Academic literature on the topic 'Lactobacillus reuteri DSM 17938 derivatives'

Increasing in the adhesive potential of probiotic bacteria on the one hand and weakening the adhesive ability of the pathobionts on the other is a pathogenetically based approach in the fight against intestinal infectious diseases and intestinal dysbiosis. At present postbiotic products are considered as one of the most promising means of influencing the intestinal microbiota. The aim of the work was to study the effect of cell-free extracts containing derivatives of Bifidobacterium bifidum 1 and Lactobacillus reuteri DSM 17938 on the adhesive properties of probiotic (L. reuteri DSM 17938 and B. bifidum 1) and opportunistic bacteria (Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922). Four cell-free extracts were investigated: L – obtained from the L. reuteri disintegrate; ML – obtained from the L. reuteri culture, cultivated in its own disintegrate; B – obtained from the B. bifidum disintegrate; MB – obtained from the B. bifidum culture, cultivated in its own disintegrate. The effect of cell-free extracts on the adhesive properties of microorganisms was studied by using Brilis method. ML, MB, and B extracts were found to be able to significantly increase the adhesive potential of B. bifidum and L. reuteri. Under their influence adhesion index calculated for bifidobacteria increased by 41.1 % (ML), 41.5 % (MB) and 50.6 % (B), and the microorganism adhesion index calculated for lactobacilli increased by 30.77 % (ML), 44.45 % (MB) and 44.97 % (B). Both studied probiotic bacteria moved up from the category of «moderately adhesive» into the category of «strongly adhesive» with microorganism adhesion index > 4.0. Lactobacilli also became «strongly adhesive» under the influence of L extract, while microorganism adhesion index increased by 37.9 %. Among the studied extracts, only L extract caused a significant increase in the adhesion index of the S. aureus test culture. The other extracts caused minor changes in the adhesive potential of the test cultures. Under their influence, there was a tendency to increase or decrease the adhesive ability of bacteria. Under the influence of MB extract, the S. aureus test culture passed from the «strongly adhesive» category to the «moderately adhesive» category, and the E. coli test culture transferred from the «moderately adhesive» category to the «weakly adhesive» category. The data obtained are of great importance when developing new metabiotics based on the B. bifidum 1 and L reuteri DSM 17938 probiotic strains derivatives.

The purpose of this study was to evaluate the effect of supplementing the culture medium with ascorbic acid on the antimicrobial properties of Lactobacillus reuteri cell-free extracts (CFEs). CFEs were prepared using commercial strain L. reuteri DSM 17938 by culturing lactobacilli in its own disintegrated cell suspension (DCS) supplemented with ascorbic acid in sub-inhibitory (5 mg/ml, CFE₅) or minimal inhibitory concentration (20 mg/ml, CFE₂₀) and without supplementation (CFE₀). Staphylococcus aureus AТСС 25923, Escherichia coli AТСС 25922 reference strains and Pseudomonas aeruginosa extensively drug resistant (XDR) clinical isolate were used as indicator cultures. Screening of the inhibitory properties of the studied CFEs and elucidation of the nature of inhibitory products were done using modified Micro scale Optical Density Assay (MODA). The inhibition indices (InhI) were calculated for the studied CFEs and ascorbic acid of appropriate concentrations. CFEs were subjected to HPLC-analysis. CFE₅ and CFE₂₀ showed significantly higher antimicrobial activity toward to indicator cultures than CFE₀. InhI calculated for extracts CFE₅ and CFE₂₀ mainly exceeded the sum of the corresponding indicators calculated for CFE₀ and ascorbic acid (АА) of appropriate concentrations: InhI CFE₅ ≥ InhI CFE_0 + InhI AA₅; InhI CFE₂₀ > InhI CFE_0 + InhI AA_20. Acidic metabolic products have made the greatest contribution to the antimicrobial effect of the studied CFEs. HPLC-nalysis showed that the modified ascorbic acid was the substance found in CFE₂₀ in the greatest quantity. The revealed effect of potentiation of antimicrobial activity of CFEs by ascorbic acid should be taken into account when developing new biotechnological products based on derivatives of L. reuteri DSM 17938.

Probiotic microorganisms are known to be able to exhibit antioxidant activity. Most of beneficial probiotics effects are due to the action of their derivatives (structural components and metabolites). The aim of the work was to investigate the antiradical activity of cell-free extracts containing bacterial derivatives of Bifidobacterium bifidum 1 and Lactobacillus reuteri DSM 17938 probiotic strains, by their hydroxyl radical scavenging activity in the model system of their generation. Cell-free extracts were obtained from disintegrators and cultures of probiotic bacteria cultured in the disintegrators of their own cells. A metabiotic HYLAK FORTE was chosen as the reference drug. At a concentration 20% vol. in the incubation medium the hydroxyl radical scavenging by L. reuteri cell-free extracts was at a level of 75–90 %, and the hydroxyl radical scavenging by B. bifidum cell-free extracts was at a level of 50–60%. The metabiotic provided the same level of the hydroxyl radical scavenging activity when its content in the incubation medium was lower in 1.5 – 2.5 times. Extracts obtained from disintegrators showed a more pronounced antiradical activity than extracts from probiotic cultures. Based on the weight of the dry residue, concentrations for 50% hydroxyl radical scavenging (ІС50) by extracts and metabiotic were calculated. According to this indicator, L. reuteri extract obtained from disintegrate was the most effective (IC50 = 1.57 mg/ml). Other investigated derivative-containing products were arranged in decreasing order of antiradical activity as follows: B. bifidum extract from disintegrate (IC50 = 1, 64 mg/ml) > B. bifidum extract from culture (IC50 = 1, 75 mg/ml) > L. reuteri extract from culture (IC50 = 1, 86 mg/ml) > HYLAK FORTE (IC50 = 11, 03 mg/ml). Thus, all the studied extracts showed antiradical activity with respect to the most reactive hydroxyl radical. The obtained results encourage further study of the antioxidant properties of L. reuteri and B. bifidum cell-free extracts in order to elucidate the mechanisms of their biological activity and justify the appropriateness of their therapeutic use.

Recent studies have shown that alterations of the immune response in the gastrointestinal mucosa are key components of the mechanism of the probiotic action of beneficial bacteria. Most of the beneficial effects of probiotics are due to the action of their structural components and metabolites. Macrophages are first-line defense cells of the immune system, which not only participate in the detection, phagocytosis and destruction of harmful microorganisms, but also determine the nature of the subsequent immune response by presenting antigens to T-cells and initiating inflammation by releasing cytokines. We researched the effect of two types of cell-free extracts (CFEs) containing probiotic derivatives (structural components and metabolites of bacteria) Bifidobacterium bifidum 1 (BbCFE) and Lactobacillus reuteri DSM 17938 (LrCFE) on the activity of mouse peritoneal macrophages and on the ability of peripheral human blood mononuclear cells to produce cytokines. CFEs were obtained by culturing probiotics in their own disintegrates and then removing cells and cell debris by centrifugation and filtration. Peritoneal macrophages were isolated from mice. Some of them were infected in vitro by Salmonella thyphimurium. Uninfected and infected macrophages were incubated in culture medium containing (30% vol) or not containing CFEs at 37 °С in a microaerobic atmosphere (5% СО2) for 18 hours. After incubation, peritoneal macrophages were lysed. The obtained suspensions were centrifuged and supernatants were carefully collected. Macrophages activity was assessed by the nitrites level, superoxide dismutase (SOD), lactate dehydrogenase (LDH) activity and antiinflammatory cytokines levels in supernatants using spectrophotometric method. Peripheral mononuclear cells were isolated from the blood of healthy volunteers. The ability of peripheral mononuclear blood cells to produce antiinflammatory cytokines was evaluated after cell stimulation with lipopolysaccharide (LPS) and incubation with or without CFEs. Cytokine levels in supernatants were determined using enzyme-linked immunosorbent assay (ELISA). After infection with S. thyphimurium in macrophages, nitrite levels increased 5.5-fold, SOD activity 4.8-fold, and LDH 2-fold. Both studied CFEs exerted a similar effect on the macrophages’ activity. Addition of BbCFE to the incubation medium of infected macrophages resulted in a 4-fold decrease in nitrite levels, and the addition of LrCFE was accompanied by a decrease in nitrite levels to levels in intact cells. Under the influence of both CFEs, the activity of SOD and LDH was significantly reduced and did not differ significantly from the activity of these enzymes in intact cells. BbCFE and LrCFE did not have a significant effect on nitrite levels, SOD and LDH activity in intact macrophages. Under the influence of BbCFE, there was a 2-fold decrease in the production of TNF, a 2-fold increase in IL10 production, and a 30% increase in IL6 production by mononuclear cells. LrCFE caused a decrease in TNF production by 26.7% and IL6 by 36%, and IL10 by 1.9 times. Thus, the studied CFEs normalized the nitrite levels in peritoneal macrophages infected with S. thyphymurium and infection-induced activation of SOD and LDH enzymes. This demonstrates their ability to modulate oxidative processes in macrophages. In addition, under the influence of the investigated CFEs, there was a decrease in the production of pro-inflammatory cytokines (TNFα and IL-6) and increased production of anti-inflammatory cytokine (IL-10) by human peripheral mononuclear cells. The results of the study indicate the ability of CFEs by influencing the functions of innate immunity cells to restrict the inflammatory response and oxidative stress. Based on this, CFEs can be considered as promising agents for the treatment of inflammatory diseases.

The role that the gut microbiota plays in maintaining human health cannot be overemphasized. Numerous studies have shown that dysbiosis is associated with several pathological conditions. Some probiotic strains have proven to be effective both in improving the composition of the gut microbiota and in preventing or correcting certain pathological conditions. This review presents data on different strains of Lactobacillus reuteri, primarily an updated information on the efficacy of the probiotic strain L. reuteri DSM 17938 in the treatment and prevention of various human diseases. Key words: Lactobacillus reuteri, Lactobacillus reuteri DSM 17938, probiotics, gut microbiota, colic, constipation, regurgitation

Purpose — to demonstrate the clinical significance of Lactobacillus reuteri DSM 17938 and vitamin D3 in common clinical problems in infants. Materials and methods. Clinical cases in pediatrics of infancy in children with infant colic (G4), infant regurgitation (G1), functional constipation (G7) are presented. Some international recommendations regarding a preventive dose of vitamin D in the first year of a child' life are considered. Results. The behavior of an infant is often a concern for parents and is a reason for seeking medical help. In particular, it has been shown when acute crying of a child is associated with threatening conditions. The prevalence of functional gastrointestinal disorders and the importance of using the Rome IV criteria in practice are emphasized. Clinical examples of infant colic (G4), infant regurgitation (G1), functional constipation (G7) demonstrated the management of patients with the importance of counseling, showing the evidence base for the use of Lactobacillus reuteri DSM 17938 and vitamin D3. Works on the importance of vitamin D for the prevention of respiratory infections and its dosage are presented. Conclusions. For children in the first year of life with infant colic (G4), infant regurgitation (G1), functional constipation (G7), counseling is important, as well as the use of, in particular, Lactobacillus reuteri DSM 17938. Additional benefits are provided by the combined use of Lactobacillus reuteri DSM 17938 with vitamin D3, which is also discussed for the prevention of respiratory infections. Provided international recommendations for a daily preventive dose of 400 IU of vitamin D for infants. No conflict of interest was declared by the author. Key words: vitamin D, infants, respiratory infections, functional gastrointestinal disorders, Lactobacillus reuteri DSM 17938.

O objetivo do presente estudo é realizar uma revisão integrativa da literatura para verificar a segurança e eficácia do uso de Lactobacillus reuteri DSM 17938 no tratamento da cólica infantil. A busca científica foi feita nas bases de dados PubMed, Medline, Lilacs e nos metabuscadores Acessss e Tripdatabase, entre os meses maio e agosto de 2020. Após a aplicação dos critérios de inclusão e exclusão definidos, 11 artigos foram selecionados para compor o trabalho. A cerca dos resultados dos estudos, oito (72,7%) apresentaram desfechos positivos em relação a eficácia do Lactobacillus reuteri DSM 17938 na diminuição dos sintomas de cólica infantil. Em contrapartida, alguns autores não encontraram diferenças significativas nos marcadores estudados, outros não relataram nenhum desfecho, apenas detalharam o protocolo de intervenção. Ainda que a suplementação de Lactobacillus reuteri DSM 17938 tenha apresentado segurança e eficácia na maior parte dos estudos analisados, não há evidências suficientes para recomendar seu uso como uma estratégia generalizada de tratamento.

Objective: Chronic functional constipation is a frequent condition. The aim of the study was to evaluate the efficacy of the probiotic Lactobacillus (L.) reuteri DSM 17938 and magnesium oxide (MgO) for relieving chronic functional constipation in children. Study design: A prospective, double-blind, placebo-controlled, randomized, and parallel-group trial was conducted in five pediatric outpatient clinics in Japan. Sixty patients who were more than six months old and under six years of age with a diagnosis of functional constipation according to Rome IV criteria were randomly divided into three groups: group A (n = 20) received L. reuteri DSM 17938 and lactose hydrate as a placebo of MgO; group B (n = 19) received L. reuteri DSM 17938 and MgO; and group C (n = 21) received a placebo of L. reuteri DSM 17938 and MgO. Results: All three groups exhibited significant improvement in defecation frequency in the fourth week compared with the baseline condition (group A: p < 0.05; group B: p < 0.05; group C: p < 0.05). The MgO group and combination group showed a significant decrease in stool consistency, but the L. reuteri DSM 17938 group did not (group A: p = 0.079; group B: p < 0.05; group C: p < 0.05). MgO significantly suppressed the presence of the genus Dialister. Defecation frequency negatively correlated with the frequency of Clostridiales-belonging bacteria among the gut microbiome. Conclusions: L. rueteri DSM 17938 and MgO were both effective in the management of functional constipation in young children. MgO caused an imbalance in the gastrointestinal microbiome, which was not the case in the probiotic group.

Статус «пробиотик» присваивается тем микроорганизмам, которые считаются безопасными и соответствуют определенным критериям. Lactobacillus reuteri DSM 17938 (L. reuteri) — хорошо изученная бактерия, способная колонизировать у людей различные участки тела. Штамм, который используется сегодня, L. reuteri DSM 17938, недавно переименованный в Limosilactobacillus reuteri (L. reuteri), является пробиотиком, хорошо идентифицированным по его благотворному влиянию на некоторые желудочно-кишечные заболевания. Пробиотический эффект L. reuteri обусловлен целым комплексом особенных свойств. L. reuteri способен влиять на биоразнообразие, состав и метаболическую функцию микробиоты кишечника, полости рта и влагалища. Эти эффекты в значительной степени штаммоспецифичны. Основной терапевтической мишенью воздействия L. reuteri являются младенческие колики. У младенцев, помимо купирования колик и модуляции кишечной микробиоты, L. reuteri способны усиливать барьерную функцию слизистой оболочки, которая необходима для блокирования проникновения внешних антигенов и токсинов. Литературные данные свидетельствуют об эффективности L. reuteri при острой водянистой диарее, против H. pylori и при других заболеваниях: атопическом дерматите, ожирении, при кариесе, расстройствах аутистического спектра, аутоиммунных заболеваниях, в том числе воспалительных заболеваниях кишечника и системной красной волчанке и др. Безопасность и переносимость L. reuteri доказана многочисленными клиническими исследованиями. Существует несколько штаммов L. reuteri с различным происхождением, и многие из пробиотических функций L. reuteri зависят от штамма. И поэтому в будущем, возможно, может быть выгодно комбинировать различные штаммы L. reuteri, чтобы максимизировать их полезные эффекты. Probiotic status is given to microorganisms that are considered safe and meet certain criteria. Lactobacillus reuteri DSM 17938 (L. reuteri) is a well-studied bacterium that can colonize various parts of the body in humans. The strain in use today, L. reuteri DSM 17938, recently renamed Limosilactobacillus reuteri (L. reuteri), is a probiotic well identifi ed for its benefi cial eff ects on several gastrointestinal diseases. The probiotic eff ect of L. reuteri is due to a whole range of special properties. L. reuteri is able to infl uence the biodiversity, composition and metabolic function of the gut, oral and vaginal microbiota. These eff ects are largely strain-specifi c. The main therapeutic target of L. reuteri is infantile colic. In infants, in addition to relieving colic and modulating the intestinal microbiota, L. reuteri is able to enhance the mucosal barrier function, which is necessary to block the entry of external antigens and toxins. Literature data indicate the eff ectiveness of L. reuteri in acute watery diarrhea, against H. pylori and other diseases: atopic dermatitis, obesity, caries, autism spectrum disorders, autoimmune diseases, incl. infl ammatory bowel disease and systemic lupus erythematosus, etc. The safety and tolerability of L. reuteri has been proven by numerous clinical studies. There are several strains of L. reuteri with different origins and many of the probiotic functions of L. reuteri are strain dependent. Therefore, in the future, it may be advantageous to combine diff erent strains of L. reuteri in order to maximize their benefi cial eff ects.

The introduction of a strain or consortium has often been considered as a potential solution to restore microbial ecosystems. Extensive research on the skin microbiota has led to the development of probiotic products (with live bacterial strains) that are likely to treat dysbiosis. However, the effects of such introductions on the indigenous microbiota have not yet been investigated. Here, through a daily application of Lactobacillus reuteri DSM 17938 on volunteers’ forearm skin, we studied in vivo the impact of a probiotic on the indigenous skin bacterial community diversity using Terminal-Restriction Fragment Length Polymorphism (T-RFLP) for 3 weeks. The results demonstrate that Lactobacillus reuteri DSM 17938 inoculum had a transient effect on the indigenous community, as the resilience phenomenon was observed within the skin microbiota. Moreover, Lactobacillus reuteri DSM 17938 monitoring showed that, despite a high level of detection after 2 weeks of application, thereafter the colonization rate drops drastically. The probiotic colonization rate was correlated significantly to the effect on the indigenous microbial community structure. These preliminary results suggest that the success of probiotic use and the potential health benefits resides in the interactions with the human microbiota.

This PhD thesis is a part of MELiSSA (Micro Ecological Life Support System Alternative) space research program aiming to develop an artificial ecosystem for regenerative life support systems for long-term space missions. Designing an efficient life support system is needed to maintain the minimum life requirements for humans in space. For this reason, the health status of astronauts has been extensively investigated. In particular, many researches were focused on the study of astronauts’ immune system changes induced by simulated or real spaceflight conditions. On the contrary, very few investigations can be found in the literature that address the issue of the intestinal microbiota and its significant role in the astronaut’s health. Moreover, little attention has been given to the study of spaceflight effects on probiotic bacteria, that may be administered to space crew for the purpose to help and improve both innate and adaptive immune responses and in the same time prevent or reduce these effects. The principal environmental stressors of spaceflight have harsh changes in microbial response to the space environment is the microgravity. This condition could increase the pathogenicity characteristics of some microorganisms and in the presence of more resistant bacteria, the natural terrestrial diversity of the gastrointestinal microflora could be reduced. The increased pathogenicity characteristics of some microorganisms, the spacecraft environment with high bacterial contamination due to reduced ventilation and a little varied diet could cause a reduction of the number and/or diversity of beneficial bacteria and, consequently, a decline in immune responses, representing a risk to the health of astronauts, already compromised by psychological stress. This PhD thesis deals with this context treating some aspects of astronauts’ safety in the space with the aim to cultivate a probiotic bacterium in one of bioreactor of MELiSSA loop to use as a direct source of supply for the astronauts’ diet. We assessed the role of a probiotic microorganism in a simulated microgravity environment and evaluate whether this spaceflight condition affect the metabolism of this bacterium and modify its probiotic features. We focused the study on the probiotic strain Lactobacillus reuteri DSM17938, that is a principle component of some commercial products, and evaluated its transcriptome and proteome under simulated microgravity conditions to improve prediction of enzymatic pathways present in a well-defined environment. The investigations in microgravity could highlight the mechanisms of regulation and adaptation of this probiotic bacterium, which will be helpful in uncovering the interactions between this bacterium and a confined environment, including human gut.

The crustacean Artemia franciscana represents a potential experimental model for human studies. The aim of the project was to assess whether Artemia could be used as a model for investigation of probiotic properties. For all the experiments, Artemia cysts were rehydrated, decapsulated and allowed to hatch for 28 hours before the developed larvae (nauplii) were challenged and/or treated with probiotics; measurement of survival rate occurred after further 24 and 48 hours. Interestingly, administration of L. reuteri 17938 during an initial study showed that the probiotic rescued Artemia from spontaneous death occurring in the absence of any established and chosen challenge in a dose-dependent manner. Assuming that Artemia death was related to some kind of stress, the mode of action by means of which L. reuteri provided protective effects was investigated. Heat-treated and bead-beaten L. reuteri positively affected Artemia survival rate to a greater extent than live L. reuteri, with the highest improvement occurring during administration of bead-beaten L. reuteri. In particular, administration of different fractions of the bead-beaten L. reuteri cultures to Artemia allowed for identification of the molecule responsible for amelioration of Artemia fitness in bacterial components ranging between 3 and 300 kDa in weight. Supernatants obtained from exudates of plate-grown bacteria instead revealed itself to be lethal when added in amounts corresponding to 10⁷ CFU/ml of the bacterial culture or higher. Further studies on a genetic and immunological level on Artemia are required in order to elucidate the complex interactions establishing among the host, the probiotic and the environment. However, based on the data gathered, it is possible to suggest that Artemia can be used as a potential chronic stress model, for example as aging or starvation models. Besides this, L. reuteri shows to provide an overall protective effect against this stress, although differences in the extent of the protection were observed according to the growth protocol and the killing mode of bacterial cultures. Also, the lethality of the supernatants demonstrates once again that the probiotic activity is the result of multiple and intertwined biological pathways, sometimes in contrast to one another.