Randomised clinical trial: the effectiveness of Lactobacillus reuteri ATCC 55730 rectal enema in children with active distal ulcerative colitis

Alteration of Gut Microbiota in Inflammatory Bowel Disease (IBD): Cause or Consequence? IBD Treatment Targeting the Gut Microbiome

Inflammatory bowel disease (IBD) is a chronic complex inflammatory gut pathological condition, examples of which include Crohn’s disease (CD) and ulcerative colitis (UC), which is associated with significant morbidity. Although the etiology of IBD is unknown, gut microbiota alteration (dysbiosis) is considered a novel factor involved in the pathogenesis of IBD. The gut microbiota acts as a metabolic organ and contributes to human health by performing various physiological functions; deviation in the gut flora composition is involved in various disease pathologies, including IBD. This review aims to summarize the current knowledge of gut microbiota alteration in IBD and how this contributes to intestinal inflammation, as well as explore the potential role of gut microbiota-based treatment approaches for the prevention and treatment of IBD. The current literature has clearly demonstrated a perturbation of the gut microbiota in IBD patients and mice colitis models, but a clear causal link of cause and effect has not yet been presented. In addition, gut microbiota-based therapeutic approaches have also shown good evidence of their effects in the amelioration of colitis in animal models (mice) and IBD patients, which indicates that gut flora might be a new promising therapeutic target for the treatment of IBD. However, insufficient data and confusing results from previous studies have led to a failure to define a core microbiome associated with IBD and the hidden mechanism of pathogenesis, which suggests that well-designed randomized control trials and mouse models are required for further research. In addition, a better understanding of this ecosystem will also determine the role of prebiotics and probiotics as therapeutic agents in the management of IBD.

An introduction of the role of probiotics in human infections and autoimmune diseases

During the last decades, studies exploring the role of microorganisms inhabiting human body in different scenarios have demonstrated the great potential of modulating them to treat and prevent diseases. Among the most outstanding applications, probiotics have been used for over a century to treat infections and inflammation. Despite the beneficial role of other probiotics, Lactobacillus and Bifidobacterium species are the most frequently used, and have been effective as a therapeutic option in the treatment/prevention of dental caries, periodontal diseases, urogenital infections, and gastrointestinal infections. Additionally, as gastrointestinal tract harbors a great diversity of microbial species that directly or indirectly modulate host metabolism and immune response, the influence of intestinal microbiota, one of the targets of therapies using probiotics, on the biology of immune cells can be explored to treat inflammatory disorders or immune-mediated diseases. Thus, it is not surprising that probiotics have presented promising results in modulating human inflammatory diseases such as type 1 diabetes, multiple sclerosis, rheumatoid arthritis and inflammatory bowel disease, among others. Hence, the purpose of this review is to discuss the potential of therapeutic approaches using probiotics to constrain infection and development of inflammation on human subjects.

Efficacy and safety of probiotics in adults with ulcerative colitis: A meta-analysis of placebo-controlled trials

BACKGROUND

In clinical work, probiotics are often used to treat ulcerative colitis (UC). However, it is unclear how and at which stage probiotics play a role in the treatment of UC.

AIM

To evaluate the efficacy and safety of probiotics vs placebo in the treatment of UC.

METHODS

PubMed, EMBASE, Cochrane Library, WanFang Database, and the Chinese Biomedical Database were searched. Data were extracted and selected using strict criteria.

RESULTS

Fourteen randomized controlled trials (RCTs) involving a total of 869 participants to investigate the effects of probiotics (n = 465) vs placebo (n = 404) on UC were included, of which nine evaluated the remission rate, and five estimated the recurrence rate. Compared with the placebo group, the remission rate of UC patients who received probiotics was significantly better (relative risk = 1.36; 95%CI: 1.11-1.66, P = 0.002). When comparing the recurrence rate of UC between the probiotics and placebo groups, it was found that there was a significant heterogeneity (P = 0.09, I² = 72%). Subgroup analysis showed that probiotics alone were better than placebo (P = 0.004), while combined with others drugs, there was no significant between the probiotics and placebo groups (P = 0.95). Four RCTs compared the safety, which showed that there was no significant difference between the two groups (P = 0.86).

CONCLUSION

Probiotics have better effects in UC maintenance therapy than placebo. However, with regard to the recurrence rate of UC, probiotics alone have benefits in UC than placebo, while combined with other drugs, probiotics are not better than placebo.

Antibiotics and probiotics in inflammatory bowel disease: when to use them?

Antibiotics and probiotics are often used as adjunctive therapy in inflammatory bowel disease. However, data are limited and randomised controlled trials are too inconsistent to provide generalised recommendations for their use in all patients with ulcerative colitis or Crohn's disease. Antibiotics are best used in the management of infectious complications and fistulas in Crohn's disease and, perhaps, in reducing the intensity of inflammation in luminal disease. Ciprofloxacin, metronidazole and rifaximin have been most widely used and studied. On the other hand, there appears to be a limited role for antibiotics in ulcerative colitis (UC). Probiotics are most effective in pouchitis, and may have a role in the initial therapy and maintenance of remission in mild UC; the probiotic cocktail VSL#3 has been the most widely studied. There is scant evidence of efficacy for probiotics in Crohn's disease.

Microbe-metabolite-host axis, two-way action in the pathogenesis and treatment of human autoimmunity

The role of microorganism in human diseases cannot be ignored. These microorganisms have evolved together with humans and worked together with body's mechanism to maintain immune and metabolic function. Emerging evidence shows that gut microbe and their metabolites open up new doors for the study of human response mechanism. The complexity and interdependence of these microbe-metabolite-host interactions are rapidly being elucidated. There are various changes of microbial levels in models or in patients of various autoimmune diseases (AIDs). In addition, the relevant metabolites involved in mechanism mainly include short-chain fatty acids (SCFAs), bile acids (BAs), and polysaccharide A (PSA). Meanwhile, the interaction between microbes and host genes is also a factor that must be considered. It has been demonstrated that human microbes are involved in the development of a variety of AIDs, including organ-specific AIDs and systemic AIDs. At the same time, microbes or related products can be used to remodel body's response to alleviate or cure diseases. This review summarizes the latest research of microbes and their related metabolites in AIDs. More importantly, it highlights novel and potential therapeutics, including fecal microbial transplantation, probiotics, prebiotics, and synbiotics. Nonetheless, exact mechanisms still remain elusive, and future research will focus on finding a specific strain that can act as a biomarker of an autoimmune disease.

Complementary and Alternative Medicine Use in Children With Inflammatory Bowel Disease

Complementary and alternative medicine (CAM) consists of products and practices that are not considered to be a part of conventional medicine. This article reviews pediatric studies on CAM in inflammatory bowel disease (IBD) along with relevant adult studies. Prevalence of CAM use ranges from 22% to 84% in children with IBD all over the world. CAM use in IBD includes diet changes, supplements, herbals, botanicals, and mind-body therapies. Common reasons for using CAM include severe disease and concern for adverse effects of conventional medicines. Despite widespread use, there are limited studies on efficacy and safety of CAM in children. Small studies suggest a favorable evidence for use of probiotics, fish oil, marijuana, and mind-body therapy in IBD. Adverse effects of CAM are reported but are rare. The article provides current state of knowledge on the topic and provides guidance to physicians to address CAM use in pediatric patients with IBD.

The Efficacy of Probiotics, Prebiotic Inulin-Type Fructans, and Synbiotics in Human Ulcerative Colitis: A Systematic Review and Meta-Analysis

Studies of probiotics, fructan-type prebiotics, and synbiotics in patients with ulcerative colitis (UC) show significant heterogeneity in methodology and results. Here, we study the efficacy of such interventions and the reasons for the heterogeneity of their results. Eligible random controlled trials were collected from the PUBMED and SCOPUS databases. A total of 18 placebo-controlled and active treatment-controlled (i.e., mesalazine) studies were selected with a Jadad score ≥ 3, including 1491 patients with UC. Data for prebiotics and synbiotics were sparse and consequently these studies were excluded from the meta-analysis. The UC remission efficacy of probiotics was measured in terms of relative risk (RR) and odds ratio (OR). Significant effects were observed in patients with active UC whenever probiotics containing bifidobacteria were used, or when adopting the US Food and Drug Administration (FDA)-recommended scales (UC Disease Activity Index and Disease Activity Index). By the FDA recommended scales, the RR was 1.55 (CI95%: 1.13–2.15, p-value = 0.007, I² = 29%); for bifidobacteria-containing probiotics, the RR was 1.73 (CI95%: 1.23–2.43, p-value = 0.002, I² = 35%). No significant effects were observed on the maintenance of remission for placebo-controlled or mesalazine-controlled studies. We conclude that a validated scale is necessary to determine the state of patients with UC. However, probiotics containing bifidobacteria are promising for the treatment of active UC.

Microbial-Based Therapies in the Treatment of Inflammatory Bowel Disease - An Overview of Human Studies

Inflammatory bowel disease (IBD) is a group of multifactorial and inflammatory infirmities comprised of two main entities: Ulcerative colitis (UC) and Crohn’s disease (CD). Classic strategies to treat IBD are focused on decreasing inflammation besides inducing and extending disease remission. However, these approaches have several limitations such as low responsiveness, excessive immunosuppression, and refractoriness. Despite the multifactorial causality of IBD, immune disturbances and intestinal dysbiosis have been suggested as the central players in disease pathogenesis. Hence, therapies aiming at modulating intestinal microbial composition may represent a promising strategy in IBD control. Fecal microbiota transplantation (FMT) and probiotics have been explored as promising candidates to reestablish microbial balance in several immune-mediated diseases such as IBD. These microbial-based therapies have demonstrated the ability to reduce both the dysbiotic environment and production of inflammatory mediators, thus inducing remission, especially in UC. Despite these promising results, there is still no consensus on the relevance of such treatments in IBD as a potential clinical strategy. Thus, this review aims to critically review and describe the use of FMT and probiotics to treat patients with IBD.

Probiotics in the Treatment of Inflammatory Bowel Disease

While considerable progress has been made in the treatment of inflammatory bowel diseases (IBD), alternative options are constantly sought by adult patients as well as frustrated parents of young patients. These include dietary modifications, food supplements, and, more recently, probiotics.Their potential use is based on the demonstrated role of the altered mucosal immune response to bacterial agents that eventually leads to the chronic intestinal inflammation that characterized IBD. In fact, probiotics might conceivably be beneficial due to multiple mechanisms: stimulation of anti-inflammatory cytokines, inhibition of inflammatory cytokines, strengthening of intestinal barrier, and antagonistic action on pathogens. Such mechanisms have been largely extensively investigated in animal models both in vitro and in vivo.Despite such premise, a relatively scarce number of clinical trials are available, and of them only a handful in pediatric age. Overall, available evidence is very disappointing in the treatment of Crohn's disease (CD), where no recommendation for probiotic use can be made. In ulcerative colitis (UC), on the other hand, there is clinical evidence of efficacy for some specific strains and especially for multi-strain preparations.In summary, more data are needed very likely to yield a better understanding on what strains and in what doses should be used in different specific clinical settings.

Gut microbiota and pediatric obesity/non-alcoholic fatty liver disease

Huge amount microorganisms resides in human intestine, and many contribute to the maturation and homeostasis of immune system. The diversity of gut ecology are affected by the gestational age, delivery type, feeding sources, and antibiotics use in neonates. Recent studies pointed out that disturbance of gut microbiota, so called dysbiosis, could result in several pediatric diseases including obesity, non-alcoholic fatty liver disease (NAFLD), metabolic syndromes, allergic diseases, and inflammatory bowel diseases. However, there are no single species can be proven to play a key factor in pediatric obesity and NAFLD at present. Various probiotics may confer benefit to these gut microbiota-related pediatric diseases. The clinical application is still limited. This review article aimed to elucidate evidently the relationship between gut microbiota and pediatric obesity/NAFLD and to discuss the potential probiotics use in pediatric obesity and NAFLD.

Therapeutic Microbiology: The Role of Bifidobacterium breve as Food Supplement for the Prevention/Treatment of Paediatric Diseases

The human intestinal microbiota, establishing a symbiotic relationship with the host, plays a significant role for human health. It is also well known that a disease status is frequently characterized by a dysbiotic condition of the gut microbiota. A probiotic treatment can represent an alternative therapy for enteric disorders and human pathologies not apparently linked to the gastrointestinal tract. Among bifidobacteria, strains of the species Bifidobacterium breve are widely used in paediatrics. B. breve is the dominant species in the gut of breast-fed infants and it has also been isolated from human milk. It has antimicrobial activity against human pathogens, it does not possess transmissible antibiotic resistance traits, it is not cytotoxic and it has immuno-stimulating abilities. This review describes the applications of B. breve strains mainly for the prevention/treatment of paediatric pathologies. The target pathologies range from widespread gut diseases, including diarrhoea and infant colics, to celiac disease, obesity, allergic and neurological disorders. Moreover, B. breve strains are used for the prevention of side infections in preterm newborns and during antibiotic treatments or chemotherapy. With this documentation, we hope to increase knowledge on this species to boost the interest in the emerging discipline known as "therapeutic microbiology".

Probiotics in Pediatric Gastroenterology: Emerging Indications: Inflammatory Bowel Diseases

Etiology of inflammatory bowel disease (IBD) is not yet completely understood, but it is hypothesized that a disruption of the immune tolerance to gut microbiota, due to several potential factors like an abnormal gut microbiota composition and activity, may lead to IBD occurrence. Manipulation of the intestinal microbiota is an attractive target for the management of IBD, and probiotics could be useful to influence the disease's course. However, the existing literature on the usefulness of probiotics in IBD is relatively limited. At present, there is no evidence of efficacy for any bacterial strain in the induction or maintenance of remission in pediatric Crohn's disease, while there is limited evidence for the use of VSL#3 and Lactobacillus reuteri ATCC 55730, in addition to standard therapy, for the induction of remission in pediatric ulcerative colitis. Moreover, current data assessing the therapeutic efficacy of probiotics in IBD do not fulfill evidence-based standards, with long-term maintenance studies and larger prospective randomized controlled trials still lacking.

Toll-Like Receptor 7 Agonist-Induced Dermatitis Causes Severe Dextran Sulfate Sodium Colitis by Altering the Gut Microbiome and Immune Cells

BACKGROUND & AIMS

Psoriasis and inflammatory bowel disease (IBD) are both chronic inflammatory diseases occurring in the skin and gut, respectively. It is well established that psoriasis and IBD have high concordance rates, and similar changes in immune cells and microbiome composition have been reported in both conditions. To study this connection, we used a combination murine model of psoriatic dermatitis and colitis in which mice were treated topically with the Toll-like receptor 7 agonist imiquimod (IMQ) and fed dextran sulfate sodium (DSS).

METHODS

We applied IMQ topically to B6 mice (IMQ mice) and subsequently fed them 2% DSS in their drinking water. Disease activity and immune cell phenotypes were analyzed, and the microbial composition of fecal samples was investigated using 16S ribosomal RNA sequencing. We transplanted feces from IMQ mice to germ-free IQI/Jic (IQI) mice and fed them DSS to assess the effect of the gut microbiome on disease.

RESULTS

We first confirmed that IMQ mice showed accelerated DSS colitis. IMQ mice had decreased numbers of IgD⁺ and IgM⁺ B cells and increased numbers of non-cytokine-producing macrophages in the gut. Moreover, the gut microbiomes of IMQ mice were perturbed, with significant reductions of Lactobacillus johnsonii and Lactobacillus reuteri populations. Germ-free mice transplanted with feces from IMQ mice, but not with feces from untreated mice, also developed exacerbated DSS colitis.

CONCLUSIONS

These results suggest that skin inflammation may contribute to pathogenic conditions in the gut via immunologic and microbiological changes. Our finding of a novel potential skin-gut interaction provides new insights into the coincidence of psoriasis and IBD.

Management of Paediatric Ulcerative Colitis, Part 1: Ambulatory Care-An Evidence-based Guideline From European Crohn's and Colitis Organization and European Society of Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND

The contemporary management of ambulatory ulcerative colitis (UC) continues to be challenging with ∼20% of children needing a colectomy within childhood years. We thus aimed to standardize daily treatment of pediatric UC and inflammatory bowel diseases (IBD)-unclassified through detailed recommendations and practice points.

METHODS

These guidelines are a joint effort of the European Crohn's and Colitis Organization (ECCO) and the Paediatric IBD Porto group of European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). An extensive literature search with subsequent evidence appraisal using robust methodology was performed before 2 face-to-face meetings. All 40 included recommendations and 86 practice points were endorsed by 43 experts in Paediatric IBD with at least an 88% consensus rate.

RESULTS

These guidelines discuss how to optimize the use of mesalamine (including topical), systemic and locally active steroids, thiopurines and, for more severe disease, biologics. The use of other emerging therapies and the role of surgery are also covered. Algorithms are provided to aid therapeutic decision-making based on clinical assessment and the Paediatric UC Activity Index (PUCAI). Advice on contemporary therapeutic targets incorporating the use of calprotectin and the role of therapeutic drug monitoring are presented, as well as other management considerations around pouchitis, extraintestinal manifestations, nutrition, growth, psychology, and transition. A brief section on disease classification using the PIBD-classes criteria and IBD-unclassified is also part of these guidelines.

CONCLUSIONS

These guidelines provide a guide to clinicians managing children with UC and IBD-unclassified management to provide modern management strategies while maintaining vigilance around appropriate outcomes and safety issues.

Krill oil, vitamin D and Lactobacillus reuteri cooperate to reduce gut inflammation

Current research into original therapies to treat intestinal inflammation is focusing on no-drug therapies. KLD is a mixture of krill oil (KO), probiotic Lactobacillus reuteri (LR), and vitamin D (VitD3). The aim of this study was to assess in vitro and in vivo the potential cooperative effects of KLD in reducing gut inflammation. Colorectal adenocarcinoma cell lines, CACO2 and HT29, and C57BL/6 mice were used for in vitro and in vivo analyses, respectively. Cells were exposed to cytomix (interferon gamma + tumour necrosis factor alpha (TNF-α)) to induce inflammation or co-exposed to cytomix and KO, LR and VitD3 alone or to cytomix and KLD. Animals were treated for 7 days with dextran sodium sulphate (DSS) to induce colitis or with DSS and KLD. In vitro assays: F-actin expression was analysed by immunofluorescence; scratch test and trans-epithelial electric resistance test were performed to measure wound healing; adhesion/invasion assays of adhesive and invasive Escherichia coli (AIEC) bacteria were made; mRNA expression of TNF-α, interleukin (IL)-8 and vitamin D receptor (VDR) was detected by quantitative PCR. In vivo assays: body weight, clinical score, histological score and large intestine weight and length were estimated; mRNA expression of TNF-α, IL-1β, IL-6, IL-10 by quantitative PCR; VDR expression was detected by quantitative PCR and immunohistochemistry. In vitro: KLD restores epithelial cell-cell adhesion and mucosal healing during inflammation, while decreases the adhesiveness and invasiveness of AIEC bacteria and TNF-α and IL-8 mRNA expression and increases VDR expression. In vivo: KLD significantly improves body weight, clinical score, histological score and large intestine length of mice with DSS-induced colitis and reduces TNF-α, IL-1β and IL-6 mRNA levels, while increases IL-10 mRNA and VDR levels. KLD has significant effects on the intestinal mucosa, strongly decreasing inflammation, increasing epithelial restitution and reducing pathogenicity of harmful commensal bacteria.

Nutrition in Pediatric Inflammatory Bowel Disease: A Position Paper on Behalf of the Porto Inflammatory Bowel Disease Group of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND AND AIMS

A growing body of evidence supports the need for detailed attention to nutrition and diet in children with inflammatory bowel disease (IBD). We aimed to define the steps in instituting dietary or nutritional management in light of the current evidence and to offer a useful and practical guide to physicians and dieticians involved in the care of pediatric IBD patients.

METHODS

A group of 20 experts in pediatric IBD participated in an iterative consensus process including 2 face-to-face meetings, following an open call to Nutrition Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition Porto, IBD Interest, and Nutrition Committee. A list of 41 predefined questions was addressed by working subgroups based on a systematic review of the literature.

RESULTS

A total of 53 formal recommendations and 47 practice points were endorsed with a consensus rate of at least 80% on the following topics: nutritional assessment; macronutrients needs; trace elements, minerals, and vitamins; nutrition as a primary therapy of pediatric IBD; probiotics and prebiotics; specific dietary restrictions; and dietary compounds and the risk of IBD.

CONCLUSIONS

This position paper represents a useful guide to help the clinicians in the management of nutrition issues in children with IBD.

Allergic Proctocolitis Is a Risk Factor for Functional Gastrointestinal Disorders in Children

OBJECTIVE

To test the hypothesis that allergic proctocolitis, a cause of self-limiting rectal bleeding in infants, can predispose to the development of functional gastrointestinal disorders (FGIDs) later in childhood.

STUDY DESIGN

We studied a cohort of 80 consecutive patients diagnosed with allergic proctocolitis. Their sibling or matched children presenting to the same hospital for minor trauma served as controls. Parents of the patients with allergic proctocolitis and controls participated in a telephone interview every 12 months until the child was at least 4 years old. At that time, they were asked to complete the parental Questionnaire on Pediatric Gastrointestinal Symptoms, Rome III version.

RESULTS

Sixteen of the 160 subjects (10.0%) included in the study met the Rome III criteria for FGIDs. Among the 80 patients with allergic proctocolitis, 12 (15.0%) reported FGIDs, compared with 4 of 80 (5.0%) controls (P = .035). After adjustment for age and sex, the OR for FGIDs in allergic proctocolitis group was 4.39 (95% CI, 1.03-18.68). FGIDs were significantly associated with iron deficiency anemia, duration of hematochezia, and younger age at presentation. In a multivariate analysis, only the duration of hematochezia was significantly associated with the development of FGIDs (OR, 3.14; 95% CI,1.72-5.74).

CONCLUSIONS

We have identified allergic proctocolitis as a new risk factor for the development of FGIDs in children. Our data suggest that not only infection, but also a transient early-life allergic inflammatory trigger may induce persistent digestive symptoms, supporting the existence of "postinflammatory" FGIDs.

Relationship between intestinal microbiota and ulcerative colitis: Mechanisms and clinical application of probiotics and fecal microbiota transplantation

Ulcerative colitis (UC) is an inflammatory disease that mainly affects the colon and rectum. It is believed that genetic factors, host immune system disorders, intestinal microbiota dysbiosis, and environmental factors contribute to the pathogenesis of UC. However, studies on the role of intestinal microbiota in the pathogenesis of UC have been inconclusive. Studies have shown that probiotics improve intestinal mucosa barrier function and immune system function and promote secretion of anti-inflammatory factors, thereby inhibiting the growth of harmful bacteria in the intestine. Fecal microbiota transplantation (FMT) can reduce bowel permeability and thus the severity of disease by increasing the production of short-chain fatty acids, especially butyrate, which help maintain the integrity of the epithelial barrier. FMT can also restore immune dysbiosis by inhibiting Th1 differentiation, activity of T cells, leukocyte adhesion, and production of inflammatory factors. Probiotics and FMT are being increasingly used to treat UC, but their use is controversial because of uncertain efficacy. Here, we briefly review the role of intestinal microbiota in the pathogenesis and treatment of UC.

Use of Probiotics to Prevent Celiac Disease and IBD in Pediatrics

The incidence of chronic inflammatory diseases (CIDs) is increasing worldwide. Their dramatic rise associated with limited effective strategies to slow down these epidemics calls for a better understanding of their pathophysiology in order to decrease the burdens on childhood. Several cross-sectional studies have demonstrated the association between intestinal dysbiosis and active diseases. Although informative, these studies do not mechanistically link alterations of the microflora with disease pathogenesis and, therefore, with potential therapeutic targets. More prospective studies are needed to determine whether intestinal dysbiosis plays a causative role in the onset and development of CIDs. Furthermore, given the complexity of the microflora interaction with the host, it is necessary to design a systems-level model of interactions between the host and the development of disease by integrating microbiome, metagenomics, metatranscriptomics, and metabolomics with either clinical either environmental data.In this chapter we will discuss the current knowledge regarding the microbiome's contribution to celiac disease and inflammatory bowel disease with a particular focus on how probiotics may be used as potential preventive therapy for CIDs.

Probiotics in Inflammatory Bowel Disease

Evidence indicates that the gut microbiota and/or interactions between the microbiota and the host immune system are involved in the pathogenesis of inflammatory bowel disease (IBD). Strategies that target the microbiota have emerged as potential therapies and, of these, probiotics have gained the greatest attention. Data derived from animal models of IBD have revealed the potential of several bacterial strains to modify the natural history of IBD. However, thought there is some evidence for efficacy in ulcerative colitis and in pouchitis, in particular, there has been little indication that probiotics exert any benefit in Crohn disease. More targeted approaches involving live bacteria, genetically modified bacteria, and bacterial products are now being evaluated.

Interactions between Intestinal Microbiota and Host Immune Response in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract. Although the etiology and pathogenesis of IBD remain unclear, both genetic susceptibility and environmental factors are implicated in the initiation and progression of IBD. Recent studies with experimental animal models and clinical patients indicated that the intestinal microbiota is one of the critical environmental factors that influence nutrient metabolism, immune responses, and the health of the host in various intestinal diseases, including ulcerative colitis and Crohn’s disease. The objective of this review is to highlight the crosstalk between gut microbiota and host immune response and the contribution of this interaction to the pathogenesis of IBD. In addition, potential therapeutic strategies targeting the intestinal micro-ecosystem in IBD are discussed.

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.

Probiotics are a good choice in remission of inflammatory bowel diseases: A meta analysis and systematic review

Altered gut bacteria and bacterial metabolic pathways are two important factors in initiation and progression of inflammatory bowel disease (IBD). However, efficacy of probiotics in remission of patients with IBD has not been characterized. This study was performed on the studies that specifically assessed the efficacy of probiotics in attaining clinical response on patients with various types of IBD. The efficacy of variant species of probiotics in different conditions and the influence of study quality in outcomes of randomized controlled trials (RCTs) were also assessed. The RCTs were collected by searching in MEDLINE Web of Science and Google scholar. Then all studies were abstracted in abstraction form and the outcomes were analyzed with fixed-effect and mixed-effect models for assessment of efficacy of variant species of probiotics in subgroups of IBDs. Analysis of 9 trials showed that probiotics had not significant effect on Crohn's disease (CD) (p = 0.07) but analysis of 3 trials in children with IBD revealed a significant advantage (p < 0.01). Analysis of 18 trials revealed that probiotics in patients with Ulcerative colitis (UC) in different conditions have significant effects (p = 0.007). VSL#3 probiotics in patients with UC had significant effect (p < 0.01). Combination of Lactobacillus probiotic, prebiotics had significant effect (p = 0.03) only in patients with UC. Combination of Saccharomyces boulardii, Lactobacillus, and VSL#3 probiotics in CD had also a trend for efficiency (p = 0.057). In children with IBD, the combination of Lactobacillus with VSL#3 probiotics had significant effect (p < 0.01). Probiotics are beneficial in IBD, especially the combination ones in UC.

Clinical Evidence for the Microbiome in Inflammatory Diseases

Clinical evidence is accumulating for a role of the microbiome in contributing to or modulating severity of inflammatory diseases. These studies can be organized by various organ systems involved, as well as type of study approach utilized, whether investigators compared the microbiome of cases versus controls, followed patients longitudinally, or intervened with antibiotics, prebiotics, or bacterial introduction. In this review, we summarize the clinical evidence supporting the microbiome as an important mechanism in the onset and maintenance of inflammation.

Applications of Genetically Modified Immunobiotics with High Immunoregulatory Capacity for Treatment of Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs), including ulcerative colitis and Crohn’s disease, are chronic inflammatory diseases characterized by dysregulated immune responses of the gastrointestinal tract. In recent years, the incidence of IBDs has increased in developed nations, but their prophylaxis/treatment is not yet established. Site-directed delivery of molecules showing anti-inflammatory properties using genetically modified (gm)-probiotics shows promise as a new strategy for the prevention and treatment of IBD. Advantages of gm-probiotics include (1) the ability to use bacteria as a delivery vehicle, enabling safe and long-term use by humans, (2) decreased risks of side effects, and (3) reduced costs. The intestinal delivery of anti-inflammatory proteins such as cytokines and enzymes using Lactococcus lactis has been shown to regulate host intestinal homeostasis depending on the delivered protein-specific machinery. Additionally, clinical experience using interleukin 10-secreting Lc. lactis has been shown to be safe and to facilitate biological containment in IBD therapy. On the other hand, some preclinical studies have demonstrated that gm-strains of immunobiotics (probiotic strains able to beneficially regulate the mucosal immunity) provide beneficial effects on intestinal inflammation as a result of the synergy between the immunoregulatory effects of the bacterium itself and the anti-inflammatory effects of the delivered recombinant proteins. In this review, we discuss the rapid progression in the development of strategies for the prophylaxis and treatment of IBD using gm-probiotics that exhibit immune regulation effects (gm-immunobiotics). In particular, we discuss the type of strains used as delivery agents.

ESPEN guideline: Clinical nutrition in inflammatory bowel disease

INTRODUCTION

The ESPEN guideline presents a multidisciplinary focus on clinical nutrition in inflammatory bowel disease (IBD).

METHODOLOGY

The guideline is based on extensive systematic review of the literature, but relies on expert opinion when objective data were lacking or inconclusive. The conclusions and 64 recommendations have been subject to full peer review and a Delphi process in which uniformly positive responses (agree or strongly agree) were required.

RESULTS

IBD is increasingly common and potential dietary factors in its aetiology are briefly reviewed. Malnutrition is highly prevalent in IBD - especially in Crohn's disease. Increased energy and protein requirements are observed in some patients. The management of malnutrition in IBD is considered within the general context of support for malnourished patients. Treatment of iron deficiency (parenterally if necessary) is strongly recommended. Routine provision of a special diet in IBD is not however supported. Parenteral nutrition is indicated only when enteral nutrition has failed or is impossible. The recommended perioperative management of patients with IBD undergoing surgery accords with general ESPEN guidance for patients having abdominal surgery. Probiotics may be helpful in UC but not Crohn's disease. Primary therapy using nutrition to treat IBD is not supported in ulcerative colitis, but is moderately well supported in Crohn's disease, especially in children where the adverse consequences of steroid therapy are proportionally greater. However, exclusion diets are generally not recommended and there is little evidence to support any particular formula feed when nutritional regimens are constructed.

CONCLUSIONS

Available objective data to guide nutritional support and primary nutritional therapy in IBD are presented as 64 recommendations, of which 9 are very strong recommendations (grade A), 22 are strong recommendations (grade B) and 12 are based only on sparse evidence (grade 0); 21 recommendations are good practice points (GPP).

Involvement of Reduced Microbial Diversity in Inflammatory Bowel Disease

A considerable number of studies have been conducted to study the microbial profiles in inflammatory conditions. A common phenomenon in inflammatory bowel disease (IBD) is the reduction of the diversity of microbiota, which demonstrates that microbial diversity negatively correlates with disease severity in IBD. Increased microbial diversity is known to occur in disease remission. Species diversity plays an important role in maintaining the stability of the intestinal ecosystem as well as normal ecological function. A reduction in microbial diversity corresponds to a decrease in the stability of the ecosystem and can impair ecological function. Fecal microbiota transplantation (FMT), probiotics, and prebiotics, which aim to modulate the microbiota and restore its normal diversity, have been shown to be clinically efficacious. In this study, we hypothesized that a reduction in microbial diversity could play a role in the development of IBD.

Therapeutic modulation of gut microbiota in inflammatory bowel disease: More questions to be answered

Patients with inflammatory bowel disease (IBD) exhibit impaired control of the microbiome in the gut, and 'dysbiosis' is commonly observed. Western diet is a risk factor for the development of IBD, but it may have different effects on gut microbiota between IBD and non-IBD individuals. Exclusive enteral nutrition (EEN) can induce remission in pediatric Crohn's disease with a decrease in gut microbial diversity. Although there are some theoretical benefits, actual treatment effects of prebiotics and probiotics in IBD vary. High-quality studies have shown that VSL#3 (a high-potency probiotic medical food containing eight different strains) exhibits benefits in treating ulcerative colitis, and gut microbial diversity is reduced after treated with VSL#3 in animal models. The effect of fecal microbiome transplantation on IBD is controversial. Increasing microbial diversity compared with impaired handling of bacteria presents a dilemma. Antibiotics are the strongest factors in the reduction of microbiome ecological diversity. Some antibiotics may help to induce remission of the disease. Microbiome alteration has been suggested to be an intrinsic property of IBD and a potential predictor in diagnosis and prognosis. However, the effects of therapeutic modulations are variable; thus, more questions remain to be answered.

Genetic and Metabolic Signals during Acute Enteric Bacterial Infection Alter the Microbiota and Drive Progression to Chronic Inflammatory Disease

Chronic inflammatory disorders are thought to arise due to an interplay between predisposing host genetics and environmental factors. For example, the onset of inflammatory bowel disease is associated with enteric proteobacterial infection, yet the mechanistic basis for this association is unclear. We have shown previously that genetic defiency in TLR1 promotes acute enteric infection by the proteobacteria Yersinia enterocolitica. Examining that model further, we uncovered an altered cellular immune response that promotes the recruitment of neutrophils which in turn increases metabolism of the respiratory electron acceptor tetrathionate by Yersinia. These events drive permanent alterations in anti-commensal immunity, microbiota composition, and chronic inflammation, which persist long after Yersinia clearence. Deletion of the bacterial genes involved in tetrathionate respiration or treatment using targeted probiotics could prevent microbiota alterations and inflammation. Thus, acute infection can drive long term immune and microbiota alterations leading to chronic inflammatory disease in genetically predisposed individuals.

Microbes and Oxytocin: Benefits for Host Physiology and Behavior

It is now understood that gut bacteria exert effects beyond the local boundaries of the gastrointestinal tract to include distant tissues and overall health. Prototype probiotic bacterium Lactobacillus reuteri has been found to upregulate hormone oxytocin and systemic immune responses to achieve a wide array of health benefits involving wound healing, mental health, metabolism, and myoskeletal maintenance. Together these display that the gut microbiome and host animal interact via immune-endocrine-brain signaling networks. Such findings provide novel therapeutic strategies to stimulate powerful homeostatic pathways and genetic programs, stemming from the coevolution of mammals and their microbiome.

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

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

Comparison of maintenance effect of probiotics and aminosalicylates on ulcerative colitis: A meta-analysis of randomized controlled trials

Objective

To evaluate the maintenance effect of probiotics versus that of aminosalicylates on ulcerative colitis.

Methods

MEDLINE, EMBASE, the Cochrane Controlled Trials Register, and the Chinese Biomedical Database were searched in English or Chinese. Data extracted were selected with strict criteria.

Results

In six randomized controlled trials (RCTs), a total of 721 participants were enrolled and the maintenance effect of probiotics (n = 364) versus that of aminosalicylates (n = 357) on ulcerative colitis was investigated. No significant difference was observed between probiotics and aminosalicylate groups (relative risk (RR) = 1.08; 95% confidence interval (CI): 0.91–1.28; P = 0.40). Three RCTs compared the incidence of adverse events with probiotics versus those with aminosalicylates. No significant difference was observed in the incidence of adverse events between the two groups (RR = 1.20; 95% CI: 0.92–1.56; P = 0.17).

Conclusions

Probiotics and aminosalicylates both showed a maintenance effect on ulcerative colitis. However, more well-designed RCTs are required.

Probiotics for prevention and treatment of respiratory tract infections in children: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Respiratory tract infections (RTIs) represent one of the main health problems in children. Probiotics are viable bacteria that colonize the intestine and affect the host intestinal microbial balance. Accumulating evidence suggests that probiotic consumption may decrease the incidence of or modify RTIs. The authors systematically reviewed data from randomized controlled trials (RCTs) to investigate the effect of probiotic consumption on RTIs in children.

METHODS

MEDLINE/PubMed, Embase, Cochrane Library, and Web of Science were systematically searched for RCTs regarding the effect of probiotics on RTIs in children. The outcomes included number of children experienced with at least 1 RTI episode, duration of illness episodes, days of illness per subject, and school/day care absenteeism due to infection. A random-effects model was used to calculate pooled relative risks, or mean difference (MD) with the corresponding 95% confidence interval (CI).

RESULTS

A total of 23 trials involving 6269 children were eligible for inclusion in the systematic review. None of the trials showed a high risk of bias. The quality of the evidence of outcomes was moderate. The age range of subjects was from newborn to 18 years. The results of meta-analysis showed that probiotic consumption significantly decreased the number of subjects having at least 1 RTI episode (17 RCTs, 4513 children, relative risk 0.89, 95% CI 0.82-0.96, P = 0.004). Children supplemented with probiotics had fewer numbers of days of RTIs per person compared with children who had taken a placebo (6 RCTs, 2067 children, MD -0.16, 95% CI -0.29 to 0.02, P = 0.03), and had fewer numbers of days absent from day care/school (8 RCTs, 1499 children, MD -0.94, 95% CI -1.72 to -0.15, P = 0.02). However, there was no statistically significant difference of illness episode duration between probiotic intervention group and placebo group (9 RCTs, 2817 children, MD -0.60, 95% CI -1.49 to 0.30, P = 0.19).

CONCLUSION

Based on the available data and taking into account the safety profile of RCTs, probiotic consumption appears to be a feasible way to decrease the incidence of RTIs in children.

Fecal Microbiota Transplantation for Ulcerative Colitis: A Systematic Review and Meta-Analysis

Background

Fecal microbiota transplantation (FMT) has been recognized as a novel treatment for ulcerative colitis (UC). However, its efficacy and safety remain unclear.

Objective

We conducted this systematic review to assess the efficacy and safety of FMT in UC.

Data Sources

PubMed, EMBASE, Cochrane Central, Web of Science Core Collection, and three other Chinese databases were searched for reports of FMT in UC with clear outcomes.

Data Extraction and Synthesis

We estimated pooled rates [with 95% confidence interval (CI)] of clinical remission among 15 cohort studies and clinical response among 16 cohort studies.

Results

Twenty five studies (2 randomized controlled trials, 15 cohort studies, and 8 case studies) with 234 UC patients were included. Overall, 41.58% (84/202) patients achieved clinical remission (CR) and 65.28% (126/193) achieved clinical response. Among the cohort studies, the pooled estimate of patients who achieved CR and clinical response were 40.5% (95% CI 24.7%-58.7%), and 66.1% (95% CI 43.7%-83.0%). Most adverse events were slight and self-resolving. The analyses of gut microbiota in 7 studies showed that FMT could increase microbiota diversity and richness, similarity, and certain change of bacterial composition.

Conclusion

FMT provides a promising effect for UC with few adverse events. Successful FMT may be associated with an increase in microbiota diversity and richness, similarity, and certain change of bacterial composition.

Modulating Composition and Metabolic Activity of the Gut Microbiota in IBD Patients

The healthy intestine represents a remarkable interface where sterile host tissues come in contact with gut microbiota, in a balanced state of homeostasis. The imbalance of gut homeostasis is associated with the onset of many severe pathological conditions, such as inflammatory bowel disease (IBD), a chronic gastrointestinal disorder increasing in incidence and severely influencing affected individuals. Despite the recent development of next generation sequencing and bioinformatics, the current scientific knowledge of specific triggers and diagnostic markers to improve interventional approaches in IBD is still scarce. In this review we present and discuss currently available and emerging therapeutic options in modulating composition and metabolic activity of gut microbiota in patients affected by IBD. Therapeutic approaches at the microbiota level, such as dietary interventions alone or with probiotics, prebiotics and synbiotics, administration of antibiotics, performing fecal microbiota transplantation (FMT) and the use of nematodes, all represent a promising opportunities towards establishing and maintaining of well-being as well as improving underlying IBD symptoms.

Lactobacillus acidophilus stimulates intestinal P-glycoprotein expression via a c-Fos/c-Jun-dependent mechanism in intestinal epithelial cells

Our previous studies showed that Lactobacillus acidophilus (LA) culture supernatant (CS) increased P-glycoprotein [Pgp/multidrug resistance 1 (MDR1)] function, expression, and promoter activity in Caco-2 cells. The current studies were designed to elucidate the molecular mechanisms mediating the stimulatory effects of LA CS on Pgp promoter activity. Deletion analysis indicated that the LA CS response element(s) is located in the -172/+428-bp region, and sequence analysis of this region revealed three potential binding sites for c-Fos or c-Jun: proximal activating protein (AP) 1a (-119/-98 bp), distal AP1b (-99/-78 bp), and AP1c (+175/+196 bp). LA CS (24 h) showed an approximately twofold increase in the protein expression of c-Fos and c-Jun in Caco-2 cells. Electrophoretic mobility shift assay showed that LA CS markedly increased the binding of Caco-2 nuclear proteins to AP1a and AP1b, but not AP1c. The DNA-protein complex was completely eliminated by c-Fos antibody, while c-Jun antibody partially eliminated the complex. Chromatin immunoprecipitation analysis also showed that LA CS enhanced the association of c-Fos and c-Jun (by ∼4- and 1.5-fold, respectively) with endogenous Pgp promoter in Caco-2 cells (p-172/+1). Interestingly, overexpression of c-Fos or c-Jun activated Pgp promoter by nearly twofold each. This increase was further enhanced (∼14-fold) when c-Fos and c-Jun were simultaneously overexpressed, suggesting that the presence of one of these transcription factors potentiates the effect of the other. These studies, for the first time, provide evidence for the involvement of c-Fos/c-Jun in stimulation of Pgp gene expression by LA CS in the human intestine.

Different Effects of Three Selected Lactobacillus Strains in Dextran Sulfate Sodium-Induced Colitis in BALB/c Mice

Aim

To analyze the changes of different Lactobacillus species in ulcerative colitis patients and to further assess the therapeutic effects of selected Lactobacillus strains on dextran sulfate sodium (DSS)-induced experimental colitis in BALB/c mice.

Methods

Forty-five active ulcerative colitis (UC) patients and 45 population-based healthy controls were enrolled. Polymerase chain reaction (PCR) amplification and real-time PCR were performed for qualitative and quantitative analyses, respectively, of the Lactobacillus species in UC patients. Three Lactobacillus strains from three species were selected to assess the therapeutic effects on experimental colitis. Sixty 8-week-old BALB/c mice were divided into six groups. The five groups that had received DSS were administered normal saline, mesalazine, L. fermentum CCTCC M206110 strain, L. crispatus CCTCC M206119 strain, or L. plantarum NCIMB8826 strain. We assessed the severity of colitis based on disease activity index (DAI), body weight loss, colon length, and histologic damage.

Results

The detection rate of four of the 11 Lactobacillus species decreased significantly (P < 0.05), and the detection rate of two of the 11 Lactobacillus species increased significantly (P < 0.05) in UC patients. Relative quantitative analysis revealed that eight Lactobacillus species declined significantly in UC patients (P < 0.05), while three Lactobacillus species increased significantly (P < 0.05). The CCTCC M206110 treatment group had less weight loss and colon length shortening, lower DAI scores, and lower histologic scores (P < 0.05), while the CCTCC M206119 treatment group had greater weight loss and colon length shortening, higher histologic scores, and more severe inflammatory infiltration (P < 0.05). NCIMB8826 improved weight loss and colon length shortening (P < 0.05) with no significant influence on DAI and histologic damage in the colitis model.

Conclusions

Administration of an L. crispatus CCTCC M206119 supplement aggravated DSS-induced colitis. L. fermentum CCTCC M206110 proved to be effective at attenuating DSS-induced colitis. The potential probiotic effect of L. plantarum NCIMB8826 on UC has yet to be assessed.

Probiotics and prebiotics in ulcerative colitis

The intestinal microbiota is one of the key players in the etiology of ulcerative colitis. Manipulation of this microflora with probiotics and prebiotics is an attractive strategy in the management of ulcerative colitis. Several intervention studies for both the induction and maintenance of remission in ulcerative colitis patients have been performed. Most of these studies evaluated VSL#3 or E. Coli Nissle 1917 and in general there is evidence for efficacy of these agents for induction and maintenance of remission. However, studies are frequently underpowered, lack a control group, and are very heterogeneous investigating different probiotic strains in different study populations. The absence of well-powered robust randomized placebo-controlled trials impedes the widespread use of probiotics and prebiotics in ulcerative colitis. However, given the promising results that are currently available, probiotics and prebiotics may find their way to the treatment algorithm for ulcerative colitis in the near future.

Microbiota in Inflammatory Bowel Disease Pathogenesis and Therapy: Is It All About Diet?

Inflammatory bowel disease (IBD), including ulcerative colitis, Crohn's disease, and unclassified IBD, continues to cause significant morbidity. While its incidence is increasing, no clear etiology and no cure have yet been discovered. Recent findings suggest that IBD may have a multifactorial etiology, where complex interactions between genetics, epigenetics, environmental factors (including diet but also infections, antibiotics, and sanitation), and host immune system lead to abnormal immune responses and chronic inflammation. Over the past years, the role of altered gut microbiota (in both composition and function) in IBD pathogenesis has emerged as an outstanding area of interest. According to new findings, gut dysbiosis may appear as a key element in initiation of inflammation in IBD and its complications. Moreover, complex metagenomic studies provide possibilities to distinguish between IBD types and appreciate severity and prognosis of the disease, as well as response to therapy. This review provides an updated knowledge of recent findings linking altered bacterial composition and functions, viruses, and fungi to IBD pathogenesis. It also highlights the complex genetic, epigenetic, immune, and microbial interactions in relation to environmental factors (including diet). We overview the actual options to manipulate the altered microbiota, such as modified diet, probiotics, prebiotics, synbiotics, antibiotics, and fecal transplantation. Future possible therapies are also included. Targeting altered microbiota could be the next therapeutic personalized approach, but more research and well-designed comparative prospective studies are required to formulate adequate directions for prevention and therapy.

Probiotics in the Management of Ulcerative Colitis

Rapid progress has been made to understand the pathophysiology of inflammatory bowel diseases and to identify new treatments. Interaction of the gut microbiota on the host inflammatory response has suggested that alternative therapies, such as probiotics, might have a complementary role in treating and preventing disease flares. Multiple probiotics and their formulations have been studied for both the induction and maintenance of remission of ulcerative colitis (UC); however, mainly Escherichia coli Nissle 1917 and VSL#3 have been shown to provide significant benefits for the prevention and treatment of mild to moderate UC. Although these data are promising, there is still a paucity of robust, randomized-controlled trials to suggest that probiotics be utilized as part of a standard treatment regimen. With continued research and a movement toward carefully selected, individualized management based on an individual's specific microbiota composition and function, probiotics may become an integral part of tailored therapy for UC.

Targeting the Microbiome in Inflammatory Bowel Disease: Critical Evaluation of Current Concepts and Moving to New Horizons

Microorganisms present in the intestine possess proinflammatory or anti-inflammatory activities which may modulate inflammatory bowel disease (IBD). The concepts followed by researchers in trying to target the microbiota in IBD were to decrease pathogens or pathobionts, or only the microbial load, and more recently, to favor growth and persistence of favorable microorganisms. We review, here, those concepts and critically analyze the clinical data (especially randomized controlled trials) obtained using antibiotics and probiotics. We eventually present and criticize the rational and data obtained so far following new research strategies including the use of new probiotics, genetically modified organisms and fecal transplantation.

Effect of Thalidomide on Clinical Remission in Children and Adolescents with Ulcerative Colitis Refractory to Other Immunosuppressives: Pilot Randomized Clinical Trial

BACKGROUND

In a randomized controlled trial, thalidomide has shown to be effective in refractory Crohn's disease in children. This pilot study aimed at evaluating thalidomide in refractory pediatric ulcerative colitis (UC).

METHODS

Double-blind, placebo-controlled randomized clinical trial on thalidomide 1.5 to 2.5 mg/kg/day in children with active UC despite multiple immunosuppressive treatments. In an open-label extension, nonresponders to placebo received thalidomide for an additional 8 weeks; all responders were followed up for a minimum of 52 weeks.

RESULTS

Twenty-six children with refractory UC were randomized to thalidomide or placebo. Clinical remission at week 8 was achieved by significantly more children treated with thalidomide {10/12 (83.3%) versus 2/11 (18.8%); risk ratio, 4.5 (95% confidence interval [CI], 1.2-16.4); P = 0.005; number needed to treat, 1.5}. Of the nonresponders to placebo who were switched to thalidomide, 8 of 11 (72.7%) subsequently reached remission at week 8 (risk ratio, 4.0 [95% CI, 1.1-14.7]; number needed to treat, 2.45; P = 0.01). Clinical remission in the thalidomide group was 135.0 weeks (95% CI, 32-238), compared with 8.0 weeks (95% CI, 2.4-13.6) in the placebo group (P < 0.0001). Cumulative incidence of severe adverse events was 3.1 per 1000 patient-weeks. Peripheral neuropathy and amenorrhea were the most frequent adverse events.

CONCLUSIONS

In this pilot randomized controlled trial on cases of UC refractory to immunosuppressive therapy, thalidomide compared with placebo resulted in improved clinical remission at 8 weeks of treatment and in longer term maintenance of remission. These findings require replication in larger clinical studies evaluating both thalidomide efficacy and safety.

The hygiene hypothesis: current perspectives and future therapies

Developed countries have experienced a steady increase in atopic disease and disorders of immune dysregulation since the 1980s. This increase parallels a decrease in infectious diseases within the same time period, while developing countries seem to exhibit the opposite effect, with less immune dysregulation and a higher prevalence of infectious disease. The “hygiene hypothesis”, proposed by Strachan in 1989, aimed to explain this peculiar generational rise in immune dysregulation. However, research over the past 10 years provides evidence connecting the commensal and symbiotic microbes (intestinal microbiota) and parasitic helminths with immune development, expanding the hygiene hypothesis into the “microflora” and “old friends” hypotheses, respectively. There is evidence that parasitic helminths and commensal microbial organisms co-evolved with the human immune system and that these organisms are vital in promoting normal immune development. Current research supports the potential for manipulation of the bacterial intestinal microbiota to treat and even prevent immune dysregulation in the form of atopic disease and other immune-mediated disorders (namely inflammatory bowel disease and type 1 diabetes). Both human and animal model research are crucial in understanding the mechanistic links between these intestinal microbes and helminth parasites, and the human immune system. Pro-, pre-, and synbiotic, as well as treatment with live helminth and excretory/secretory helminth product therapies, are all potential therapeutic options for the treatment and prevention of these diseases. In the future, therapeutics aimed at decreasing the prevalence of inflammatory bowel disease, type 1 diabetes, and atopic disorders will likely involve personalized microbiota and/or helminth treatments used early in life.

Delivery of a mucin domain enriched in cysteine residues strengthens the intestinal mucous barrier

A weakening of the gut mucous barrier permits an increase in the access of intestinal luminal contents to the epithelial cells, which will trigger the inflammatory response. In inflammatory bowel diseases, there is an inappropriate and ongoing activation of the immune system, possibly because the intestinal mucus is less protective against the endogenous microflora. General strategies aimed at improving the protection of the intestinal epithelium are still missing. We generated a transgenic mouse that secreted a molecule consisting of 12 consecutive copies of a mucin domain into its intestinal mucus, which is believed to modify the mucus layer by establishing reversible interactions. We showed that the mucus gel was more robust and that mucin O-glycosylation was altered. Notably, the gut epithelium of transgenic mice housed a greater abundance of beneficial Lactobacillus spp. These modifications were associated with a reduced susceptibility of transgenic mice to chemically induced colitis. Furthermore, transgenic mice cleared faster Citrobacter rodentium bacteria which were orally given and mice were more protected against bacterial translocation induced by gavage with adherent–invasive Escherichia coli. Our data show that delivering the mucin CYS domain into the gut lumen strengthens the intestinal mucus blanket which is impaired in inflammatory bowel diseases.

Safety of probiotics and synbiotics in children under 18 years of age

This study aimed to systematically evaluate safety of probiotics and synbiotics in children ageing 0-18 years. This study is the third and final part in a safety trilogy and an update is provided using the most recent available clinical data (2008-2013) by means of the Common Terminology Clinical Adverse Events (CTCAE version 4.0) classification. Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. Analysis of 74 clinical studies indicated that probiotic and/or synbiotic administration in children is safe with regard to the specific evaluated strains, dosages and duration. The population of children include healthy, immune compromised and obese subjects, as well as subjects with intestinal disorders, infections and inflammatory disorders. This study revealed no major safety concerns, as the adverse events (AEs) were unrelated, or not suspected to be related, to the probiotic or synbiotic product. In general the study products were well tolerated. Overall, AEs occurred more frequent in the control arm compared to children receiving probiotics and/or synbiotics. Furthermore, the results indicate inadequate reporting and classification of AEs in the majority of the studies. In addition, generalizability of conclusions are greatly limited by the inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes.

Ablation of tumor necrosis factor is associated with decreased inflammation and alterations of the microbiota in a mouse model of inflammatory bowel disease

Inflammatory bowel disease (IBD) is associated with prolonged, excess secretions of Tumor Necrosis Factor (TNF). Many patients with IBD have successful management of IBD symptoms by blocking TNF secretion or signaling. However, some patients are non-responsive to this therapy, eventually become refractory to therapy, or may develop harmful side-effects [corrected]. Alterations in the microbiota that are associated with the lack of TNF could be a contributing cause of this therapeutic insufficiency seen in some patients. Here we use wildtype (WT) and mice lacking Tnf (Tnf-/-) in an acute TNBS colitis model to investigate the role of TNF in colitis and how its presence or absence affects the colonic microbiota. As expected, Tnf-/- had less severe inflammation than WT mice. Microbiome analysis revealed significant Tnf dependent-differences in alpha and beta diversity. There were also notable differences in many species that were also primarily Tnf dependent. Taken together, our data indicates that TNF contributes significantly to the inflammation and microbiotal alterations in that occur in IBD.

The role of probiotic lactic acid bacteria and bifidobacteria in the prevention and treatment of inflammatory bowel disease and other related diseases: a systematic review of randomized human clinical trials

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammation of the small intestine and colon caused by a dysregulated immune response to host intestinal microbiota in genetically susceptible subjects. A number of fermented dairy products contain lactic acid bacteria (LAB) and bifidobacteria, some of which have been characterized as probiotics that can modify the gut microbiota and may be beneficial for the treatment and the prevention of IBD. The objective of this review was to carry out a systematic search of LAB and bifidobacteria probiotics and IBD, using the PubMed and Scopus databases, defined by a specific equation using MeSH terms and limited to human clinical trials. The use of probiotics and/or synbiotics has positive effects in the treatment and maintenance of UC, whereas in CD clear effectiveness has only been shown for synbiotics. Furthermore, in other associated IBD pathologies, such as pouchitis and cholangitis, LAB and bifidobacteria probiotics can provide a benefit through the improvement of clinical symptoms. However, more studies are needed to understand their mechanisms of action and in this way to understand the effect of probiotics prior to their use as coadjuvants in the therapy and prevention of IBD conditions.