25 mg/dL, respectively. In conclusion, L. casei L1 can use both inulin and FOS to maintain its viability both at digestive conditions and also the relevant prebiotics, and show broad antagonistic activity and cholesterol assimilation.

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Ulrich Landry, Bemmo Kamdem, Kaktcham Pierre-Marie, Momo Kenfack Chancel Hector, Foko Kouam Edith Marius, ZAMBOU NGOUFACK FRANCOIS, Wang Rui Yan, ZHU Taicheng, and YIN LI. "Bile salt hydrolase and antimicrobial activities of three bile resistant probiotics Lactobacillus plantarum strains isolated from Cameroonian artisanal fermented milk." Journal of Microbiology and Biotechnology Research 7, no. 5 (December 5, 2017): 21. http://dx.doi.org/10.24896/jmbr.2017754.

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Probiotics are well known for their efficacy as dietary adjuncts providing benefits to consumers. However, the selection of probiotics before incorporation into diet requires the scrutiny of a well-defined set of criteria. Hence, three Lactobacillus plantarum strains (GGU, GLA51 and GLP56, having KU949009, KU949010 and KU949011 respectively as GenBank accession numbers) previously isolated from Cameroonian traditional fermented milk have been used in this study for the evaluation of their Bile salt hydrolase and antimicrobial activities. Bile tolerance test was carried out by monitoring the bacterial growth at different Oxgall bile concentration (0.3%, 0.5% and 1%). The bile salt hydrolase activity was measured by determining the amount of amino acid liberated from conjugated bile salts by lactobacilli strains. Also, three bshgenes (bsh1 gene specific to Lactobacillus plantarum species, bshA and bshB genes specific to Lactobacillus acidophilus species) involved in the bile salt hydrolase activity were screened. The antimicrobial activity of the strains was evaluated using the agar-spot test. The three Lactobacillus plantarum strains showed survival percentages higher than 90% in the presence of 0.3% of Oxgall bile, and the delays of growth ranged from 0 to 10 min. Their bile salt hydrolase activity ranged from 15.62 ± 3.00 to 23.91 ± 5.82 U/mg towards Oxgall and from 10.47 ± 2.76 to 24.57 ± 6.31 U/mg towards Taurodeoxycholate. Only Lactobacillus plantarum GLA51 was found to harbor thebsh1 gene. Its sequence was deposited in the Genbank under the accession number MF098542. The analysis of thisbsh1 gene sequence from L. plantarum GLA51 indicated that it contained an open reading frame (ORF) of 838 nucleotides encoding a 278 amino acids protein. The three Lactobacilli strains showed inhibitory activity against the pathogenic or spoilage bacteria tested, except for Shigella flexneri. These results suggest that the three Lactobacillus plantarum strain show potential for probiotic applications.Keywords: Bile salt hydrolase activity, antimicrobial activity, Lactobacillus plantarum, bile tolerance

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Dollerup, Ole L., Samuel A. J. Trammell, Bolette Hartmann, Jens J. Holst, Britt Christensen, Niels Møller, Matthew P. Gillum, Jonas T. Treebak, and Niels Jessen. "Effects of Nicotinamide Riboside on Endocrine Pancreatic Function and Incretin Hormones in Nondiabetic Men With Obesity." Journal of Clinical Endocrinology & Metabolism 104, no. 11 (August 7, 2019): 5703–14. http://dx.doi.org/10.1210/jc.2019-01081.

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Abstract Objective Augmenting nicotinamide adenine dinucleotide (NAD+) metabolism through dietary provision of NAD+ precursor vitamins translates to improved glucose handling in rodent models of obesity and diabetes. Preclinical evidence suggests that the NAD+/SIRT1 axis may be implicated in modulating important gut-related aspects of glucose regulation. We sought to test whether NAD+ precursor supplementation with nicotinamide riboside (NR) affects β-cell function, α-cell function, and incretin hormone secretion as well as circulating bile acid levels in humans. Design A 12-week randomized, double-blind, placebo-controlled, parallel-group trial in 40 males with obesity and insulin resistance allocated to NR at 1000 mg twice daily (n = 20) or placebo (n = 20). Two-hour 75-g oral glucose tolerance tests were performed before and after the intervention, and plasma concentrations of glucose, insulin, C-peptide, glucagon, glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) were determined. β-Cell function indices were calculated based on glucose, insulin, and C-peptide measurements. Fasting plasma concentrations of bile acids were determined. Results NR supplementation during 12 weeks did not affect fasting or postglucose challenge concentrations of glucose, insulin, C-peptide, glucagon, GLP-1, or GIP, and β-cell function did not respond to the intervention. Additionally, no changes in circulating adipsin or bile acids were observed following NR supplementation. Conclusion The current study does not provide evidence to support that dietary supplementation with the NAD+ precursor NR serves to impact glucose tolerance, β-cell secretory capacity, α-cell function, and incretin hormone secretion in nondiabetic males with obesity. Moreover, bile acid levels in plasma did not change in response to NR supplementation.

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Bustos, Ana Yanina, Lucila Saavedra, Graciela Font de Valdez, Raúl Ricardo Raya, and María Pía Taranto. "Relationship between bile salt hydrolase activity, changes in the internal pH and tolerance to bile acids in lactic acid bacteria." Biotechnology Letters 34, no. 8 (April 18, 2012): 1511–18. http://dx.doi.org/10.1007/s10529-012-0932-5.

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Kou, Xiaohong, Qiong Chen, Xiaoying Ju, Huiping Liu, Wenrong Chen, and Zhaohui Xue. "A tolerant lactic acid bacteria, Lactobacillus paracasei, and its immunoregulatory function." Canadian Journal of Microbiology 60, no. 11 (November 2014): 729–36. http://dx.doi.org/10.1139/cjm-2014-0383.

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The aim of the present investigation was to isolate a probiotic strain from 23 samples of yurts cheese and 21 samples of kumiss (collected from scattered households in Xinjiang and Inner Mongolia), and from eN-Lac Capsules, a health-promoting product. The isolates were subjected to biochemical characterization analysis and were tested for tolerance to low pH, sodium salt, bile salt, pepsin, and trypsin. 16S DNA sequence analysis was conducted to identify the strain. The possible dose-dependent role of strain LP2 in immunomodulation was investigated using the ICR mouse model (from the Institute of Cancer Research). Daily, we conducted clinical observations, a carbon clearance test, a spleen lymphocyte proliferation test, and measurements of body mass and lymphoid organ index. Natural killer cell activity and delayed-type hypersensitivity reaction were determined. The results showed that 3 selected strains (LP2, LP4, and LP9) had high tolerance to low pH, sodium chloride, and bile salt and were not significantly different from Lactobacillus paracasei in terms of morphology, colony, and biochemistry characterizations. A further tolerance test showed that LP2 had the highest survival rate (90%) under the conditions of pH 3.0, 0.3% bile salt, 10 mg/mL pepsin, and 10 mg/mL trypsin for 24 h. The sequence heterogeneities within the 16S rDNA genes molecularly elucidated that the LP2 belongs to the L. paracasei family, on the basis of a homology of 99.6%. A significant enhanced footpad swelling reaction and natural killer cell activity in the middle-dose (108 cfu/mL) and the high-dose (109 cfu/mL) groups were observed but without obvious dose dependence (P < 0.05). Lymphocyte proliferation was also increased significantly in a dose-dependent manner (P < 0.01) compared with that of the control group, indicating a positive immunoregulatory effect.

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Doumbouya, Ibrahima, Owino Owino, and Kevin Omolo. "PROBIOTIC PROPERTIES OF LACTIC ACID BACTERIA ISOLATED FROM “TCHOUKOU” TRADITIONAL MILK CHEESES PRODUCED IN SELECTED REGION OF NIGER." International Journal of Food Sciences 5, no. 1 (February 9, 2022): 1–15. http://dx.doi.org/10.47604/ijf.1457.

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Purpose: The current study’s aim is to evaluate the probiotic potential of lactic acid bacteria strains isolated from traditional "Tchoukou" milk cheeses produced in a selected region of Niger. Methodology: Nine Samples were collected in selected regions of Niger (Tahoua, Maradi, and Zinder).Probiotic properties of isolated LAB were identified based on their acid tolerance, bile salt tolerance, auto-aggregation ability, simulated stomach and duodenum passage, simulated gastric juice survivability and their antimicrobial activities. Findings: A total of eighteen strains were analysed in vitro for acid tolerance, bile tolerance, survival under simulated gastro-intestinal tract conditions and antimicrobial activity against index organisms. The results indicated that all seventeen strains exhibited a high viability after twenty-four hours of incubation at pH 2.5 and pH 3, but a decreased viability at pH 2.0 in which only eight strains were able to survive, strain C13 failed to grow at the three different pH. In this study, the isolates generally survived better after exposure to 0.3% bile salt. Also were able to survive exposure to simulated stomach and duodenum passage (SSDP) for three hours ranging from (89%-100%).All strains were able to survive under simulated gastric juice at different pH (2, 2.5 and 3). for auto-aggregation Only fifteen isolates showed the best auto-aggregation abilities ranging from (15-83%) and the other two had less auto-aggregation ability (2-11%). The isolates showed diverse antimicrobial activity against the index organisms. Among the isolates, only three (C1, C2 and C9) could not inhibit any of the selected pathogens. Unique contribution to theory, practice and policy: This study was conducted to characterize the probiotic properties of LAB isolate which could serve as a potential source for industries and commercial applications.

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Liong, Min T., and Nagendra P. Shah. "Acid and Bile Tolerance and The Cholesterol Removal Ability of Bifidobacteria Strains." Bioscience and Microflora 24, no. 1 (2005): 1–10. http://dx.doi.org/10.12938/bifidus.24.1.

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Succi, M., P. Tremonte, A. Reale, E. Sorrentino, L. Grazia, S. Pacifico, and R. Coppola. "Bile salt and acid tolerance ofLactobacillus rhamnosusstrains isolated from Parmigiano Reggiano cheese." FEMS Microbiology Letters 244, no. 1 (March 2005): 129–37. http://dx.doi.org/10.1016/j.femsle.2005.01.037.

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Journal articles on the topic 'Acid and bile tolerance'

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