Systematic review with meta-analysis: the efficacy of probiotics in inflammatory bowel disease

A systematic review of the effects of probiotic administration in inflammatory arthritis

OBJECTIVE

To systematically identify and appraise evidence of the formulation specific effects and population specific responses of probiotics in inflammatory arthritis.

METHODS

MEDLINE (PubMed), CINAHL, EMBASE, and SCOPUS databases were searched for studies utilising probiotics in populations with inflammatory arthritis. The Joanna Briggs Institute (JBI) method was used to conduct the systematic review. A single reviewer undertook screening and data extraction. Two independent reviewers assessed the quality of evidence using JBI tools.

RESULTS

The search identified 5876 unique articles, with 154 potentially relevant full text articles retrieved. Twelve studies met the inclusion criteria and were included in the review, of which ten (83%) were randomised control trials (RCT) and two (17%) were quasi-experimental studies. Four studies included a variety of spondyloarthopathies (SpAs) and eight studies focused on rheumatoid arthritis (RA). Probiotics were supplied for a median of 60 days and mode of 56 days across all included studies (range 7-365 days). Overall, 17 different probiotics were supplied in colony forming units (CFU) per 24 hrs ranging from 1 × 10⁸ to 2.25 × 10¹¹. The order of probiotics supplied to the most participants and across the most studies was Lactobacillales. There was no statistical difference in the relative risk (RR) of minor adverse events between probiotic and control groups (RR 1.02, 95% CI 0.69 to 1.51) when including nil event studies. Meta-analysis identified a statistically significant benefit of probiotics on quality of life with a standard mean difference (SMD) of -0.37 (95% CI -0.59,-0.15) with subgroup analysis favouring Lactobacillales-only formulations. Small but statistically significant reductions in pain were identified, with a mean difference (MD) of -8.97 (95% CI-15.38, -2.56) on a 100mm visual analogue scale, independent of formulation. Meta-analysis confirmed the known statistically significant benefit of probiotics on the inflammatory marker C-reactive protein (CRP) concentration MD (mg/L) -2.33 (95% CI -4.26, -0.41), with subgroup analysis demonstrating a greater effect in RA and from combined Bifidobacteriales and Lactobacillales formulations.

CONCLUSION

This review indicates there may be differential benefits to combined formulations of Bifidobacteriales and Lactobacillales compared to purely Lactobacillales formulations, with respect to reducing pain, lowering CRP and improving quality of life. It also suggests variable benefits associated with the type of inflammatory arthritis. Relatively less benefit for lowering CRP was attributed to individuals with SpA compared to individuals with RA. Generalisability of results to clinical practice is limited by the dominant demographic of older individuals with established disease beyond the 'therapeutic window of intervention'. Small but statistically significant benefits require confirmation in clinical studies with greater consideration to potentially confounding factors of age, gender, diet and individual microbial signature.

IRT5 Probiotics Changes Immune Modulatory Protein Expression in the Extraorbital Lacrimal Glands of an Autoimmune Dry Eye Mouse Model

Purpose

While the association between the gut microbiome and the immune system has been studied in autoimmune disorders, little is known about ocular disease. Previously we reported that IRT5, a mixture of five probiotic strains, could suppress autoimmune dry eye. In this study, we investigated the mechanism by which IRT5 performs its immunomodulatory function in a mouse model of autoimmune dry eye.

Methods

NOD.B10.H2b mice were used as an autoimmune dry eye model. Either IRT5 or PBS was gavaged orally for 3 weeks, with or without 5 days of antibiotic pretreatment. The effects on clinical features, extraorbital lacrimal gland and spleen proteins, and fecal microbiota were analyzed.

Results

The ocular staining score was lower, and tear secretion was higher, in the IRT5-treated groups than in the PBS-treated groups. After IRT5 treatment, the downregulated lacrimal gland proteins were enriched in the biological processes of defense response and immune system process. The relative abundances of 33 operational taxonomic units were higher, and 53 were lower, in the feces of the IRT5-treated groups than in those of the PBS-treated groups. IRT5 administration without antibiotic pretreatment also showed immunomodulatory functions with increases in the Lactobacillus helveticus group and Lactobacillus hamsteri. Additional proteomic assays revealed a decrease of proteins related to antigen-presenting processes in the CD11b⁺ and CD11c⁺ cells of spleen in the IRT5-treated groups.

Conclusions

Changes in the gut microbiome after IRT5 treatment improved clinical manifestations in the autoimmune dry eye model via the downregulation of antigen-presenting processes in immune networks.

The microbiome in inflammatory bowel diseases: from pathogenesis to therapy

Inflammatory bowel disease (IBD) has become a global disease with accelerating incidence worldwide in the 21st century while its accurate etiology remains unclear. In the past decade, gut microbiota dysbiosis has consistently been associated with IBD. Although many IBD-associated dysbiosis have not been proven to be a cause or an effect of IBD, it is often hypothesized that at least some of alteration in microbiome is protective or causative. In this article, we selectively reviewed the hypothesis supported by both association studies in human and pathogenesis studies in biological models. Specifically, we reviewed the potential protective bacterial pathways and species against IBD, as well as the potential causative bacterial pathways and species of IBD. We also reviewed the potential roles of some members of mycobiome and virome in IBD. Lastly, we covered the current status of therapeutic approaches targeting microbiome, which is a promising strategy to alleviate and cure this inflammatory disease.

[Yoghurt-induced Lactobacillus bacteremia in a patient with Crohn's disease on therapy with ustekinumab and concomitant HIV-Infection]

Probiotics are live microorganisms that are often used as adjunctive therapy in patients with inflammatory bowel disease. Although there is a lack of evidence for their benefit, the use of probiotics is encouraged by the perceived lack of adverse events. However, in rare instances, probiotics can cause systemic infections through bacteremia. We report about a patient with Crohn's disease and HIV-infection, who developed a septicemia. A Lactobacillus-bacteremia was diagnosed, the causative agents could be traced back to the consumption of self-made yoghurt. The utility of probiotics in IBD patients with underlying immune-compromising diseases is a risk which is difficult to predict, therefore their use in these patients should be discouraged.

In Vitro Effects of Live and Heat-Inactivated Bifidobacterium animalis Subsp. Lactis, BB-12 and Lactobacillus rhamnosus GG on Caco-2 Cells

Probiotic–host interaction can be cell-to-cell or through metabolite production. Dead (inactive) organisms could interact with the host, leading to local effects and possible health benefits. This research examined the effects of live and heat-inactivated Bifidobacterium animalis subsp. lactis, BB-12 (BB-12) and Lactobacillus rhamnosus GG (LGG) on cultured Caco-2 cells focusing on epithelial integrity and production of inflammatory mediators. Live organisms increased transepithelial electrical resistance (TEER), a barrier-integrity marker, with LGG having a greater effect than BB-12. When mildly heat-treated, both organisms had a more modest effect on TEER than when alive. When they were heat-inactivated, both organisms had only a limited effect on TEER. Neither live nor heat-inactivated organisms affected production of six inflammatory mediators produced by Caco-2 cells compared to control conditions. Pre-treatment with heat-inactivated LGG or BB-12 did not alter the decline in TEER caused by exposure to an inflammatory cocktail of cytokines. However, pre-treatment of Caco-2 cells with heat-inactivated organisms alone or their combination decreased the production of interleukin (IL)-6, IL-18, and vascular endothelial growth factor. To conclude, while the live organisms improve the epithelial barrier using this model, neither live nor heat-inactivated organisms directly elicit an inflammatory response by the epithelium. Pre-treatment with heat-inactivated BB-12 or LGG can reduce some components of the response induced by an inflammatory stimulus.

Complementary and alternative medications in the management of inflammatory bowel disease

The use of complementary and alternative medications (CAM), products, and therapies not considered to be part of conventional medicine is common among patients with inflammatory bowel disease (IBD). Patients often turn to these therapies as they are considered natural and safe, with significant benefit reported beyond disease control. There is emerging evidence that some of these therapies may have anti-inflammatory activity; however, robust evidence for their efficacy in modulating disease activity is currently lacking. Patients often avoid discussing the use of CAM with their physicians, which may lead to drug interactions and/or reduced adherence with conventional therapy. It is important for physicians to be aware of the commonly used CAM and current evidence behind these therapies in order to better counsel their patients about their use in the management of IBD. This narrative review provides an overview of the evidence of the more commonly used CAM in patients with IBD.

Effectiveness of probiotics, prebiotics, and prebiotic-like components in common functional foods

The bioactive ingredients in commonly consumed foods include, but are not limited to, prebiotics, prebiotic-like components, probiotics, and postbiotics. The bioactive ingredients in functional foods have also been associated with beneficial effects on human health. For example, they aid in shaping of gut microflora and promotion of immunity. These functional components also contribute in preventing serious diseases such as cardiovascular malfunction and tumorigenesis. However, the specific mechanisms of these positive influences on human health are still under investigation. In this review, we aim to emphasize the major contents of probiotics, prebiotics, and prebiotic-like components commonly found in consumable functional foods, and we present an overview of direct and indirect benefits they provide on human health. The major contributors are certain families of metabolites, specifically short-chain fatty acids and polyunsaturated fatty acids produced by probiotics, and prebiotics, or prebiotic-like components such as flavonoids, polyphenols, and vitamins that are found in functional foods. These functional ingredients in foods influence the gut microbiota by stimulating the growth of beneficial microbes and the production of beneficial metabolites that, in turn, have direct benefits to the host, while also providing protection from pathogens and maintaining a balanced gut ecosystem. The complex interactions that arise among functional food ingredients, human physiology, the gut microbiota, and their respective metabolic pathways have been found to minimize several factors that contribute to the incidence of chronic disease, such as inflammation oxidative stress.

Perioperative Dietary Therapy in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The incidence of inflammatory bowel disease [IBD] is rising worldwide and no cure is available. Many patients require surgery and they often present with nutritional deficiencies. Although randomised controlled trials of dietary therapy are lacking, expert IBD centres have long-established interdisciplinary care, including tailored nutritional therapy, to optimise clinical outcomes and resource utilisation. This topical review aims to share expertise and offers current practice recommendations to optimise outcomes of IBD patients who undergo surgery.

METHODS

A consensus expert panel consisting of dietitians, surgeons, and gastroenterologists, convened by the European Crohn's and Colitis Organisation, performed a systematic literature review. Nutritional evaluation and dietary needs, perioperative optimis ation, surgical complications, long-term needs, and special situations were critically appraised. Statements were developed using a Delphi methodology incorporating three successive rounds. Current practice positions were set when ≥80% of participants agreed on a recommendation.

RESULTS

A total of 26 current practice positions were formulated which address the needs of IBD patients perioperatively and in the long term following surgery. Routine screening, perioperative optimisation by oral, enteral, or parenteral nutrition, dietary fibre, and supplements were reviewed. IBD-specific situations, including management of patients with a restorative proctocolectomy, an ostomy, strictures, or short-bowel syndrome, were addressed.

CONCLUSIONS

Perioperative dietary therapy improves the outcomes of IBD patients who undergo a surgical procedure. This topical review shares interdisciplinary expertise and provides guidance to optimise the outcomes of patients with Crohn's disease and ulcerative colitis. taking advantage of contemporary nutrition science.

The Role of Gut Microbiota Biomodulators on Mucosal Immunity and Intestinal Inflammation

Alterations of the gut microbiota may cause dysregulated mucosal immune responses leading to the onset of inflammatory bowel diseases (IBD) in genetically susceptible hosts. Restoring immune homeostasis through the normalization of the gut microbiota is now considered a valuable therapeutic approach to treat IBD patients. The customization of microbe-targeted therapies, including antibiotics, prebiotics, live biotherapeutics and faecal microbiota transplantation, is therefore considered to support current therapies in IBD management. In this review, we will discuss recent advancements in the understanding of host−microbe interactions in IBD and the basis to promote homeostatic immune responses through microbe-targeted therapies. By considering gut microbiota dysbiosis as a key feature for the establishment of chronic inflammatory events, in the near future it will be suitable to design new cost-effective, physiologic, and patient-oriented therapeutic strategies for the treatment of IBD that can be applied in a personalized manner.

Connecting the Dots Between Inflammatory Bowel Disease and Metabolic Syndrome: A Focus on Gut-Derived Metabolites

The role of the microbiome in health and disease has gained considerable attention and shed light on the etiology of complex diseases like inflammatory bowel disease (IBD) and metabolic syndrome (MetS). Since the microorganisms inhabiting the gut can confer either protective or harmful signals, understanding the functional network between the gut microbes and the host provides a comprehensive picture of health and disease status. In IBD, disruption of the gut barrier enhances microbe infiltration into the submucosae, which enhances the probability that gut-derived metabolites are translocated from the gut to the liver and pancreas. Considering inflammation and the gut microbiome can trigger intestinal barrier dysfunction, risk factors of metabolic diseases such as insulin resistance may have common roots with IBD. In this review, we focus on the overlap between IBD and MetS, and we explore the role of common metabolites in each disease in an attempt to connect a common origin, the gut microbiome and derived metabolites that affect the gut, liver and pancreas.

Enteral Nutrition Supplemented with Transforming Growth Factor-β, Colostrum, Probiotics, and Other Nutritional Compounds in the Treatment of Patients with Inflammatory Bowel Disease

Enteral nutrition seems to play a significant role in the treatment of both adults and children with active Crohn's disease, and to a lesser degree in the treatment of patients with active ulcerative colitis. The inclusion of some special factors in the enteral nutrition formulas might increase the rate of the efficacy. Actually, enteral nutrition enriched in Transforming Growth Factor-β reduced the activity index and maintained remission in patients with Crohn's disease. In addition, a number of experimental animal studies have shown that colostrum exerts a significantly positive result. Probiotics of a special type and a certain dosage could also reduce the inflammatory process in patients with active ulcerative colitis. Therefore, the addition of these factors in an enteral nutrition formula might increase its effectiveness. Although the use of these formulas is not supported by large clinical trials, it could be argued that their administration in selected cases as an exclusive diet or in combination with the drugs used in patients with inflammatory bowel disease could benefit the patient. In this review, the authors provide an update on the role of enteral nutrition, supplemented with Transforming Growth Factor-β, colostrum, and probiotics in patients with inflammatory bowel disease.

Gut Mycobiota and Fungal Metabolites in Human Homeostasis

BACKGROUND

Accumulating evidence suggests that microbiota play an important role in host's homeostasis. Thus far, researchers have mostly focused on the role of bacterial microbiota. However, human gut is a habitat for several fungal species, which produce numerous metabolites. Furthermore, various types of food and beverages are rich in a wide spectrum of fungi and their metabolites.

METHODS

We searched PUBMED and Google Scholar databases to identify clinical and pre-clinical studies on fungal metabolites, composition of human mycobiota and fungal dysbiosis.

RESULTS

Fungal metabolites may serve as signaling molecules and exert significant biological effects including trophic, anti-inflammatory or antibacterial actions. Finally, research suggests an association between shifts in gut fungi composition and human health. Changes in mycobiota composition have been found in obesity, hepatitis and inflammatory bowel diseases.

CONCLUSION

The influence of mycobiota and dietary fungi on homeostasis in mammals suggests a pharmacotherapeutic potential of modulating the mycobiota which may include treatment with probiotics and fecal transplantation. Furthermore, antibacterial action of fungi-derived molecules may be considered as a substitution for currently used antibacterial agents and preservatives in food industry.

Beneficial Propionibacteria within a Probiotic Emmental Cheese: Impact on Dextran Sodium Sulphate-Induced Colitis in Mice

BACKGROUNDS AND AIMS

Inflammatory Bowel Diseases (IBD), including Ulcerative Colitis (UC), coincide with alterations in the gut microbiota. Consumption of immunomodulatory strains of probiotic bacteria may induce or prolong remission in UC patients. Fermented foods, including cheeses, constitute major vectors for bacteria consumption. New evidences revealed anti-inflammatory effects in selected strains of Propionibacterium freudenreichii. We thus hypothesized that consumption of a functional cheese, fermented by such a strain, may exert a positive effect on IBD.

METHODS

We investigated the impact of cheese fermented by P. freudenreichii on gut inflammation. We developed an experimental single-strain cheese solely fermented by a selected immunomodulatory strain of P. freudenreichii, CIRM-BIA 129. We moreover produced, in industrial conditions, an Emmental cheese using the same strain, in combination with Lactobacillus delbrueckii CNRZ327 and Streptococcus thermophilus LMD-9, as starters. Consumption of both cheeses was investigated with respect to prevention of Dextran Sodium Sulphate (DSS)-induced colitis in mice.

RESULTS

Consumption of the single-strain experimental cheese, or of the industrial Emmental, both fermented by P. freudenreichii CIRM-BIA 129, reduced severity of subsequent DSS-induced colitis, weight loss, disease activity index and histological score. Both treatments, in a preventive way, reduced small bowel Immunoglobulin A (IgA) secretion, restored occludin gene expression and prevented induction of Tumor Necrosis Factor α (TNFα), Interferon γ (IFNγ) and Interleukin-17 (IL-17).

CONCLUSIONS

A combination of immunomodulatory strains of starter bacteria can be used to manufacture an anti-inflammatory cheese, as revealed in an animal model of colitis. This opens new perspectives for personalised nutrition in the context of IBD.

Saccharomyces boulardii CNCM I-745 probiotic does not alter the pharmacokinetics of amoxicillin

Background Probiotics are live microbial organisms that provide benefit to the host while co-habitating in the gastrointestinal tract. Probiotics are safe, available over the counter, and have clinical benefit by reducing the number of antibiotic-associated diarrhea days. Prescriptions from providers and direct consumer demand of probiotics appear to be on the rise. Several recent animal studies have demonstrated that probiotics may have significant effect on absorption of co-administered drugs. However, to date, most probiotic-drug interaction studies in animal models have been limited to bacterial probiotics and nonantibiotic drugs. Methods We performed a traditional pharmacokinetic mouse study examining the interactions between a common commercially available yeast probiotic, Saccharomyces boulardii CNCM I-745 (Florastor®) and an orally administered amoxicillin. Results We showed that there were no significant differences in pharmacokinetic parameters (half-life, area under the curve, peak concentrations, time to reach maximum concentration, elimination rate constant) of amoxicillin between the probiotic treated and untreated control groups. Conclusions Altogether, our findings suggest that coadministration or concurrent use of S. boulardii probiotic and amoxicillin would not likely alter the efficacy of amoxicillin therapy.

Microbial-Based and Microbial-Targeted Therapies for Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD), including Crohn's disease, ulcerative colitis, and pouchitis, are chronic, relapsing intestinal inflammatory disorders mediated by dysregulated immune responses to resident microbiota. Current standard therapies that block immune activation with oral immunosuppressives or biologic agents are generally effective, but each therapy induces a sustained remission in only a minority of patients. Furthermore, these approaches can have severe adverse events. Recent compelling evidence of a role of unbalanced microbiota (dysbiosis) driving immune dysfunction and inflammation in IBD supports the therapeutic rationale for manipulating the dysbiotic microbiota. Traditional approaches using currently available antibiotics, probiotics, prebiotics, and synbiotics have not produced optimal results, but promising outcomes with fecal microbiota transplant provide a proof of principle for targeting the resident microbiota. Rationally designed oral biotherapeutic products (LBPs) composed of mixtures of protective commensal bacterial strains demonstrate impressive preclinical results. Resident microbial-based and microbial-targeted therapies are currently being studied with increasing intensity for IBD primary therapy with favorable early results. This review presents current evidence and therapeutic mechanisms of microbiota modulation, emphasizing clinical studies, and outlines prospects for future IBD treatment using new approaches, such as LBPs, bacteriophages, bacterial function-editing substrates, and engineered bacteria. We believe that the optimal clinical use of microbial manipulation may be as adjuvants to immunosuppressive for accelerated and improved induction of deep remission and as potential safer solo approaches to sustained remission using personalized regimens based on an individual patient's microbial profile.

5-Aminosalicylic acid intolerance is associated with a risk of adverse clinical outcomes and dysbiosis in patients with ulcerative colitis

Background/Aims

5-Aminosalicylic acid (ASA) causes intolerance reactions in some patients. This study was performed to examine the prognosis of patients with ulcerative colitis (UC) and 5-ASA intolerance, and to evaluate the potential interaction between 5-ASA intolerance and the intestinal microbiota.

Methods

We performed a retrospective cohort study of patients with UC who visited participating hospitals. The primary endpoint was to compare the incidence of hospitalization within 12 months between the 5-ASA intolerance group and the 5-ASA tolerance group. The secondary endpoint was to compare the risk of adverse clinical outcomes after the start of biologics between the 2 groups. We also assessed the correlation between 5-ASA intolerance and microbial change in an independently recruited cohort of patients with UC.

Results

Of 793 patients, 59 (7.4%) were assigned to the 5-ASA intolerance group and 734 (92.5%) were assigned to the 5-ASA tolerance group. The admission rate and incidence of corticosteroid use were significantly higher in the intolerance than tolerance group (P< 0.001). In 108 patients undergoing treatment with anti-tumor necrosis factor biologics, 5-ASA intolerance increased the incidence of additional induction therapy after starting biologics (P< 0.001). The 5-ASA intolerance group had a greater abundance of bacteria in the genera Faecalibacterium, Streptococcus, and Clostridium than the 5-ASA tolerance group (P< 0.05).

Conclusions

In patients with UC, 5-ASA intolerance is associated with a risk of adverse clinical outcomes and dysbiosis. Bacterial therapeutic optimization of 5-ASA administration may be important for improving the prognosis of patients with UC.

Recent advances in modulating the microbiome

We are in the midst of “the microbiome revolution”—not a day goes by without some new revelation on the potential role of the gut microbiome in some disease or disorder. From an ever-increasing recognition of the many roles of the gut microbiome in health and disease comes the expectation that its modulation could treat or prevent these very same diseases. A variety of interventions could, at least in theory, be employed to alter the composition or functional capacity of the microbiome, ranging from diet to fecal microbiota transplantation (FMT). For some, such as antibiotics, prebiotics, and probiotics, an extensive, albeit far from consistent, literature already exists; for others, such as other dietary supplements and FMT, high-quality clinical studies are still relatively few in number. Not surprisingly, researchers have turned to the microbiome itself as a source for new entities that could be used therapeutically to manipulate the microbiome; for example, some probiotic strains currently in use were sourced from the gastrointestinal tract of healthy humans. From all of the extant studies of interventions targeted at the gut microbiome, a number of important themes have emerged. First, with relatively few exceptions, we are still a long way from a precise definition of the role of the gut microbiome in many of the diseases where a disturbed microbiome has been described—association does not prove causation. Second, while animal models can provide fascinating insights into microbiota–host interactions, they rarely recapitulate the complete human phenotype. Third, studies of several interventions have been difficult to interpret because of variations in study population, test product, and outcome measures, not to mention limitations in study design. The goal of microbiome modulation is a laudable one, but we need to define our targets, refine our interventions, and agree on outcomes.

Probiotics for people with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a multisystem disease and the importance of growth and nutrition has been well established, given its implications for lung function and overall survival. It has been established that intestinal dysbiosis (i.e. microbial imbalance) and inflammation is present in people with CF. Probiotics are commercially available (over-the-counter) and may improve both intestinal and overall health.

OBJECTIVES

To assess the efficacy and safety of probiotics for improving health outcomes in children and adults with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last register search: 20 January 2020. We also searched ongoing trials registries and the reference lists of relevant articles and reviews. Date of last search: 29 January 2019.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials (RCTs) assessing efficacies and safety of probiotics in children and adults with CF. Cross-over RCTs with a washout phase were included and for those without a washout period, only the first phase of each trial was analysed.

DATA COLLECTION AND ANALYSIS

We independently extracted data and assessed the risk of bias of the included trials; we used GRADE to assess the certainty of the evidence. We contacted trial authors for additional data. Meta-analyses were undertaken on outcomes at several time points.

MAIN RESULTS

We identified 17 trials and included 12 RCTs (11 completed and one trial protocol - this trial was terminated early) (464 participants). Eight trials included only children, whilst four trials included both children and adults. Trial duration ranged from one to 12 months. Nine trials compared a probiotic (seven single strain and three multistrain preparations) with a placebo preparation, two trials compared a synbiotic (multistrain) with a placebo preparation and one trial compared two probiotic preparations. Overall we judged the risk of bias in the 12 trials to be low. Three trials had a high risk of performance bias, two trials a high risk of attrition bias and six trials a high risk of reporting bias. Only two trials were judged to have low or unclear risk of bias for all domains. Four trials were sponsored by grants only, two trials by industry only, two trials by both grants and industry and three trials had an unknown funding source. Combined data from four trials (225 participants) suggested probiotics may reduce the number of pulmonary exacerbations during a four to 12 month time-frame, mean difference (MD) -0.32 episodes per participant (95% confidence interval (CI) -0.68 to 0.03; P = 0.07) (low-certainty evidence); however, the 95% CI includes the possibility of both an increased and a reduced number of exacerbations. Additionally, two trials (127 participants) found no evidence of an effect on the duration of antibiotic therapy during the same time period. Combined data from four trials (177 participants) demonstrated probiotics may reduce faecal calprotectin, MD -47.4 µg/g (95% CI -93.28 to -1.54; P = 0.04) (low-certainty evidence), but the results for other biomarkers mainly did not show any difference between probiotics and placebo. Two trials (91 participants) found no evidence of effect on height, weight or body mass index (low-certainty evidence). Combined data from five trials (284 participants) suggested there was no difference in lung function (forced expiratory volume at one second (FEV₁) % predicted) during a three- to 12-month time frame, MD 1.36% (95% CI -1.20 to 3.91; P = 0.30) (low-certainty evidence). Combined data from two trials (115 participants) suggested there was no difference in hospitalisation rates during a three- to 12-month time frame, MD -0.44 admissions per participant (95% CI -1.41 to 0.54; P = 0.38) (low-certainty evidence). One trial (37 participants) reported health-related quality of life and while the parent report favoured probiotics, SMD 0.87 (95% CI 0.19 to 1.55) the child self-report did not identify any effect, SMD 0.59 (95% CI -0.07 to 1.26) (low-certainty evidence). There were limited results for gastrointestinal symptoms and intestinal microbial profile which were not analysable. Only four trials and one trial protocol (298 participants) reported adverse events as a priori hypotheses. No trials reported any deaths. One terminated trial (12 participants and available as a protocol only) reported a severe allergic reaction (severe urticaria) for one participant in the probiotic group. Two trials reported a single adverse event each (vomiting in one child and diarrhoea in one child). The estimated number needed to harm for any adverse reaction (serious or not) is 52 people (low-certainty evidence).

AUTHORS' CONCLUSIONS

Probiotics significantly reduce faecal calprotectin (a marker of intestinal inflammation) in children and adults with CF, however the clinical implications of this require further investigation. Probiotics may make little or no difference to pulmonary exacerbation rates, however, further evidence is required before firm conclusions can be made. Probiotics are associated with a small number of adverse events including vomiting, diarrhoea and allergic reactions. In children and adults with CF, probiotics may be considered by patients and their healthcare providers. Given the variability of probiotic composition and dosage, further adequately-powered multicentre RCTs of at least 12 months duration are required to best assess the efficacy and safety of probiotics for children and adults with CF.

Meta-analysis of randomized controlled trials of the effects of probiotics on functional constipation in adults

BACKGROUND & AIMS

Clinical trials have reported controversial results regarding the effectiveness of probiotics in alleviating functional constipation in adults. We reviewed relevant randomized controlled trials to elucidate the effectiveness of probiotics on constipation symptoms in adults with functional constipation.

METHODS

We searched Medline, the Cochrane Library, Web of Science, and Google Scholar for relevant articles published up to April 2019. The primary outcomes of interest were stool frequency, gut transit time (GTT), stool consistency, and bloating. Two authors independently performed the study selection, risk-of-bias assessment, and data extraction. The outcome data were extracted from each included study and synthesized using weighted mean differences (WMDs) or standardized mean differences (SMDs). Pooled data synthesis was performed using a random-effects model.

RESULTS

In total, 2327 relevant studies were identified, 15 of which were found to be eligible randomized controlled trials and were included in the meta-analysis. Pooling of the extracted data demonstrated that probiotic consumption significantly reduced the whole GTT by 13.75 h [95% confidence interval (CI): -21.93 to -5.56 h] and increased the stool frequency by 0.98 (95% CI: 0.36 to 1.60) bowel movements per week. This increase was significant with the consumption of multispecies probiotics [at least two bacteria; WMD: 1.22 (95% CI: 0.50 to 1.94) bowel movements per week] but not with the consumption of Bifidobacterium lactis [WMD: 1.34 (95% CI: -0.27 to 2.94) bowel movements per week] or B. longum [WMD: -0.02 (95% CI: -0.56 to 0.53) bowel movements per week] alone. Multispecies probiotics (WMD: 1.37; 95% CI: 0.72 to 2.01), but not single-species probiotics (WMD: 1.18; 95% CI: -0.59 to 2.96), improved stool consistency (WMD: 1.30; 95% CI: 0.22 to 2.38). Similarly, multispecies probiotics (at least two bacteria; WMD: -0.49; 95% CI: -0.85 to -0.13), but not single-species probiotics (WMD: -0.24; 95% CI: -0.55 to 0.07), significantly decreased bloating. Performance bias were high, whereas detection bias was unclear because of inadequate reporting.

CONCLUSION

Consumption of probiotics, in particular, multispecies probiotics, may substantially reduce the GTT, increase the stool frequency, and improve the stool consistency. Thus, probiotics can be regarded as safe and natural agents for alleviation of functional constipation in adults.

Probiotics, Nutrition, and the Small Intestine

PURPOSE OF REVIEW

Probiotics are promising remedial treatments for symptoms of small intestine (SI) diseases and promoters of overall good health. Probiotics play an important role in supporting a healthy SI microbiome (eubiosis), and in preventing establishment of unhealthy microbiota. SI eubiosis promotes optimal nutrient uptake, and optimal nutritional status maintains a healthy SI, reducing the likelihood of SI diseases. It is important to understand the advantages and limitations of probiotic therapies.

RECENT FINDINGS

Microbial dysbiosis decreases the capacity of the small bowel to utilize and absorb dietary compounds. In some studies, probiotic supplements containing lactic acid bacteria and Bifidobacterium have been demonstrated effective in supporting beneficial microbes in the SI while improving barrier integrity and reducing nutrient malabsorption and SI disease-related pathology. Strain-specific probiotic therapy may be a natural and effective approach to restoring SI barrier integrity and eubiosis, resulting in improved nutrient absorption and better health, including reducing the incidence of and severity of SI diseases.

Prebiotics and Probiotics in Inflammatory Bowel Disease: Where are we now and where are we going?

The incidence, prevalence, and cost of care associated with diagnosis and management of inflammatory bowel disease are on the rise. The role of gut microbiota in the causation of Crohn's disease and ulcerative colitis has not been established yet. Nevertheless, several animal models and human studies point towards the association. Targeting intestinal dysbiosis for remission induction, maintenance, and relapse prevention is an attractive treatment approach with minimal adverse effects. However, the data is still conflicting. The purpose of this article is to provide the most comprehensive and updated review on the utility of prebiotics and probiotics in the management of active Crohn's disease and ulcerative colitis/pouchitis and their role in the remission induction, maintenance, and relapse prevention. A thorough literature review was performed on PubMed, Ovid Medline, and EMBASE using the terms "prebiotics AND ulcerative colitis", "probiotics AND ulcerative colitis", "prebiotics AND Crohn's disease", "probiotics AND Crohn's disease", "probiotics AND acute pouchitis", "probiotics AND chronic pouchitis" and "prebiotics AND pouchitis". Observational studies and clinical trials conducted on humans and published in the English language were included. A total of 71 clinical trials evaluating the utility of prebiotics and probiotics in the management of inflammatory bowel disease were reviewed and the findings were summarized. Most of these studies on probiotics evaluated lactobacillus, De Simone Formulation or Escherichia coli Nissle 1917 and there is some evidence supporting these agents for induction and maintenance of remission in ulcerative colitis and prevention of pouchitis relapse with minimal adverse effects. The efficacy of prebiotics such as fructooligosaccharides and Plantago ovata seeds in ulcerative colitis are inconclusive and the data regarding the utility of prebiotics in pouchitis is limited. The results of the clinical trials for remission induction and maintenance in active Crohn's disease or post-operative relapse with probiotics and prebiotics are inadequate and not very convincing. Prebiotics and probiotics are safe, effective and have great therapeutic potential. However, better designed clinical trials in the multicenter setting with a large sample and long duration of intervention are needed to identify the specific strain or combination of probiotics and prebiotics which will be more beneficial and effective in patients with inflammatory bowel disease.

Endothelial and Cardiac Dysfunction in Inflammatory Bowel Diseases: Does Treatment Modify the Inflammatory Load on Arterial and Cardiac Structure and Function?

Inflammatory bowel diseases (IBD), largely represented by Crohn's disease (CD) and ulcerative colitis (UC), alter gastrointestinal physiology and mucosal immunity through a complex inflammatory process. These diseases can lead to significant arterial endothelial dysfunction. There is also evidence linking IBD with a modification of cardiac structure and function. A growing body of research has associated IBD with an acceleration of arterial stiffness and atherosclerosis and an increased risk of cardiovascular (CV) morbidity and mortality. The focus of this review is two-fold. Firstly, the literature on IBD in relation to CV dysfunction was evaluated (mainly based on 25 relevant surveys carried out between 2005 and 2018). The vast majority of these studies support a significant association of IBD with a deterioration in CV function. Secondly, the literature available regarding the effect of IBD treatment on CV dysfunction was considered based on studies published between 2007 and 2018. This literature search suggests that IBD treatment may have the potential to ameliorate CV dysfunction resulting in CV benefits. This review will analyse the literature as well as consider emerging research perspectives regarding how IBD treatment could improve CV dysfunction.

Effects of Low FODMAP Diet on Symptoms, Fecal Microbiome, and Markers of Inflammation in Patients With Quiescent Inflammatory Bowel Disease in a Randomized Trial

BACKGROUND & AIMS

There is limited evidence that a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) reduces gut symptoms in quiescent inflammatory bowel disease (IBD). We performed a randomized, controlled trial to investigate the effects of a low FODMAP diet on persistent gut symptoms, the intestinal microbiome, and circulating markers of inflammation in patients with quiescent IBD.

METHODS

We performed a single-blind trial of 52 patients with quiescent Crohn's disease or ulcerative colitis and persistent gut symptoms at 2 large gastroenterology clinics in the United Kingdom. Patients were randomly assigned to groups that followed a diet low in FODMAPs (n = 27) or a control diet (n = 25), with dietary advice, for 4 weeks. Gut symptoms and health-related quality of life were measured using validated questionnaires. Stool and blood samples were collected at baseline and end of trial. We assessed fecal microbiome composition and function using shotgun metagenomic sequencing and phenotypes of T cells in blood using flow cytometry.

RESULTS

A higher proportion of patients reported adequate relief of gut symptoms following the low FODMAP diet (14/27, 52%) than the control diet (4/25, 16%, P=.007). Patients had a greater reduction in irritable bowel syndrome severity scores following the low FODMAP diet (mean reduction of 67; standard error, 78) than the control diet (mean reduction of 34; standard error, 50), although this difference was not statistically significant (P = .075). Following the low FODMAP diet, patients had higher health-related quality of life scores (81.9 ± 1.2) than patients on the control diet (78.3 ± 1.2, P = .042). A targeted analysis revealed that in stool samples collected at the end of the study period, patients on the low FODMAP diet had significantly lower abundance of Bifidobacterium adolescentis, Bifidobacterium longum, and Faecalibacterium prausnitzii than patients on control diet. However, microbiome diversity and markers of inflammation did not differ significantly between groups.

CONCLUSIONS

In a trial of the low FODMAP diet vs a control diet in patients with quiescent IBD, we found no significant difference after 4 weeks in change in irritable bowel syndrome severity scores, but significant improvements in specific symptom scores and numbers reporting adequate symptom relief. The low FODMAP diet reduced fecal abundance of microbes believed to regulate the immune response, compared with the control diet, but had no significant effect on markers of inflammation. We conclude that a 4-week diet low in FODMAPs is safe and effective for managing persistent gut symptoms in patients with quiescent IBD. www.isrctn.com no.: ISRCTN17061468.

Side Effects Associated with Probiotic Use in Adult Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Probiotics demonstrated to be effective in the treatment of inflammatory bowel disease (IBD). However, the safety profile of probiotics is insufficiently explored. In the present systematic review and meta-analysis, we examined the occurrence of side effects related to probiotic/synbiotic use in randomized controlled trials (RCTs) of IBD patients as compared with placebo. Eligible RCTs in adult patients with IBD were identified by accessing the Medline database via PubMed, EMBASE, CENTRAL and the Cochrane central register of controlled trials up to December 2018. Occurrence of side effects was retrieved and recorded. Data were pooled and the relative risks (RRs) with their 95% confidence intervals (CIs) were calculated. The low-moderate study heterogeneity, assessed by the I2 statistic, allowed to use of a fixed-effects modelling for meta-analysis. Nine RCTs among 2337, including 826 patients (442 treated with probiotics/symbiotic and 384 with placebo) were analyzed. Eight were double-blind RCTs, and six enrolled ulcerative colitis (UC) patients. Although the risk for the overall side effects (RR 1.35, 95%CI 0.93-1.94; I2 = 25%) and for gastrointestinal symptoms (RR 1.78, 95%CI 0.99-3.20; I2 = 20%) was higher in IBD patients taking probiotics than in those exposed to placebo, statistical significance was achieved only for abdominal pain (RR 2.59, 95%CI 1.28-5.22; I2 = 40%). In conclusion, despite the small number of RCTs and the variety of probiotic used and schedule across studies, these findings highlight the level of research effort still required to identify the most appropriate use of probiotics in IBD.

The role of the gut microbiota in the treatment of inflammatory bowel diseases

The human intestinal microbiota coevolves with its host through a symbiotic relationship and exerts great influence on substantial functions including aspects of physiology, metabolism, nutrition and regulation of immune responses leading to physiological homeostasis. Over the last years, several studies have been conducted toward the assessment of the host-gut microbiota interaction, aiming to elucidate the mechanisms underlying the pathogenesis of several diseases. A defect on the microbiota-host crosstalk and the concomitant dysregulation of immune responses combined with genetic and environmental factors have been implicated in the pathogenesis of inflammatory bowel diseases (IBD). To this end, novel therapeutic options based on the gut microbiota modulation have been an area of extensive research interest. In this review we present the recent findings on the association of dysbiosis with IBD pathogenesis, we focus on the role of gut microbiota on the treatment of IBD and discuss the novel and currently available therapeutic strategies in manipulating the composition and function of gut microbiota in IBD patients. Applicable and emerging microbiota treatment modalities, such as the use of antibiotics, prebiotics, probiotics, postbiotics, synbiotics and fecal microbiota transplantation (FMT) constitute promising therapeutic options. However, the therapeutic potential of the aforementioned approaches is a topic of investigation and further studies are needed to elucidate their position in the present treatment algorithms of IBD.

Alternative & complementary treatment for pediatric inflammatory bowel disease

Alternative medicine includes treatments that are not considered mainstream and is suggested to replace the accepted treatment, while complementary treatment is added to the conventional treatment. The estimated prevalence of their use in patients with inflammatory bowel disease (IBD) is high, ranging between 21-60%. This review summarizes the data on these treatments and their efficacy in the setting of IBD.

Immunological mechanisms underpinning faecal microbiota transplantation for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disease that results from a dysregulated immune response against specific environmental triggers in a genetically predisposed individual. Increasing evidence has indicated a causal role for changes in gut microbiota (dysbiosis) contributing to this immune-mediated intestinal inflammation. These mechanisms involve dysregulation of multiple facets of the host immune pathways that are potentially reversible. Faecal microbiota transplantation (FMT) is the transfer of processed stool from a healthy donor into an individual with an illness. FMT has shown promising results in both animal model experiments and clinical studies in IBD in the resolution of intestinal inflammation. The underlying mechanisms, however, are unclear. Insights from these studies have shown interactions between modulation of dysbiosis via changes in abundances of specific members of the gut microbial community and changes in host immunological pathways. Unravelling these causal relationships has promising potential for a translational therapy role to develop targeted microbial therapies and understand the mechanisms that underpin IBD aetiopathogenesis. In this review, we discuss current evidence for the contribution of gut microbiota in the disruption of intestinal immune homeostasis and immunoregulatory mechanisms that are associated with the resolution of inflammation through FMT in IBD.

Therapeutic effect of n-butanol fraction of Huang-lian-Jie-du Decoction on ulcerative colitis and its regulation on intestinal flora in colitis mice

Huang-lian-Jie-du Decoction (HLJDD) is a classical prescription for clearing away heat and detoxification. In order to screen the effective fraction of HLJDD in the treatment of ulcerative colitis (UC) in mice and explore its effects on intestinal flora in UC mice, we prepared different polar fractions of HLJDD by system solvent extraction method. Subsequently, the contents of 13 active compounds in different polar fractions of HLJDD were determined by HPLC. Further, the UC model induced by dextran sodium sulfate was used to evaluate the therapeutic effects of different polar fractions of HLJDD. Finally, cecal contents were used for sequencing and analysis of bacterial 16S rRNA genes. The results showed that the yield of HLJDD-n-butanol (HLJDD-NBA) fraction was the highest, and the content or proportion of 13 active compounds in HLJDD-NBA fraction were the most similar to HLJDD. In addition, in vivo pharmacodynamic experiments showed that HLJDD-NBA intervention not only significantly alleviated the clinical symptoms of UC mice and ameliorated the pathological damage of colon tissue, but also showed significant anti-inflammatory and antioxidative effects (p < 0.05), which were comparable to HLJDD (p > 0.05). Moreover, both HLDD and HLJDD-NBA treatments can restore the intestinal flora homeostasis of UC mice by inhibiting the growth of intestinal pathogens and preventing the decrease of beneficial bacteria. Meanwhile, they can also significantly correct the dysfunction of intestinal flora in UC mice. In conclusion, we proved that HLJDD-NBA fraction is an effective fraction of HLJDD in treating UC in mice, and it can maintain the intestinal flora homeostasis of UC mice, which increases our understanding of the mechanism of HLJDD in treating UC and lays a foundation for the development of new anti-ulcer drugs.

Effect of Diet on the Gut Microbiota: Rethinking Intervention Duration

The human gut is inhabited by trillions of microorganisms composing a dynamic ecosystem implicated in health and disease. The composition of the gut microbiota is unique to each individual and tends to remain relatively stable throughout life, yet daily transient fluctuations are observed. Diet is a key modifiable factor influencing the composition of the gut microbiota, indicating the potential for therapeutic dietary strategies to manipulate microbial diversity, composition, and stability. While diet can induce a shift in the gut microbiota, these changes appear to be temporary. Whether prolonged dietary changes can induce permanent alterations in the gut microbiota is unknown, mainly due to a lack of long-term human dietary interventions, or long-term follow-ups of short-term dietary interventions. It is possible that habitual diets have a greater influence on the gut microbiota than acute dietary strategies. This review presents the current knowledge around the response of the gut microbiota to short-term and long-term dietary interventions and identifies major factors that contribute to microbiota response to diet. Overall, further research on long-term diets that include health and microbiome measures is required before clinical recommendations can be made for dietary modulation of the gut microbiota for health.

Long-Chain Polyphosphate Is a Potential Agent for Inducing Mucosal Healing of the Colon in Ulcerative Colitis

The goal of ulcerative colitis (UC) treatment has recently been shown to be “mucosal healing,” as no drug directly induces mucosal healing. Probiotics possess sufficient safety, but their efficacy in the treatment of UC remains controversial because of the influence of intestinal conditions. It is believed that the identification of bioactive molecules produced by probiotics and their application will help to solve this issue. We therefore identified a probiotic‐derived long‐chain polyphosphate as a molecule enhancing the intestinal barrier function. This study demonstrated that long‐chain polyphosphate exhibited antiinflammatory effects in a human macrophage and interleukin‐10 knockout transfusion mouse model. The first‐in‐human trial showed that 7 of the 10 enrolled patients acquired clinical remission, 4 of whom achieved endoscopic remission despite a history of treatment with anti–tumor necrosis factor (TNF)–α agents. No adverse reactions were observed. Long‐chain polyphosphate might be useful for the treatment of refractory UC, even in patients with failure or intolerance to anti‐TNF‐α therapy.

Efficacy and safety of bifid triple viable plus aminosalicylic acid for the treatment of ulcerative colitis: A systematic review and meta-analysis

OBJECTIVE

Ulcerative colitis (UC), one of the most stubborn diseases, is mainly treated by aminosalicylic acid (ASA). However, the side effects of ASA include vomiting, nausea, rash, diarrhea, headache, etc, which seriously affect life-quality of UC patients. Probiotics such as bifid triple viable (BTV) could reduce drug-induced adverse reactions and has a good clinical effect on UC. Therefore, we aimed to evaluate the clinical efficacy and safety of BTV plus ASA in treating UC.

METHODS

PubMed, Cochrane Library, Embase, Chinese Biomedical Literature Database, Chinese Scientific Journal Database, Chinese National Knowledge Infrastructure, and Wanfang databases were searched from the inception dates to October 12, 2018. Randomized controlled trials (RCTs) were included by comparing BTV plus ASA programs with ASA alone in patients with UC. Methodological quality was assessed by 2 independent researchers according to the inclusion criteria and exclusion criteria. Meta-analysis was performed by using the Review Manager 5.3 Software. Risk ratios (RRs), 95% confidence interval (CI), and standardized mean difference were calculated.

RESULTS

Sixty RCTs involving 4954 participants were selected for final review. Compared with ASA, BTV plus ASA significantly improved the clinical effect rate [RR = 1.23, 95% CI (1.20, 1.26), P < .00001]; reduced the relapse rate [RR = 0.34, 95% CI (0.18, 0.62), P = .0005]; and adverse effect rate [RR = 0.66, 95% CI (0.53, 0.82), P = .0002]. Compared with the controls, levels of tumor necrosis factor-α, interleukin-6 (IL-6), IL-8, C-reactive protein (CRP), hypersensitive CRP, erythrocyte sedimentation rate, and malondialdehyde were reduced; levels of IL-10, CD3+, CD4+, and superoxide dismutase were increased in BTV plus ASA group.

CONCLUSIONS

BTV plus ASA has positive therapeutic effects on UC, and it might be a safe way to treat UC. However, comprehensive clinical trials are needed to obtain high level of clinical evidence.

Nutritional approach as therapeutic manipulation in inflammatory bowel disease

Malnutrition is observed more frequently in patients with inflammatory bowel disease (IBD) than in the general population and associated with adverse clinical outcomes. This study aimed to review the current knowledge regarding the efficacy of dietary and nutritional intervention in IBD patients. Exclusive enteral nutrition might be inferior to corticosteroid treatment in adults with active Crohn’s disease (CD) but might even be superior considering the adverse effects of corticosteroid treatment in children. Total parenteral nutrition has no advantage over enteral nutrition, which is considered a more physiologic modality in organ function. Current guidelines do not yet recommend ω3-polyunsaturated fatty acid supplementation for the prevention and maintenance of remission in IBD patients. Dietary fiber supplementation could be effective in the relief of symptoms and maintenance of remission in ulcerative colitis (UC). Although vitamin D may be favorable to clinical course of IBD and bone density. Probiotic supplementation has proven to be effective in preventing and treating pouchitis for UC but is less effective in treating CD. Nutritional interventions not only correct nutritional deficiencies but also improve symptoms and clinical courses of the disease. Hence, nutritional approaches need to be developed to significantly evaluate the effectiveness of dietary interventions used to treat IBD.

The Microbiota-Gut-Brain Axis

The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within and on our bodies) as one of the key regulators of gut-brain function and has led to the appreciation of the importance of a distinct microbiota-gut-brain axis. This axis is gaining ever more traction in fields investigating the biological and physiological basis of psychiatric, neurodevelopmental, age-related, and neurodegenerative disorders. The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans. Many factors can influence microbiota composition in early life, including infection, mode of birth delivery, use of antibiotic medications, the nature of nutritional provision, environmental stressors, and host genetics. At the other extreme of life, microbial diversity diminishes with aging. Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life. Much recent work has implicated the gut microbiota in many conditions including autism, anxiety, obesity, schizophrenia, Parkinson’s disease, and Alzheimer’s disease. Animal models have been paramount in linking the regulation of fundamental neural processes, such as neurogenesis and myelination, to microbiome activation of microglia. Moreover, translational human studies are ongoing and will greatly enhance the field. Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.

Importance of nutritional therapy in the management of intestinal diseases: beyond energy and nutrient supply

The gut is an immune-microbiome-epithelial complex. Gut microbiome-host interactions have widespread biological implications, and the role of this complex system extends beyond the digestion of food and nutrient absorption. Dietary nutrients can affect this complex and play a key role in determining gut homeostasis to maintain host health. In this article, we review various dietary nutrients and their contribution to the pathogenesis and treatment of various intestinal diseases including inflammatory bowel disease, irritable bowel syndrome, colorectal cancer, and diverticulitis, among other such disorders. A better understanding of diet-host-gut microbiome interactions is essential to provide beneficial nutrients for gut health and to limit nutritional hazards to ensure successful nutritional management of gastrointestinal conditions in clinical practice.

Beneficial effect of a mixture of vitamin-producing and immune-modulating lactic acid bacteria as adjuvant for therapy in a recurrent mouse colitis model

Inflammatory bowel diseases are chronic and relapsing-remitting disorders that affect the gastrointestinal tract. Previously, the administration of folate and riboflavin-producing lactic acid bacteria (LAB) or an immune-modulating strain showed beneficial effects as they were able to reduce the acute inflammation in mouse models. The aim of this work was to evaluate a mixture of vitamin-producing and immune-modulating LAB administering together with an anti-inflammatory drug during the remission period of a mouse model of recurrent colitis. BALB/c mice were intrarectally instilled with trinitrobenzene sulfonic acid (TNBS) and those who recovered from this acute challenge were given the LAB mixture, mesalazine, or the combination of both (mesalazine + LAB) during 21 days, followed by a second challenge with TNBS. Control mice instilled with ethanol (vehicle of TNBS) and receiving the different treatments were also evaluated in order to study the effect of chronic anti-inflammatory therapy. The combination of mesalazine and LAB mixture was the most effective to decrease the intestinal damage at macroscopic and histological levels and to reduce pro-inflammatory cytokines (IL-6 and TNF-α) in intestinal fluids. In animals instilled with ethanol, mesalazine produced a loss of body weight and intestinal damages with increased IL-6. These side effects were prevented by the co-administration of mesalazine and the LAB mixture. The LAB blend did not affect the primary anti-inflammatory treatment, was able to improve it, and also prevented the side effects of this therapy.

Dose-dependent effects of kefir on colitis induced by trinitrobenzene sulfonic acid in rats

Evidence suggests that gut microbiota dysbiosis plays a critical role in the initiation and promotion of inflammatory bowel disease (IBD). Kefir is a fermented dairy product including yeast and bacterial species. We aimed to investigate the effect of kefir on trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats using two different doses. Fifty-four Wistar rats were divided into six groups. For 14 days, the normal control and colitis control groups were given tap water, kefir10 control, kefir10 colitis, and kefir30 control, and the kefir30 colitis groups were given phosphate-buffered saline containing 10% or 30% kefir, respectively, instead of tap water. Colitis was induced by intracolonically administrating TNBS in the colitis control, kefir10 colitis, and kefir30 colitis groups. On the 14th day, the rats were sacrificed. The weights and lengths of the colons were measured and macroscopically evaluated, and the distal 10 cm segments were subjected to a histopathological examination. The incidence of bloody stool and diarrhea in the kefir10 colitis group was found to be less than the colitis control and kefir30 colitis groups. The colonic weight/length ratio in the kefir10 colitis group was lower than that in the colitis control and kefir30 colitis groups. We detected that the 10% kefir treatment reduced TNBS-induced macroscopic colonic damage, while it was exacerbated by the 30% kefir treatment. No significant difference was observed between the colitis groups in terms of microscopic colonic damage scoring. These results indicate that kefir, with a careful dose selection, may be a useful agent in the treatment of IBD.

Probiotics Efficacy on Oxidative Stress Values in Inflammatory Bowel Disease: A Randomized Double-Blinded Placebo-Controlled Pilot Study

BACKGROUND

Inflammatory bowel diseases (IBD), which include Crohn's disease (CD) and ulcerative colitis (UC), are described as a chronic inflammation of the small intestine and colon, caused by a dysregulated immune response to host intestinal microbiota in genetically susceptible subjects.

OBJECTIVE

The aim of this study was to compare probiotic therapy versus placebo in Oxidative Stress Values and clinical features in patients affected by IBD.

METHOD

Forty (40) patients previously diagnosed for IBD were recruited and randomized to receive probiotics (test group, n=20) or placebo (control group, n=20) administered for 90 days. Subjects in both the groups were assessed for overall oxidant ability (d-ROMs test) and for the antioxidant response (BAP test): data were reported at baseline, after 1 and 3 months. Additional data from anamnesis and haematological investigation were also reported during the study.

RESULTS

d-ROM assay clearly showed that the values observed in the test group were significantly improved, leading to oxidative stress values which are not pathological. The test group showed increasing BAP values, thus confirming the overall improvements of patients 'health following administration of probiotics.

CONCLUSION

Oral administration of the specific probiotics demonstrated its efficacy and safety on patients affected by IBD.

Gut Microbiota as a Therapeutic Target to Ameliorate the Biochemical, Neuroanatomical, and Behavioral Effects of Traumatic Brain Injuries

Current efficacious treatments for traumatic brain injury (TBI) are lacking. Establishment of a protective gut microbiota population offers a compelling therapeutic avenue, as brain injury induces disruptions in the composition of the gut microbiota, i.e., gut dysbiosis, which has been shown to contribute to TBI-related neuropathology and impaired behavioral outcomes. The gut microbiome is involved in the modulation of a multitude of cellular and molecular processes fundamental to the progression of TBI-induced pathologies including neuroinflammation, blood brain barrier permeability, immune system response, microglial activation, and mitochondrial dysfunction, as well as intestinal motility and permeability. Additionally, gut dysbiosis further aggravates behavioral impairments in animal models of TBI and spinal cord injury, as well as negatively affects health outcomes in murine stroke models. Recent studies indicate that microbiota transplants and probiotics ameliorate neuroanatomical damage and functional impairments in animal models of stroke and spinal cord injury. In addition, probiotics have been shown to reduce the rate of infection and time spent in intensive care of hospitalized patients suffering from brain trauma. Perturbations in the composition of the gut microbiota and its metabolite profile may also serve as potential diagnostic and theragnostic biomarkers for injury severity and progression. This review aims to address the etiological role of the gut microbiome in the biochemical, neuroanatomical, and behavioral/cognitive consequences of TBI, as well as explore the potential of gut microbiome manipulation in the form of probiotics as an effective therapeutic to ameliorate TBI-induced pathology and symptoms.

Using Twitter to Understand the Human Bowel Disease Community: Exploratory Analysis of Key Topics

BACKGROUND

Nowadays, the use of social media is part of daily life, with more and more people, including governments and health organizations, using at least one platform regularly. Social media enables users to interact among large groups of people that share the same interests and suffer the same afflictions. Notably, these channels promote the ability to find and share information about health and medical conditions.

OBJECTIVE

This study aimed to characterize the bowel disease (BD) community on Twitter, in particular how patients understand, discuss, feel, and react to the condition. The main questions were as follows: Which are the main communities and most influential users?; Where are the main content providers from?; What are the key biomedical and scientific topics under discussion? How are topics interrelated in patient communications?; How do external events influence user activity?; What kind of external sources of information are being promoted?

METHODS

To answer these questions, a dataset of tweets containing terms related to BD conditions was collected from February to August 2018, accounting for a total of 24,634 tweets from 13,295 different users. Tweet preprocessing entailed the extraction of textual contents, hyperlinks, hashtags, time, location, and user information. Missing and incomplete information about the user profiles was completed using different analysis techniques. Semantic tweet topic analysis was supported by a lexicon-based entity recognizer. Furthermore, sentiment analysis enabled a closer look into the opinions expressed in the tweets, namely, gaining a deeper understanding of patients' feelings and experiences.

RESULTS

Health organizations received most of the communication, whereas BD patients and experts in bowel conditions and nutrition were among those tweeting the most. In general, the BD community was mainly discussing symptoms, BD-related diseases, and diet-based treatments. Diarrhea and constipation were the most commonly mentioned symptoms, and cancer, anxiety disorder, depression, and chronic inflammations were frequently part of BD-related tweets. Most patient tweets discussed the bad side of BD conditions and other related conditions, namely, depression, diarrhea, and fibromyalgia. In turn, gluten-free diets and probiotic supplements were often mentioned in patient tweets expressing positive emotions. However, for the most part, tweets containing mentions to foods and diets showed a similar distribution of negative and positive sentiments because the effects of certain food components (eg, fiber, iron, and magnesium) were perceived differently, depending on the state of the disease and other personal conditions of the patients. The benefits of medical cannabis for the treatment of different chronic diseases were also highlighted.

CONCLUSIONS

This study evidences that Twitter is becoming an influential space for conversation about bowel conditions, namely, patient opinions about associated symptoms and treatments. So, further qualitative and quantitative content analyses hold the potential to support decision making among health-related stakeholders, including the planning of awareness campaigns.

Beneficial effects of nutritional supplements on intestinal epithelial barrier functions in experimental colitis models in vivo

Acute and chronic colitis affect a huge proportion of the population world-wide. The etiology of colitis cases can be manifold, and diet can significantly affect onset and outcome of colitis. While many forms of acute colitis are easily treatable, chronic forms of colitis such as ulcerative colitis and Crohn's disease (summarized as inflammatory bowel diseases) are multifactorial with poorly understood pathogenesis. Inflammatory bowel diseases are characterized by exacerbated immune responses causing epithelial dysfunction and bacterial translocation. There is no cure and therapies aim at reducing inflammation and restoring intestinal barrier function. Unfortunately, most drugs can have severe side effects. Changes in diet and inclusion of nutritional supplements have been extensively studied in cell culture and animal models, and some supplements have shown promising results in clinical studies. Most of these nutritional supplements including vitamins, fatty acids and phytochemicals reduce oxidative stress and inflammation and have shown beneficial effects during experimental colitis in rodents induced by dextran sulphate sodium or 2,4,6-trinitrobenzene sulfonic acid, which remain the gold standard in pre-clinical colitis research. Here, we summarize the mechanisms through which such nutritional supplements contribute to epithelial barrier stabilization.

Probiotics and prebiotics in clinical tests: an update

Probiotics have been explored in an exponentially increasing number of clinical trials for their health effects. Drawing conclusions from the published literature for the medical practitioner is difficult since rarely more than two clinical trials were conducted with the same probiotic strain against the same medical condition. Consequently, the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) made a few recommendations restricting it to probiotic use against acute gastroenteritis and antibiotic-associated diarrhea. Recent studies also made a strong case for probiotic use against sepsis in preterm and term infants from developing countries. Conclusions on the value of probiotics are best based on detailed meta-analyses (MA) of randomized controlled trials (RCT). Outcomes of MA are discussed in the present review for a number of gastroenterology conditions. Since these MA pool data from trials using different probiotic species, large RCT published sometimes come to different conclusions than MA including these studies. This is not necessarily a contradiction but may only mean that the specific probiotic species did not work under the specified conditions. Positive or negative generalization about probiotics and prebiotics should be avoided. Credible effects are those confirmed in independent trials with a specified probiotic strain or chemically defined prebiotic in a specified patient population under the specified treatment conditions. Even distinct technological preparations of the same probiotic strain might affect clinical outcomes if they alter bacterial surface structures. Underpowered clinical trials are another problem in the probiotic field. Data obtained with sophisticated omics technologies, but derived from less than ten human subjects should be interpreted with caution even when published in high impact journals.

The Microbiota and the Immune Response: What Is the Chicken and What Is the Egg?

The underlying factors driving the onset and progression of inflammatory bowel disease (IBD) include the interplay between host genetics, microbiota, and mucosal inflammation. The same environmental triggers that are a risk factor for IBD also alter the microbiota, suggesting a link between the microbiome and IBD. Specific IBD-associated genetic polymorphisms change the microbiome linking host genetics to the microbiota. Microbial changes occur at least simultaneously with new onset IBD, and fecal microbial transplant can ameliorate certain types of IBD. A current debate in the field is which comes first, dysbiosis or inflammation? Can restitution of the microbiome "cure" IBD?

Diet and inflammatory bowel disease: The Asian Working Group guidelines

INTRODUCTION

These Asian Working Group guidelines on diet in inflammatory bowel disease (IBD) present a multidisciplinary focus on clinical nutrition in IBD in Asian countries.

METHODOLOGY

The guidelines are based on evidence from existing published literature; however, if objective data were lacking or inconclusive, expert opinion was considered. The conclusions and 38 recommendations have been subject to full peer review and a Delphi process in which uniformly positive responses (agree or strongly agree) were required.

RESULTS

Diet has an important role in IBD pathogenesis, and an increase in the incidence of IBD in Asian countries has paralleled changes in the dietary patterns. The present consensus endeavors to address the following topics in relation to IBD: (i) role of diet in the pathogenesis; (ii) diet as a therapy; (iii) malnutrition and nutritional assessment of the patients; (iv) dietary recommendations; (v) nutritional rehabilitation; and (vi) nutrition in special situations like surgery, pregnancy, and lactation.

CONCLUSIONS

Available objective data to guide nutritional support and primary nutritional therapy in IBD are presented as 38 recommendations.