A systematic review and meta-analysis: probiotics in the treatment of irritable bowel syndrome

Recommendations to Improve Quality of Probiotic Systematic Reviews With Meta-Analyses

Importance

Systematic reviews and meta-analyses often report conflicting results when assessing evidence for probiotic efficacy, partially because of the lack of understanding of the unique features of probiotic trials. As a consequence, clinical decisions on the use of probiotics have been confusing.

Objective

To provide recommendations to improve the quality and consistency of systematic reviews with meta-analyses on probiotics, so evidence-based clinical decisions can be made with more clarity.

Evidence Review

For this consensus statement, an updated literature review was conducted (January 1, 2020, to June 30, 2022) to supplement a previously published 2018 literature search to identify areas where probiotic systematic reviews with meta-analyses might be improved. An expert panel of 21 scientists and physicians with experience on writing and reviewing probiotic reviews and meta-analyses was convened and used a modified Delphi method to develop recommendations for future probiotic reviews.

Findings

A total of 206 systematic reviews with meta-analysis components on probiotics were screened and representative examples discussed to determine areas for improvement. The expert panel initially identified 36 items that were inconsistently reported or were considered important to consider in probiotic meta-analyses. Of these, a consensus was reached for 9 recommendations to improve the quality of future probiotic meta-analyses.

Conclusions and Relevance

In this study, the expert panel reached a consensus on 9 recommendations that should promote improved reporting of probiotic systematic reviews with meta-analyses and, thereby, assist in clinical decisions regarding the use of probiotics.

Golden bifid might improve diarrhea-predominant irritable bowel syndrome via microbiota modulation

Objective

Gut microbiota might play a crucial role in the pathogenesis of irritable bowel syndrome (IBS), and probiotics supplement may be an effective treatment option. This study aims to explore the therapeutic effects of Golden bifid on the diarrhea-predominant IBS (IBS-D).

Methods

Twenty-one consecutive IBS-D patients were recruited based on Rome IV criteria. All patients took 2000 mg Golden bifid triple daily for 4 weeks. Gastrointestinal (GI) symptoms, psychological symptoms, small intestine bacterial overgrowth (SIBO) and fecal microbiota characteristics were evaluated in IBS-D patients before and after treatment.

Results

After 4-week treatment of Golden bifid, the GI symptoms such as abdominal pain (2.90 ± 1.04 vs. 1.90 ± 1.26, P = 0.002), abdominal distension (2.00 ± 1.34 vs. 1.29 ± 1.31, P = 0.007), diarrhea (3.24 ± 1.37 vs. 1.81 ± 1.21, P = 0.001), defecatory urgency (3.48 ± 1.03 vs. 2.33 ± 1.35, P = 0.000) and incomplete evacuation (2.71 ± 1.15 vs. 1.76 ± 1.26, P = 0.003) were significantly alleviated in IBS-D patients. The Self-Rating Depression Scale (SDS) decreased significantly (46.19 ± 11.36 vs. 43.33 ± 9.65, P = 0.041), and SIBO could be eradicated in 25% (4/16) of IBS-D patients with SIBO. Meanwhile, the abundance of Unclassified Lachnospiraceae and Dorea in genus level and Unclassified Lachnospiraceae, Bacterium Dorea, Bacterium Butyricicoccus and Dorea formicigenerans ATCC 27755 in species level were increased in fecal microbiota (P < 0.05).

Conclusions

Golden bifid could improve most of GI symptoms and depressive symptoms in IBS-D patients and eradicate a small proportion of SIBO in those IBS-D patients with SIBO. What's more, Golden bifid could also modulate the fecal microbiota in IBS-D patients, which implied that the Golden bifid might improve IBS-D via microbiota modulation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41043-022-00302-0.

Dietary Polyphenol, Gut Microbiota, and Health Benefits

Polyphenols, which are probably the most important secondary metabolites produced by plants, have attracted tremendous attention due to their health-promoting effects, including their antioxidant, anti-inflammatory, antibacterial, anti-adipogenic, and neuro-protective activities, as well as health properties. However, due to their complicated structures and high molecular weights, a large proportion of dietary polyphenols remain unabsorbed along the gastrointestinal tract, while in the large intestine they are biotransformed into bioactive, low-molecular-weight phenolic metabolites through the residing gut microbiota. Dietary polyphenols can modulate the composition of intestinal microbes, and in turn, gut microbes catabolize polyphenols to release bioactive metabolites. To better investigate the health benefits of dietary polyphenols, this review provides a summary of their modulation through in vitro and in vivo evidence (animal models and humans), as well as their possible actions through intestinal barrier function and gut microbes. This review aims to provide a basis for better understanding the relationship between dietary polyphenols, gut microbiota, and host health.

Effectiveness and Safety of Probiotics for Patients with Constipation-Predominant Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of 10 Randomized Controlled Trials

To perform a systematic review and meta-analysis to evaluate the effectiveness and safety of probiotics in the treatment of constipation-predominant irritable bowel syndrome (IBS-C), we searched for randomized controlled trials (RCTs) comparing probiotic care versus placebos for patients with IBS-C in five comprehensive databases (March 2022). The risk of bias was assessed using the Cochrane Collaboration Risk of Bias Tool. RevMan 5.3 was used to perform a meta-analysis on stool consistency, abdominal pain, bloating, quality of life (QoL), fecal Bifidobacterium and Lactobacillus counts, and adverse events. The GRADE approach was used to evaluate the certainty of the evidence. Ten RCTs involving 757 patients were included. Only three studies were rated as having a low risk of bias. The meta-analysis results show that, compared to the placebo, probiotics significantly improved stool consistency (MD = 0.72, 95% CI (0.18, 1.26), p < 0.05, low quality) and increased the number of fecal Bifidobacteria (MD = 1.75, 95% CI (1.51, 2.00), p < 0.05, low quality) and Lactobacillus (MD = 1.69, 95% CI (1.48, 1.89), p < 0.05, low quality), while no significant differences were found in abdominal pain scores, bloating scores, QoL scores, or the incidence of adverse events (p > 0.05). The low-to-very low certainty evidence suggests that probiotics might improve the stool consistency of patients with IBS-C and increase the number of Bifidobacteria and Lactobacilli in feces with good safety. However, more high-quality studies with large samples are needed to verify the findings.

Probiotics for preventing and treating infant regurgitation: A systematic review and meta-analysis

Infant regurgitation is common during infancy and can cause substantial parental distress. Regurgitation can lead to parental perception that their infant is in pain. Parents often present in general practitioner surgeries, community baby clinics and accident and emergency departments which can lead to financial burden on parents and the health care system. Probiotics are increasingly reported to have therapeutic effects for preventing and treating infant regurgitation. The objective of this systematic review and meta-analysis was to evaluate the efficacy of probiotic supplementation for the prevention and treatment of infant regurgitation. Literature searches were conducted using MEDLINE, CINAHL, and the Cochrane Central Register of Controlled trials. Only randomised controlled trials (RCTs) were included. A meta-analysis was performed using the Cochrane Collaboration methodology where possible. Six RCTs examined the prevention or treatment with probiotics on infant regurgitation. A meta-analysis of three studies showed a statistically significant reduction in regurgitation episodes for the probiotic group compared to the placebo group (mean difference [MD]: -1.79 episodes/day: 95% confidence interval [CI]: -3.30 to -0.27, N = 560), but there was high heterogeneity (96%). Meta-analysis of two studies found a statistically significant increased number of stools per day in the probiotic group compared to the placebo group at 1 month of age (MD: 1.36, 95% CI: 0.99 to 1.73, N = 488), with moderate heterogeneity (69%). Meta-analysis of two studies showed no statistical difference in body weight between the two groups (MD: -91.88 g, 95% CI: 258.40-74.63: I2  = 23%, N = 112) with minimal heterogeneity 23%. Probiotic therapy appears promising for infant regurgitation with some evidence of benefit, but most studies are small and there was relatively high heterogeneity. The use of probiotics could potentially be a noninvasive, safe, cost effective, and preventative positive health strategy for both women and their babies. Further robust, well controlled RCTs examining the effect of probiotics for infant regurgitation are warranted.

The Effect of Bifidobacterium on Reducing Symptomatic Abdominal Pain in Patients with Irritable Bowel Syndrome: A Systematic Review

Probiotics, specifically Bifidobacteria, may improve abdominal pain in patients with irritable bowel syndrome (IBS); however, results from randomised controlled trials (RCTs) are conflicting. Here, we systematically reviewed the efficacy of Bifidobacteria on abdominal pain in IBS. We searched MEDLINE, EMBASE and the Cochrane Controlled Trials Register from inception to 20 May 2019, without language or date restrictions. The search strategy comprised of the combination of three concepts: supplementation, abdominal pain, and IBS. Inclusion criteria included double-blind placebo-controlled RCTs featuring Bifidobacteria supplementation in Rome-diagnosed IBS patients. A total of 8 RCTs involving a total of 1045 patients with Rome diagnosed IBS were included. The dose of total Bifidobacteria ranged from 10⁶ to > 10¹¹ cfu (colony-forming unit) and duration of supplementation ranged between 2 and 8 weeks. Bifidobacteria was delivered through either intake of fermented milk products, encapsulation or via a malted milk beverage, with all studies assessing abdominal pain via a visual analogue Likert scale. From the studies included, 50% (n = 4) of studies found a statistically significant improvement in abdominal pain following Bifidobacteria supplementation compared to placebo, 38% (n = 3) of studies found non-significant improvements and 12% (n = 1) showed a statistically significant dose-response effect of improvement. The evidence shows a heterogeneity of effect for Bifidobacteria dependent upon strain, dosage and delivery method. While not all studies demonstrate significant improvements in abdominal pain, none of the selected studies reported an increase in pain or other adverse effects.

Probiotics/ prebiotics in viral respiratory infections: implication for emerging pathogens

BACKGROUND

Viral respiratory infections could result in perturbation of the gut microbiota due to a probable cross-talk between lungs and gut microbiota. This can affect the pulmonary health and the gastrointestinal system.

OBJECTIVE

This review aimed to discuss the impact of probiotics/ prebiotics and supplements on the prevention and treatment of respiratory infections, especially emerging pathogens.

METHODS

The data were searched were searched in PubMed, Scopus, Google Scholar, Google Patents, and The Lens-Patent using keywords of probiotics and viral respiratory infections in the title, abstract, and keywords.

RESULT

Probiotics consumption could decrease the susceptibility to viral respiratory infections, such as COVID-19 and simultaneously enhance vaccine efficiency in infectious disease prevention through the immune system enhancement. Probiotics improve the gut microbiota and the immune system via regulating the innate system response and production of anti-inflammatory cytokines. Moreover, treatment with probiotics contributes to the intestinal homeostasis restitution under antibiotic pressure and decreasing the risk of secondary infections due to viral respiratory infections. Probiotics present varied performances in different conditions; thus, promoting their efficacy through combining with supplements (prebiotics, postbiotics, nutraceuticals, berberine, curcumin, lactoferrin, minerals, and vitamins) is important. Several supplements reported to enhance the probiotics' efficacy and their mechanisms as well as probiotics related patents are summarized in this review. Using nanotechnology and microencapsulation techniques can also improve probiotics efficiency.

CONCLUSION

Given the global challenge of COVID-19, probiotic/prebiotic and following nutritional guidelines should be regarded seriously. Additionally, their role as an adjuvant in vaccination for immune response augmentation needs attention.

Evidence-based clinical practice guidelines for irritable bowel syndrome 2020

Managing irritable bowel syndrome (IBS) has attracted international attention because single-agent therapy rarely relieves bothersome symptoms for all patients. The Japanese Society of Gastroenterology (JSGE) published the first edition of evidence-based clinical practice guidelines for IBS in 2015. Much more evidence has accumulated since then, and new pharmacological agents and non-pharmacological methods have been developed. Here, we report the second edition of the JSGE-IBS guidelines comprising 41 questions including 12 background questions on epidemiology, pathophysiology, and diagnostic criteria, 26 clinical questions on diagnosis and treatment, and 3 questions on future research. For each question, statements with or without recommendations and/or evidence level are given and updated diagnostic and therapeutic algorithms are provided based on new evidence. Algorithms for diagnosis are requisite for patients with chronic abdominal pain or associated symptoms and/or abnormal bowel movement. Colonoscopy is indicated for patients with one or more alarm symptoms/signs, risk factors, and/or abnormal routine examination results. The diagnosis is based on the Rome IV criteria. Step 1 therapy consists of diet therapy, behavioral modification, and gut-targeted pharmacotherapy for 4 weeks. For non-responders, management proceeds to step 2 therapy, which includes a combination of different mechanistic gut-targeted agents and/or psychopharmacological agents and basic psychotherapy for 4 weeks. Step 3 therapy is for non-responders to step 2 and comprises a combination of gut-targeted pharmacotherapy, psychopharmacological treatments, and/or specific psychotherapy. These updated JSGE-IBS guidelines present best practice strategies for IBS patients in Japan and we believe these core strategies can be useful for IBS diagnosis and treatment globally.

Probiotics Modulate Intestinal Motility and Inflammation in Zebrafish Models

This study was aimed to assess effects of three strains of probiotics Lactobacillus acidophilus NCFM, Lactobacillus rhamnosus HN001, and Bifidobacterium animalis subsp. lactis Bi-07 on the intestinal motility and inflammation in the zebrafish models. The intestinal motility model was established using 5 days postfertilization (dpf) zebrafish administered with a fluorescent dye Nile red at 10 ng/mL for 16 h, followed by probiotics treatment for 24 h and the intestinal motility was inversely proportional to the intestinal fluorescence intensity that was quantitatively measured by image analysis. The intestinal inflammation was induced by treating 3 dpf neutrophil fluorescent zebrafish with 0.0125% of trinitrobenzenesulfonic acid for 48 h. Probiotics were administered at low, moderate, and high concentrations determined based on maximum tolerable concentration through soaking. All three strains of probiotics promoted intestinal movement, of which B. animalis subsp. lactis Bi-07 was most potent at lower concentrations. L. rhamnosus HN001 and B. animalis subsp. lactis Bi-07 had the therapeutic effects on the intestinal inflammation and the inflammation-associated mucosal damage recovery. The anti-inflammatory mechanisms of L. rhamnosus HN001 was related to both reduce inflammatory factor interleukin-6 (IL-6) and restored tissue repair factor transforming growth factor-β-1 (TGFβ-1); whereas B. animalis subsp. lactis Bi-07 was probably only associated with TGFβ-1 elevation. Using larval zebrafish models for probiotics screening and assessment would speed up product research and development and improve products' efficacy and quality.

Chromatin Dynamics in Intestinal Epithelial Homeostasis: A Paradigm of Cell Fate Determination versus Cell Plasticity

The rapid renewal of intestinal epithelium is mediated by a pool of stem cells, located at the bottom of crypts, giving rise to highly proliferative progenitor cells, which in turn differentiate during their migration along the villus. The equilibrium between renewal and differentiation is critical for establishment and maintenance of tissue homeostasis, and is regulated by signaling pathways (Wnt, Notch, Bmp…) and specific transcription factors (TCF4, CDX2…). Such regulation controls intestinal cell identities by modulating the cellular transcriptome. Recently, chromatin modification and dynamics have been identified as major actors linking signaling pathways and transcriptional regulation in the control of intestinal homeostasis. In this review, we synthesize the many facets of chromatin dynamics involved in controlling intestinal cell fate, such as stemness maintenance, progenitor identity, lineage choice and commitment, and terminal differentiation. In addition, we present recent data underlying the fundamental role of chromatin dynamics in intestinal cell plasticity. Indeed, this plasticity, which includes dedifferentiation processes or the response to environmental cues (like microbiota’s presence or food ingestion), is central for the organ’s physiology. Finally, we discuss the role of chromatin dynamics in the appearance and treatment of diseases caused by deficiencies in the aforementioned mechanisms, such as gastrointestinal cancer, inflammatory bowel disease or irritable bowel syndrome.

Modulation of the Gut Microbiota by Olive Oil Phenolic Compounds: Implications for Lipid Metabolism, Immune System, and Obesity

There is extensive information of the beneficial effects of virgin olive oil (VOO), especially on cardiovascular diseases. Some VOO healthy properties have been attributed to their phenolic-compounds (PCs). The aim of this review is to present updated data on the effects of olive oil (OO) PCs on the gut microbiota, lipid metabolism, immune system, and obesity, as well as on the crosstalk among them. We summarize experiments and clinical trials which assessed the specific effects of the olive oil phenolic-compounds (OOPCs) without the synergy with OO-fats. Several studies have demonstrated that OOPC consumption increases Bacteroidetes and/or reduces the Firmicutes/Bacteroidetes ratio, which have both been related to atheroprotection. OOPCs also increase certain beneficial bacteria and gut-bacteria diversity which can be therapeutic for lipid-immune disorders and obesity. Furthermore, some of the mechanisms implicated in the crosstalk between OOPCs and these disorders include antimicrobial-activity, cholesterol microbial metabolism, and metabolites produced by bacteria. Specifically, OOPCs modulate short-chain fatty-acids produced by gut-microbiota, which can affect cholesterol metabolism and the immune system, and may play a role in weight gain through promoting satiety. Since data in humans are scarce, there is a necessity for more clinical trials designed to assess the specific role of the OOPCs in this crosstalk.

The Evolving Role of Gut Microbiota in the Management of Irritable Bowel Syndrome: An Overview of the Current Knowledge

The intestinal microbiota is one of the most rapidly evolving areas in biology and medicine. Extensive research in the last decade has escalated our understanding of the role of the microbiota in the pathogenesis of several intestinal and extra-intestinal disorders. Marked by high prevalence, substantial morbidity, and enormous costs, irritable bowel syndrome (IBS) is an important chronic gastrointestinal disorder that is widely encountered by gastroenterologists. Despite advances in our understanding of its pathophysiology, curative interventions have yet to be discovered, and therapeutic approaches remain symptom-driven. Recently, accumulating evidence has enlightened the possible impact of an imbalanced gut microbiome in the pathogenesis of IBS. In fact, several studies have documented altered microbiota in patients, while others have shown that IBS severity was associated with a distinct microbiota signature. These findings may pave the way for the use of microbiota manipulation strategies as an attractive option for IBS management, and may have an essential role in efforts to reduce the societal and economic effects of this ever-growing disorder. In this review, we have outlined the results of the latest research on the association between microbiota and IBS and their implications for the clinical management of affected patients.

Efficacy and Safety of New Lactobacilli Probiotics for Unconstipated Irritable Bowel Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial

Irritable bowel syndrome (IBS) is a common and chronic gastrointestinal disorder. Probiotics may have the potential to impact the management of IBS; however, the results of trials are conflicting. This study aimed to investigate whether a mixture of lactobacilli probiotics could improve abdominal symptoms in patients with unconstipated IBS. Fifty Vietnamese patients with unconstipated IBS were randomly assigned to either the probiotics or placebo groups. During the intervention, participants took the probiotic supplement, named Foodis Lactobacillus, or placebo capsule once a day. Patients recorded their subject global assessment (SGA) weekly and were assessed with the visual analogue scale (VAS) during the 4-week study period. Patients with SGA score of 2 points or more or a decrease of more than 30% in VAS score were considered responders. Patients who responded weekly for more than 2 of the 4 weeks were considered overall responders. There was no significant difference in demographic characteristics between the groups. Overall responder rates of improvement of global IBS symptoms assessed by SGA score were significantly higher in the probiotics group (80.8%) than in the placebo group (45.8%) (p = 0.009). The overall responder rates assessed by VAS score were also higher in the probiotics group (69.2%, 41.7%, p = 0.048). There were no adverse events in either group during the study period. Our findings suggest that the new combination of Lactobacilli appears to be promising in the relief of abdominal symptoms in Vietnamese patients with unconstipated IBS.

Clinical effect of probiotics in prevention or treatment of gastrointestinal disease in dogs: A systematic review

BACKGROUND

Gastrointestinal diseases are prevalent in dogs, and probiotics could provide safe alternatives to conventional treatments.

OBJECTIVE

To evaluate the clinical effects of probiotics when used in the prevention or treatment of gastrointestinal disease in dogs compared with no treatment, only symptomatic treatment, or conventional treatment.

METHODS

A systematic review was preformed searching AGRICOLA, AGRIS, CAB Abstracts, Embase, Ovid MEDLINE, and Web of Science to identify articles published before April 1, 2017. Selection criteria were original research report, those published in peer reviewed journal, and study investigating in vivo use of probiotic for prevention or treatment of gastrointestinal disease in dogs. Studies were rated based on the level of evidence, and methodological quality was evaluated by the following variables: similarities between groups at baseline, risk of bias, and study group size.

RESULTS

One hundred sixty-five studies were identified, of which 17 met the inclusion criteria-12 concerned acute gastrointestinal disease and 5 concerned chronic gastrointestinal disease. The level of evidence ranged between randomized controlled studies and crossover uncontrolled trials; estimated risk of bias was generally moderate to high; and sample sizes were small. Feces consistency was the most frequently evaluated clinical variable.

CONCLUSIONS AND CLINICAL IMPORTANCE

The current data point toward a very limited and possibly clinically unimportant effect for prevention or treatment of acute gastrointestinal disease. For chronic gastrointestinal disease, dietary intervention remains the major key in treatment, whereas probiotic supplement seems not to add significant improvement. However, studies were often underpowered, underscoring the need for future larger, preferably multicenter studies.

Are probiotics useful in the treatment of chronic idiopathic constipation in adults? A review of existing systematic reviews, meta-analyses, and recommendations

Chronic idiopathic constipation (CIC) has emerged as common problem for contemporary gastroenterology and is one of the most frequent complaints in primary care. Chronic idiopathic constipation significantly affects patients' quality of life and has an impact on global health and economy. Functional gastrointestinal disorders and bowel disorders, according to Rome IV criteria, result from inappropriate gut-brain interactions. The pathophysiology is complex and poorly understood, with evidence accumulating that gut microbiota can be implicated in the development and function of the enteric nervous system. Gut bacteria modulate gut barrier function, short chain fatty acid synthesis, and bile acid metabolism, factors which play roles in the gut peristalsis regulation. The high prevalence of CIC, with poor treatment outcomes, warrants searches for new forms of therapy, including probiotic therapies. Probiotics are often recommended by medical practitioners, but evidence-based utility in adults with CIC is uncertain. Recommendations/guidelines are often based on results from individual studies, rather than meta-analyses or umbrella reviews. Additionally, meta-analyses often indicate a group of probiotics rather than individual strains, and they create difficulty for physicians in making therapeutic choices. More CIC patient randomised clinical studies utilising well-defined strains, or combinations, are necessary.

Pharmacological and non-pharmacological treatments for irritable bowel syndrome: Protocol for a systematic review and network meta-analysis

BACKGROUND

The global prevalence of Irritable bowel syndrome (IBS) is estimated to be as high as 15% and a number of different non-pharmacological and pharmacological treatments have been used to manage IBS in clinical practice, which poses great challenges for clinicians to make appropriate decisions. Hence, a systematic review and network meta-analysis on all available pharmacological and non-pharmacological treatments for IBS is needed to provide reliable evidence.

METHODS

We will search the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane IBD Group Specialized Trials Register, MEDLINE, EMBASE, and Chinese Biomedical medicine (CBM) from inception to 31, May 2019. Randomized controlled trials of pharmacological and nonpharmacological interventions for IBS will be included. Study quality will be assessed on the basis of the methodology and categories described in the Cochrane Collaboration Handbook. Primary outcomes are global or clinical improvement and quality of life. A Bayesian network meta-analysis would be performed, and relative ranking of agents would be assessed. A node splitting method will be used to examine the inconsistency between direct and indirect comparisons when a loop connecting 3 arms exists.

RESULTS

Researchers will rank the effectiveness and safety of the potentials interventions for IBS according the characteristics of patients by conducting an advanced network meta-analysis based on Bayesian statistical model, and interpret the results by using GRADE approach.

CONCLUSION

The conclusion of our study will provide updated evidence to rank the effectiveness and safety of pharmacological and non-pharmacological interventions for IBS.

ETHICS AND DISSEMINATION

Ethical approval is not applicable since this study is a network meta-analysis based on published trials.

PROTOCOL REGISTRATION NUMBER

CRD42018083844.

The Case for a More Holistic Approach to Dry Eye Disease: Is It Time to Move beyond Antibiotics?

Dry eye disease (DED) is one of the most frequent presentations to optometrists with over 16 million US adults (6.8% of adult population) diagnosed as having this disorder. The majority of associated marketed products offer relief from symptomatology but do not address aetiology. DED harbours many distinguishing features of a chronic inflammatory disorder. The recent explosion in human microbiome research has sparked interest in the ocular microbiome and its role in the preservation and extension of ocular surface health and in the contribution of the gut microbiome to chronic systemic inflammation and associated "Western life-style" diseases. With a significant lack of success for many patients using currently available DED treatments, in this era of the microbiome, we are interested in exploring potential novel therapies that aim to reconstitute healthy bacterial communities both locally and distally (in the gut) as a treatment for DED. Although this direction of investigation is in its infancy, burgeoning interest makes such a review timely. This paper considers a number of studies into the use functional foods and associated products to ameliorate dry eye.

Thirty Years of Lactobacillus rhamnosus GG: A Review

Lactobacillus rhamnosus GG (LGG) was the first strain belonging to the genus Lactobacillus to be patented in 1989 thanks to its ability to survive and to proliferate at gastric acid pH and in medium containing bile, and to adhere to enterocytes. Furthermore LGG is able to produces both a biofilm that can mechanically protect the mucosa, and different soluble factors beneficial to the gut by enhancing intestinal crypt survival, diminishing apoptosis of the intestinal epithelium, and preserving cytoskeletal integrity. Moreover LGG thanks to its lectin-like protein 1 and 2 inhibits some pathogens such as Salmonella species. Finally LGG is able to promote type 1 immune-responsiveness by reducing the expression of several activation and inflammation markers on monocytes and by increasing the production of interleukin-10, interleukin-12 and tumor necrosis factor-α in macrophages. A large number of research data on Lactobacillus GG is the basis for the use of this probiotic for human health. In this review we have considered predominantly randomized controlled trials, meta-analysis, Cochrane Review, guide lines of Scientific Societies and anyway studies whose results were evaluated by means of relative risk, odds ratio, weighted mean difference 95% confidence interval. The effectiveness of LGG in gastrointestinal infections and diarrhea, antibiotic and Clostridium difficile associated diarrhea, irritable bowel syndrome, inflammatory bowel disease, respiratory tract infections, allergy, cardiovascular diseases, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, cystic fibrosis, cancer, elderly end sport were analyzed.

Exercise influence on the microbiome-gut-brain axis

The microbiome in the gut is a diverse environment, housing the majority of our bacterial microbes. This microecosystem has a symbiotic relationship with the surrounding multicellular organism, and a balance and diversity of specific phyla of bacteria support general health. When gut bacteria diversity diminishes, there are systemic consequences, such as gastrointestinal and psychological distress. This pathway of communication is known as the microbiome-gut-brain axis. Interventions such as probiotic supplementation that influence microbiome also improve both gut and brain disorders. Recent evidence suggests that aerobic exercise improves the diversity and abundance of genera from the Firmcutes phylum, which may be the link between the positive effects of exercise on the gut and brain. The purpose of this review is to explain the complex communication pathway of the microbiome-gut-brain axis and further examine the role of exercise on influencing this communication highway.

Gut microbes as future therapeutics in treating inflammatory and infectious diseases: Lessons from recent findings

The human gut microbiota has been the interest of extensive research in recent years and our knowledge on using the potential capacity of these microbes are growing rapidly. Microorganisms colonized throughout the gastrointestinal tract of human are coevolved through symbiotic relationship and can influence physiology, metabolism, nutrition and immune functions of an individual. The gut microbes are directly involved in conferring protection against pathogen colonization by inducing direct killing, competing with nutrients and enhancing the response of the gut-associated immune repertoire. Damage in the microbiome (dysbiosis) is linked with several life-threatening outcomes viz. inflammatory bowel disease, cancer, obesity, allergy, and auto-immune disorders. Therefore, the manipulation of human gut microbiota came out as a potential choice for therapeutic intervention of the several human diseases. Herein, we review significant studies emphasizing the influence of the gut microbiota on the regulation of host responses in combating infectious and inflammatory diseases alongside describing the promises of gut microbes as future therapeutics.

Probiotic use in clinical practice: Results of a national survey of gastroenterologists and nutritionists

INTRODUCTION AND AIMS

Probiotics are effective in gastrointestinal disease management. In Mexico, there are no studies on the use and prescription of probiotics by healthcare professionals. Our aim was to evaluate probiotic use and prescription on the part of gastroenterologists and nutritionists.

MATERIALS AND METHODS

An online survey questionnaire was sent to members of the Asociación Mexicana de Gastroenterología (n = 1042), the Asociación Mexicana de Nutriología (n = 220), and healthcare professionals registered at the Fourth International Symposium: Intestinal Microbiota (n = 1328).

RESULTS

Response was 34% (997 questionnaires answered) and 570 (64%) of the respondents were women. Mean participant age was 36.2 years (range 18-83). Thirty-six percent of the participants were gastroenterologists, 46% were nutritionists, and 18% were chemists and microbiologists. Seventy-one percent of the respondents knew the Food and Agriculture Organization (FAO) definition of probiotics and recommended them «always» (64.9%), «rarely» (31.7%), and «never» (3.6%). Gastroenterologists indicated probiotics for the treatment of disease (56.5%) and nutritionists for health maintenance (39%). Ninety-seven percent of the gastroenterologists and 98% of the nutritionists evaluated probiotics as effective in gastrointestinal symptom management and considered them safe. The majority of the respondents did not know which probiotic strain was contained in the commercial probiotic product.

CONCLUSIONS

The survey results showed that the participating gastroenterologists and nutritionists understood the concept of probiotics, recommended them frequently, and considered them safe. The gastroenterologists prescribed probiotics as therapeutic agents and the nutritionists to maintain health. There was a lack of knowledge about the microbial composition of the products containing probiotics available in Mexico.

The gut microbiome and irritable bowel syndrome: State of art review

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract, the physiology of which is not very well understood. There are multiple factors and pathways involved in pathogenesis of this entity. Among all, dysmotility, dysregulation of the brain-gut axis, altered intestinal microbiota and visceral hypersensitivity play a major role. Over the last years, research has shown that the type of gut microbiome present in an individual plays a significant role in the pathophysiology of IBS. Multiple studies have consistently shown that subjects diagnosed with IBS have disruption in gut microbiota balance. It has been established that host immune system and its interaction with metabolic products of gut microbiota play an important role in the gastrointestinal tract. Therefore, probiotics, prebiotics and antibiotics have shown some promising results in managing IBS symptoms via modulating the interaction between the above. This paper discusses the various factors involved in pathophysiology of IBS, especially gut microbiota.

Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R and Lactobacillus rhamnosus CLR2 improve quality-of-life and IBS symptoms: a double-blind, randomised, placebo-controlled study

A combination of Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R and Lactobacillus rhamnosus CLR2 was compared to placebo for relief of symptoms of irritable bowel syndrome (IBS). A total of 113 subjects at 3 clinical sites were randomised in a 2:1 ratio and followed for 12 weeks. Subjects ingested either 2 capsules of active study product, containing 50×10⁹ cfu of live organisms, or 2 placebo capsules daily. Endpoints included improvement in abdominal pain, days of pain, distention, stool consistency and frequency, quality of life (QOL), and adequate relief (AR) of IBS symptoms. IBS subtypes constipation (IBS-C), diarrhoea (IBS-D), and mixed (IBS-M) were evaluated separately; the effect of gender was also examined. For all efficacy endpoints improvement of 30% or more vs placebo was considered clinically significant. With the exception of pain intensity and AR, the endpoints demonstrated a therapeutic advantage of active over placebo for IBS symptoms in at least some subject subgroups. The IBS-D and female subgroups showed the largest and most consistent effects. Stool frequency and consistency were evaluated in the IBS-C and IBS-D subgroups, and improvement of active vs placebo was noted in both. QOL improvement was seen overall and in specific domains. Adverse events (AEs) were limited to 7 subjects; all were of mild or moderate intensity except one, severe cramping. Four AEs in the same subject in the placebo group were judged to be related to study product; these resolved by the end of study. There were no serious AEs.

Interactions of Gut Microbiota, Endotoxemia, Immune Function, and Diet in Exertional Heatstroke

Exertional heatstroke (EHS) is a medical emergency that cannot be predicted, requires immediate whole-body cooling to reduce elevated internal body temperature, and is influenced by numerous host and environmental factors. Widely accepted predisposing factors (PDF) include prolonged or intense exercise, lack of heat acclimatization, sleep deprivation, dehydration, diet, alcohol abuse, drug use, chronic inflammation, febrile illness, older age, and nonsteroidal anti-inflammatory drug use. The present review links these factors to the human intestinal microbiota (IM) and diet, which previously have not been appreciated as PDF. This review also describes plausible mechanisms by which these PDF lead to EHS: endotoxemia resulting from elevated plasma lipopolysaccharide (i.e., a structural component of the outer membrane of Gram-negative bacteria) and tissue injury from oxygen free radicals. We propose that recognizing the lifestyle and host factors which are influenced by intestine-microbial interactions, and modifying habitual dietary patterns to alter the IM ecosystem, will encourage efficient immune function, optimize the intestinal epithelial barrier, and reduce EHS morbidity and mortality.

Systematic review: probiotics in the management of lower gastrointestinal symptoms - an updated evidence-based international consensus

BACKGROUND

In 2013, a systematic review and Delphi consensus reported that specific probiotics can benefit adult patients with irritable bowel syndrome (IBS) and other gastrointestinal (GI) problems.

AIM

To update the consensus with new evidence.

METHODS

A systematic review identified randomised, placebo-controlled trials published between January 2012 and June 2017. Evidence was graded, previously developed statements were reassessed by an 8-expert panel, and agreement was reached via Delphi consensus.

RESULTS

A total of 70 studies were included (IBS, 34; diarrhoea associated with antibiotics, 13; diarrhoea associated with Helicobacter pylori eradication therapy, 7; other conditions, 16). Of 15 studies that examined global IBS symptoms as a primary endpoint, 8 reported significant benefits of probiotics vs placebo. Consensus statements with 100% agreement and "high" evidence level indicated that specific probiotics help reduce overall symptom burden and abdominal pain in some patients with IBS and duration/intensity of diarrhoea in patients prescribed antibiotics or H. pylori eradication therapy, and have favourable safety. Statements with 70%-100% agreement and "moderate" evidence indicated that, in some patients with IBS, specific probiotics help reduce bloating/distension and improve bowel movement frequency/consistency.

CONCLUSIONS

This updated review indicates that specific probiotics are beneficial in certain lower GI problems, although many of the new publications did not report benefits of probiotics, possibly due to inclusion of new, less efficacious preparations. Specific probiotics can relieve lower GI symptoms in IBS, prevent diarrhoea associated with antibiotics and H. pylori eradication therapy, and show favourable safety. This study will help clinicians recommend/prescribe probiotics for specific symptoms.

Fecal microbiota transplantation and its potential therapeutic uses in gastrointestinal disorders

Typical human gut flora has been well characterized in previous studies and has been noted to have significant differences when compared with the typical microbiome of various disease states involving the gastrointestinal tract. Such diseases include Clostridium difficile colitis, inflammatory bowel disease, functional bowel syndromes, and various states of liver disease. A growing number of studies have investigated the use of a fecal microbiota transplant as a potential therapy for these disease states.

Bio-prospectus of cadmium bioadsorption by lactic acid bacteria to mitigate health and environmental impacts

Foodstuffs and water are the key sources of cadmium biomagnifiaction. The available strategies to mitigate this problem are unproductive and expensive for practical large-scale use. Biological decontamination of metals through environmental microbes has been known since long time, whereas lactic acid bacteria (LAB) have not been extensively studied for this purpose. The LAB are known for maintaining homeostasis and suppression of pathogens in humans and animals. They also play a vital role in bioremediation of certain heavy metals. Recently in-vivo research findings strongly complement the in-vitro results in relation to decreased total body cadmium burden in animal model. This review summarizes the currently available information on impact of toxic metal (Cd) on human and animal health as well as cadmium sequestration through microbes placed broadly, whereas preeminent attention grabbed on LAB-cadmium interaction to explore their possible role in bioremediation of cadmium from foods and environment to safeguard human as well as environment health.

Gut dysbiosis and irritable bowel syndrome: The potential role of probiotics

OBJECTIVE

To discuss the role of gut dysbiosis in the development of irritable bowel syndrome (IBS) and the impact of probiotics as a potential therapeutic measure.

METHODS

PubMed was used to search for all of the studies published over the last 15 years using the key words: "irritable bowel syndrome" and "gut dysbiosis" or "probiotic". More than 800 articles were found, but only those published in English or providing evidence-based data were included in the evaluation.

RESULTS

IBS is a common disease for which no resolutive therapy is presently available. In recent years, strong evidence of a possible relationship between modifications of the gut microbiota composition and development of IBS has been collected. Moreover, the evidence showed that attempts to treat acute infectious and post-antibiotic gastroenteritis with some probiotics were significantly effective in a great number of patients, leading many experts to suggest the use of probiotics to address all of the clinical problems associated with IBS.

CONCLUSION

The available data are promising, but presently, a precise definition of which probiotic or which mixture of probiotics is effective cannot be made. Moreover, the dose and duration of treatment has not been established. Finally, we do not know whether probiotic treatment should be different according to the type of IBS. Further studies are needed before probiotics can be considered a reliable treatment for IBS.

From clinical uncertainties to precision medicine: the emerging role of the gut barrier and microbiome in small bowel functional diseases

Over the last decade, remarkable progress has been made in the understanding of disease pathophysiology. Many new theories expound on the importance of emerging factors such as microbiome influences, genomics/omics, stem cells, innate intestinal immunity or mucosal barrier complexities. This has introduced a further dimension of uncertainty into clinical decision-making, but equally, may shed some light on less well-understood and difficult to manage conditions. Areas covered: Comprehensive review of the literature on gut barrier and microbiome relevant to small bowel pathology. A PubMed/Medline search from 1990 to April 2017 was undertaken and papers from this range were included. Expert commentary: The scenario of clinical uncertainty is well-illustrated by functional gastrointestinal disorders (FGIDs). The movement towards achieving a better understanding of FGIDs is expressed in the Rome IV guidelines. Novel diagnostic and therapeutic protocols focused on the GB and SB microbiome can facilitate diagnosis, management and improve our understanding of the underlying pathological mechanisms in FGIDs.

New therapeutic perspectives in irritable bowel syndrome: Targeting low-grade inflammation, immuno-neuroendocrine axis, motility, secretion and beyond

Irritable bowel syndrome (IBS) is a chronic, recurring, and remitting functional disorder of the gastrointestinal tract characterized by abdominal pain, distention, and changes in bowel habits. Although there are several drugs for IBS, effective and approved treatments for one or more of the symptoms for various IBS subtypes are needed. Improved understanding of pathophysiological mechanisms such as the role of impaired bile acid metabolism, neurohormonal regulation, immune dysfunction, the epithelial barrier and the secretory properties of the gut has led to advancements in the treatment of IBS. With regards to therapies for restoring intestinal permeability, multiple studies with prebiotics and probiotics are ongoing, even if to date their efficacy has been limited. In parallel, much progress has been made in targeting low-grade inflammation, especially through the introduction of drugs such as mesalazine and rifaximin, even if a better knowledge of the mechanisms underlying the low-grade inflammation in IBS may allow the design of clinical trials that test the efficacy and safety of such drugs. This literature review aims to summarize the findings related to new and investigational therapeutic agents for IBS, most recently developed in preclinical as well as Phase 1 and Phase 2 clinical studies.

Probiotic guidelines and physician practice: a cross-sectional survey and overview of the literature

Probiotic use by patients and physicians has dramatically increased over the last decade, although definitive evidence is often lacking for their use. We examined probiotic-prescribing practices among health care providers (HCP) at a tertiary medical centre and compared these practices to clinical guidelines. HCP at the Stanford Medical Center received a survey on probiotic prescribing practices including choice of probiotic and primary indications. A broad overview of the literature was performed. Among 2,331 HCP surveyed, 632 responded. Of the 582 of these who routinely prescribed medications, 61% had recommended probiotic foods or supplements to their patients. Women and gastroenterologists were more likely to prescribe probiotics (odds ratio (OR): 1.5, 95% confidence interval (CI): 1.0-2.1; OR: 3.9, 95% CI: 1.5-10.1, respectively). Among probiotic prescribers, 50% prescribed inconsistently or upon patient request, and 40% left probiotic choice to the patient. Common indications for probiotics, particularly Lactobacillus GG, were prevention and treatment of antibiotic-associated diarrhoea (79 and 66%, respectively). Probiotics were often prescribed for ‘general bowel health’ or at patient request (27 and 39% of responders, respectively). Most respondents (63%) thought an electronic medical record (EMR) pop-up would change probiotic prescribing patterns. However, a review of published guidelines and large trials found inconsistencies in probiotic indications, dosages and strain selection. Probiotic prescribing is common but lacks consistency, with choice of probiotic frequently left to the patient, even for indications with some strain-specific evidence. Implementation of EMR pop-ups/pocket guides may increase consistency in probiotic prescribing, although the lack of clear and consistent guidelines must first be addressed with large, well-designed clinical trials.

Efficacy of Bifidobacterium infantis 35624 in patients with irritable bowel syndrome: a meta-analysis

BACKGROUND

The treatment of irritable bowel syndrome (IBS) is a challenge because its cause remains unknown. Previous clinical trials to examine the efficacy of probiotic Bifidobacterium infantis 35624 (B. infantis) in patients with IBS have shown inconsistent findings. This study aimed to assess the combined effect of B. infantis on reducing the symptom severity of IBS based on the published data.

METHODS

A meta-analysis was conducted using fixed-effect models to estimate the combined effect of B. infantis on primary outcomes, which included abdominal pain, bloating/distention, and bowel habit satisfaction. A systematic review was performed based on PubMed, Cochrane Library, and EMBASE databases to identify the randomized controlled trials comparing probiotic B. infantis with placebo in treating IBS symptoms, published up until 31 December 2016. The standardized mean difference (SMD) method was used to combine data since scales to measure the efficacy of probiotics were different among studies.

RESULTS

A total of five studies were identified as suitable for inclusion, including three studies with single probiotic B. infantis and two studies with composite probiotics containing B. infantis. Treatment with single probiotic B. infantis didn't impact on abdominal pain, bloating/distention, or bowel habit satisfaction among IBS patients. However, patients who received composite probiotics containing B. infantis had significantly reduced abdominal pain (SMD, 0.22; 95% CI, 0.03-0.41) and bloating/distention (SMD, 0.30; 95% CI, 0.04-0.56). After combining the data from six studies, the improvement of bloating/distention among IBS patients remained significant (SMD, 0.21; 95% CI, 0.07-0.35).

CONCLUSION

Composite probiotics containing B. infantis might be an effective therapeutic option for IBS patients, which could significantly alleviate the symptoms of IBS without significant adverse effects. However, the efficacy of single probiotic B. infantis on IBS has not been confirmed yet, which needs to be further validated by more large-sized randomized clinical trials.

Lactobacillus reuteri DSM 17938 in the Treatment of Functional Abdominal Pain in Children: RCT Study

OBJECTIVES

Beneficial therapeutic effect of probiotics has been reported in children with the irritable bowel syndrome (IBS) but not consistently in other functional abdominal pain-related disorders. The aim of the present study was to investigate the effect of Lactobacillus reuteri DSM 17938 in the treatment of functional abdominal pain (FAP) and IBS in children.

METHODS

Children (age 4-18 years) referred to pediatric gastroenterologist at Children's Hospital Zagreb from May 2012 to December 2014, diagnosed as FAP or IBS, were randomized to receive L reuteri DSM 17938 10⁸ CFU daily or placebo. The study was a prospective, randomized, double-blind, placebo-controlled parallel study. Symptoms were evaluated using Wong-Baker FACES pain rating scale for pain and Bristol scale for stool shape and consistence.

RESULTS

Data were analyzed for 55 children (26 in the intervention group and 29 in the placebo group). Children in the intervention group had significantly more days without pain (median 89.5 vs 51 days, P = 0.029). Abdominal pain was less severe in children taking probiotics during the second month (P < 0.05) and fourth month (P < 0.01). The 2 groups did not differ in the duration of abdominal pain, stool type, or absence from school. Both groups experienced significant reduction in the severity of abdominal pain from first to fourth month, with the reduction more prominent in the intervention group (P < 0.001 vs P = 0.004).

CONCLUSIONS

Administration of L reuteri DSM 17938 was associated with a possible reduction of the intensity of pain and significantly more days without pain in children with FAP and IBS.

Probiotics, fibre and herbal medicinal products for functional and inflammatory bowel disorders

Functional bowel disorders (FBD), mainly irritable bowel syndrome (IBS) and functional constipation (FC, also called chronic idiopathic constipation), are very common worldwide. Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, although less common, has a strong impact on patients' quality of life, as well as being highly expensive for our healthcare. A definite cure for those disorders is still yet to come. Over the years, several therapeutic approaches complementary or alternative to traditional pharmacological treatments, including probiotics, prebiotics, synbiotics, fibre and herbal medicinal products, have been investigated for the management of both groups of diseases. However, most available studies are biased by several drawbacks, including small samples and poor methodological quality. Probiotics, in particular Saccharomyces boulardii and Lactobacilli (among which Lactobacillus rhamnosus), synbiotics, psyllium, and some herbal medicinal products, primarily peppermint oil, seem to be effective in ameliorating IBS symptoms. Synbiotics and fibre seem to be beneficial in FC patients. The probiotic combination VSL#3 may be effective in inducing remission in patients with mild-to-moderate ulcerative colitis, in whom Escherichia coli Nissle 1917 seems to be as effective as mesalamine in maintaining remission. No definite conclusions can be drawn as to the efficacy of fibre and herbal medicinal products in IBD patients due to the low number of studies and the lack of randomized controlled trials that replicate the results obtained in the individual studies conducted so far. Thus, further, well-designed studies are needed to address the real role of these therapeutic options in the management of both FBD and IBD.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

The effects of administration of the Lactobacillus gasseri strain CP2305 on quality of life, clinical symptoms and changes in gene expression in patients with irritable bowel syndrome

AIMS

To clarify the effects of Lactobacillus gasseri CP2305 (CP2305) on quality of life and clinical symptoms and its functional mechanisms in patients with irritable bowel syndrome (IBS).

METHODS AND RESULTS

After the patients were administered CP2305 daily for 4 weeks, the IBS-severity index score was significantly improved compared with that of the placebo group, and this improvement was accompanied by a reduction in health-related worry and changes in intestinal microbiota. The gene expression profiling of the peripheral blood leucocytes showed that CP2305 treatment significantly up-regulated genes related to eukaryotic initiation factor 2 (EIF2) signalling. Eighty-two genes were down-regulated in IBS patients compared with healthy controls. The expression of 23 of these genes exhibited a CP2305-dependent increase associated with an improvement in IBS severity. The majority of the restored genes were related to EIF2 signalling.

CONCLUSIONS

CP2305 administration is a potential candidate therapeutic option for patients with IBS.

SIGNIFICANCE AND IMPACT OF THE STUDY

Although probiotics have been proposed to benefit IBS patients, objective clinical evidence and elucidation of the functional mechanism remain insufficient. Our study demonstrated that CP2305 administration beneficially influences IBS patients in both subjective and objective evaluations, and gene expression profiling provided insights into the functional mechanism.

Review of the role of probiotics in gastrointestinal diseases in adults

BACKGROUND

Probiotics may act as biological agents that modify the intestinal microbiota and certain cytokine profiles, which can lead to an improvement in certain gastrointestinal diseases.

OBJECTIVES

To conduct a review of the evidence of the role of probiotics in certain gastrointestinal diseases in adults.

SEARCH METHODS

Review conducted using appropriate descriptors, filters and limits in the PubMed database (MEDLINE).

SELECTION CRITERIA

The MeSH terms used were Probiotics [in the title] AND Gastrointestinal Diseases, with the following limits or filters: Types of study: Systematic Reviews, Meta-Analysis, Guideline, Practice Guideline, Consensus Development Conference (and Consensus Development Conference NIH), Randomized Controlled Trial, Controlled Clinical Trial and Clinical Trial; age: adults (19 or older); language: English and Spanish; in humans, and with at least one abstract.

DATA COLLECTION AND ANALYSIS

Full texts of all the Systematic Reviews and meta-analyses directly related to the review's objective were obtained, as well as the Randomised Controlled Trials of the studies that were considered relevant and of sufficient quality for this review.

MAIN RESULTS

Certain probiotics, different for each process, have proven to be effective and beneficial in cases of acute infectious diarrhoea, antibiotic-associated diarrhoea, Clostridium difficile-associated diarrhoea, pouchitis and Helicobacter pylori infection eradication.

AUTHORS' CONCLUSIONS

Although some probiotics have not demonstrated any benefit, there are certain gastrointestinal diseases in which the use of probiotics, true biological agents, can be recommended.

The Mexican consensus on probiotics in gastroenterology

INTRODUCTION

Probiotics are frequently prescribed in clinical practice. Their efficacy in treating gastrointestinal disorders is supported by a significant number of clinical trials. However, the correct prescription of these agents is hampered due to a lack of knowledge of the scientific evidence and to the different presentations and microbial compositions of the probiotics that are currently available.

AIM

To provide the clinician with a consensus review of probiotics and recommendations for their use in gastroenterology.

MATERIALS AND METHODS

Controlled clinical trials, meta-analyses, and systematic reviews published up to 2015 were selected, using the MESH terms: probiotics, gastrointestinal diseases, humans, adults, AND children. The Delphi method was employed. Eighteen gastroenterologists treating adult patients and 14 pediatric gastroenterologists formulated statements that were voted on until agreement>70% was reached. The level of evidence based on the GRADE system was evaluated for each statement.

RESULTS AND CONCLUSIONS

Eleven statements on the general concepts of probiotics and 27 statements on the use of probiotics in gastrointestinal diseases in both adults and children were formulated. The consensus group recommends the use of probiotics under the following clinical conditions: the prevention of diarrhea associated with antibiotics, the treatment of acute infectious diarrhea, the prevention of Clostridium difficile infection and necrotizing enterocolitis, the reduction of adverse events from Helicobacter pylori eradication therapy, relief from irritable bowel syndrome symptoms, the treatment of functional constipation in the adult, and the induction and maintenance of remission in patients with ulcerative colitis and pouchitis, and the treatment of covert and overt hepatic encephalopathy.

Saccharomyces cerevisiae CNCM I-3856 in irritable bowel syndrome: An individual subject meta-analysis

AIM

To confirm previous conclusions on Saccharomyces cerevisiae (S. cerevisiae) CNCM I-3856 for irritable bowel syndrome (IBS) management.

METHODS

An individual patient data meta-analysis was performed on two randomized clinical trials studying the effect of S. cerevisiae CNCM I-3856 supplementation on gastrointestinal (GI) symptoms in IBS subjects. A total of 579 IBS subjects were included. Outcomes were the daily Likert scale scores of abdominal pain/discomfort and bloating [area under the curve (AUC) and weekly means], responder status, and bowel movements (stool frequency and consistency). Statistical analyses were conducted in Intent to Treat (ITT) population, IBS-C subjects and IBS-C subjects with an abdominal pain/discomfort score higher than or equal to 2 at baseline ("IBS-C ≥ 2 subpopulation").

RESULTS

S. cerevisiae CNCM I-3856 significantly improved abdominal pain/discomfort and bloating during the second month of supplementation [AUC (W5-W8)] with improvement up to the minimal clinically relevant threshold of 10%: a 12.3% reduction of abdominal pain/discomfort in the ITT population compared to the Placebo group (P = 0.0134) has been observed. In the IBS-C ≥ 2 subpopulation, there were a 13.1% reduction of abdominal pain/discomfort and a 14.9% reduction of bloating compared to the Placebo group (P = 0.0194 and P = 0.0145, respectively). GI symptoms significantly decreased during supplementation but no statistical differences were reported between groups at the end of the supplementation period. Responder status was defined as a subject who experienced a decrease of 1 arbitrary unit (a.u.) or 50% of the abdominal discomfort score from baseline for at least 2 wk out of the last 4 wk of the study. A significant difference between groups was reported in the ITT population, when considering the first definition: subjects in the Active group had 1.510 higher odds to be a responder (reduction of 1 a.u. of abdominal pain/discomfort) compared with subjects in the Placebo group (P = 0.0240). At the end of supplementation period, stool consistency in the Active group of the ITT population was significantly improved and classified as "normal" compared to Placebo (respectively 3.13 ± 1.197 a.u. vs 2.58 ± 1.020 a.u., P = 0.0003). Similar results were seen in the IBS-C ≥ 2 subpopulation (Active group: 3.14 ± 1.219 a.u. vs Placebo group: 2.59 ± 1.017 a.u., P = 0.0009).

CONCLUSION

This meta-analysis supports previous data linking S. cerevisiae I-3856 and improvement of GI symptoms, in IBS overall population and in the IBS-C and IBS-C ≥ 2 subpopulations.

Can probiotics modulate human disease by impacting intestinal barrier function?

Intestinal barrier integrity is a prerequisite for homeostasis of mucosal function, which is balanced to maximise absorptive capacity, while maintaining efficient defensive reactions against chemical and microbial challenges. Evidence is mounting that disruption of epithelial barrier integrity is one of the major aetiological factors associated with several gastrointestinal diseases, including infection by pathogens, obesity and diabetes, necrotising enterocolitis, irritable bowel syndrome and inflammatory bowel disease. The notion that specific probiotic bacterial strains can affect barrier integrity fuelled research in which in vitro cell lines, animal models and clinical trials are used to assess whether probiotics can revert the diseased state back to homeostasis and health. This review catalogues and categorises the lines of evidence available in literature for the role of probiotics in epithelial integrity and, consequently, their beneficial effect for the reduction of gastrointestinal disease symptoms.

A Mixture of 3 Bifidobacteria Decreases Abdominal Pain and Improves the Quality of Life in Children With Irritable Bowel Syndrome: A Multicenter, Randomized, Double-Blind, Placebo-Controlled, Crossover Trial

GOALS

We assessed the efficacy of a probiotic mixture of Bifidobacterium infantis M-63, breve M-16V, and longum BB536 in improving abdominal pain (AP) and quality of life (QoL) in children with irritable bowel syndrome (IBS) and functional dyspepsia (FD).

BACKGROUND

AP-associated functional gastrointestinal disorders, particularly IBS and FD, are common in pediatrics, and no well-established treatment is currently available. Although probiotics have shown promising results in adults, data in children are heterogeneous.

STUDY

Forty-eight children with IBS (median age, 11.2 y; range, 8 to 17.9 y) and 25 with FD (age, 11.6 y; range, 8 to 16.6 y) were randomized to receive either a mixture of 3 Bifidobacteria or a placebo for 6 weeks. After a 2-week "washout" period, each patient was switched to the other group and followed up for further 6 weeks. At baseline and follow-up, patients completed a symptom diary and a QoL questionnaire. AP resolution represented the primary outcome parameter.

RESULTS

In IBS, but not in FD, Bifidobacteria determined a complete resolution of AP in a significantly higher proportion of children, when compared with placebo (P=0.006), and significantly improved AP frequency (P=0.02). The proportion of IBS children with an improvement in QoL was significantly higher after probiotics than after placebo (48% vs. 17%, P=0.001), but this finding was not confirmed in FD.

CONCLUSIONS

In children with IBS a mixture of Bifidobacterium infantis M-63, breve M-16V, and longum BB536 is associated with improvement in AP and QoL. These findings were not confirmed in FD subjects. Trial identifier: NCT02566876 (http://www.clinicaltrial.gov).

A review of dose-responses of probiotics in human studies

The probiotic definition requires the administration of an 'adequate amount' in order to obtain a health benefit. What that amount should be is not indicated. Here, an overview is given of studies that investigated the dose-response relation of probiotics in human interventions. Studies were divided in; meta-analyses, meta-analyses on specific probiotic strains, and studies testing two or more doses of a probiotic (combination) in the same study. Meta-analyses on the effect of probiotics on antibiotic associated diarrhoea (AAD) suggest a dose-response effect; for Clostridium difficile-associated diarrhoea on the other hand no dose-response was observed. For other end-points; such as necrotising enterocolitis, prevention of atopic dermatitis and slow intestinal transit, no dose-response relation was identified in meta-analyses. For prophylaxis in colorectal cancer and relief of irritable bowel syndrome, no dose-response relation was determined. However, for blood pressure, a meta-analysis observed that higher doses (greater than 10¹¹ cfu) were more effective than lower doses. Meta-analyses of specific strains suggest a break-point for effectiveness of Lactobacillus rhamnosus GG in the treatment of acute gastroenteritis in children; no dose-response was observed for two other probiotics assessed. Studies comparing two or more doses indicate that faecal recovery and risk reduction of AAD follow a positive dose-response relationship. Other end-points such as immune markers, general health, and bowel function did not exhibit clear dose-response relations. For AAD, the findings are very compelling; both meta-analyses and dedicated dose-response studies observe a positive correlation between dose and AAD risk. These findings do not allow for extrapolation, but suggest that studying higher doses for this end-point would be worthwhile. The lack of a clear dose-response for other end-points, does not mean it does not exist; present data does just not allow drawing any conclusions.

Probiotics for the Treatment of Symptomatic Uncomplicated Diverticular Disease: Rationale and Current Evidence

Changes in the colonic microbiota are critical to the pathogenesis of diverticular complications such as diverticulitis and peridiverticular abscesses. However, more subtle changes in microbiota composition may well be important to the more chronic manifestations of diverticulosis. Some studies have shown the presence of bacterial overgrowth in subgroups of patients with diverticular disease and recent studies, using molecular biology techniques, found an increase of proteobacteria and actinobacteria in patients with symptomatic uncomplicated diverticular disease (SUDD), compared with healthy controls. The use of probiotics to modulate intestinal microecology in SUDD appears therefore rational. Although several investigations evaluating the clinical efficacy of probiotics have been performed, no definitive results have yet been achieved, mainly due to the heterogeneity of the available studies. Most of the studies used probiotics in combination with poorly absorbed antimicrobials or anti-inflammatory drugs. In only 4 studies, there was a harm using probiotics alone, but only 1 was a placebo-controlled, double-blind trial. The analysis of the available evidence reveals a poor quality of the published studies, whose design was heterogeneous, with only 2 out of 11 trials being double-blind and randomized. Therefore, available data can only suggest a benefit of probiotics in SUDD, but do not allow any evidence-based definite conclusion. As a consequence, current guidelines state that there is insufficient evidence to recommend probiotics for symptom relief in patients with diverticular disease.

Manipulation of the Microbiota Using Probiotics

A number of diseases are associated with alterations in the composition of the microbiota of various niches of the human body. Although, in most cases, it is unclear if these alterations are the cause or the consequence of disease, they provide a rationale for therapeutic or prophylactic manipulation of a dysbiotic microbiota. Approaches to manipulate the microbiome include administration of either live bacteria, which are underrepresented in the diseased individual, substances that aim at increasing the populations of these bacteria, or a combination of the two. This chapter summarizes the available data in therapeutic manipulation of a various diseased states including irritable bowel syndrome, inflammatory bowel disease, necrotizing enterocolitis, atopic and allergic diseases, and antibiotic-associated and infectious diarrhoea.

Efficacy of the low FODMAP diet for treating irritable bowel syndrome: the evidence to date

This review summarizes the published clinical studies concerning the management of irritable bowel syndrome (IBS) using restriction of Fermentable Oligosaccharide, Disaccharide, Monosaccharide, and Polyols in the diet (low FODMAP diet). In recent years, the data supporting low FODMAP diet for the management of IBS symptoms have emerged, including several randomized controlled trials, case-control studies, and other observational studies. Unlike most dietary manipulations tried in the past to alleviate gastrointestinal symptoms of IBS, all studies on low FODMAP diet have consistently shown symptomatic benefits in the majority of patients with IBS. However, dietary adherence by the patients and clear dietary intervention led by specialized dietitians appear to be vital for the success of the diet. Up to 86% of patients with IBS find improvement in overall gastrointestinal symptoms as well as individual symptoms such as abdominal pain, bloating, constipation, diarrhea, abdominal distention, and flatulence following the diet. FODMAP restriction reduces the osmotic load and gas production in the distal small bowel and the proximal colon, providing symptomatic relief in patients with IBS. Long-term health effects of a low FODMAP diet are not known; however, stringent FODMAP restriction is not recommended owing to risks of inadequate nutrient intake and potential adverse effects from altered gut microbiota. In conclusion, the evidence to date strongly supports the efficacy of a low FODMAP diet in the treatment of IBS. Further studies are required to understand any potential adverse effects of long-term restriction of FODMAPs.

Eluxadoline for the treatment of diarrhoea-predominant irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) treatment is challenging physicians because of its multifactorial physiopathology. In particular, abdominal pain and diarrhea management lack one unique effective pharmacological remedy. Opioid receptors, present in the central nervous system (CNS) and the enteric nervous system (ENS), are involved in visceral sensitivity and gastrointestinal motility control. To date only a few opioid receptor modulators are currently in use for the treatment of IBS but with dosage limitations due to the early development of severe constipation.

AREAS COVERED

In this drug evaluation manuscript we review the irritable bowel syndrome therapeutic needs and chemistry, pharmacokinetics and -dynamics, clinical study results with the new opioid receptor ligand eluxadoline for the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D).

EXPERT OPINION

Eluxadoline shows a peculiar pharmacological profile with μ-opioid agonism and δ-opioid antagonism actions. Its efficacy over placebo for the treatment of abdominal pain and diarrhea in IBS-D has been demonstrated in short- and long-term clinical studies in humans. Its safety has been evaluated in the same studies. Interestingly, eluxadoline showed a low rate of constipation development in IBS patients in comparison with known effects of other opioid receptor modulators. Patients with a history of acute pancreatitis should not be treated with eluxadoline.