Clinical and Microbiological Effect of a Multispecies Probiotic Supplementation in Celiac Patients With Persistent IBS-type Symptoms: A Randomized, Double-Blind, Placebo-controlled, Multicenter Trial

Can a Synbiotic Supplementation Contribute to Decreasing Anti-Tissue Transglutaminase Levels in Children with Potential Celiac Disease?

PURPOSE

Synbiotics can alleviate some intestinal pathologies or prevent trigger mechanisms for some diseases such as celiac disease (CD). If patients with high levels of anti-tissue transglutaminase (anti-tTG) immunoglobulin A (IgA) antibodies have normal duodenal histology, they are followed as potential CD patients. The aim of this study was to investigate the effect of synbiotic use on the blood levels of anti-tTG antibodies in children.

METHODS

Eighty-two patients with high anti-tTG levels were included in this study. Patients were randomly divided into two groups. The synbiotic group was treated with a daily dose of a synbiotic including multi-strain probiotics for 20 days. The control group was not administered any medication. Anti-tTG values at baseline and repeat measurements and the percentage change in anti-tTG levels between groups were compared.

RESULTS

The anti-tTG level at baseline was 36 U/mL (interquartile range [IQR], 26.4-68 U/mL) in the synbiotic group, and it decreased significantly to 13 U/mL (IQR, 6.5-27.5 U/mL) after 20 days (p<0.05). The anti-tTG level at baseline was 46 U/mL (IQR, 31-89 U/mL) in the control group, which also decreased significantly to 23 U/mL (IQR, 7-41 U/mL) after 20 days (p<0.05). Anti-tTG levels exhibited 73% and 56% decreases in the synbiotic and control groups, respectively (p<0.05).

CONCLUSION

It may be speculated that a synbiotic supplementation can contribute to decreasing anti-tTG levels in children with potential CD.

Advances in understanding the potential therapeutic applications of gut microbiota and probiotic mediated therapies in celiac disease

INTRODUCTION

Celiac Disease (CD) is an autoimmune enteropathy caused by exposure to gluten in genetically predisposed people. While gluten is the main driving force in CD, evidence has shown that microbiota might be involved in the pathogenesis, development, and clinical presentation of CD. Microbiota manipulation may modify its functional capacity and may be crucial for setting-up potential preventive or therapeutic application. Moreover, probiotics are an excellent source of endopeptidases for digesting gluten.

AREAS COVERED

In this narrative review we illustrate all the recent scientific discoveries in this field including CD pathogenetic mechanism where gut microbiota might be involved and possible use of probiotics in CD prevention and treatment.

EXPERT OPINION

In the future, probiotics could be used as an add-on medication for strengthening/facilitating the gluten-free diet (GFD) and improving symptoms; the prospect of using it for therapeutic purposes is to be sought in a more distant future.

A Probiotic Preparation Hydrolyzes Gliadin and Protects Intestinal Cells from the Toxicity of Pro-Inflammatory Peptides

Celiac disease (CD) is an autoimmune enteropathy caused by an intolerance to gluten proteins. It has been hypothesized that probiotic bacteria may exert beneficial effects by modulating inflammatory processes and by sustaining peptide hydrolysis at the intestinal level. This study aims at evaluating the capacity of a probiotic mixture (two different strains of lactobacilli and three of bifidobacteria) to hydrolyze gluten peptides following simulated gastrointestinal digestion of gliadin (PT-gliadin). The capacity of bacterial hydrolysates to counteract the toxic effects of gliadin-derived peptides in Caco-2 cells was also assessed. The protein and peptide mixtures, untreated or proteolyzed with the probiotic preparation, were analyzed before and after each proteolytic step with different techniques (SDS-PAGE, reverse phase HPLC, filtration on different molecular cut-off membranes). These experiments demonstrated that PT-gliadin can be further digested by bacteria into lower molecular weight peptides. PT-gliadin, untreated or digested with the probiotics, was then used to evaluate oxidative stress, IL-6 cytokine production and expression of tight junctions’ proteins—such as occludin and zonulin—in Caco-2 cells. PT-gliadin induced IL-6 production and modulation and redistribution of zonulin and occludin, while digestion with the probiotic strains reversed these effects. Our data indicate that this probiotic mixture may exert a protective role in CD.

Non-Responsive Coeliac Disease: A Comprehensive Review from the NHS England National Centre for Refractory Coeliac Disease

Coeliac disease is a common small intestinal enteropathy which manifests following ingestion of gluten in genetically susceptible individuals. Since gluten was identified as the driving factor in coeliac disease, the gluten-free diet (GFD) has remained the mainstay of treatment. While most individuals will display improvement in symptoms and signs of coeliac disease following institution of the GFD, up to 30% will continue to experience symptoms and/or have persisting intestinal inflammation. These individuals can be classified as having non-responsive coeliac disease (NRCD), which may be associated with dietary indiscretion, slow healing, refractory coeliac disease, and/or an alternative condition. The purpose of this review is to provide an overview of the causes of NRCD in adults, highlight a systematic approach to investigate these patients, and appraise the latest management aspects of this subset of coeliac disease.

Gut Microbiota Imbalance is Related to Sporadic Colorectal Neoplasms. A Pilot Study

(1) Background: Colorectal cancer (CRC) development is sustained by multiple factors including the gut microbiota, as suggested by a growing body of evidence. Most CRCs have a sporadic (non-hereditary) onset and develop from sporadic colorectal adenomas/polyp (SCA/P). In the present study, we investigated the characteristic of anaerobic microorganisms in stool samples obtained from 20 patients with SCA/P and 20 subjects without evidence of proliferative lesions at colonoscopy (Controls). (2) Material and Methods: We designed this clinical trial using adaptive randomization by minimization. Selective culture media and Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) mass spectrometry techniques were used to identify the components of microbiota. The data obtained revealed a different variability of gut microbiota in stool samples of controls and SCA/P subjects. (3) Results: The most interesting difference was observed for Bacteroides species, which represent the 50% of all bacterial species identified in the stool samples: two species, Bacteroides stercoris and Parabacteroides distasonis, were found only in the feces from control group, whereas Bacteroides fragilis and Prevotella melaningenica species were presents only in SCA/P patients. Among Gram+ bacteria also, specific species were found in the two groups of feces: Clostridium clostridioforme, Propionibacterium avidum and Pediococcus pentasaceus were identified only in controls, while Eubacterium limosum, Clostridium innocuum and Corybebacterium xerosus were identified in SCA/P stool samples only. (4) Conclusions: Our findings suggest that, compared to control stool samples, a different intestinal microbiota is present in SCA/P stool samples, that may create a micro-environment predisposing for the development of proliferative phenomena. As a consequence, gut microbiota manipulation could be a future target for personalized treatments.

The Gut Microbiota in Celiac Disease and probiotics

Celiac disease (CeD) is an immune-mediated enteropathy, and unique in that the specific trigger is known: gluten. The current mainstay of therapy is a gluten-free diet (GFD). As novel therapies are being developed, complementary strategies are also being studied, such as modulation of the gut microbiome. The gut microbiota is involved in the initiation and perpetuation of intestinal inflammation in several chronic diseases. Intestinal dysbiosis has been reported in CeD patients, untreated or treated with GFD, compared to healthy subjects. Several studies have identified differential bacterial populations associated with CeD patients and healthy subjects. However, it is still not clear if intestinal dysbiosis is the cause or effect of CeD. Probiotics have also been considered as a strategy to modulate the gut microbiome to an anti-inflammatory state. However, there is a paucity of data to support their use in treating CeD. Further studies are needed with therapeutic microbial formulations combined with human trials on the use of probiotics to treat CeD by restoring the gut microbiome to an anti-inflammatory state.

How to manage adult coeliac disease: perspective from the NHS England Rare Diseases Collaborative Network for Non-Responsive and Refractory Coeliac Disease

Adult coeliac disease (CD) affects approximately 1% of the population. Most patients diagnosed will respond to a gluten-free diet; however, up to 30% may have persisting symptoms. Such patients may have ongoing issues associated with adherence, non-responsive CD or refractory CD. This article provides a clinical overview of how to manage this group of patients with persisting symptoms, including an investigational algorithm and details of how to contact the National Health Service England Rare Diseases Collaborative Network for Non-Responsive and Refractory Coeliac Disease. We hope this will be a valuable source of contemporary information for all UK gastroenterologists and internationally.

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 Impact of Low-FODMAPs, Gluten-Free, and Ketogenic Diets on Gut Microbiota Modulation in Pathological Conditions

The gut microbiota performs several essential protective, structural, and metabolic functions for host health. The maintenance of a beneficial microbiota requires a homeostatic equilibrium within microbial communities, and between the microorganisms and the host. The gut microbiota composition may be affected by external factors, among them diet habits may be considered most important. In some pathological conditions such as irritable bowel syndrome (IBS), celiac disease (CD), or neurological disorders (ND), specific dietary regimens as low-fermentable, oligo-, di-, mono-saccharides and polyols (FODMAPs), ketogenic (KD), and gluten-free (GFD) diets are considered therapeutic. These kinds of diets are characterized by a reduction or exclusion of a specific nutrient from the entire dietary pattern. Despite these alimentary regimens showing beneficial effects on disease symptoms, they can affect microbiota composition, especially if they are protracted for a long time. To date, only a few studies have reported the effects of these diets on gut microbiota. In this review, we discuss the effects of low-FODMAPs, KD, and GFD on gut microbiota modulation in pathological conditions, advancing the possibility of depicting a balanced diet and developing personalized dietary intervention protocols.

Probiotics in Celiac Disease

Recently, the interest in the human microbiome and its interplay with the host has exploded and provided new insights on its role in conferring host protection and regulating host physiology, including the correct development of immunity. However, in the presence of microbial imbalance and particular genetic settings, the microbiome may contribute to the dysfunction of host metabolism and physiology, leading to pathogenesis and/or the progression of several diseases. Celiac disease (CD) is a chronic autoimmune enteropathy triggered by dietary gluten exposure in genetically predisposed individuals. Despite ascertaining that gluten is the trigger in CD, evidence has indicated that intestinal microbiota is somehow involved in the pathogenesis, progression, and clinical presentation of CD. Indeed, several studies have reported imbalances in the intestinal microbiota of patients with CD that are mainly characterized by an increased abundance of Bacteroides spp. and a decrease in Bifidobacterium spp. The evidence that some of these microbial imbalances still persist in spite of a strict gluten-free diet and that celiac patients suffering from persistent gastrointestinal symptoms have a desert gut microbiota composition further support its close link with CD. All of this evidence gives rise to the hypothesis that probiotics might play a role in this condition. In this review, we describe the recent scientific evidences linking the gut microbiota in CD, starting from the possible role of microbes in CD pathogenesis, the attempt to define a microbial signature of disease, the effect of a gluten-free diet and host genetic assets regarding microbial composition to end in the exploration of the proof of concept of probiotic use in animal models to the most recent clinical application of selected probiotic strains.