Immune response and intestinal permeability in children with acute gastroenteritis treated with Lactobacillus rhamnosus GG: a randomized, double-blind, placebo-controlled trial

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.

Intestinal organoid/enteroid-based models for Cryptosporidium

Cryptosporidium is a leading cause of diarrhea and death in young children and untreated AIDS patients in resource-poor settings, and of waterborne outbreaks of disease in developed countries. However, there is no consistently effective treatment for vulnerable populations. Progress towards development of therapeutics for cryptosporidiosis has been hampered by lack of optimal culture systems to study it. New advances in organoid/enteroid technology have contributed to improved platforms to culture and propagate Cryptosporidium. Here we discuss recent breakthroughs in the field and highlight different models for functional ex vivo organoid or enteroidderived culture systems. These systems will lead to a better understanding of the mechanisms of host-parasite interactions in vivo.

A Systematic Review and Meta-Analysis: The Effectiveness of Probiotics for Viral Gastroenteritis

BACKGROUND

Probiotics can be used for the treatment of viral gastroenteritis.

OBJECTIVE

This systematic review is to evaluate the evidence regarding the effect of probiotics on human cases of viral gastroenteritis.

METHODS

The objective of this review is to evaluate the effectiveness of probiotics against placebo or standard treatment for viral gastroenteritis. A comprehensive search of Cochrane Library, EMBASE, MEDLINE via PubMed and Ovid databases, and unpublished studies (till 27 January 2018) was conducted followed by a process of study selection and critical appraisal by two independent reviewers. Randomized controlled trials assessing probiotic administration in human subjects infected with any species of gastroenteritis viruses were considered for inclusion. Only studies with a confirmed viral cause of infection were included. This study was developed using the JBI methodology for systematic reviews, which is in accordance with the PRISMA guideline. Meta-analysis was conducted where feasible. Data were pooled using the inverse variance method with random effects models and expressed as Mean Differences (MDs) with 95% Confidence Intervals (CIs). Heterogeneity was assessed by Cochran Q statistic and quantified by the I2 statistic. We included 17 RCTs, containing 3,082 patients.

RESULTS

Probiotics can improve symptoms of viral gastroenteritis, including the duration of diarrhea (mean difference 0.7 days, 95% CI 0.31 to 1.09 days, n = 740, ten trials) and duration of hospitalization (mean difference 0.76 days, 95% CI 0.61 to 0.92 days, n = 329, four trials).

CONCLUSION

The results of this review show that the administration of probiotics in patients with viral gastroenteritis should be considered.

Diet Supplementation, Probiotics, and Nutraceuticals in SARS-CoV-2 Infection: A Scoping Review

The severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) global pandemic is a devastating event that is causing thousands of victims every day around the world. One of the main reasons of the great impact of coronavirus disease 2019 (COVID-19) on society is its unexpected spread, which has not allowed an adequate preparation. The scientific community is fighting against time for the production of a vaccine, but it is difficult to place a safe and effective product on the market as fast as the virus is spreading. Similarly, for drugs that can directly interfere with viral pathways, their production times are long, despite the great efforts made. For these reasons, we analyzed the possible role of non-pharmacological substances such as supplements, probiotics, and nutraceuticals in reducing the risk of Sars-CoV-2 infection or mitigating the symptoms of COVID-19. These substances could have numerous advantages in the current circumstances, are generally easily available, and have negligible side effects if administered at the already used and tested dosages. Large scientific evidence supports the benefits that some bacterial and molecular products may exert on the immune response to respiratory viruses. These could also have a regulatory role in systemic inflammation or endothelial damage, which are two crucial aspects of COVID-19. However, there are no specific data available, and rigorous clinical trials should be conducted to confirm the putative benefits of diet supplementation, probiotics, and nutraceuticals in the current pandemic.

Lactobacillus rhamnosus GG Usage in the Prevention of Gastrointestinal and Respiratory Tract Infections in Children with Gastroesophageal Reflux Disease Treated with Proton Pump Inhibitors: A Randomized Double-Blinded Placebo-Controlled Trial

PURPOSE

Proton-pump inhibitors (PPIs) are frequently used to treat gastroesophageal reflux disease (GERD) in children, but recent evidence suggests a potential association between PPI treatment and some types of infections. The aim of this study was to assess the effectiveness of Lactobacillus rhamnosus GG (LGG) for the prevention of gastrointestinal and respiratory tract infections in children with GERD treated with PPI (omeprazol).

METHODS

Children younger than 5 years with GERD were assigned by a computer-generated list to receive LGG (109 colony-forming units) or placebo, twice daily, concomitantly with PPI treatment for 4-6 weeks; they were followed up for 12 weeks after therapy. The primary outcome measures were the percentage of children with a minimum of one episode of respiratory tract infection and the percentage of children with a minimum of one episode of gastrointestinal infection during the study.

RESULTS

Of 61 randomized children, 59 patients (LGG n=30; placebo n=29, mean age 11.3 months) were analyzed. There was no significant difference found between the LGG and placebo groups, either for the proportion of children with at least one respiratory tract infection (22/30 vs. 25/29, respectively; relative risk [RR] 0.85, 95% confidence interval [CI] 0.66-1.10) or for the proportion of children with at least one gastrointestinal infection (9/30 vs. 9/29, respectively; RR 0.97, 95% CI 0.45-2.09).

CONCLUSION

LGG was not effective in the prevention of infectious complications in children with GERD receiving PPI. Caution is needed in interpreting these results, as the study was terminated early due to slow subject recruitment.

Use of coconut water (Cocus nucifera L) for the development of a symbiotic functional drink

Many studies suggest that probiotic, prebiotic and symbiotic foods may be beneficial in the prevention and management of nutrition and health, the objective of this work was to develop a symbiotic drink based on coconut water. Fermentation was performed using lyophilized Lactobacillus rhamnosus SP1 and inulin as a source of soluble fiber. Different formulations were developed, determining the concentrations of fiber and probiotics. The growth of the probiotic in MRS broth was evaluated, using the plate counting technique in different periods of time. The fermentation time of the drink was 8 h and the shelf life in refrigeration was 14 days evaluated by pH and hedonic scale. The pH of the final drink was 3.48 and the probiotic content was 82 × 10 ⁸ CFU/ml. It is concluded that coconut water can be processed by adding probiotic and prebiotic characteristics with sensory acceptance and adequate preservation characteristics.

Strain-Specific Probiotic Properties of Bifidobacteria and Lactobacilli for the Prevention of Diarrhea Caused by Rotavirus in a Preclinical Model

Probiotic supplementation with different lactobacilli and bifidobacterial strains has demonstrated beneficial effects in infectious diarrhea caused by rotavirus (RV) in young children. Preclinical models of RV infection might be a good strategy to screen for the efficacy of new probiotic strains or to test their comparative efficacy. Neonatal Lewis rats were supplemented with Bifidobacterium breve M-16V, Lactobacillus acidophilus NCFM, Lactobacillus helveticus R0052, or Lactobacillus salivarius PS2 from days 2–14 of life. On day five, animals received RV SA-11 orally. Fecal samples were collected daily, weighed, and scored for the calculation of severity and incidence of diarrhea. In addition, fecal pH and fecal viral shedding were measured. Animals were sacrificed at the end of the study and their blood was obtained for the quantification of RV-specific immunoglobulins. RV infection was induced in ~90% of the animals. All probiotics caused a reduction of several clinical variables of severity and incidence of diarrhea, except L. salivarius PS2. L. acidophilus NCFM, B. breve M-16V, and L. helveticus R0052 seemed to be very effective probiotic strains. In addition, all Lactobacillus strains reduced the viral elimination one day post-inoculation. No differences were detected in the specific anti-RV humoral response. The present study highlights the strain-specific effects of probiotics and identifies promising probiotics for use in ameliorating and preventing RV-induced diarrhea in children, for example by including them in infant formulas.

Murine Gut Microbiome Association With APOE Alleles

Background: Since APOE alleles represent the most impactful genetic risk factors for Alzheimer's disease (AD), their differential mechanism(s) of action are under intense scrutiny. APOE4 is robustly associated with increased AD risk compared to the neutral APOE3 and protective APOE2. APOE alleles have also been associated with differential inflammation and gastrointestinal recovery after insult in human and murine studies, leading us to hypothesize that APOE alleles impact the gut microbiome. Methods: To assess this hypothesis, we compared 16S ribosomal RNA gene amplicon-based microbiome profiles in a cohort of mice that were homozygous for APOE2, APOE3, or APOE4, and included both males and females as well as carriers and non-carriers of five familial AD (5xFAD) mutations. Fecal samples were analyzed from mice at 4 and 6 months of age. APOE genotype, as well as sex and 5xFAD status, was then tested for influence on alpha diversity (Shannon H index) and beta diversity (principal coordinate analyses and PERMANOVA). A Random Forest analysis was used to identify features that predicted APOE, sex and 5xFAD status. Results: The richness and evenness (alpha diversity) of the fecal microbiome was not robustly associated with APOE genotype, 5xFAD status or sex. In contrast, microbial community composition (beta-diversity) was consistently and strongly associated with APOE genotype. The association between beta-diversity and sex or 5xFAD status was less consistent and more modest. Comparison of the differences underlying APOE effects showed that the relative abundance of multiple bacterial taxa was significantly different as a function of APOE genotype. Conclusions: The structure of the gut microbiome was strongly and significantly associated with APOE alleles in this murine model. Further evaluation of these findings in humans, as well as studies evaluating the impact of the APOE-associated microbiota on AD-relevant phenotypes in murine models, will be necessary to determine if alterations in the gut microbiome represent a novel mechanism whereby APOE genotype impacts AD.

Probiotics and Paraprobiotics in Viral Infection: Clinical Application and Effects on the Innate and Acquired Immune Systems

Recently, the risk of viral infection has dramatically increased owing to changes in human ecology such as global warming and an increased geographical movement of people and goods. However, the efficacy of vaccines and remedies for infectious diseases is limited by the high mutation rates of viruses, especially, RNA viruses. Here, we comprehensively review the effectiveness of several probiotics and paraprobiotics (sterilized probiotics) for the prevention or treatment of virally-induced infectious diseases. We discuss the unique roles of these agents in modulating the cross-talk between commensal bacteria and the mucosal immune system. In addition, we provide an overview of the unique mechanism by which viruses are eliminated through the stimulation of type 1 interferon production by probiotics and paraprobiotics via the activation of dendritic cells. Although further detailed research is necessary in the future, probiotics and/or paraprobiotics are expected to be among the rational adjunctive options for the treatment of various viral diseases.

Efficacy of Lactobacillus rhamnosus GG in treatment of acute pediatric diarrhea: A systematic review with meta-analysis

BACKGROUND

Diarrhea is a major infectious cause of childhood morbidity and mortality worldwide. In clinical trials, Lactobacillus rhamnosus GG ATCC 53013 (LGG) has been used to treat diarrhea. However, recent randomized controlled trials (RCTs) found no evidence of a beneficial effect of LGG treatment.

AIM

To evaluate the efficacy of LGG in treating acute diarrhea in children.

METHODS

The EMBASE, MEDLINE, PubMed, Web of Science databases, and the Cochrane Central Register of Controlled Trials were searched up to April 2019 for meta-analyses and RCTs. The Cochrane Review Manager was used to analyze the relevant data.

RESULTS

Nineteen RCTs met the inclusion criteria and showed that compared with the control group, LGG administration notably reduced the diarrhea duration [mean difference (MD) -24.02 h, 95% confidence interval (CI) (-36.58, -11.45)]. More effective results were detected at a high dose ≥ 10¹⁰ CFU per day [MD -22.56 h, 95%CI (-36.41, -8.72)] vs a lower dose. A similar reduction was found in Asian and European patients [MD -24.42 h, 95%CI (-47.01, -1.82); MD -32.02 h, 95%CI (-49.26, -14.79), respectively]. A reduced duration of diarrhea was confirmed in LGG participants with diarrhea for less than 3 d at enrollment [MD -15.83 h, 95%CI (-20.68, -10.98)]. High-dose LGG effectively reduced the duration of rotavirus-induced diarrhea [MD -31.05 h, 95%CI (-50.31, -11.80)] and the stool number per day [MD -1.08, 95%CI (-1.87, -0.28)].

CONCLUSION

High-dose LGG therapy reduces the duration of diarrhea and the stool number per day. Intervention at the early stage is recommended. Future trials are expected to verify the effectiveness of LGG treatment.

Systematic review with meta-analysis: Lactobacillus rhamnosus GG for treating acute gastroenteritis in children - a 2019 update

BACKGROUND

Recently, evidence from a large randomised controlled trial (RCT) negated efficacy of Lactobacillus rhamnosus GG for treating acute gastroenteritis in children.

AIM

To review RCTs in which L rhamnosus GG was used to treat acute gastroenteritis in children.

METHODS

The Cochrane Library, MEDLINE, and EMBASE databases were searched from May 2013 (end of last search) to January 2019. The primary outcomes were stool volume and duration of diarrhoea.

RESULTS

Eighteen RCTs (n = 4208) were included. Compared with placebo or no treatment, L rhamnosus GG use had no effect on stool volume but was associated with a reduced duration of diarrhoea (15 RCTs, n = 3820, mean difference, MD -0.85 day, 95% CI -1.15 to -0.56). L rhamnosus GG was effective when used at a daily dose of ≥10¹⁰ CFU or <10¹⁰ CFU; however, the latter produced results of borderline significance. L rhamnosus GG was more effective when used in European countries compared with non-European countries, particularly when considered by region. L rhamnosus GG use was associated with a reduced duration of hospitalisation. One RCT found that L rhamnosus GG had no effect on the total clinical severity score at 14 days after enrolment.

CONCLUSIONS

Despite a recent large RCT demonstrating no effect of L rhamnosus GG, current evidence shows that, overall, L rhamnosus GG reduced both the duration of diarrhoea (with a higher impact in European countries) and hospitalisation in inpatients. These findings should be viewed in the context of the high heterogeneity and methodological limitations of the included trials.

Cutting Edge: Probiotics and Fecal Microbiota Transplantation in Immunomodulation

Probiotics are commensal or nonpathogenic microbes that confer beneficial effects on the host through several mechanisms such as competitive exclusion, antibacterial effects, and modulation of immune responses. Some probiotics have been found to regulate immune responses via immune regulatory mechanisms. T regulatory (Treg) cells, T helper cell balances, dendritic cells, macrophages, B cells, and natural killer (NK) cells can be considered as the most determinant dysregulated mediators in immunomodulatory status. Recently, fecal microbiota transplantation (FMT) has been defined as the transfer of distal gut microbial communities from a healthy individual to a patient's intestinal tract to cure some immune disorders (mainly inflammatory bowel diseases). The aim of this review was followed through the recent literature survey on immunomodulatory effects and mechanisms of probiotics and FMT and also efficacy and safety of probiotics and FMT in clinical trials and applications.

Use of a Probiotic to Enhance Iron Absorption in a Randomized Trial of Pediatric Patients Presenting with Iron Deficiency

OBJECTIVE

To evaluate the efficacy of low dose ferrous sulfate for the treatment of iron deficiency and if the probiotic Lactobacillus plantarum 299v (LP299v) enhances treatment.

STUDY DESIGN

This randomized, double-blinded, controlled trial of the treatment of iron deficiency in children compared the use of low-dose ferrous sulfate (1-3 mg/kg/day), with or without probiotic (LP299v).

RESULTS

Serum ferritin level increased in all children from a baseline of 23.7 ng/mL to 45.4 ng/mL after 6-8 weeks of treatment. There was no significant difference in the increase in serum ferritin in children taking the probiotic LP299v compared with controls (23.2 vs 20.0 ng/mL, respectively). Additionally, an increase in ferritin level was not significantly associated with probiotic use when controlling for other factors, including child weight and dosing. Overall, the treatments were well-tolerated, with mild side effects.

CONCLUSIONS

Treatment with low-dose ferrous sulfate is well-tolerated and effective in correcting iron deficiency in children. However, the probiotic LP299v did not enhance treatment. Further attention should examine the dose-response effect in children, including an alternate day dosing schedule.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01617044.

Effects of probiotics on chemotherapy in patients with lung cancer

Chemotherapy damages the intestinal mucosa, causing adverse gastrointestinal reactions. Clostridium butyricum (C. butyricum) reduces the incidence of diarrhea in digestive diseases, including inflammatory bowel disease. Therefore, the aim of the present study was to investigate the role of C. butyricum in patients undergoing chemotherapy. A total of 41 participants with lung cancer were enrolled, and divided into the C. butyricum (CB) or placebo group using 1:1 randomization to obtain 20 CB and 21 placebo participants. On the first and last day of the 3-week intervention, blood and stool samples were collected and analyzed. To analyze stool flora, 16S ribosomal RNA sequencing was performed. The incidence of chemotherapy-induced diarrhea was lower in the CB group compared with the placebo group. The lymphocyte count and platelet/lymphocyte ratio (PLR) was markedly altered between the two groups. Neutrophil/lymphocyte ratio (NLR) and PLR decreased within the CB group. At week 3, the lymphocyte/monocyte ratio (LMR) was higher in the CB group compared with the placebo group. Alterations in lymphocyte subsets and immunoglobulin levels were not significantly different. Albumin (ALB) level and weight did not differ significantly between the two groups. At 3 weeks the total flora diversity did not decrease in either group. Phyla in the CB group varied slightly, while the proportion of Firmicutes in the placebo group decreased significantly. No statistically significant difference was observed between the two groups, though the genera producing short-chain fatty acids tended to increase, and the pathogenic genera tended to decrease in the CB group, which was almost the opposite of the observation in the placebo group. Operational taxonomy unit analysis revealed a notable increase in beneficial flora, including the Clostridium and Lactobacillus genera of the CB group, compared with the placebo group. The present study highlighted that C. butyricum reduced chemotherapy-induced diarrhea in patients with lung cancer, reduced the systemic inflammatory response system and encouraged homeostatic maintenance.

Effectiveness of Multistrain Versus Single-strain Probiotics: Current Status and Recommendations for the Future

Probiotics are investigated as single-strain and multistrain products. In the market, however, there is an increasing tendency to work with multistrain probiotics, in particular, products with a high number of different strains. There are some thoughts behind this: more strains imply more chances of success; it can mean a broader spectrum of efficacy, and there is often the hope that there are at least additive and, potentially, even synergistic effects. The present review did not find convincing evidence that these assumptions are valid. There is, however, also no strong evidence that the assumptions are incorrect and/or that there is antagonistic activity between strains in a combination. We suggest that, to answer these questions, structured research is conducted. Starting with a systematic review of meta-analyses that have compared single-strain and multistrain probiotic efficacy, dedicated human studies need to be performed, comparing single-strain and multistrain probiotics to each other and placebo. In vitro and animal studies can provide indications and may help understand mechanisms. For human, animal, and in vitro studies, it is recommended to work with the simple setup of 2 single strains, a 2-strain combination, and placebo. It is also important in such research to take into consideration the doses, as a combination product will have a higher total dose.

Preventive Effect of a Synbiotic Combination of Galacto- and Fructooligosaccharides Mixture With Bifidobacterium breve M-16V in a Model of Multiple Rotavirus Infections

Rotavirus (RV) causes morbidity and mortality among infants worldwide, and there is evidence that probiotics and prebiotics can have a positive influence against infective processes such as that due to RV. The aim of this study was to evidence a preventive role of one prebiotic mixture (of short-chain galactooligosaccharide/long-chain fructooligosaccharide), the probiotic Bifidobacterium breve M-16V and the combination of the prebiotic and the probiotic, as a synbiotic, in a suckling rat double-RV infection model. Hyperimmune bovine colostrum was used as protection control. The first infection was induced with RV SA11 and the second one with EDIM. Clinical variables and immune response were evaluated after both infections. Dietary interventions ameliorated clinical symptoms after the first infection. The prebiotic and the synbiotic significantly reduced viral shedding after the first infection, but all the interventions showed higher viral load than in the RV group after the second infection. All interventions modulated ex vivo antibody and cytokine production, gut wash cytokine levels and small intestine gene expression after both infections. In conclusion, a daily supplement of the products tested in this preclinical model is highly effective in preventing RV-induced diarrhea but allowing the boost of the early immune response for a future immune response against reinfection, suggesting that these components may be potential agents for modulating RV infection in infants.

Interventions to reduce post-acute consequences of diarrheal disease in children: a systematic review

BACKGROUND

Although acute diarrhea often leads to acute dehydration and electrolyte imbalance, children with diarrhea also suffer long term morbidity, including recurrent or prolonged diarrhea, loss of weight, and linear growth faltering. They are also at increased risk of post-acute mortality. The objective of this systematic review was to identify interventions that address these longer term consequences of diarrhea.

METHODS

We searched Medline for randomized controlled trials (RCTs) of interventions conducted in low- and middle-income countries, published between 1980 and 2016 that included children under 15 years of age with diarrhea and follow-up of at least 7 days. Effect measures were summarized by intervention. PRISMA guidelines were followed.

RESULTS

Among 314 otherwise eligible RCTs, 65% were excluded because follow-up did not extend beyond 7 days. Forty-six trials were included, the majority of which (59%) were conducted in Southeast Asia (41% in Bangladesh alone). Most studies were small, 76% included less than 200 participants. Interventions included: therapeutic zinc alone (28.3%) or in combination with vitamin A (4.3%), high protein diets (19.6%), probiotics (10.9%), lactose free diets (10.9%), oral rehydration solution (ORS) formulations (8.7%), dietary supplements (6.5%), other dietary interventions (6.5%), and antimicrobials (4.3%). Prolonged or recurrent diarrhea was the most commonly reported outcome, and was assessed in ORS, probiotic, vitamin A, and zinc trials with no consistent benefit observed. Seven trials evaluated mortality, with follow-up times ranging from 8 days to 2 years. Only a single trial found a mortality benefit (therapeutic zinc). There were mixed results for dietary interventions affecting growth and diarrhea outcomes in the post-acute period.

CONCLUSION

Despite the significant post-acute mortality and morbidity associated with diarrheal episodes, there is sparse evidence evaluating the effects of interventions to decrease these sequelae. Adequately powered trials with extended follow-up are needed to identify effective interventions to prevent post-acute diarrhea outcomes.

Immune-Mediated Mechanisms of Action of Probiotics and Synbiotics in Treating Pediatric Intestinal Diseases

The pediatric population is continually at risk of developing infectious and inflammatory diseases. The treatment for infections, particularly gastrointestinal conditions, focuses on oral or intravenous rehydration, nutritional support and, in certain case, antibiotics. Over the past decade, the probiotics and synbiotics administration for the prevention and treatment of different acute and chronic infectious diseases has dramatically increased. Probiotic microorganisms are primarily used as treatments because they can stimulate changes in the intestinal microbial ecosystem and improve the immunological status of the host. The beneficial impact of probiotics is mediated by different mechanisms. These mechanisms include the probiotics' capacity to increase the intestinal barrier function, to prevent bacterial transferation and to modulate inflammation through immune receptor cascade signaling, as well as their ability to regulate the expression of selected host intestinal genes. Nevertheless, with respect to pediatric intestinal diseases, information pertaining to these key mechanisms of action is scarce, particularly for immune-mediated mechanisms of action. In the present work, we review the biochemical and molecular mechanisms of action of probiotics and synbiotics that affect the immune system.

The Gut Microbiota and the Emergence of Autoimmunity: Relevance to Major Psychiatric Disorders

BACKGROUND

Autoimmune phenotypes are prevalent in major psychiatric disorders. Disequilibria of cellular processes occurring in the gastrointestinal (GI) tract likely contribute to immune dysfunction in psychiatric disorders. As the venue of a complex community of resident microbes, the gut in a homeostatic state equates with a functional digestive system, cellular barrier stability and properly regulated recognition of self and non-self antigens. When gut processes become disrupted as a result of environmental or genetic factors, autoimmunity may ensue.

METHODS

Here, we review the issues pertinent to autoimmunity and the microbiome in psychiatric disorders and show that many of the reported immune risk factors for the development of these brain disorders are in fact related and consistent with dysfunctions occurring in the gut. We review the few human microbiome studies that have been done in people with psychiatric disorders and supplement this information with mechanistic data gleaned from experimental rodent studies.

RESULTS

These investigations demonstrate changes in behavior and brain biochemistry directly attributable to alterations in the gut microbiome. We present a model by which autoantigens are produced by extrinsicallyderived food and microbial factors bound to intrinsic components of the gut including receptors present in the enteric nervous system.

CONCLUSION

This new focus on examining activities outside of the CNS for relevance to the etiology and pathophysiology of psychiatric disorders may require new modalities or a re-evaluation of pharmaceutical targets found in peripheral systems.

2017 Infectious Diseases Society of America Clinical Practice Guidelines for the Diagnosis and Management of Infectious Diarrhea

These guidelines are intended for use by healthcare professionals who care for children and adults with suspected or confirmed infectious diarrhea. They are not intended to replace physician judgement regarding specific patients or clinical or public health situations. This document does not provide detailed recommendations on infection prevention and control aspects related to infectious diarrhea.

Rotavirus infection

Rotavirus infections are a leading cause of severe, dehydrating gastroenteritis in children <5 years of age. Despite the global introduction of vaccinations for rotavirus over a decade ago, rotavirus infections still result in >200,000 deaths annually, mostly in low-income countries. Rotavirus primarily infects enterocytes and induces diarrhoea through the destruction of absorptive enterocytes (leading to malabsorption), intestinal secretion stimulated by rotavirus non-structural protein 4 and activation of the enteric nervous system. In addition, rotavirus infections can lead to antigenaemia (which is associated with more severe manifestations of acute gastroenteritis) and viraemia, and rotavirus can replicate in systemic sites, although this is limited. Reinfections with rotavirus are common throughout life, although the disease severity is reduced with repeat infections. The immune correlates of protection against rotavirus reinfection and recovery from infection are poorly understood, although rotavirus-specific immunoglobulin A has a role in both aspects. The management of rotavirus infection focuses on the prevention and treatment of dehydration, although the use of antiviral and anti-emetic drugs can be indicated in some cases.

Innate immune responses play a key role in controlling infection of the intestinal epithelium by Cryptosporidium

Cryptosporidium infection leads to acute diarrhea worldwide. The development of cryptosporidiosis is closely related to the immune status of its host, affecting primarily young ruminants, infants, and immunocompromised individuals. In recent years, several studies have improved our knowledge on the immune mechanisms responsible for the control of the acute phase of the infection and have highlighted the importance of innate immunity. The parasite develops in the apical side of intestinal epithelial cells, giving these cells a central role, as they are both the exclusive host cell for replication of the parasite and participate in the protective immune response. Epithelial cells signal the infection by producing chemokines, attracting immune cells to the infected area. They also actively participate in host defense by inducing apoptosis and releasing antimicrobial peptides, free or incorporated into luminal exosomes, with parasiticidal activity. The parasite has developed several escape mechanisms to slow down these protective mechanisms. Recent development of several three-dimensional culture models and the ability to genetically manipulate Cryptosporidium will greatly help to further investigate host-pathogen interactions and identify virulence factors. Intestinal epithelial cells require the help of immune cells to clear the infection. Intestinal dendritic cells, well known for their ability to induce and orchestrate adaptive immunity, play a key role in controlling the very early steps of Cryptosporidium parvum infection by acting as immunological sentinels and active effectors. However, inflammatory monocytes, which are quickly and massively recruited to the infected mucosa, seem to participate in the loss of epithelial integrity. In addition to new promising chemotherapies, we must consider stimulating the innate immunity of neonates to strengthen their ability to control Cryptosporidium development. The microbiota plays a fundamental role in the development of intestinal immunity and may be considered to be a third actor in host-pathogen interactions. There is an urgent need to reduce the incidence of this yet poorly controlled disease in the populations of developing countries, and decrease economic losses due to infected livestock.

The effect of probiotics and zinc supplementation on the immune response to oral rotavirus vaccine: A randomized, factorial design, placebo-controlled study among Indian infants

BACKGROUND

Strategies are needed to improve oral rotavirus vaccine (RV), which provides suboptimal protection in developing countries. Probiotics and zinc supplementation could improve RV immunogenicity by altering the intestinal microbiota and immune function.

METHODS

Infants 5weeks old living in urban Vellore, India were enrolled in a randomized, double-blind, placebo-controlled trial with a 4-arm factorial design to assess the effects of daily zinc (5mg), probiotic (10¹⁰Lactobacillus rhamnosus GG) or placebo on the immunogenicity of two doses of RV (Rotarix®, GlaxoSmithKline Biologicals) given at 6 and 10weeks of age. Infants were eligible for participation if healthy, available for the study duration and without prior receipt of RV or oral poliovirus vaccine other than the birth dose. The primary outcome was seroconversion to rotavirus at 14weeks of age based on detection of VP6-specific IgA at ≥20U/ml in previously seronegative infants or a fourfold rise in concentration.

RESULTS

The study took place during July 2012 to February 2013. 620 infants were randomized equally between study arms and 551 (88.9%) completed per protocol. Seroconversion was recorded in 54/137 (39.4%), 42/136 (30.9%), 40/143 (28.0%), and 37/135 (27.4%) infants receiving (1) probiotic and zinc, (2) probiotic and placebo, (3) placebo and zinc, (4) two placebos. Seroconversion showed a modest improvement among infants receiving probiotic (difference between groups 1, 2 and 3, 4 was 7.5% (97.5% Confidence Interval (CI): -1.4%, 16.2%), p=0.066) but not zinc (difference between groups 1, 3 and 2, 4 was 4.4% (97.5% CI: -4.4%, 13.2%), p=0.272). 16 serious adverse events were recorded, none related to study interventions.

CONCLUSIONS

Zinc or probiotic supplementation did not significantly improve the low immunogenicity of rotavirus vaccine given to infants in a poor urban community in India. A modest effect of combined supplementation deserves further investigation.

TRIAL REGISTRATION

The trial was registered in India (CTRI/2012/05/002677).

Dietary Pectic Oligosaccharide Administration Improves Growth Performance and Immunity in Weaned Pigs Infected by Rotavirus

Rotavirus infection is one of the main pathogenic causes of gastroenteritis and diarrhea in children and young animals. The present study aimed to determine whether dietary pectic oligosaccharide (POS) supplementation could improve the growth performance and immunity in weaned pigs infected by porcine rotavirus (PRV). Twenty-eight crossbred weaned galts were randomly divided into two groups fed basal diet with or without POS for 18 days. On the 15th day, PRV was orally infused to half of the pigs. ADFI, ADG, and F/G ratio were impaired by PRV infection in weaned pigs (P < 0.05). PRV challenge also induced diarrhea and enhanced serum levels of urea nitrogen (P < 0.05), MDA (P < 0.05), IgA (P < 0.05), and IgG (P = 0.08), rotavirus antibody levels in serum, jejunal, and ileal mucosa (P < 0.05), and IL-2 levels in the jejunal (P = 0.07) and ileal (P = 0.08) mucosa, but decreased digestive enzyme activities of the jejunal digesta (P < 0.05) and concentrations of sIgA, IL-4, and IFN-γ in the jejunal and ileal mucosa (P < 0.05) and serum T-AOC (P < 0.05) in the weaned pigs. POS administration could improve the growth performance of the weaned pigs (P < 0.05) and enhance the serum IgA level (P < 0.05), the lipase and tryptase activities of jejunal digesta (P < 0.05), and the sIgA, IL-4, and IFN-γ levels of jejunal and/or ileal mucosa (P < 0.05) in the weaned pigs. Furthermore, supplementing POS in diets could alleviate diarrhea and decreased growth performance in the weaned pigs orally infused by PRV (P < 0.05), increase serum, jejunal, and ileal rotavirus antibody levels (P < 0.05) and attenuate the effect of PRV challenge on serum T-AOC and concentrations of IgG and MDA (P < 0.05), lipase and tryptase activities in jejunal digesta (P < 0.05), and sIgA, IL-4, and IFN-γ levels in jejunal and/or ileal mucosa (P < 0.05) in the weaned pigs. These results suggest that dietary POS supplementation could improve growth performance, which was possibly because POS administration improved the immune function and the utilization of nutrients in the PRV-infected piglets. This offers a potential dietary intervention strategy against intestinal exposure to rotavirus in piglets.

Lactobacillus helveticus Lafti L10 Supplementation Modulates Mucosal and Humoral Immunity in Elite Athletes: A Randomized, Double-Blind, Placebo-Controlled Trial

Michalickova, DM, Kostic-Vucicevic, MM, Vukasinovic-Vesic, MD, Stojmenovic, TB, Dikic, NV, Andjelkovic, MS, Djordjevic, BI, Tanaskovic, BP, and Minic, RD. Lactobacillus helveticus Lafti L10 supplementation modulates mucosal and humoral immunity in elite athletes: a randomized, double-blind, placebo-controlled trial. J Strength Cond Res 31(1): 62-70, 2017-To test the influence of probiotic supplementation on humoral immune response, a double-blind, placebo-controlled trial was conducted. Thirty athletes (24 males and 6 females, females: V[Combining Dot Above]O2max 38.2 ± 4.9 ml·kg·min, age 23.2 ± 1.4 years; males: V[Combining Dot Above]O2max 57.5 ± 9.2 ml·kg·min, age 24.0 ± 2.4 years, mean ± SD) were randomized either to the probiotic group (Lactobacillus helveticus Lafti L10, 2 × 10 colony-forming units) or to the placebo group. Serum and saliva samples were collected at the baseline and after 14 weeks. Total and specific antibacterial antibody levels of IgM, IgG, and IgA classes were determined for different bacteria in the serum, and in saliva, total and specific antibacterial IgA levels were examined. Total IgM was elevated in both probiotic (18%, 15-20%; mean, 90% confidence interval; p = 0.02) and placebo group (35%, 22-47%; p = 0.02), without observed differences in changes between the groups. No significant changes in IgM levels specific for tested bacteria were found. Total IgG level was constant in both groups. A significant (16%, -2.8 to 35%, p = 0.04) reduction of anti-Enterococcus faecalis IgG was noted in the placebo group, in comparison with the probiotic group. There was a substantial decrease in total IgA level in the placebo group, when measured either in serum (15%, 12-18%, p = 0.04) or in saliva (35%, -1.4 to 53%, p = 0.03). Significantly reduced levels of serum anti-lactic acid bacteria IgA antibodies in the placebo group compared with the probiotic group were detected for Lactobacillus rhamnosus LA68 (24%, 5.8-42%, p = 0.02) and for L. rhamnosus LB64 (15%, 2.7-27%, p = 0.02). Probiotic administration could have beneficial effects on systemic humoral and mucosal immune responses.

Unraveling the Differences between Gram-Positive and Gram-Negative Probiotics in Modulating Protective Immunity to Enteric Infections

The role of intestinal microbiota and probiotics in prevention and treatment of infectious diseases, including diarrheal diseases in children and animal models, is increasingly recognized. Intestinal commensals play a major role in development of the immune system in neonates and in shaping host immune responses to pathogens. Lactobacilli spp. and Escherichia coli Nissle 1917 are two probiotics that are commonly used in children to treat various medical conditions including human rotavirus diarrhea and inflammatory bowel disease. Although the health benefits of probiotics have been confirmed, the specific effects of these established Gram-positive (G+) and Gram-negative (G−) probiotics in modulating immunity against pathogens and disease are largely undefined. In this review, we discuss the differences between G+ and G− probiotics/commensals in modulating the dynamics of selected infectious diseases and host immunity. These probiotics modulate the pathogenesis of infectious diseases and protective immunity against pathogens in a species- and strain-specific manner. Collectively, it appears that the selected G− probiotic is more effective than the various tested G+ probiotics in enhancing protective immunity against rotavirus in the gnotobiotic piglet model.

High Protective Efficacy of Probiotics and Rice Bran against Human Norovirus Infection and Diarrhea in Gnotobiotic Pigs

Probiotics have been recognized as vaccine adjuvants and therapeutic agents to treat acute gastroenteritis in children. We previously showed that rice bran (RB) reduced human rotavirus diarrhea in gnotobiotic pigs. Human noroviruses (HuNoVs) are the major pathogens causing non-bacterial acute gastroenteritis worldwide. In this study, Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle 1917 (EcN) were first screened for their ability to bind HuNoV P particles and virions derived from clinical samples containing HuNoV genotype GII.3 and GII.4, then the effects of LGG+EcN and RB on HuNoV infection and diarrhea were investigated using the gnotobiotic pig model. While LGG+EcN colonization inhibited HuNoV shedding, probiotic cocktail regimens in which RB feeding started 7 days prior to or 1 day after viral inoculation in the LGG+EcN colonized gnotobiotic pigs exhibited high protection against HuNoV diarrhea and shedding, characterized by significantly reduced incidence (89 versus 20%) and shorter mean duration of diarrhea (2.2 versus 0.2 days), as well as shorter mean duration of virus shedding (3.2 versus 1.0 days). In both probiotic cocktail groups, the diarrhea reduction rates were 78% compared with the control group, and diarrhea severity was reduced as demonstrated by the significantly lower cumulative fecal scores. The high protective efficacy of the probiotic cocktail regimens was attributed to stimulation of IFN-γ⁺ T cell responses, increased production of intestinal IgA and IgG, and maintenance of healthy intestinal morphology (manifested as longer villi compared with the control group). Therefore, probiotic cocktail regimens containing LGG+EcN and RB may represent highly efficacious strategies to prevent and treat HuNoV gastroenteritis, and potentially other human enteric pathogens.

Lactobacillus acidophilus Mixture in Treatment of Children Hospitalized With Acute Diarrhea

Despite unproven effectiveness, Lactobacillus acidophilus is a widely used probiotic in the treatment of pediatric diarrhea. In this report, we evaluated the association between length of stay (LOS) for 290 young children hospitalized with acute diarrhea and adjuvant therapy with a probiotic mixture containing 80% L acidophilus that was included in treatment for 22.4% of them. Overall, no association between LOS and use of L acidophilus was recorded after controlling for age, length of diarrhea symptoms, duration of intravenous fluids, and prior exposure to antibiotic. However, LOS was directly associated with use of L acidophilus in children with negative stool studies, and no such association was recorded in children with positive stool for rotavirus or other infections. We concluded that adjuvant therapy with L acidophilus mixture is not beneficial for young children hospitalized with acute diarrhea.

The role of probiotics in the prevention of severe infections following abdominal surgery

Administration of probiotics has been proposed for various medical and surgical conditions. Their effect has been largely attributed to their ability to maintain the integrity of the intestinal mucosal barrier as well as to modulate the innate immune response. Multiple studies have demonstrated their effect in reducing infectious complications in critically ill patients, minimising bacterial translocation and increasing the secretion of anti-inflammatory cytokines. Furthermore, they have been shown to be effective in reducing infections following colorectal surgery, while at the same time preventing overgrowth of bacterial species such as Pseudomonas aeruginosa that has been implicated in the pathogenesis of anastomotic leak. Recent experimental studies have demonstrated that probiotics may decrease expression of the SOCS3 gene, which encodes the protein SOCS3 that suppresses cytokine production, implying a direct interaction of probiotics with the innate immune system. These results hold high promises for the development of new therapeutic strategies.

Supplementation with Lactobacillus rhamnosus SP1 normalises skin expression of genes implicated in insulin signalling and improves adult acne

Systemic supplementation with probiotics is increasingly being explored as a potential treatment strategy for skin disorders. Because both the gut-skin axis and dysregulation of insulin signalling have been implicated in the pathogenesis of adult acne, we designed the current study to evaluate the effect of supplementation with the probiotic strain Lactobacillus rhamnosus SP1 (LSP1) on skin expression of genes involved in insulin signalling and acne improvement in adult subjects. A pilot, randomised, double-blinded, placebo-controlled study was conducted with 20 adult subjects (14 females and 6 males; mean age: 33.7±3.3 years) with acne. Over a 12-week period, the probiotic group (n=10) consumed a liquid supplement containing LSP1 at a dose of 3×109 cfu/day (75 mg/day), whereas the placebo group (n=10) received a liquid lacking probiotics. Paired skin biopsies - one obtained before treatment initiation and one obtained at the end of the 12-week treatment period - were analysed for insulin-like growth factor 1 (IGF1) and forkhead box protein O1 (FOXO1) gene expression. The clinical criterion for efficacy was the investigator's global improvement rating on a five-point scale. Compared with baseline, the probiotic group showed a 32% (P<0.001) reduction, as well as a 65% increase (P<0.001) in IGF1 and FOXO1 gene expression in the skin, respectively. No such differences were observed in the placebo group. Patients in the probiotic group had an adjusted odds ratio of 28.4 (95% confidence interval = 2.2-411.1, P<0.05) to be rated by physicians as improved/markedly improved (versus worsened or unchanged) compared with the placebo group. We conclude that supplementation with the probiotic strain LSP1 normalises skin expression of genes involved in insulin signalling and improves the appearance of adult acne.

Use of Pathogen-Specific Antibody Biomarkers to Estimate Waterborne Infections in Population-Based Settings

PURPOSE OF REVIEW

This review discusses the utility of pathogen-specific antibody biomarkers for improving estimates of the population burden of waterborne infections, assessing the fraction of infections that can be prevented by specific water treatments, and understanding transmission routes and the natural history and ecology of disease in different populations (including asymptomatic infection rates).

RECENT FINDINGS

We review recent literature on the application of pathogen-specific antibody response data to estimate incidence and prevalence of acute infections and their utility to assess the contributions of waterborne transmission pathways. Advantages and technical challenges associated with the use of serum versus minimally invasive salivary antibody biomarkers in cross-sectional and prospective surveys are discussed. We highlight recent advances and challenges and outline future directions for research, development, and application of antibody-based and other immunological biomarkers of waterborne infections.

Bugs and Guts: Practical Applications of Probiotics for Gastrointestinal Disorders in Children

Probiotics are foods or products that contain live microorganisms that benefit the host when administered. In this clinical review, we evaluate the literature associated with using probiotics in common pediatric gastrointestinal disorders, focusing specifically on antibiotic-associated diarrhea, acute gastroenteritis, Clostridium difficile infection (CDI), colic, inflammatory bowel disease, and functional gastrointestinal diseases. Meta-analysis of several randomized controlled trials have confirmed benefit for the administration of Lactobacillus rhamnosus GG and Saccharomyces boulardii to prevent antibiotic-associated diarrhea and to treat acute infectious diarrhea. Individual studies have also suggested benefit of probiotics to prevent acute gastroenteritis and serve as an adjunct in ulcerative colitis, pouchitis, antibiotic-associated diarrhea, CDI, functional abdominal pain, irritable bowel syndrome, and colic in breastfed babies. Although promising, larger well-designed studies need to confirm these findings. There is currently insufficient evidence to recommend probiotics for the treatment of constipation-predominant irritable bowel syndrome or Crohn's disease.

Fecal Indole as a Biomarker of Susceptibility to Cryptosporidium Infection

Cryptosporidium causes significant diarrhea worldwide, especially among children and immunocompromised individuals, and no effective drug treatment is currently available for those who need it most. In this report, previous volunteer infectivity studies have been extended to examine the association between fecal indole and indole-producing (IP) gut microbiota on the outcome of a Cryptosporidium infection. Fecal indole concentrations (FICs) of 50 subjects and 19 taxa of common gut microbiota, including six IP taxa (11 subjects) were determined in stool samples collected before and after a challenge with Cryptosporidium oocysts. At the baseline, the mean FIC (± the standard deviation) was 1.66 ± 0.80 mM in those who became infected after a challenge versus 3.20 ± 1.23 mM in those who remained uninfected (P = 0.0001). Only 11.1% of the subjects with a FIC of >2.5 mM became infected after a challenge versus 65.2% of the subjects with a FIC of <2.5 mM. In contrast, the FICs of infected subjects at the baseline or during diarrhea were not correlated with infection intensity or disease severity. The relative abundances (percent) of Escherichia coli, Bacillus spp., and Clostridium spp. were greater ≥2.5-fold in volunteers with a baseline FIC of >2.5 mM, while those of Bacteroides pyogenes, B. fragilis, and Akkermansia muciniphila were greater in those with a baseline FIC of <2.5 mM. These data indicate that some IP bacteria, or perhaps indole alone, can influence the ability of Cryptosporidium to establish an infection. Thus, preexisting indole levels in the gut join the oocyst dose and immune status as important factors that determine the outcome of Cryptosporidium exposure.

Cryptosporidium parvum increases intestinal permeability through interaction with epithelial cells and IL-1β and TNFα released by inflammatory monocytes

Intestinal epithelial cells form a single layer separating the intestinal lumen containing nutriments and microbiota from the underlying sterile tissue and therefore play a key role in maintaining homeostasis. We investigated the factors contributing to the alteration of the epithelial barrier function during Cryptosporidium parvum infection. Infected polarized epithelial cell monolayers exhibit a drop in transepithelial resistance associated with a delocalization of E-cadherin and β-catenin from their intercellular area of contact, the adherens junction complex. In neonatal mice infected by C. parvum, the increased permeability is correlated with parasite development and with an important recruitment of Ly6c⁺ inflammatory monocytes to the subepithelial space. TNFα and IL-1β produced by inflammatory monocytes play a key role in the loss of barrier function. Our findings demonstrate for the first time that both the parasite and inflammatory monocytes contribute to the loss of intestinal barrier function during cryptosporidiosis.

Immunobiotic Lactobacillus strains reduce small intestinal injury induced by intraepithelial lymphocytes after Toll-like receptor 3 activation

OBJECTIVE

Intestinal intraepithelial lymphocytes (IELs) play critical roles in disrupting epithelial homeostasis after Toll-like receptor (TLR)-3 activation with genomic rotavirus dsRNA or the synthetic dsRNA analog poly(I:C). The capacity of immunobiotic Lactobacillus rhamnosus CRL1505 (Lr1505) or Lactobacillus plantarum CRL1506 (Lp1506) to beneficially modulate IELs response after TLR3 activation was investigated in vivo using a mice model.

RESULTS

Intraperitoneal administration of poly(I:C) induced inflammatory-mediated intestinal tissue damage through the increase of inflammatory cells (CD3(+)NK1.1(+), CD3(+)CD8αα(+), CD8αα(+)NKG2D(+)) and pro-inflammatory mediators (TNF-α, IL-1β, IFN-γ, IL-15, RAE1, IL-8). Increased expression of intestinal TLR3, MDA5, and RIG-I was also observed after poly(I:C) challenge. Treatment with Lr1505 or Lp1506 prior to TLR3 activation significantly reduced the levels of TNF-α, IL-15, RAE1, and increased serum and intestinal IL-10. Moreover, CD3(+)NK1.1(+), CD3(+)CD8αα(+), and CD8αα(+)NKG2D(+) cells were lower in lactobacilli-treated mice when compared to controls. The immunomodulatory capacities of lactobacilli allowed a significant reduction of intestinal tissue damage.

CONCLUSIONS

This work demonstrates the reduction of TLR3-mediated intestinal tissue injury by immunobiotic lactobacilli through the modulation of intraepithelial lymphocytes response. It is a step forward in the understanding of the cellular mechanisms involved in the antiviral capabilities of immunobiotic strains.

Antiviral effect of vitamin A on norovirus infection via modulation of the gut microbiome

The effect and underlying mechanism of vitamin A on norovirus infection are largely unknown. This study aimed to investigate how vitamin A administration affects the gut microbiome after norovirus infection. Here, we demonstrate that treatment with either retinol or retinoic acid (RA) inhibits murine norovirus (MNV) replication using both in vitro and in vivo models. Compositional changes in the gut microbiome associated with RA administration and/or norovirus infection were also investigated. Oral administration of RA and/or MNV significantly altered intestinal microbiome profiles. Particularly, bacterial species belonging to the Lactobacillaceae families were remarkably increased by MNV inoculation and RA administration, suggesting that the antiviral effects of RA occur via the modulation of specific microbiota. The antiviral causal effect of Lactobacillus was identified and demonstrated using in vitro models in RAW264.7 cells. The antiviral immune response to MNV was mediated by IFN-β upregulation. This study represents the first comprehensive profiling of gut microbiota in response to RA treatment against norovirus infection. Moreover, we conclude that the abundance of Lactobacillus through gut microbiota modulation by RA is at least partially responsible for norovirus inhibition.

Identification of a Peptide Produced by Bifidobacterium longum CECT 7210 with Antirotaviral Activity

Rotavirus is one of the main causes of acute diarrhea and enteritis in infants. Currently, studies are underway to assess the use of probiotics to improve rotavirus vaccine protection. A previous work demonstrated that the probiotic strain Bifidobacterium longum subsp. infantis CECT 7210 is able to hinder rotavirus replication both in vitro and in vivo. The present study takes a systematic approach in order to identify the molecule directly involved in rotavirus inhibition. Supernatant protease digestions revealed both the proteinaceous nature of the active substance and the fact that the molecule responsible for inhibiting rotavirus replication is released to the supernatant. Following purification by cationic exchange chromatography, active fractions were obtained and the functional compound was identified as an 11-amino acid peptide (MHQPHQPLPPT, named 11-mer peptide) with a molecular mass of 1.282 KDa. The functionality of 11-mer was verified using the synthesized peptide in Wa, Ito, and VA70 rotavirus infections of both HT-29 and MA-104 cell lines. Finally, protease activity was detected in B. longum subsp. infantis CECT 7210 supernatant, which releases 11-mer peptide. A preliminary identification of the protease is also included in the study.

A combination of scGOS/lcFOS with Bifidobacterium breve M-16V protects suckling rats from rotavirus gastroenteritis

PURPOSE

Rotavirus (RV) is the leading cause of severe diarrhoea among infants and young children, and although more standardized studies are needed, there is evidence that probiotics can help to fight against RV and other infectious and intestinal pathologies. On the other hand, the effects of prebiotics have not been properly addressed in the context of an RV infection. The aim of this study was to demonstrate a protective role for a specific scGOS/lcFOS 9:1 prebiotic mixture (PRE) separately, the probiotic Bifidobacterium breve M-16V (PRO) separately and the combination of the prebiotic mixture and the probiotic (synbiotic, SYN) in a suckling rat RV infection model.

METHODS

The animals received the intervention from the 3rd to the 21st day of life by oral gavage. On day 7, RV was orally administered. Clinical parameters and immune response were evaluated.

RESULTS

The intervention with the PRO reduced the incidence, severity and duration of the diarrhoea (p < 0.05). The PRE and SYN products improved clinical parameters as well, but a change in stool consistency induced by the PRE intervention hindered the observation of this effect. Both the PRE and the SYN, but not the PRO, significantly reduced viral shedding. All interventions modulated the specific antibody response in serum and intestinal washes at day 14 and 21 of life.

CONCLUSIONS

A daily supplement of a scGOS/lcFOS 9:1 prebiotic mixture, Bifidobacterium breve M-16V or a combination of both is highly effective in modulating RV-induced diarrhoea in this preclinical model.

Comparison of probiotic lactobacilli and bifidobacteria effects, immune responses and rotavirus vaccines and infection in different host species

Different probiotic strains of Lactobacillus and Bifidobacterium genera possess significant and widely acknowledged health-promoting and immunomodulatory properties. They also provide an affordable means for prevention and treatment of various infectious, allergic and inflammatory conditions as demonstrated in numerous human and animal studies. Despite the ample evidence of protective effects of these probiotics against rotavirus (RV) infection and disease, the precise immune mechanisms of this protection remain largely undefined, because of limited mechanistic research possible in humans and investigated in the majority of animal models. Additionally, while most human clinical probiotic trials are well-standardized using the same strains, uniform dosages, regimens of the probiotic treatments and similar host age, animal studies often lack standardization, have variable experimental designs, and non-uniform and sometime limited selection of experimental variables or observational parameters. This review presents selected data on different probiotic strains of lactobacilli and bifidobacteria and summarizes the knowledge of their immunomodulatory properties and the associated protection against RV disease in diverse host species including neonates.

Intestinal Microbiota and Susceptibility to Viral Infections

During pathogenesis, viruses come in contact with the microbiota that colonizes the mucosal sites they infect. The intestinal microbiota has emerged as a critical factor in intestinal viral susceptibility. While the interaction of virus-intestinal commensal bacteria can lead to enhanced or decreased viral infection capacity, several scientific studies support the use of probiotics as antiviral therapies. Thus, probiotics and the modulation of the intestinal microbiota are envisaged as therapeutic strategies in the prevention and treatment of viral infection.

Gut permeability, its interaction with gut microflora and effects on metabolic health are mediated by the lymphatics system, liver and bile acid

There is evidence to link obesity (and metabolic syndrome) with alterations in gut permeability and microbiota. The underlying mechanisms have been questioned and have prompted this review. We propose that the gut barrier function is a primary driver in maintaining metabolic health with poor health being linked to ‘gut leakiness'. This review will highlight changes in intestinal permeability and how it may change gut microflora and subsequently affect metabolic health by influencing the functioning of major bodily organs/organ systems: the lymphatic system, liver and pancreas. We also discuss the likelihood that metabolic syndrome undergoes a cyclic worsening facilitated by an increase in intestinal permeability leading to gut dysbiosis, culminating in ongoing poor health leading to further exacerbated gut leakiness.

Gastroenterology issues in schizophrenia: why the gut matters

Genetic and environmental studies implicate immune pathologies in schizophrenia. The body's largest immune organ is the gastrointestinal (GI) tract. Historical associations of GI conditions with mental illnesses predate the introduction of antipsychotics. Current studies of antipsychotic-naïve patients support that gut dysfunction may be inherent to the schizophrenia disease process. Risk factors for schizophrenia (inflammation, food intolerances, Toxoplasma gondii exposure, cellular barrier defects) are part of biological pathways that intersect those operant in the gut. Central to GI function is a homeostatic microbial community, and early reports show that it is disrupted in schizophrenia. Bioactive and toxic products derived from digestion and microbial dysbiosis activate adaptive and innate immunity. Complement C1q, a brain-active systemic immune component, interacts with gut-related schizophrenia risk factors in clinical and experimental animal models. With accumulating evidence supporting newly discovered gut-brain physiological pathways, treatments to ameliorate brain symptoms of schizophrenia should be supplemented with therapies to correct GI dysfunction.