Probiotics in the treatment of human inflammatory bowel diseases: update 2011

Specific probiotics or 'fecal transplantation'

The intestinal ecosystem consists mainly of the enteric flora and to a large extent determines intestinal but also extraintestinal health and disease. General alterations and specific molecular changes of intestinal bacteria cause local as well as systemic immune reactions. Nonantibiotic treatment of the enteric flora has a long tradition and spans a range of different interventions from nutrition to specific probiotics and complete fecal transplantation. When comparing therapy to specific probiotics and fecal transplantation, several aspects need to be considered, like biological consequences, safety and therapeutic evidence. The introduction of probiotics into therapy occurred more than hundred years ago. In contrast, experiences with fecal transplantation are more recent and more limited. Safety issues have not been definitively clarified. Because of the different biological activities of probiotics and fecal transplantation, it can be hypothesized that they may play different roles in the treatment of various diseases. More research is needed before the details, safety and therapeutic effects of bacteriotherapy for IBD become sufficiently clear.

Probiotic prophylaxis after pullthrough for Hirschsprung disease to reduce incidence of enterocolitis: a prospective, randomized, double-blind, placebo-controlled, multicenter trial

OBJECTIVE

Hirschsprung-associated enterocolitis (HAEC) is one of the most troublesome problems encountered after a pullthrough. We hypothesized that prophylactic administration of probiotics after a pullthrough procedure would decrease the incidence of HAEC.

STUDY DESIGN

A prospective, double-blind, placebo-controlled, randomized trial was conducted at 2 children's hospitals. Infants undergoing pullthrough were randomized to probiotic or placebo for a period of 3 months post-pullthrough. Primary outcome was incidence of post-operative HAEC. Other outcomes included severity of HAEC by clinical grade, number of HAEC episodes and extent of aganglionosis. Pearson Chi Square analysis, as well as logistic regression, was used for statistical analysis.

RESULTS

Sixty-two patients were recruited (Sites: A=40; B=22). One was lost to follow up and one immediate post-op death was not included in final analysis. Probiotics were administered to 32 patients. Distribution of placebo/probiotics was equal between sites (P=0.858). Mean age at pullthrough was 6.5 ± 8.1(± SD) months. The incidence of HAEC was 28.3%. The incidence of HAEC was not statistically different between probiotic and placebo study groups.

CONCLUSIONS

Incidence of HAEC was not reduced with prophylactic probiotics. Future studies are needed to better determine the etiology and possible ways of preventing this complex condition.

'Someone should oversee it': patient perspectives on the ethical issues arising with the regulation of probiotics

BACKGROUND

Although many probiotic products are currently available in yogurt or pill form in the United States (US), there is uncertainty surrounding the structure of regulation of these products. As more therapeutic probiotics are developed, changes to existing regulatory process in the United States may be required to meet the needs of patients and users in the population.

OBJECTIVE

This study examined how patients with chronic gastrointestinal (GI) diseases view the regulation of probiotics.

DESIGN

We conducted a multi-site qualitative study consisting of focus groups of patients with chronic gastrointestinal diseases at three tertiary hospitals: at [institutions removed for blinded review].

RESULTS

We conducted 22 focus groups with 136 patients with major gastrointestinal (GI) diseases between March and August 2009. Participants were not familiar with the existing regulation of probiotic products but wanted assurances of accurate labelling of strain as well as safety. Participants raised concerns that regulation of probiotics might be accompanied by greater costs, reduced access and increased involvement of pharmaceutical companies. Although participants voiced significant doubt of government regulators, they felt that products containing genetically modified probiotic strains should have oversight comparable to that of pharmaceutical drugs.

DISCUSSION AND CONCLUSION

If GI patient perspectives are indicative of public perceptions of therapeutic probiotics in the United States, consumers may expect more rigorous regulation in the future while simultaneously wanting low costs, easy access and low involvement of pharmaceutical companies. Manufacturers, translational scientists, clinicians and regulators should be sensitive to consumer attitudes when designing, testing and regulating new therapeutic probiotics.

Prebiotics, probiotics and digestive health

PURPOSE OF REVIEW

The human gastrointestinal lumen is inhabited by a wide variety of microbiota. Our understanding of the intestinal microbiota and its full consequences on gastrointestinal health is still evolving. However, it is well accepted that altered colonic flora drives the pathogenesis of many disorders and diseases as seen in antibiotic-associated diarrhea and Clostridium difficile infection. Recent works published in the area of probiotics are reviewed here.

RECENT FINDINGS

Alterations in colonic microbiota, or dysbiosis, are now implicated in irritable bowel syndrome and inflammatory bowel diseases. Probiotics and prebiotics are evolving treatment options that are targeted at restoring nonpathogenic digestive flora. There has been great interest in the role of these therapies in treatment of many diseases including childhood diarrhea, antibiotic-associated diarrhea, Clostridium difficile infection, irritable bowel syndrome, and inflammatory bowel disease.

SUMMARY

Trials of probiotics have been shown to be helpful in some of these, not in others, and more work is needed in others. We review recent work done in these areas.

Probiotics for the treatment of inflammatory bowel disease

Probiotics are organisms which provide a desired and beneficial effect on human health. With recent evidence implicating a disruption in the balance of the gastrointestinal microbiome and intestinal immunity as a potential trigger for inflammatory bowel disease (IBD), there has been growing interest in using probiotics as an adjunct to standard anti-inflammatory and immune suppressing therapy. Animal models describe potential and plausible mechanisms of action for probiotics to counter inflammation of colonic mucosa. Although there are insufficient data to recommend probiotics in ulcerative colitis or Crohn's disease, good evidence supports the use of specific probiotics for maintenance of remission in pouchitis. Although there are limited regulatory standards for the agents, probiotics are relatively safe with minimal reported side effects or contraindications. More rigorous studies need to be published supporting efficacy and safety of these agents before they become a mainstay of IBD medical treatment.

The microbiome and inflammatory bowel disease: is there a therapeutic role for fecal microbiota transplantation?

One hypothesis for the etiology of inflammatory bowel disease is that an altered or pathogenic microbiota causes inflammation in a genetically susceptible individual. Understanding the microbiota's role in the pathogenesis of the disease could lead to new IBD treatments aimed at shifting the bacteria in the gut back to eubiosis. Probiotics have some efficacy in the treatment of ulcerative colitis (UC), but our current repertoire is limited in potency. Fecal microbiota therapy (FMT) is an emerging treatment for several gastrointestinal and metabolic disorders. It has demonstrated efficacy in treating refractory Clostridium difficile infection, and there are case reports of FMT successfully treating UC. Further clinical studies are justified, and could be complemented by mouse models of fecal transplantation, in which variables can be controlled and manipulated.

The human gut microbiome: current knowledge, challenges, and future directions

The Human Genome Project was completed a decade ago, leaving a legacy of process, tools, and infrastructure now being turned to the study of the microbes that reside in and on the human body as determinants of health and disease, and has been branded "The Human Microbiome Project." Of the various niches under investigation, the human gut houses the most complex and abundant microbial community and is an arena for important host-microbial interactions that have both local and systemic impact. Initial studies of the human microbiome have been largely descriptive, a testing ground for innovative molecular techniques and new hypotheses. Methods for studying the microbiome have quickly evolved from low-resolution surveys of microbial community structure to high-definition description of composition, function, and ecology. Next-generation sequencing technologies combined with advanced bioinformatics place us at the doorstep of revolutionary insight into the composition, capability, and activity of the human intestinal microbiome. Renewed efforts to cultivate previously "uncultivable" microbes will be important to the overall understanding of gut ecology. There remain numerous methodological challenges to the effective study and understanding of the gut microbiome, largely relating to study design, sample collection, and the number of predictor variables. Strategic collaboration of clinicians, microbiologists, molecular biologists, computational scientists, and bioinformaticians is the ideal paradigm for success in this field. Meaningful interpretation of the gut microbiome requires that host genetic and environmental influences be controlled or accounted for. Understanding the gut microbiome in healthy humans is a foundation for discovering its influence in various important gastrointestinal and nutritional diseases (eg, inflammatory bowel disease, diabetes, and obesity), and for rational translation to human health gains.

A gastroenterologist's guide to probiotics

The enteric microbiota contribute to gastrointestinal health, and their disruption has been associated with many disease states. Some patients consume probiotic products in attempts to manipulate the intestinal microbiota for health benefit. It is important for gastroenterologists to improve their understanding of the mechanisms of probiotics and the evidence that support their use in practice. Clinical trials have assessed the therapeutic effects of probiotic agents for several disorders, including antibiotic- or Clostridium difficile-associated diarrhea, irritable bowel syndrome, and the inflammatory bowel diseases. Although probiotic research is a rapidly evolving field, there are sufficient data to justify a trial of probiotics for treatment or prevention of some of these conditions. However, the capacity of probiotics to modify disease symptoms is likely to be modest and varies among probiotic strains-not all probiotics are right for all diseases. The current review provides condition-specific rationale for using probiotic therapy and literature-based recommendations.

Systematic review: faecal microbiota transplantation in the management of inflammatory bowel disease

BACKGROUND

The intestinal microbiota is involved in the pathogenesis of inflammatory bowel disease (IBD). Faecal microbiota transplantation (FMT) has been used for the management of IBD as well as infectious diarrhoea.

AIM

To undertake a systematic review of FMT in patients with IBD.

METHODS

The systematic review followed Cochrane and PRISMA recommendations. Nine electronic databases were searched in addition to hand searching and contacting experts. Inclusion criteria were reports (RCT, nonrandomised trials, case series and case reports) of FMT in patients with IBD.

RESULTS

Of the 5320 articles identified, 17 fulfilled the inclusion criteria, none of which were controlled trials. There were nine case series/case reports of patients receiving FMT for management of their IBD, and eight where FMT was for the treatment of infectious diarrhoea in IBD. These 17 articles reported on 41 patients with IBD (27 UC, 12 Crohn's, 2 unclassified) with a follow-up period of between 2 weeks and 13 years. Where reported, FMT was administered via colonoscopy/enema (26/33) or via enteral tube (7/33). In patients treated for their IBD, the majority experienced a reduction of symptoms (19/25), cessation of IBD medications (13/17) and disease remission (15/24). There was resolution of C. difficile infection in all those treated for such (15/15).

CONCLUSIONS

Whilst the available evidence is limited and weak, it suggests that faecal microbiota transplantation has the potential to be an effective and safe treatment for IBD, at least when standard treatments have failed. Well-designed randomised controlled trials are required to investigate these findings.

Diet-induced dysbiosis of the intestinal microbiota and the effects on immunity and disease

The gastrointestinal (GI) microbiota is the collection of microbes which reside in the GI tract and represents the largest source of non-self antigens in the human body. The GI tract functions as a major immunological organ as it must maintain tolerance to commensal and dietary antigens while remaining responsive to pathogenic stimuli. If this balance is disrupted, inappropriate inflammatory processes can result, leading to host cell damage and/or autoimmunity. Evidence suggests that the composition of the intestinal microbiota can influence susceptibility to chronic disease of the intestinal tract including ulcerative colitis, Crohn’s disease, celiac disease and irritable bowel syndrome, as well as more systemic diseases such as obesity, type 1 diabetes and type 2 diabetes. Interestingly, a considerable shift in diet has coincided with increased incidence of many of these inflammatory diseases. It was originally believed that the composition of the intestinal microbiota was relatively stable from early childhood; however, recent evidence suggests that diet can cause dysbiosis, an alteration in the composition of the microbiota, which could lead to aberrant immune responses. The role of the microbiota and the potential for diet-induced dysbiosis in inflammatory conditions of the GI tract and systemic diseases will be discussed.

Beneficial effects of probiotics in upper respiratory tract infections and their mechanical actions to antagonize pathogens

Probiotics are live micro‐organisms with beneficial effects on human health, which have the ability to counteract infections at different locations of the body. Clinical trials have shown that probiotics can be used as preventive and therapeutic agents in upper respiratory tract infections (URTIs) and otitis. Their mechanical properties allow them to aggregate and to compete with pathogens for nutrients, space and attachment to host cells. Consequently, they can directly antagonize pathogens and thus exert beneficial effects without directly affecting the metabolism of the host. An overview of the probiotics with such traits, tested up to date in clinical trials for the prevention or treatment of URTIs and otitis, is presented in this review. Their mechanical properties in the respiratory tract as well as at other locations are also cited. Species with interesting in vitro properties towards pharyngeal cells or against common respiratory pathogens have also been included. The potential safety risks of the cited species are then discussed. This review could be of help in the screening of probiotic strains with specific mechanical properties susceptible to have positive effects in clinical trials against URTIs.

Recommendations for probiotic use-2011 update

This study describes the consensus opinion of the participants of the third Yale Workshop on probiotic use. There were 10 experts participating. The recommendations update those of the first 2 meetings that were published in 2005 and 2008. The workshop presentations and papers in this supplement relate to the involvement of normal microbiota involved in intestinal microecology, how the microbes interact with the intestine to affect our immunologic responses, the stability and natural history of probiotic organisms, and the role of the intestinal microbatome with regard to affecting cardiac risk factors and obesity. Recommendations for the use of probiotics in necrotizing enterocolitis, childhood diarrhea, inflammatory bowel disease, irritable bowel syndrome, and Clostridium difficile diarrhea are reviewed. As in previous publications, the recommendations are given as A, B, or C ratings. The recent positive experiences with bacteriotherapy (fecal microbiome transplant) are also discussed in detail and a positive recommendation is made for use in severe resistant C. difficile diarrhea.