Lactobacillus reuteri as a therapeutic agent in acute diarrhea in young children

Gut microbiota-derived LCA mediates the protective effect of PEDV infection in piglets

BACKGROUND

The gut microbiota is a critical factor in the regulation of host health, but the relationship between the differential resistance of hosts to pathogens and the interaction of gut microbes is not yet clear. Herein, we investigated the potential correlation between the gut microbiota of piglets and their disease resistance using single-cell transcriptomics, 16S amplicon sequencing, metagenomics, and untargeted metabolomics.

RESULTS

Porcine epidemic diarrhea virus (PEDV) infection leads to significant changes in the gut microbiota of piglets. Notably, Landrace pigs lose their resistance quickly after being infected with PEDV, but transplanting the fecal microbiota of Min pigs to Landrace pigs alleviated the infection status. Macrogenomic and animal protection models identified Lactobacillus reuteri and Lactobacillus amylovorus in the gut microbiota as playing an anti-infective role. Moreover, metabolomic screening of the secondary bile acids' deoxycholic acid (DCA) and lithocholic acid (LCA) correlated significantly with Lactobacillus reuteri and Lactobacillus amylovorus, but only LCA exerted a protective function in the animal model. In addition, LCA supplementation altered the distribution of intestinal T-cell populations and resulted in significantly enriched CD8+ CTLs, and in vivo and in vitro experiments showed that LCA increased SLA-I expression in porcine intestinal epithelial cells via FXR receptors, thereby recruiting CD8+ CTLs to exert antiviral effects.

CONCLUSIONS

Overall, our findings indicate that the diversity of gut microbiota influences the development of the disease, and manipulating Lactobacillus reuteri and Lactobacillus amylovorus, as well as LCA, represents a promising strategy to improve PEDV infection in piglets. Video Abstract.

Acute gastroenteritis-changes to the recommended original oral rehydrating salts: a review

The World Health Organization recommended a formulation of oral rehydration salts as the intervention of choice for the treatment of acute gastroenteritis. While of value for the replacement of fluids and electrolytes, the formulation does not reduce stool volume, frequency, or symptom duration. This may prevent wide acceptance. To increase tolerability, shorten the duration of diarrhea and improve parental quality of life, several modifications to the original formula have been proposed. These include; low osmolarity, rice-based, glucose polymers as an alternative to glucose, the addition of probiotics, prebiotics and/or zinc, and various other ingredients. Here we summarize evidence regarding such changes and additions.

Revisiting geophagy: An evolved sickness behavior to microbiome-mediated gastrointestinal inflammation

Geophagy, the consumption of clay or similar substances, is known as an evolved behavior that protects vulnerable populations, such as pregnant women and children, against gastrointestinal injury. However, perplexing questions remain, like the presence of geophagy in the absence of overt gastrointestinal infection and the potential causal relationship between geophagy and iron deficiency anemia. In this review, we hypothesize that geophagy is an inflammation-mediated sickness behavior regulated via the vagus nerve. We further hypothesize that the gut microbiome plays a critical role in mediating the relationship between inflammation and geophagy. By including inflammation and the microbiome within the existing protection hypothesis, we can explain how subclinical gastrointestinal states induce geophagy. Furthermore, we can explain how gastrointestinal inflammation is responsible for both geophagy and iron-deficiency anemia, explaining why the two phenomena frequently co-occur. Ultimately, defining geophagy as a sickness behavior allows us to integrate the gut-brain axis into geophagy research.

Using metabolomics to understand stress responses in Lactic Acid Bacteria and their applications in the food industry

BACKGROUND

Lactic Acid Bacteria (LAB) are commonly used as starter cultures, probiotics, to produce lactic acid and other useful compounds, and even as natural preservatives. For use in any food product however, LAB need to survive the various stresses they encounter in the environment and during processing. Understanding these mechanisms may enable direction of LAB biochemistry with potential beneficial impact for the food industry.

AIM OF REVIEW

To give an overview of the use of LAB in the food industry and then generate a deeper biochemical understanding of LAB stress response mechanisms via metabolomics, and methods of screening for robust strains of LAB.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Uses of LAB in food products were assessed and factors which contribute to survival and tolerance in LAB investigated. Changes in the metabolic profiles of LAB exposed to stress were found to be associated with carbohydrates, amino acids and fatty acid levels and these changes were proposed to be a result of the bacteria trying to maintain cellular homeostasis in response to external conditions and minimise cellular damage from reactive oxygen species. This correlates with morphological analysis which shows that LAB can undergo cell elongation and shortening, as well as thinning and thickening of cell membranes, when exposed to stress. It is proposed that these innate strategies can be utilised to minimise negative effects caused by stress through selection of intrinsically robust strains, genetic modification and/or prior exposure to sublethal stress. This work demonstrates the utility of metabolomics to the food industry.

Controlling Intestinal Infections and Digestive Disorders Using Probiotics

After consumption, probiotics provide health benefits to the host. Probiotics and their metabolites have therapeutic and nutritional properties that help to alleviate gastrointestinal, neurological, and cardiovascular problems. Probiotics strengthen host immunity through various mechanisms, including improved gut barrier function, receptor site blocking, competitive exclusion of pathogens, and the production of bioactive molecules. Emerging evidence suggests that intestinal bowel diseases can be fatal, but regular probiotic consumption can alleviate disease symptoms. The use and detailed description of the health benefits of probiotics to consumers in terms of reducing intestinal infection, inflammation, and digestive disorders are discussed in this review. The well-designed and controlled studies that examined the use of probiotics to reduce life-threatening activities caused by intestinal bowel diseases are also covered. This review discussed the active principles and potency of probiotics as evidenced by the known effects on host health, in addition to providing information on the mechanism of action.

Association of Short-Chain Fatty Acids with Gut Microbiota and Lipid Metabolism in Mice with Diarrhea Induced by High-Fat Diet in a Fatigued State

SCOPE

Preliminary research finds that a high-fat diet (HFD) in a fatigued state triggers diarrhea, but the exact mechanism has not been clarified. To address concerns about the pathogenesis of diarrhea, the study evaluates the composition and metabolomics of the gut microbiota.

METHODS AND RESULTS

The study uses the multiple platform apparatus device to induce fatigue in mice, combined with intragastric administration of lard-caused diarrhea. Subsequently, the characteristics and interaction relationship of gut microbiota, short-chain fatty acids (SCFAs), inflammatory biomarkers, brain-gut peptides, and lipid metabolism are analyzed at the end of the experiment. HFD in a fatigued state results in a significant increase in interleukin-17, interleukin-6, cholecystokinin, somatostatin, and malondialdehyde content in mice (p < 0.05), along with a substantial decrease in high-density lipoprotein (p < 0.05). Additionally, an HFD in a fatigued state causes changes in the structure and composition of the gut microbiota, with Lactobacillus murinus as its characteristic bacteria, and reduces the production of SCFAs.

CONCLUSIONS

An HFD in a fatigued state triggers diarrhea, possibly associated with gut content microbiota dysbiosis, SCFAs deprivation, increased inflammation, and dysregulated lipid metabolism.

Lactobacillus reuteri in digestive system diseases: focus on clinical trials and mechanisms

Objectives

Digestive system diseases have evolved into a growing global burden without sufficient therapeutic measures. Lactobacillus reuteri (L. reuteri) is considered as a new potential economical therapy for its probiotic effects in the gastrointestinal system. We have provided an overview of the researches supporting various L. reuteri strains' application in treating common digestive system diseases, including infantile colic, diarrhea, constipation, functional abdominal pain, Helicobacter pylori infection, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases.

Methods

The summarized literature in this review was derived from databases including PubMed, Web of Science, and Google Scholar.

Results

The therapeutic effects of L. reuteri in digestive system diseases may depend on various direct and indirect mechanisms, including metabolite production as well as modulation of the intestinal microbiome, preservation of the gut barrier function, and regulation of the host immune system. These actions are largely strain-specific and depend on the activation or inhibition of various certain signal pathways. It is well evidenced that L. reuteri can be effective both as a prophylactic measure and as a preferred therapy for infantile colic, and it can also be recommended as an adjuvant strategy to diarrhea, constipation, Helicobacter pylori infection in therapeutic settings. While preclinical studies have shown the probiotic potential of L. reuteri in the management of functional abdominal pain, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases, its application in these disease settings still needs further study.

Conclusion

This review focuses on the probiotic effects of L. reuteri on gut homeostasis via certain signaling pathways, and emphasizes the importance of these probiotics as a prospective treatment against several digestive system diseases.

Probiotic-Derived Ecto-5'-Nucleotidase Produces Anti-Inflammatory Adenosine Metabolites in Treg-Deficient Scurfy Mice

Probiotic Limosilactobacillus reuteri DSM 17938 (DSM 17938) prolongs the survival of Treg-deficient scurfy (SF) mice and reduces multiorgan inflammation by a process requiring adenosine receptor 2A (A2A) on T cells. We hypothesized that L. reuteri-derived ecto-5'-nucleotidase (ecto-5'NT) activity acts to generate adenosine, which may be a central mediator for L. reuteri protection in SF mice. We evaluated DSM 17938-5'NT activity and the associated adenosine and inosine levels in plasma, gut, and liver of SF mice. We examined orally fed DSM 17938, DSM 17938Δ5NT (with a deleted 5'NT gene), and DSM 32846 (BG-R46) (a naturally selected strain derived from DSM 17938). Results showed that DSM 17938 and BG-R46 produced adenosine while "exhausting" AMP, whereas DSM 17938∆5NT did not generate adenosine in culture. Plasma 5'NT activity was increased by DSM 17938 or BG-R46, but not by DSM 17938Δ5NT in SF mice. BG-R46 increased both adenosine and inosine levels in the cecum of SF mice. DSM 17938 increased adenosine levels, whereas BG-R46 increased inosine levels in the liver. DSM 17938Δ5NT did not significantly change the levels of adenosine or inosine in the GI tract or the liver of SF mice. Although regulatory CD73+CD8+ T cells were decreased in spleen and blood of SF mice, these regulatory T cells could be increased by orally feeding DSM 17938 or BG-R46, but not DSM 17938Δ5NT. In conclusion, probiotic-5'NT may be a central mediator of DSM 17938 protection against autoimmunity. Optimal 5'NT activity from various probiotic strains could be beneficial in treating Treg-associated immune disorders in humans.

A systematic review and meta-analysis: the therapeutic and preventive effect of Lactobacillus reuteri DSM 17,938 addition in children with diarrhea

OBJECTIVE

To summarize the effect of adding Lactobacillus reuteri in the treatment plan for diarrheal disease in children, and analyze the potential of probiotics in preventing the occurrence of diarrheal disease.

METHODS

Search for randomized controlled trials of Lactobacillus reuteri for the treatment and prevention of diarrhea in the Pubmed, Web of science, Medline, and Cochrane databases. Data such as the number of diarrhea patients, time, length of stay, clinical symptoms and effect of diarrhea prevention were extracted for meta-analysis. Relative risk and confidence interval (RR and 95% CI) were used as outcome indicators.

RESULTS

963 participants in the 9 RCTs came from multiple countries/regions. Compared with placebo/no intervention, the number of diarrhea patients in the Lactobacillus reuteri group was significantly reduced on the day 1 (RR = 0.87, 95%CI: 0.78-0.97) and day 2 (RR = 0.61, 95%CI: 0.44-0.83). Cumulative statistics analysis showed that the effect was stable and significant starting on the 4th day after treatment. A few studies have shown that Lactobacillus reuteri can reduce the time of diarrhea, the number of days with watery stools, and days of hospital stay. However, it has no effect on the occurrence of nosocomial diarrhea (RR = 1.11, 95%CI: 0.68-1.83), rotavirus diarrhea (RR = 1.46, 95%CI: 0.78-2.72), antibiotic-related diarrhea (RR = 1.76, 95%CI: 0.77-4.05), and diarrhea (RR = 1.35, 95%CI: 0.95-1.92).

CONCLUSION

Addition of Lactobacillus reuteri in the treatment plan has a significant effect on reducing the number of diarrhea and reducing the symptoms of diarrhea, but has no obvious effect on the prevention of diarrhea. Combining probiotics and improving the ability of probiotics to respond is the focus of attention.

Probiotic-derived ecto-5'-nucleotidase produces anti-inflammatory adenosine metabolites in Treg-deficient scurfy mice

Probiotic Limosilactobacillus reuteri DSM 17938 (DSM 17938) prolonges the survival of Treg-deficient scurfy (SF) mice and reduces multiorgan inflammation by a process requiring adenosine receptor 2A (A _2A ) on T cells. We hypothesized that L. reuteri -derived ecto-5'-nucleotidase (ecto-5'NT) activity acts to generate adenosine, which may be a central mediator for L. reuteri protection in SF mice. We evaluated DSM 17938-5'NT activity and the associated adenosine and inosine levels in plasma, gut and liver of SF mice. We examined orally fed DSM 17938, DSM 17938Δ5NT (with a deleted 5'NT gene), and DSM 32846 (BG-R46) (a naturally selected strain derived from DSM 17938). Results showed that DSM 17938 and BG-R46 produced adenosine while "exhausting" AMP, whereas DSM 17938∆5NT did not generate adenosine in culture. Plasma 5'NT activity was increased by DSM 17938 or BG-R46, but not by DSM 17938Δ5NT in SF mice. BG-R46 increased both adenosine and inosine levels in the cecum of SF mice. DSM 17938 increased adenosine levels, whereas BG-R46 increased inosine levels in the liver. DSM 17938Δ5NT did not significantly change the levels of adenosine or inosine in the GI tract or the liver of SF mice. Although regulatory CD73 ⁺ CD8 ⁺ T cells were decreased in spleen and blood of SF mice, these regulatory T cells could be increased by orally feeding DSM 17938 or BG-R46, but not DSM 17938Δ5NT. In conclusion, probiotic-5'NT may be a central mediator of DSM 17938 protection against autoimmunity. Optimal 5'NT activity from various probiotic strains could be beneficial in treating Treg-associated immune disorders in humans.

Nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome

Obesity and metabolic disorders represent a significant global health problem and the gut microbiota plays an important role in modulating systemic homeostasis. Recent evidence shows that microbiota and its signaling pathways may affect the whole metabolism and the Renin-Angiotensin System (RAS), which in turn seems to modify microbiota. The present review aimed to investigate nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome components. A description of metabolic changes was obtained based on relevant scientific literature. The molecular and physiological mechanisms that impact the human microbiome were addressed, including the gut microbiota associated with obesity, diabetes, and hepatic steatosis. The RAS interaction signaling and modulation were analyzed. Strategies including the use of prebiotics, symbiotics, probiotics, and biotechnology may affect the gut microbiota and its impact on human health.

Pathogen-Specific Benefits of Probiotic and Synbiotic Use in Childhood Acute Gastroenteritis: An Updated Review of the Literature

Probiotics represent viable microorganisms which are found within the normal gut microbiota, that exert strain-specific benefits in the management of several gastrointestinal disorders in children, including acute gastroenteritis. This review aims to evaluate the pathogen-specific role of probiotic supplementation in childhood diarrhea. A search of scientific databases was conducted to identify studies which investigated efficacy of probiotics and synbiotics in influencing outcome of acute gastroenteritis of known etiology. We identified 32 studies, most of which analyzed impact of probiotic supplementation in rotavirus gastroenteritis, while a very limited number of these conducted a separate analysis on bacterial diarrhea. Lactobacillus rhamnosus (L. rhamnosus), L. reuteri and S. boulardii still remain the most researched strains, with a proven role in decreasing diarrhea and hospitalization duration, especially in the setting of rotavirus infection. Combined products containing at least one of the aforementioned strains also performed similarly and might also influence rotavirus fecal shedding. Rotavirus immunization status has also been proposed as a significant influencing factor of probiotic use impact. The paucity of research focusing on bacterial etiologies, as well as of clinical trials conducted within ambulatory care units leaves room for further research on the matter, which needs to include larger cohort studies.

Opportunities for growth in the growing field of psychobiotics

There is growing interest in the field of psychobiotics, which are probiotics that confer a mental health benefit when ingested. As this field grows, it should pay particular attention to three areas within psychobiotics research that are currently under-studied - sex (and gender) representation, fungi and the mycobiome, and vagus nerve activity. Giving these three domains more attention is currently feasible without significant increased investment of time or money. We discuss these three domains briefly, why they are of particular relevance for psychobiotics research, and how psychobiotics research can easily integrate their perspectives. Our recommendations are summarised in the conclusion, but include equal sex representation at all phases of research (human and animal studies), investigating the relationship between psychobiotics and commensal fungi, and measuring the activity of the vagus nerve in psychobiotics studies.

Integrated metagenomics and targeted-metabolomics analysis of the effects of phenylalanine on loperamide-induced constipation in rats

Functional constipation is a common functional gastrointestinal disease. In our previous study, we found that the gut microbiota structure was disordered and the level of phenylalanine (Phe) in serum was decreased in constipated women. We conducted the present study to elucidate the role of Phe in remodeling the composition of gut microbiota and the relationship between gut microbiota and serum metabolites. Here, we demonstrated that Phe treatment significantly enhanced intestinal motility, suppressed inflammatory responses, and prevented intestinal barrier damage in rats with loperamide (Lop)-induced constipation. By metagenomic sequencing, the disbalanced gut microbial profile was analyzed in constipated rats. Phe treatment reversed changes in the abundance of several gut bacteria at the phylum, genus, and species levels. Further, we observed distinct metabolic patterns in constipated rats through targeted metabolomics and identified constipation-related gut microbial species linked to changes in circulating neurotransmitter metabolites. The abundances of species s_Lactobacillus murinus, s_Enterococcus italicus, s_Lactobacillus animalis, s_Lactobacillus apodemi, s_Enterococcus faecalis, and s_Lactobacillus backii were positively correlated with L-asparagine, L-Glutamic acid, Putrescine, and Spermidine levels. The abundances of s_Lactobacillus johnsonii and s_Butyricimonas virosa were negatively correlated with L-asparagine, L-Glutamic acid, Putrescine, and Spermidine levels. Taken together, our findings suggest that Phe can ameliorate the development of Lop-induced constipation in rats by remodeling the gut microbial community structure and changing metabolite levels.

In Silico Genomic and Metabolic Atlas of Limosilactobacillus reuteri DSM 20016: An Insight into Human Health

Probiotics are bacterial strains that are known to provide host health benefits. Limosilactobacillus reuteri is a well-documented lactic acid bacterium that has been cultured from numerous human sites. The strain investigated was L. reuteri DSM 20016, which has been found to produce useful metabolites. The strain was explored using genomic and proteomic tools, manual searches, and databases, including KEGG, STRING, BLAST Sequence Similarity Search, and UniProt. This study located over 200 key genes that were involved in human health benefit pathways. L. reuteri DSM 20016 has metabolic pathways to produce acetate, propionate, and lactate, and there is evidence of a pathway for butanoate production through a FASII mechanism. The bacterium produces histamine through the hdc operon, which may be able to suppress proinflammatory TNF, and the bacterium also has the ability to synthesize folate and riboflavin, although whether they are secreted is yet to be explored. The strain can bind to human Caco2 cells through srtA, mapA/cnb, msrB, and fbpA and can compete against enteric bacteria using reuterin, which is an antimicrobial that induces oxidative stress. The atlas could be used for designing metabolic engineering approaches to improve beneficial metabolite biosynthesis and better probiotic-based cures.

Lactobacillus plantarum improves LPS-induced Caco2 cell line intestinal barrier damage via cyclic AMP-PKA signaling

Lactobacillus plantarum (LP) has been shown to exhibit protective effects on intestinal barrier function in septic rats, although the regulatory mechanism has not been established. We determined whether LP imparts such protective effects in a lipopolysaccharide (LPS)-induced Caco2 cell monolayer model and whether cAMP-PKA signaling is the underlying mechanism of action. The cyclic adenosine monophosphate (cAMP) agonist, forskolin (FSK), and the protein kinase A (PKA) inhibitor, HT89, were used to study the protective effect of LP on the destruction of the tight junction (TJ) structure of cells treated with LPS and the corresponding changes in cAMP-PKA signaling. Our experimental results demonstrated that LP promoted the expression of TJ proteins between Caco2 cells after LPS treatment, and increased the electrical barrier detection (TEER) between Caco2 cells. Moreover, transmission electron microscopy (TEM) revealed that the TJ structural integrity of cells treated with LPS + LP was improved compared to cells treated with LPS alone. In addition, our findings were consistent between the FSK and LP intervention group, while HT89 inhibited LP influence. Taken together, our results indicate that LP has an improved protective effect on LPS-induced damage to the monolayer membrane barrier function of Caco2 cells and is regulated by the cAMP-PKA pathway.

Development of a novel human intestinal model to elucidate the effect of anaerobic commensals on Escherichia coli infection

The gut microbiota plays a crucial role in protecting against enteric infection. However, the underlying mechanisms are largely unknown owing to a lack of suitable experimental models. Although most gut commensals are anaerobic, intestinal epithelial cells require oxygen for survival. In addition, most intestinal cell lines do not produce mucus, which provides a habitat for the microbiota. Here, we have developed a microaerobic, mucus-producing vertical diffusion chamber (VDC) model and determined the influence of Limosilactobacillus reuteri and Ruminococcus gnavus on enteropathogenic Escherichia coli (EPEC) infection. Optimization of the culture medium enabled bacterial growth in the presence of mucus-producing T84/LS174T cells. Whereas L. reuteri diminished EPEC growth and adhesion to T84/LS174T and mucus-deficient T84 epithelia, R. gnavus only demonstrated a protective effect in the presence of LS174T cells. Reduced EPEC adherence was not associated with altered type III secretion pore formation. In addition, co-culture with L. reuteri and R. gnavus dampened EPEC-induced interleukin 8 secretion. The microaerobic mucin-producing VDC system will facilitate investigations into the mechanisms underpinning colonization resistance and aid the development of microbiota-based anti-infection strategies. This article has an associated First Person interview with the first author of the paper.

Which Probiotic Is the Most Effective for Treating Acute Diarrhea in Children? A Bayesian Network Meta-Analysis of Randomized Controlled Trials

Acute diarrhea is a major cause of morbidity and mortality in children under five. Probiotics are beneficial for treating acute diarrhea in children, but unclear which specific probiotic is the most effective. We performed a Bayesian network meta-analysis to examine the comparative effectiveness of probiotics. By searching EMBASE, PubMed, and the Cochrane Library up to 31 March 2021, randomized clinical trials (RCTs) on probiotics for treating acute diarrhea in children were included. Primary outcomes included the duration of diarrhea and diarrhea lasting ≥2 days, and secondary outcomes included the mean stool frequency on day 2 and duration of hospitalization, fever, and vomiting. We assessed the certainty of the evidence of outcomes according to Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guideline. Eighty-four studies with twenty-one different interventions in 13,443 children were included. For the primary outcomes, moderate evidence indicated that, Lactobacillus reuteri [mean difference (MD) = -0.84 day; 95% confidence interval (CI), -1.39, -0.29], Bifidobacterium lactis (MD = -0.98 day; 95%CI, -1.82, -0.14), Saccharomyces boulardii (MD = -1.25 day; 95%CI, -1.59, -0.91), Lactobacillus species (spp.) plus Bifidobacterium spp. plus Saccharomyces spp. (MD = -1.19 day; 95%CI, -1.81, -0.58), and Bacillus spp. plus Enterococcus spp. plus Clostridium spp. (MD = -1.1 day; 95%CI, -1.84, -0.35) significantly reduced the duration of diarrhea when compared with placebo. Saccharomyces boulardii [Odds ratio (OR) = 0.22; 95%CI, 0.11, 0.41] and Lactobacillus reuteri (OR = 0.23; 95%CI, 0.090, 0.60) significantly reduced the risk of diarrhea lasting ≥2 days when compared with placebo or no treatment, with moderate evidence. Among all probiotics, Saccharomyces boulardii may be the most effective in reducing both duration of diarrhea (compared with placebo) and risk of diarrhea lasting ≥2 days (compared with placebo or no treatment), with moderate evidence. To be conclusive, Saccharomyces boulardii may be the most effective probiotic for treating acute diarrhea in children, followed by several other single-strain and multi-strain probiotics.

Bigels-oleocolloid matrices-as probiotic protective systems in yogurt

The probiotic yogurt market is strong because of the potential benefits that probiotics provide to the host, such as relieving lactose intolerance symptoms, easing diarrhea, and improving the immune system. However, probiotics are sensitive to processing conditions and the high acidity of yogurt can reduce survival of probiotics and limit yogurt shelf life. Here, oleocolloid technology (bigels) was used to improve the survival of probiotics during yogurt shelf life. Bigels are semisolid systems containing a polar and a non-polar phase mixed forming a material with improved properties. Probiotic bigels were prepared by mixing a soy lecithin-stearic acid oleogel emulsion and a whey protein hydrogel, followed by the incorporation of Lactobacillus acidophilus and Bifidobacterium lactis suspended in milk. Yogurt was prepared with 18% wt/wt probiotic bigels with (Swiss-style) and without (sundae-style) agitation. Probiotic viability was monitored for 6 weeks. The total counts of L. acidophilus and B. lactis entrapped in bigels were significantly higher than free bacteria in yogurt after 3 and 5 weeks, respectively, indicating that probiotics could be entrapped and their survival enhanced. Both yogurt styles showed a meant total count of 3.3 and 4.5 log CFU/g for L. acidophilus and B. lactis, respectively at the end of storage time suggesting that despite agitation of yogurt, bigel structure played a key role in protecting probiotic viability.

Effectiveness of probiotics and synbiotics in reducing duration of acute infectious diarrhea in pediatric patients in developed countries: a systematic review and meta-analysis

Acute diarrhea is one of the most frequent causes of doctor visits and hospital admissions for children. Our objective was to evaluate the association between probiotics administration and reduction of acute infectious diarrhea duration in children dwelling in developed countries. Bibliographic databases, gray literature, and reference lists were searched up to September 29, 2019. Double-blind, randomized controlled trials that examined probiotics efficacy in children with acute infectious diarrhea residing in developed countries were included. Data were synthesized by generic inverse variance method using fixed- and random-effects model. Twenty trials met the eligibility criteria (n = 3469 patients) and were included in the qualitative synthesis, and 19 studies in meta-analysis. Twelve trials (n = 840) were assessed as high/unclear risk of bias and eight (n = 2629) as low risk of bias. Comparisons revealed a moderate effectiveness of probiotics in low risk of bias studies (MD = - 13.45 h; 95% CI - 24.26, - 2.62; p = 0.02, Bayesian meta-analysis pooled effect MD = - 0.38, 95% CrI - 2.3, 1.58) and a notable effect in studies with high/unclear risk for bias (MD = - 19.70 h; 95% CI - 28.09, - 11.31; p = 0.0004). In trials of optimal methodological quality (n = 1989), probiotics effect was absent (MD = - 3.32 h; 95% CI - 8.78, 2.13, p = 0.23).Conclusion: Outcomes suggest that probiotics do not demonstrate sufficient clinical impact in reducing diarrhea duration in children in the developed countries.Systematic Review Registration: This review is registered at PROSPERO (ID: CRD42020152966). What is Known: • Probiotics, due to the conflicting study results, are administered without adequate evidence as an adjuvant therapeutic agent for eliminating duration of acute infectious diarrhea in pediatric patients. What is New: • In developed countries, probiotics are demonstrated as ineffective in reducing the duration of acute infectious diarrhea in children.

Lactobacillus Reuteri DSM 17938 (Limosilactobacillus reuteri) in Diarrhea and Constipation: Two Sides of the Same Coin?

Background and Objectives: Lactobacillus reuteri DSM 17938 (L. reuteri) is a probiotic that can colonize different human body sites, including primarily the gastrointestinal tract, but also the urinary tract, the skin, and breast milk. Literature data showed that the administration of L. reuteri can be beneficial to human health. The aim of this review was to summarize current knowledge on the role of L. reuteri in the management of gastrointestinal symptoms, abdominal pain, diarrhea and constipation, both in adults and children, which are frequent reasons for admission to the emergency department (ED), in order to promote the best selection of probiotic type in the treatment of these uncomfortable and common symptoms. Materials and Methods: We searched articles on PubMed^® from January 2011 to January 2021. Results: Numerous clinical studies suggested that L. reuteri may be helpful in modulating gut microbiota, eliminating infections, and attenuating the gastrointestinal symptoms of enteric colitis, antibiotic-associated diarrhea (also related to the treatment of Helicobacter pylori (HP) infection), irritable bowel syndrome, inflammatory bowel disease, and chronic constipation. In both children and in adults, L. reuteri shortens the duration of acute infectious diarrhea and improves abdominal pain in patients with colitis or inflammatory bowel disease. It can ameliorate dyspepsia and symptoms of gastritis in patients with HP infection. Moreover, it improves gut motility and chronic constipation. Conclusion: Currently, probiotics are widely used to prevent and treat numerous gastrointestinal disorders. In our opinion, L. reuteri meets all the requirements to be considered a safe, well-tolerated, and efficacious probiotic that is able to contribute to the beneficial effects on gut-human health, preventing and treating many gastrointestinal symptoms, and speeding up the recovery and discharge of patients accessing the emergency department.

Limosilactobacillus reuteri and Lacticaseibacillus rhamnosus GG differentially affect gut microbes and metabolites in mice with Treg deficiency

Treg deficiency causes a lethal, CD4+ T cell-driven autoimmune disease called IPEX syndrome (immunodysregulation, polyendocrinopathy, and enteropathy, with X-linked inheritance) in humans and in the scurfy (SF) mouse, a mouse model of the disease. Feeding Limosilactobacillus reuteri DSM 17938 (LR 17938, LR) to SF mice reprograms the gut microbiota, reduces disease progression, and prolongs lifespan. However, the efficacy and mechanism of LR, compared with other probiotics, in producing these effects is unknown. We compared LR with Lacticaseibacillus rhamnosus GG (LGG), an extensively investigated probiotic. LR was more effective than LGG in prolonging survival. Both probiotics restored the fecal microbial alpha diversity, but they produced distinct fecal bacterial clusters and differentially modulated microbial relative abundance (RA). LR increased the RA of phylum_Firmicutes, genus_Oscillospira whereas LR reduced phylum_Bacteroidetes, genus_Bacteroides and genus_Parabacteroides, reversing changes attributed to the SF phenotype. LGG primarily reduced the RA of genus_Bacteroides. Both LR and LGG reduced the potentially pathogenic taxon class_γ-proteobacteria. Plasma metabolomics revealed substantial differences among 696 metabolites. We observed similar changes of many clusters of metabolites in SF mice associated with treatment with either LR or LGG. However, a unique effect of LR was to increase the abundance of plasma adenosine metabolites such as inosine, which we previously showed had immune modulatory effects. In conclusion: 1) different probiotics produce distinct signatures in the fecal microbial community in mice with Treg deficiency; and 2) when comparing different probiotics, there are strain-specific microbial products with different anti-inflammatory properties, reinforcing the concept that "one size does not fit all" in the treatment of autoimmune disease.NEW & NOTEWORTHY In the treatment of Treg-deficiency-induced autoimmunity, Limosilactobacillus reuteri DSM 17938 (LR) showed greater efficacy than Lacticaseibacillus rhamnosus GG (LGG). The study demonstrated that two different probiotics produce distinct signatures in the fecal microbial community in mice with Treg deficiency, but with many similarities in global plasma metabolites in general. However, there are strain-specific microbial products with different anti-inflammatory properties, reinforcing the concept that "one size does not fit all" in the treatment of autoimmune disease.

Role of probiotics in prevention and treatment of enteric infections: a comprehensive review

Microorganisms that inhabits human digestive tract affect global health and enteric disorders. Previous studies have documented the effectiveness and mode of action of probiotics and classified as human-friendly biota and a competitor to enteric pathogens. Statistical studies reported more than 1.5 billion cases of gastrointestinal infections caused by enteric pathogens and their long-term exposure can lead to mental retardation, temporary or permanent physical weakness, and leaving the patient susceptible for opportunistic pathogens, which can cause fatality. We reviewed previous literature providing evidence about therapeutic approaches regarding probiotics to cure enteric infections efficiently by producing inhibitory substances, immune system modulation, improved barrier function. The therapeutic effects of probiotics have shown success against many foodborne pathogens and their therapeutic effectiveness has been exponentially increased using genetically engineered probiotics. The bioengineered probiotic strains are expected to provide a better and alternative approach than traditional antibiotic therapy against enteric pathogens, but the novelty of these strains also raise doubts about the possible untapped side effects, for which there is a need for further studies to eliminate the concerns relating to the use and safety of probiotics. Many such developments and optimization of the classical techniques will revolutionize the treatments for enteric infections.

Probiotics for the Management of Infantile Colic: A Systematic Review

BACKGROUND

Colic is defined as periods of inconsolable crying, fussing, or irritability that have no apparent cause and present in healthy infants under 5 months of age. Although colic is a benign and self-limiting condition, it can be distressing to parents and there are few robust treatment interventions. This systematic review explored the evidence for administration of probiotics to prevent or decrease symptoms of colic.

METHODS

Literature searches were conducted in PubMed, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane Library, and Web of Science.

SAMPLE

Twenty articles were included: 15 randomized controlled trials and 5 meta-analyses.

RESULTS

Based on the evidence in this systematic review, the oral administration of probiotics to breastfed infants with colic resulted in at least a 50% reduction in crying time compared with placebo. Efficacy of probiotics to reduce colic symptoms in formula-fed infants needs further study. In this review, we did not find evidence to support or refute efficacy of probiotics to prevent infantile colic. Clinical Implication: Probiotics (especially the strain Lactobacillus reuteri DSM 17938) can safely be recommended if parents desire a treatment option for their infants with colic.

GUT MICROBIOTA, PREBIOTICS, PROBIOTICS, AND SYNBIOTICS IN GASTROINTESTINAL AND LIVER DISEASES: PROCEEDINGS OF A JOINT MEETING OF THE BRAZILIAN SOCIETY OF HEPATOLOGY (SBH), BRAZILIAN NUCLEUS FOR THE STUDY OF HELICOBACTER PYLORI AND MICROBIOTA (NBEHPM), AND BRAZILIAN FEDERATION OF GASTROENTEROLOGY (FBG)

Over the last years, there is growing evidence that microorganisms are involved in the maintenance of our health and are related to various diseases, both intestinal and extraintestinal. Changes in the gut microbiota appears to be a key element in the pathogenesis of hepatic and gastrointestinal disorders, including non-alcoholic fatty liver disease, alcoholic liver disease, liver cirrhosis, inflammatory bowel disease, irritable bowel syndrome, and Clostridium difficile - associated diarrhea. In 2019, the Brazilian Society of Hepatology (SBH) in cooperation with the Brazilian Nucleus for the Study of Helicobacter Pylori and Microbiota (NBEHPM), and Brazilian Federation of Gastroenterology (FBG) sponsored a joint meeting on gut microbiota and the use of prebiotics, probiotics, and synbiotics in gastrointestinal and liver diseases. This paper summarizes the proceedings of the aforementioned meeting. It is intended to provide practical information about this topic, addressing the latest discoveries and indicating areas for future studies.

Combined use of lactic-acid-producing bacteria as probiotics and rotavirus vaccine candidates expressing virus-specific proteins

Due to the lower efficacy of currently approved live attenuated rotavirus (RV) vaccines in developing countries, a new approach to the development of safe mucosally administered live bacterial vectors is being considered, using probiotic bacteria as an efficient delivery platform for heterologous RV antigens. Lactic acid bacteria (LAB), which are considered food-grade bacteria and normal microbiota, have been utilized throughout history as probiotics and developed since the 1990s as a delivery system for recombinant heterologous proteins. Over the last decade, LAB have frequently been used as a platform for the delivery of various RV antigens to the mucosa. Given the appropriate safety profile for neonates and providing the benefits of probiotics, recombinant LAB-based vaccines could potentially address the need for a subunit RV vaccine. The present review focuses mainly on different recombinant LAB vaccine constructs for RV and their potential as an alternative recombinant vaccine against RV disease.

Probiotics for treating acute infectious diarrhoea

BACKGROUND

Probiotics may be effective in reducing the duration of acute infectious diarrhoea.

OBJECTIVES

To assess the effects of probiotics in proven or presumed acute infectious diarrhoea.

SEARCH METHODS

We searched the trials register of the Cochrane Infectious Diseases Group, MEDLINE, and Embase from inception to 17 December 2019, as well as the Cochrane Controlled Trials Register (Issue 12, 2019), in the Cochrane Library, and reference lists from studies and reviews. We included additional studies identified during external review.

SELECTION CRITERIA

Randomized controlled trials comparing a specified probiotic agent with a placebo or no probiotic in people with acute diarrhoea that is proven or presumed to be caused by an infectious agent.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied inclusion criteria, assessed risk of bias, and extracted data. Primary outcomes were measures of diarrhoea duration (diarrhoea lasting ≥ 48 hours; duration of diarrhoea). Secondary outcomes were number of people hospitalized in community studies, duration of hospitalization in inpatient studies, diarrhoea lasting ≥ 14 days, and adverse events.

MAIN RESULTS

We included 82 studies with a total of 12,127 participants. These studies included 11,526 children (age < 18 years) and 412 adults (three studies recruited 189 adults and children but did not specify numbers in each age group). No cluster-randomized trials were included. Studies varied in the definitions used for "acute diarrhoea" and "end of the diarrhoeal illness" and in the probiotic(s) tested. A total of 53 trials were undertaken in countries where both child and adult mortality was low or very low, and 26 where either child or adult mortality was high. Risk of bias was high or unclear in many studies, and there was marked statistical heterogeneity when findings for the primary outcomes were pooled in meta-analysis. Effect size was similar in the sensitivity analysis and marked heterogeneity persisted. Publication bias was demonstrated from funnel plots for the main outcomes. In our main analysis of the primary outcomes in studies at low risk for all indices of risk of bias, no difference was detected between probiotic and control groups for the risk of diarrhoea lasting ≥ 48 hours (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.91 to 1.09; 2 trials, 1770 participants; moderate-certainty evidence); or for duration of diarrhoea (mean difference (MD) 8.64 hours shorter, 95% CI 29.4 hours shorter to 12.1 hours longer; 6 trials, 3058 participants; very low-certainty evidence). Effect size was similar and marked heterogeneity persisted in pre-specified subgroup analyses of the primary outcomes that included all studies. These included analyses limited to the probiotics Lactobacillus rhamnosus GG and Saccharomyces boulardii. In six trials (433 participants) of Lactobacillus reuteri, there was consistency amongst findings (I² = 0%), but risk of bias was present in all included studies. Heterogeneity also was not explained by types of participants (age, nutritional/socioeconomic status captured by mortality stratum, region of the world where studies were undertaken), diarrhoea in children caused by rotavirus, exposure to antibiotics, and the few studies of children who were also treated with zinc. In addition, there were no clear differences in effect size for the primary outcomes in post hoc analyses according to decade of publication of studies and whether or not trials had been registered. For other outcomes, the duration of hospitalization in inpatient studies on average was shorter in probiotic groups than in control groups but there was marked heterogeneity between studies (I² = 96%; MD -18.03 hours, 95% CI -27.28 to -8.78, random-effects model: 24 trials, 4056 participants). No differences were detected between probiotic and control groups in the number of people with diarrhoea lasting ≥ 14 days (RR 0.49, 95% CI 0.16 to 1.53; 9 studies, 2928 participants) or in risk of hospitalization in community studies (RR 1.26, 95% CI 0.84 to 1.89; 6 studies, 2283 participants). No serious adverse events were attributed to probiotics.

AUTHORS' CONCLUSIONS

Probiotics probably make little or no difference to the number of people who have diarrhoea lasting 48 hours or longer, and we are uncertain whether probiotics reduce the duration of diarrhoea. This analysis is based on large trials with low risk of bias.

Microcin J25 Exhibits Inhibitory Activity Against Salmonella Newport in Continuous Fermentation Model Mimicking Swine Colonic Conditions

Microcin J25 (MccJ25), a 21-amino acid bacteriocin produced by Escherichia coli (E. coli), is a potent inhibitor of Enterobacteriaceae, including pathogenic E. coli, Salmonella, and Shigella. Its lasso structure makes it highly stable and therefore of interest as a possible antimicrobial agent in foods or as an alternative to antibiotics in livestock production. In the present study, we aimed to evaluate in vitro the inhibitory activity of MccJ25 against Salmonella enterica subsp. enterica serovar Newport ATCC 6962 (Salmonella Newport) used as a model pathogen under conditions simulating those of the swine proximal colon. The growth inhibition activity of MccJ25 against Salmonella Newport was examined in lysogeny broth (LB) and in modified MacFarlane medium that allows miming the swine colonic conditions. The MccJ25 activity was further determined using the Polyfermentor intestinal model (PolyFermS), an in vitro continuous fermentation model that permits deciphering the activity of any antimicrobial molecule in real colon fermentation conditions using selected microbiota. It was set up here to simulate the porcine proximal colon fermentation. In these conditions, the inhibition activity of MccJ25 was compared to those of two antimicrobial agents, reuterin and rifampicin. The minimal inhibitory concentration (MIC) of MccJ25 was determined at 0.03 μM in LB medium, compared to 1,079 and 38 μM for reuterin and rifampicin, respectively, showing a significantly higher potency of MccJ25. Total inhibition of Salmonella Newport was observed in LB medium over 24 h of incubation at concentrations starting from the MIC. In the PolyFermS model, MccJ25 induced a significantly stronger inhibition of Salmonella Newport growth than reuterin or rifampicin. A specific and sensitive LC-MS method allowed to detect and quantify MccJ25 in the PolyFermS fermentation system, showing that MccJ25 remains stable and active against Salmonella in conditions mimicking those found in swine colon. This study paves the way for further exploring the potential of this bacteriocin as an alternative to antibiotics in livestock.

The potential of proteins, hydrolysates and peptides as growth factors forLactobacillusandBifidobacterium: current research and future perspectives

Probiotics are live microorganisms that provide health benefits to the host when consumed in adequate concentrations.

Enteroadsorbent Polymethylsiloxane Polyhydrate vs. Probiotic Lactobacillus reuteri DSM 17938 in the Treatment of Rotaviral Gastroenteritis in Infants and Toddlers, a Randomized Controlled Trial

Purpose: The aim of this study was to compare two adjunct therapies in the treatment of childhood rotavirus gastroenteritis (RVGE). We compared the recommended treatment, probiotic Lactobacillus reuteri DSM 17938 (BioGaia®), vs. a novel treatment, enterosorbent polymethylsiloxane polyhydrate (Enterosgel®). Methods: This was an open-label, randomized, clinical controlled trial at the University Hospital for Infectious Diseases (UHID) in Zagreb, Croatia. A total of 149 children aged 6-36 months with acute rotaviral gastroenteritis over a period of <48 h, with no significant chronic comorbidity, were randomized to receive the standard therapy with L. reuteri DSM 17938 (hereafter L. reuteri) or polymethylsiloxane polyhydrate (hereafter PMSPH) therapy, during 5 days. The primary end point was time to recovery in days in both groups. The recovery was defined as absence of fever and vomiting and either the first firm stool, absence of stool for more than 24 h, or return of usual bowel habit. Results: A total of 75 children were randomized into the L. reuteri group and 74 were randomized into the PMSPH group; after excluding missing data, the data from 65 children in each group were analyzed. There was no significant difference in the treatment efficacy between the two regimens with an estimated median time of recovery of 6 days in both groups (p = 0.754). No significant side effects were observed in either group. Conclusion: Novel enterosorbent PMSPH had a similar efficacy to probiotic L. reuteri in the treatment of rotaviral gastroenteritis in preschool children. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT04116307 [October 3, 2019] (retrospectively registered). https://clinicaltrials.gov/show/NCT04116307.

Lactobacillus reuteri DSM 17938 feeding of healthy newborn mice regulates immune responses while modulating gut microbiota and boosting beneficial metabolites

Early administration of Lactobacillus reuteri DSM 17938 (LR) prevents necrotizing enterocolitis and inhibits regulatory T-cell (Treg)-deficiency-associated autoimmunity in mice. In humans, LR reduces crying time in breastfed infants with colic, modifies severity in infants with acute diarrheal illnesses, and improves pain in children with functional bowel disorders. In healthy breastfed newborns with evolving microbial colonization, it is unclear if early administration of LR can modulate gut microbiota and their metabolites in such a way as to promote homeostasis. We gavaged LR (107 colony-forming units/day, daily) to C57BL/6J mice at age of day 8 for 2 wk. Both male and female mice were investigated in these experiments. We found that feeding LR did not affect clinical phenotype or inflammatory biomarkers in plasma and stool, but LR increased the proportion of Foxp3+ regulatory T cells (Tregs) in the intestine. LR also increased bacterial diversity and the relative abundance of p_Firmicutes, f_Lachnospiraceae, f_Ruminococcaceae, and genera Clostridium and Candidatus arthromitus, while decreasing the relative abundance of p_Bacteriodetes, f_Bacteroidaceae, f_Verrucomicrobiaceae, and genera Bacteroides, Ruminococcus, Akkermansia, and Sutterella. Finally, LR exerted a major impact on the plasma metabolome, upregulating amino acid metabolites formed via the urea, tricarboxylic acid, and methionine cycles and increasing tryptophan metabolism. In conclusion, early oral administration of LR to healthy breastfed mice led to microbial and metabolic changes which could be beneficial to general health.NEW & NOTEWORTHY Oral administration of Lactobacillus reuteri DSM 17938 (LR) to healthy breastfed mice promotes intestinal immune tolerance and is linked to proliferation of beneficial gut microbiota. LR upregulates plasma metabolites that are involved in the urea cycle, the TCA cycle, methionine methylation, and the polyamine pathway. Herein, we show that LR given to newborn mice specifically increases levels of tryptophan metabolites and the purine nucleoside adenosine that are known to enhance tolerance to inflammatory stimuli.

Infant dietary intake of yogurt and cheese and gastroenteritis at 1 year of age: The Japan Environment and Children's Study

BACKGROUND

The important role played by intestinal bacterial flora in human health has recently attracted public attention worldwide. Although yogurt is thought to help in preventing the onset of gastroenteritis, this property has rarely been examined in epidemiological studies.

METHOD

This study analyzed data obtained by the Japan Environment and Children's Study. From a dataset of 103,062 pregnancies, 82,485 were selected for this analysis. Dietary intake of fermented foods (yogurt and cheese) in 1-year-old infants was assessed with a food frequency questionnaire. Parent-reported physician-diagnosed gastroenteritis in early childhood was determined from a questionnaire conducted when the child was 1 year old.

RESULT

The incidence of gastroenteritis was significantly lower in infants who consumed yogurt ≥ 7 and 3-6 times/week than in infants who consumed yogurt < 1 time/week in crude models (n = 82,485) and after adjustment for covariates (adjusted odds ratio [95% confidence interval], 0.78 [0.70-0.86] versus 0.82 [0.76-0.89], respectively; n = 65,051). Frequency of weekly cheese consumption was not associated with the incidence of gastroenteritis.

CONCLUSION

Consumption of yogurt, but not cheese, at 1 year of age was associated with a reduced risk of gastroenteritis. Further studies of this association, including interventional studies, are warranted.

Safety of Lactobacillus Reuteri DSM 17938 in Healthy Children 2-5 Years of Age

Probiotics are increasingly used for diarrhea, but studies under the Food and Drug Administration and Investigational New Drug program are few. We conducted a phase-one placebo-controlled study of Lactobacillus reuteri DSM 17938 under Investigational New Drug program in 60 children 2-5 years of age (41 L. reuteri, 19 placebos) in a resource-constrained community in Peru. No differences in objective data on adverse events were noted, although some differences based on subjective parental reports for fever and diarrhea were seen.

Resveratrol protects Lactobacillus reuteri against H2O2- induced oxidative stress and stimulates antioxidant defenses through upregulation of the dhaT gene

Understanding of the mechanisms implicated in the protective role of probiotic bacteria is of the utmost scientific interest. This study provides original insight into the genetic and molecular basis of the responses of Lactobacillus reuteri PL503 against hydrogen peroxide (H₂O₂)-induced oxidative stress. Six experimental groups were considered depending on the addition and concentration of H₂O₂ and resveratrol: 1. CONTROL (L. reuteri in MRS broth); 2. H₂O₂ (L. reuteri in MRS broth + 0.5 mM H₂O₂); 3. LRES (L. reuteri in MRS broth + 20 μM resveratrol); 4. HRES (L. reuteri in MRS broth + 100 μM resveratrol); 5. H₂O₂-LRES (L. reuteri in MRS broth + 0.5 mM H₂O₂ + 20 μM resveratrol); 6. H₂O₂-HRES (L. reuteri in MRS broth + 0.5 mM H₂O₂ + 100 μM resveratrol). Three replicates were incubated at 37 °C for 24 h in microaerophilic conditions sampled at 12, 16, 20 and 24 h. The NADH-dependent-oxidoreductase encoded by the dhaT gene is a plausible candidate to be strongly implicated in the antioxidant response of L. reuteri. Resveratrol (100 μM) is found to protect L. reuteri against protein carbonylation plausibly through various mechanisms including direct scavenging of reactive oxygen species (ROS), upregulation of the dhaT gene and promoting the synthesis of sulfur containing compounds. The hypothesis formulated on the ability of L. reuteri to detoxify H₂O₂ and its underlying mechanism needs to be clarified. Furthermore, the consequences of protein carbonylation as a reflection of oxidative damage to bacteria and its role in the responses of bacteria to oxidative stress need to be further investigated.

Industry funding effect on positive results of probiotic use in the management of acute diarrhea: a systematized review

Several investigations have found that industry-funded studies tend to inform results favoring the sponsored products. The pressure to demonstrate that a drug or a product causes a favorable outcome may result in investigation biases from industry-funded research. One example of this could be found in the probiotic research funded by the industry. The aim of this study was to assess the effect of industry funding on positive outcomes of the use of probiotics in the management of acute diarrhea. A systematized review of clinical trials on the use of probiotics in the management of acute diarrhea was performed. The associations between the source of funding, clinical outcomes, probiotic genus, and quality of the study were assessed using the χ-test and Fisher's exact test. Sixty-six clinical trials were included; 27 were industry funded, 18 were nonindustry funded, and 21 did not disclose their funding source. There were 48 positive and 30 negative clinical outcomes. There was no significant association between the source of funding and clinical outcomes (P=0.491). No association between the rest of the studied variables and outcomes was observed either (P>0.05). In clinical trials on the use of probiotics in the management of acute diarrhea, the source of funding has no influence on positive clinical outcomes.

Genomic analysis of Lactobacillus reuteri WHH1689 reveals its probiotic properties and stress resistance

Lactobacillus reuteri (L. reuteri) WHH1689, which was isolated from Chinese traditional highland barley wine, exhibited high survival period at room temperature in drinkable probiotic yogurt. This article aimed to indicate the genes involved in probiotic function of WHH1689 and reveal potential stress resistance based on genomic analysis. Analysis of comparative genome with closely related L. reuteri strains identified special stress adaptation. MUMmer and ACT softwares were applied for collinear analysis, and OrthoMCL program was used for sequence alignment involved in distribution of protein cluster. We identified genes coding for carbohydrate transport and enzymes, carbon metabolism pathway, gastrointestinal tract resistance, adhesive ability, and folic acid biosynthesis, etc. Genome sequence and comparative genome analysis of L. reuteri WHH1689 demonstrated specific genes for genetic adaptation and stress resistance. Tolerance, adhesion, and folate test indicated the strain had multiple probiotics. L. reuteri WHH1689 has the potential to be a probiotic candidate in dairy foods.

Probiotics, mechanisms of action, and clinical perspectives for diarrhea management in children

Infectious diarrhea is the second most common cause of morbidity and mortality in children under 5 years of age in the underdeveloped areas of the world. Conventional treatment consists of rehydration, which may be coupled with antimicrobial agents in more severe bacterial infections or with antiprotozoal agents. In the last few decades, research on the use of probiotic strains, such as Lactobacillus rhamnosus GG ATCC 53013 (LGG), Lactobacillus reuteri DSM 17938 and Saccharomyces boulardii, has gained much attention to prevent and treat diarrheal diseases. However, they are rarely used in the clinical routine, perhaps because there are still gaps in the knowledge about the effective benefit to the patient in terms of the reduction of the duration of diarrhea and its prevention. Furthermore, only a few probiotic strains are safely indicated for usage in pediatric practice. This review summarizes the current knowledge on the antimicrobial mechanisms of probiotics on distinct enteropathogens and their role in stimulating host defense mechanisms against intestinal infections. In addition, we highlight the potential of probiotics for the treatment and prevention of diarrhea in children. We conclude that the use of probiotics is beneficial for both the treatment and prevention of diarrhea in children and that the identification of other candidate probiotics might represent an important advance to a greater reduction in hospital stays and to prevent infectious diarrhea in a larger portion of this population.

Efficacy of an Oral Rehydration Solution Enriched with Lactobacillus reuteri DSM 17938 and Zinc in the Management of Acute Diarrhoea in Infants: A Randomized, Double-Blind, Placebo-Controlled Trial

The efficacy of oral rehydration solution (ORS) enriched with Lactobacillus reuteri DSM 17938 and zinc in infants with acute gastroenteritis, is poorly defined. The aim of this double-blind, randomized, placebo-controlled study, was to assess the efficacy of an ORS enriched with Lactobacillus reuteri DSM 17938 and zinc (ORS⁺Lr&Z) in well-nourished, non-hospitalized infants with acute diarrhoea. Fifty one infants with acute diarrhoea were randomly assigned to receive either ORS⁺Lr&Z (28 infants, mean ± SD age 1.7 ± 0.7 years, 21 males), or standard ORS (ORS-Lr&Z; 23 infants, mean ± SD age 1.8 ± 0.7 years, 16 males). Stools volume and consistency were recorded pre- and posttreatment using the Amsterdam Infant Stool Scale and were compared between the two groups, as well as lost work/day care days, drug administration and need for hospitalization. Both groups showed reduction in the severity of diarrhoea on day two (p < 0.001) while, all outcomes showed a trend to be better in the ORS⁺Lr&Z group, without reaching statistical significance, probably due to the relatively small number of patients. No adverse effects were recorded. In conclusion, both ORS were effective in managing acute diarrhoea in well-nourished, non-hospitalized infants. ORS enriched with L. reuteri DSM 17938 and zinc was well tolerated with no adverse effects.

Role of Lactobacillus reuteri in Human Health and Diseases

Lactobacillus reuteri (L. reuteri) is a well-studied probiotic bacterium that can colonize a large number of mammals. In humans, L. reuteri is found in different body sites, including the gastrointestinal tract, urinary tract, skin, and breast milk. The abundance of L. reuteri varies among different individuals. Several beneficial effects of L. reuteri have been noted. First, L. reuteri can produce antimicrobial molecules, such as organic acids, ethanol, and reuterin. Due to its antimicrobial activity, L. reuteri is able to inhibit the colonization of pathogenic microbes and remodel the commensal microbiota composition in the host. Second, L. reuteri can benefit the host immune system. For instance, some L. reuteri strains can reduce the production of pro-inflammatory cytokines while promoting regulatory T cell development and function. Third, bearing the ability to strengthen the intestinal barrier, the colonization of L. reuteri may decrease the microbial translocation from the gut lumen to the tissues. Microbial translocation across the intestinal epithelium has been hypothesized as an initiator of inflammation. Therefore, inflammatory diseases, including those located in the gut as well as in remote tissues, may be ameliorated by increasing the colonization of L. reuteri. Notably, the decrease in the abundance of L. reuteri in humans in the past decades is correlated with an increase in the incidences of inflammatory diseases over the same period of time. Direct supplementation or prebiotic modulation of L. reuteri may be an attractive preventive and/or therapeutic avenue against inflammatory diseases.

Adenosine A2A Receptor Deletion Blocks the Beneficial Effects of Lactobacillus reuteri in Regulatory T-Deficient Scurfy Mice

The lack of a functional Foxp3 transcription factor and regulatory T (Treg) cells causes lethal, CD4⁺ T cell-driven autoimmune diseases in scurfy (SF) mice and humans. Recent studies have shown that adenosine A_2A receptor activation limits inflammation and tissue damage, thereby playing an anti-inflammatory role. However, the role of the adenosine A_2A receptor in the development of disease in SF mice remains unclear. Using a genetic approach, we found that adenosine A_2A receptor deletion in SF mice (SF⋅A2A-/-) does not affect early life events, the development of a lymphoproliferative disorder, or hyper-production of pro-inflammatory cytokines seen in the Treg-deficiency state. As shown previously, Lactobacillus reuteri DSM 17938 treatment prolonged survival and reduced multiorgan inflammation in SF mice. In marked contrast, A_2A receptor deletion completely blocked these beneficial effects of L. reuteri in SF mice. Altogether, these results suggest that although absence of the adenosine A_2A receptor does not affect the development of disease in SF mice, it plays a critical role in the immunomodulation by L. reuteri in Treg-deficiency disease. The adenosine A_2A receptor and its activation may have a role in treating other Treg dysfunction-mediated autoimmune diseases.

Impact of Lactobacillus reuteri colonization on gut microbiota, inflammation, and crying time in infant colic

Infant colic is a distressing condition of unknown etiology. An aberrant gastrointestinal microbiota has been associated, and Lactobacillus reuteri supplementation has been shown to reduce crying and/or fussing time (‘crying time’) in some infants with colic. The relationship between L. reuteri gut colonization and crying time has not been examined. We investigated the relationship between L. reuteri colonization and fecal microbiota (microbial diversity and Escherichia coli), intestinal inflammation, and crying time in infants with colic, using a subset of 65 infants from the Baby Biotics trial, which randomized healthy term infants aged <13 weeks with infant colic to receive probiotic L. reuteri DSM 17938 (1 × 10⁸ colony forming units) or placebo daily for 28 days. We observed an overall reduction in median crying time, regardless of L. reuteri colonization status (n = 14 colonized). There were no differences in E. coli colonization rates or densities, microbial diversity or intestinal inflammation by L. reuteri colonization status. We found that L. reuteri density positively correlated with crying time, and E. coli density negatively correlated with microbial diversity. As density of L. reuteri was associated with increased crying time, L. reuteri supplementation may not be an appropriate treatment for all infants with colic.

Next-Generation Probiotics Targeting Clostridium difficile through Precursor-Directed Antimicrobial Biosynthesis

Integration of antibiotic and probiotic therapy has the potential to lessen the public health burden of antimicrobial-associated diseases. Clostridium difficile infection (CDI) represents an important example where the rational design of next-generation probiotics is being actively pursued to prevent disease recurrence. Because intrinsic resistance to clinically relevant antibiotics used to treat CDI (vancomycin, metronidazole, and fidaxomicin) is a desired trait in such probiotic species, we screened several bacteria and identified Lactobacillus reuteri to be a promising candidate for adjunct therapy. Human-derived L. reuteri bacteria convert glycerol to the broad-spectrum antimicrobial compound reuterin. When supplemented with glycerol, strains carrying the pocR gene locus were potent reuterin producers, with L. reuteri 17938 inhibiting C. difficile growth at a level on par with the level of growth inhibition by vancomycin. Targeted pocR mutations and complementation studies identified reuterin to be the precursor-induced antimicrobial agent. Pathophysiological relevance was demonstrated when the codelivery of L. reuteri with glycerol was effective against C. difficile colonization in complex human fecal microbial communities, whereas treatment with either glycerol or L. reuteri alone was ineffective. A global unbiased microbiome and metabolomics analysis independently confirmed that glycerol precursor delivery with L. reuteri elicited changes in the composition and function of the human microbial community that preferentially targets C. difficile outgrowth and toxicity, a finding consistent with glycerol fermentation and reuterin production. Antimicrobial resistance has thus been successfully exploited in the natural design of human microbiome evasion of C. difficile, and this method may provide a prototypic precursor-directed probiotic approach. Antibiotic resistance and substrate bioavailability may therefore represent critical new determinants of probiotic efficacy in clinical trials.

Antiviral Probiotics: A New Concept in Medical Sciences

In recent decades, probiotics have shown beneficial effects on animal and human health. Probiotics can protect the host against several health threats, including infectious diseases. Before 1995, researchers believed that the effect of probiotics was only on gut microbiota which can restore the gut flora and thus prevent pathogenic bacteria from triggering gastroenteritis. Recent studies have shown that the immunomodulatory activity is the most important mechanism of action of probiotics. From this information, researchers started to evaluate the effect of some immunobiotics, not only on pathogenic bacteria but also on viruses, including enteric and respiratory viruses. Several studies have confirmed the potential antiviral activity of some probiotics due to the immunomodulatory effect. These studies were conducted on humans (clinical trials) and in animal models. In this chapter, probiotics with antiviral effect against respiratory and enteric viruses will be presented and discussed, as well as their mechanisms of action.

Intestinal Innate Antiviral Immunity and Immunobiotics: Beneficial Effects against Rotavirus Infection

The mucosal tissues of the gastrointestinal tract are the main portal entry of pathogens such as rotavirus (RV), which is a leading cause of death due to diarrhea among young children across the globe and a major cause of severe acute intestinal infection in livestock animals. The interactions between intestinal epithelial cells (IECs) and immune cells with RVs have been studied for several years, and now, it is known that the innate immune responses triggered by this virus can have both beneficial and detrimental effects for the host. It was demonstrated that natural RV infection in infants and experimental challenges in mice result in the intestinal activation of pattern recognition receptors (PRRs) such as toll-like receptor 3 (TLR3) and striking secretion of proinflammatory mediators that can lead to increased local tissue damage and immunopathology. Therefore, modulating desregulated intestinal immune responses triggered by PRRs activation are a significant promise for reducing the burden of RV diseases. The ability of immunoregulatory probiotic microorganisms (immunobiotics) to protect against intestinal infections, such as those caused by RVs, is among the oldest effects studied for these important group of beneficial microbes. In this review, we provide an update of the current status on the modulation of intestinal antiviral innate immunity by immunobiotics and their beneficial impact on RV infection. In addition, we describe the research of our group that demonstrated the capacity of immunobiotic strains to beneficially modulated TLR3-triggered immune response in IECs, reduce the disruption of intestinal homeostasis caused by intraepithelial lymphocytes, and improve the resistance to RV infections.