Probiotics and Crohn's disease

Strain-Specificity and Disease-Specificity of Probiotic Efficacy: A Systematic Review and Meta-Analysis

Background

As the use and diversity of probiotic products expands, the choice of an appropriate type of probiotic is challenging for both medical care professionals and the public alike. Two vital factors in choosing the appropriate probiotic are often ignored, namely, the probiotic strain-specificity and disease-specificity for efficacy. Reviews and meta-analyses often pool together different types of probiotics, resulting in misleading conclusions of efficacy.

Methods

A systematic review of the literature (1970-2017) assessing strain-specific and disease-specific probiotic efficacy was conducted. Trials were included for probiotics with an identifiable strain (either single strain or mixtures of strains) that had at least two randomized, controlled trials for each type of disease indication. The goal was to determine if probiotic strains have strain and/or disease-specific efficacy.

Results

We included 228 trials and found evidence for both strain specificity and disease specificity for the efficacy of specific probiotic strains. Significant efficacy evidence was found for 7 (70%) of probiotic strain(s) among four preventive indications and 11 (65%) probiotic strain(s) among five treatment indications. Strain-specific efficacy for preventing adult antibiotic-associated diarrhea was clearly demonstrated within the Lactobacillus species [e.g., by the mixture of Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+^®), by L. casei DN114001 (Actimel^®) and by Lactobacillus reuteri 55730], while other Lactobacillus strains did not show efficacy. Significant disease-specific variations in efficacy was demonstrated by L. rhamnosus GG and Saccharomyces boulardii CNCM I-745, as well as other probiotic strains.

Conclusion

Strong evidence was found supporting the hypothesis that the efficacy of probiotics is both strain-specific and disease-specific. Clinical guidelines and meta-analyses need to recognize the importance of reporting outcomes by both specific strain(s) of probiotics and the type of disease. The clinical relevance of these findings indicates that health-care providers need to take these two factors into consideration when recommending the appropriate probiotic for their patient.

Lactobacillus plantarum LP‑Onlly alters the gut flora and attenuates colitis by inducing microbiome alteration in interleukin‑10 knockout mice

The association between inflammatory bowel disease (IBD) and gut microbes has been widely investigated. Our previous study demonstrated that Lactobacillus plantarum LP‑Onlly (LP) applied as a probiotic altered the gut flora and attenuated colitis in interleukin (IL)‑10 knockout (IL‑10‑/‑) mice. In the present study, metagenome sequencing was performed to investigate the gut microbiome in IL‑10‑/‑mice and the influence of oral administration of LP on microbial composition. Metagenomics sequencing was performed to investigate the influence of IBD on the gut microbiome with and without LP treatment. The alteration of the abundances of various taxonomic and functional groups were investigated across these gut microbiomes. The present study demonstrates that Akkermansia muciniphila was significantly enriched in IL‑10‑/‑ mice, and bacteroides were significantly increased following LP administration. In addition, the phylum Bacteroidetes and Firmicutes were significantly influenced by LP administration. Further characterization of functional capacity revealed that in the gut metagenomes of IL‑10‑/‑mice, genes encoding cell cycle control, replication, recombination, repair and cell envelope biogenesis were decreased, but intracellular trafficking, secretion, and vesicular transport were increased. The present findings indicate that the gut metagenome is associated with IBD, and oral administration of LP contributes to prevention of gut inflammation, providing insight into the treatment of IBD.

The role of dietary supplements in inflammatory bowel disease: a systematic review

Inflammatory bowel diseases (IBD) are chronic immune disorders of unclear aetiology. Dietary deficiencies may be a potential pathogenic factor in their development. Patients often take food supplements without knowledge of any evidence base. We have therefore assessed the evidence for food supplementation in the management of IBD. A PubMed search was performed for the terms Inflammatory bowel disease; nutritional deficiencies; dietary supplements; curcumin; green tea; vitamin D/other vitamins; folic acid; iron; zinc; probiotics; andrographis paniculata; and boswellia serrate. PubMed was used to search for all relevant articles published between January 1975 and September 2015. Curcumin supplementation has been reported to be effective in reducing the symptoms and the inflammatory indices in IBD patients. Similar results have been observed for green tea; however, pertinent studies are limited. Vitamin D supplementation may help to increase bone mineral density in IBD patients and to reduce disease activity. IBD patients with ileal resections higher than 20 cm may develop vitamin B12 deficiency that requires parenteral supplementation. There is no current evidence to support fat-soluble vitamin supplementation in IBD patients. Zinc and iron should be supplemented in selected cases. Probiotics (VSL#3) may reduce disease activity in IBD patients with pouchitis. Complementary and alternative medicines are used by IBD patients and some studies have shown promising results. In summary, attention to dietary factors such as curcumin, green tea and vitamins, including vitamins D and B12, appears to be beneficial and, if necessary, supplementation may be appropriate.

Beneficial Effects of Probiotics, Prebiotics, Synbiotics, and Psychobiotics in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a group of diseases characterized by inflammation of the small and large intestine and primarily includes ulcerative colitis and Crohn's disease. Although the etiology of IBD is not fully understood, it is believed to result from the interaction of genetic, immunological, and environmental factors, including gut microbiota. Recent studies have shown a correlation between changes in the composition of the intestinal microbiota and IBD. Moreover, it has been suggested that probiotics and prebiotics influence the balance of beneficial and detrimental bacterial species, and thereby determine homeostasis versus inflammatory conditions. In this review, we focus on recent advances in the understanding of the role of prebiotics, probiotics, and synbiotics in functions of the gastrointestinal tract and the induction and maintenance of IBD remission. We also discuss the role of psychobiotics, which constitute a novel class of psychotropic agents that affect the central nervous system by influencing gut microbiota.

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.

Guidance for substantiating the evidence for beneficial effects of probiotics: probiotics in chronic inflammatory bowel disease and the functional disorder irritable bowel syndrome

Ulcerative colitis and Crohn's disease, the 2 distinct idiopathic pathologies of inflammatory bowel diseases, are spontaneously relapsing, immunologically mediated disorders of the gastrointestinal tract. Selected probiotics strains have been proven to be clinically effective in maintaining remission in patients with ulcerative colitis. None of the probiotics thus far tested has been shown to be effective in induction of remission or in maintenance of remission in patients with Crohn's disease. The multispecies probiotics mixture of 8 strains seems effective in the maintenance of remission in pouchitis. Irritable bowel syndrome is a functional bowel disorder manifested by chronic, recurring abdominal pain or discomfort associated with disturbed bowel habit in the absence of structural abnormalities likely to account for these symptoms. Recently conducted appropriately powered studies with different (combinations of) probiotics show positive results on reduction of symptoms, although a considerable placebo effect is also found. Mechanistic studies aimed at pathophysiological mechanisms of inflammatory bowel diseases can identify new targets for probiotic bacteria.

Probiotic Lactobacillus reuteri suppress proinflammatory cytokines via c-Jun

BACKGROUND

Differential immunoregulatory capabilities of probiotic Lactobacillus were explored in the context of pediatric Crohn's disease. Experimental strategies addressed molecular mechanisms of tumor necrosis factor (TNF) suppression in activated macrophages by transcriptional regulation.

METHODS

Secreted factors produced by probiotic Lactobacillus reuteri strains were harvested and tested with human monocytes and macrophages. Quantitative immunoassays and real-time reverse-transcriptase polymerase chain reaction (RT-PCR) were used to examine relative quantities of human cytokines and TNF mRNA, respectively, and reporter assays assessed transcriptional regulation of TNF by probiotics. DNA-protein macroarrays interrogated probiotic-mediated effects on transcription factor activation. Finally, enzyme-linked immunosorbent assays (ELISAs) and immunoblots examined the involvement of the specific transcription factor AP-1 and its components.

RESULTS

Probiotic L. reuteri strain ATCC PTA 6475 demonstrated the ability to potently suppress human TNF production by lipopolysaccharide-activated monocytes and primary monocyte-derived macrophages from children with Crohn's disease. Quantities of the chemokine MCP-1/CCL2 were also reduced by probiotic L. reuteri strain ATCC PTA 6475 in macrophages of children in remission. Quantitative real-time RT-PCR and luciferase reporter assays showed that transcriptional regulation of human TNF was a primary mechanism of probiotic-mediated immunomodulation. Probiotic L. reuteri suppressed TNF transcription by inhibiting activation of MAP kinase-regulated c-Jun and the transcription factor, AP-1.

CONCLUSIONS

Human TNF and MCP-1 suppression by probiotic L. reuteri was strain-dependent, and the activation of c-Jun and AP-1 represent primary targets for probiotic-mediated suppression of TNF transcription. This report emphasizes the clonal nature of immunoprobiosis and delineation of a specific immunomodulatory mechanism for probiotic strain selection in future inflammatory bowel disease-oriented clinical trials.

Effect of oral lactulose on clinical and immunohistochemical parameters in patients with inflammatory bowel disease: a pilot study

Background

The prebiotic potential of lactulose is well established and preclinical studies demonstrated a protective effect of lactulose in murine models of colitis. The aim of the present study was to investigate the clinical and histological efficacy of lactulose in patients with inflammatory bowel disease (IBD), for which probiotic therapy yielded promising results.

Methods

Patients were treated with standard medication alone or combined with 10 g lactulose daily as adjuvant therapy for 4 months. Clinical efficacy of treatment was assessed using clinical activity indices, a quality of life index (IBDQ), endoscopic scores, defecation frequency and monitoring corticosteroid medication. Orsomucoid, alpha1-antitrypsin and other laboratory parameters were determined. In addition, in some participants colonic biopsies were analyzed with haematoxylin-eosin staining or with antibodies against HLA-DR, CD68, IgA and CD3, and evaluated systematically. All measurements were performed both at enrolment and at the end of the trial.

Results

14 patients presenting ulcerative colitis (UC) and 17 patients presenting Crohn's disease (CD), most of them in a clinically active state, were enrolled in this pilot study. After 4 month no significant improvement of clinical activity index, endoscopic score or immunohistochemical parameters was observed in CD or UC patients receiving lactulose in comparison to the control group. However, significant improvement of quality of life was observed in UC patients receiving lactulose compared to the control group (p = 0.04).

Conclusion

The findings of the present pilot study indicate that oral lactulose has no beneficial effects in IBD patients in particular with regard to clinical activity, endoscopic score or immunohistochemical parameters. The importance of the beneficial effect of lactulose in UC patients regarding the quality of life needs further evaluation in larger controlled clinical trials.

Trial registration

Current Controlled Trials ISRCTN92101486

High dose probiotic and prebiotic cotherapy for remission induction of active Crohn's disease

BACKGROUND

Clinical trials of probiotic treatment for Crohn's disease (CD) have yielded conflicting results. This study assessed the clinical usefulness of combined probiotic and prebiotic therapy in the treatment of active CD.

METHOD

Ten active CD outpatients without history of operation for CD were enrolled. Their mean (+/-SD) age was 27 +/- 7 years and the main symptoms presented were diarrhea and abdominal pain. Patients' initial therapeutic regimen of aminosalicylates and prednisolone failed to achieve remission. Patients were thus initiated on a synbiotic therapy, consisting of both probiotics (75 billion colony forming units [CFU] daily) and prebiotics (psyllium 9.9 g daily). Probiotics mainly comprised Bifidobacterium and Lactobacillus. Patients were free to adjust their intake of probiotics or prebiotics throughout the trial. Crohn's disease activity index (CDAI), International Organization for the Study of Inflammatory Bowel Disease (IOIBD) score and blood sample variables were evaluated and compared before and after the trial.

RESULTS

The duration of the trial was 13.0 +/- 4.5 months. By the end of therapy, each patient had taken a 45 +/- 24 billion CFU daily probiotic dose, with six patients taking an additional 7.9 +/- 3.6 g daily psyllium dose. Seven patients had improved clinical symptoms following combined probiotic and prebiotic therapy. Both CDAI and IOIBD scores were significantly reduced after therapy (255-136, P = 0.009; 3.5-2.1, P = 0.03, respectively). Six patients had a complete response, one had a partial response, and three were non-responders. Two patients were able to discontinue their prednisolone therapy, while four patients decreased their intake. There were no adverse events.

CONCLUSION

High-dose probiotic and prebiotic cotherapy can be safely and effectively used for the treatment of active CD.

Probiotics for maintenance of remission in Crohn's disease

BACKGROUND

Crohn's disease (CD) is characterised by episodes of disease activity and symptom-free remission. Probiotics are microorganisms that can potentially benefit health, and have been evaluated as an alternate means of preventing relapse in patients with CD.

OBJECTIVES

To assess the effectiveness of probiotics for the maintenance of remission in CD.

SEARCH STRATEGY

The following databases were searched: the Cochrane Database of Systematic Reviews (2005, Issue 3); the Cochrane Central Register of Controlled Trials (2005, Issue 3); the Cochrane IBD/FBD Group Trials Register (2005), MEDLINE (1966-2005); EMBASE (1980-2005); ISI Web of Knowledge (BIDS) 1981-2005; On-line clinical trials databases (2005); and review articles. Experts in the field were contacted for unpublished data.

SELECTION CRITERIA

Randomised controlled trials of probiotic therapy.

DATA COLLECTION AND ANALYSIS

Two independent reviewers performed data extraction and assessment of methodological quality. The primary outcome was the relative risk (RR) of relapse after maintenance treatment (and 95% confidence intervals [CI]).

MAIN RESULTS

Seven small studies were identified and varied according to probiotics tested, methodological quality and medication regimen. No studies were pooled for statistical analysis. There was no statistically significant benefit of E. coli Nissle for reducing the risk of relapse compared to placebo (RR 0.43, 95% CI 0.15 to 1.20), or Lactobacillus GG after surgically-induced remission (RR 1.58, 95% CI 0.30 to 8.40) or medically-induced remission (RR 0.83, 95% CI 0.25 to 2.80). There was no statistically significant benefit of probiotics for reducing the risk of relapse compared to maintenance therapy employing aminosalicylates or azathioprine (RR 0.67, 95% CI 0.13 to 3.30), and in this study the probiotic Lactobacillus GG was associated with adverse events. In children, there was there was no statistically significant difference between Lactobacillus GG and placebo for reducing the risk of relapse (RR 1.85, 95% CI 0.77 to 4.40). A small study using the yeast Saccharomyces boulardii demonstrated a difference that was not statistically significant in favour of probiotic combined with a reduced level of maintenance therapy over standard maintenance treatment alone (RR 0.17, 95% CI 0.02 to 1.23).

AUTHORS' CONCLUSIONS

There is no evidence to suggest that probiotics are beneficial for the maintenance of remission in CD. All of the included studies enrolled small numbers of patients and may have lacked statistical power to show differences should they exist. Larger trials are required to determine if probiotics are of benefit in Crohn's disease.

Probiotics and prebiotics in chronic inflammatory bowel diseases

The prokaryotic and eukaryotic cells of the colon exist in a highly complex, but harmonious relationship. Disturbances in this remarkable symbiosis can result in the development of inflammatory bowel diseases (IBD). Although the etiology of IBD is not entirely understood, it is known that the chronic inflammation of Crohn’s disease, ulcerative colitis and chronic pouchitis are a result of an overly aggressive immune response to the commensal intestinal flora in genetically susceptible hosts. Recent studies have enhanced our ability to understand the interaction between the host and its intestinal microflora and the role the microflora plays in maintaining intestinal homeostasis. As we begin to understand the benefits conferred to the intestine by the microflora, the notion of modifying the composition of the bacterial load to improve human health has arisen. A significant body of research now exists investigating the role of probiotics and prebiotics in ameliorating chronic intestinal inflammation. This article will begin with an overview of the role of the commensal microflora in maintaining mucosal immune homeostasis, and how a dysregulated immune response to the intestinal microflora results in IBD. This will be followed by a summary of the use of probiotics and prebiotics in experimental and human IBD.

Probiotics used in human studies

GOAL

To investigate the literature from 1980 to 2004 for the types of studies and organisms used as probiotics in human studies and diseases.

METHODS

PubMed search for probiotic organisms used in studies from 1980 to August 2004. The data from those papers were evaluated for organisms used, dose, vehicle, frequency, and investigator's report of positive or negative results.

RESULTS

A total of 185 manuscripts were identified. Investigators reported results of both single and multiple organisms in the same manuscript. A single organism was used in 125 reports, and multiple organisms, ranging from 2 to 9, were used in 60 reports. Positive results were reported in 239 clinical situations and negative results reported in 49 in a total of 288 clinical conclusions drawn by the respective investigators. The studies are tabulated in this review.

CONCLUSION

There is a large literature available in credible journals that report benefit of probiotic administration using a wide range of doses, organisms, and clinical situations. Most of the studies are simple reports of a clinical situation and require additional evaluation.

Antagonistic activities of lactobacilli and bifidobacteria against microbial pathogens

The gastrointestinal tract is a complex ecosystem that associates a resident microbiota and cells of various phenotypes lining the epithelial wall expressing complex metabolic activities. The resident microbiota in the digestive tract is a heterogeneous microbial ecosystem containing up to 1 x 10(14) colony-forming units (CFUs) of bacteria. The intestinal microbiota plays an important role in normal gut function and maintaining host health. The host is protected from attack by potentially harmful microbial microorganisms by the physical and chemical barriers created by the gastrointestinal epithelium. The cells lining the gastrointestinal epithelium and the resident microbiota are two partners that properly and/or synergistically function to promote an efficient host system of defence. The gastrointestinal cells that make up the epithelium, provide a physical barrier that protects the host against the unwanted intrusion of microorganisms into the gastrointestinal microbiota, and against the penetration of harmful microorganisms which usurp the cellular molecules and signalling pathways of the host to become pathogenic. One of the basic physiological functions of the resident microbiota is that it functions as a microbial barrier against microbial pathogens. The mechanisms by which the species of the microbiota exert this barrier effect remain largely to be determined. There is increasing evidence that lactobacilli and bifidobacteria, which inhabit the gastrointestinal microbiota, develop antimicrobial activities that participate in the host's gastrointestinal system of defence. The objective of this review is to analyze the in vitro and in vivo experimental and clinical studies in which the antimicrobial activities of selected lactobacilli and bifidobacteria strains have been documented.

Lactobacillus GG bacteria ameliorate arthritis in Lewis rats

Probiotic bacteria have beneficial effects in infectious and inflammatory diseases, principally in bowel disorders. In the case of chronic progressive autoimmune arthritides, a major goal of treatment is to reduce inflammation. We hypothesized that probiotic bacteria would ameliorate inflammation found in arthritis models. To assess this effect, Lewis rats were injected with 50 microg bovine alpha-tropomyosin (TRM) or complete Freund's adjuvant (CFA) to induce tropomyosin arthritis (TA) or adjuvant arthritis (AA), respectively. In both models, the rats were divided into 6 groups and fed 0.5 mL/d of the following suspensions: 1) heat-killed Lactobacillus GG (LGG) bacteria; 2) live LGG, both 10(11) colony-forming units (cfu)/L; 3) sterilized milk; 4) plain yogurt; 5) yogurt containing 10(11) cfu/L LGG; or 6) sterilized water. In the disease-prevention experiments, feeding started 1 wk before or after disease induction. In the therapeutic experiments, feeding was initiated at the onset of clinical arthritis. In all experiments, there were significant interactions between time and treatment (P < 0.001), except for milk, which had no effect in the therapeutic experiment. Histologically, rats fed yogurt containing LGG had a milder inflammation in all experiments (P < 0.05), whereas rats fed plain yogurt exhibited a moderate inflammatory score only in the prevention experiments. Anti-TRM antibody titers were not affected by any of the treatments in any of the experiments. Ingestion of live or heat-killed human LGG had a clinically beneficial effect on experimental arthritis. Our observation of the remarkable preventive and curative effect on arthritis using commercial yogurts containing lactobacilli, especially LGG, suggests the need for investigation of these agents in arthritic patients.

Probiotics for mother and child

For the survival of humankind, nothing can be as important as the health of a mother and a child. As the world's population grows to more than 6 billion, it might seem ridiculous to suggest that any real threat exists to the human species. Diseases have long ravaged populations, as have wars, poverty, and malnutrition. Life today is no different with new and emerging diseases such as SARS and Mad Cow Disease leaving a trail of concern around the planet. All that being said, the AIDS crisis is threatening humans like no other. In countries such as Botswana, close to half the population of pregnant women is infected. Of great concern, the disease is now prevalent among women and teenage girls, threatening not only their lives but those of their offspring. Efforts to control this spread are quite abysmal, albeit well intentioned. Likewise, the death of a child every 15 seconds from diarrheal disease is not being addressed with the same vigor as SARS, even though the risk of dying from the latter for most people is similar to being struck by lightning. In the end, it is the economy and politics that dictate health spending. Image and perception are everything. While deaths mount among women and children from AIDS and other infections, the potential to intervene with a low-risk natural concept of probiotics seemed all too distant. As evidence mounts of the attributes of certain probiotic strains to treat diarrhea and reduce the risk of urogenital and other diseases, the developing world has failed to embrace it, support its evaluation and implementation, and take it to where it is needed the most. In this review, the case for and against probiotics for urogenital and intestinal infections is presented based on current literature. The story is far from complete, but the potential for improving the health of the mother and child is significant. United Nations and World Health Organization guidelines have now been developed to vanquish the unproved marketing hype products that have given probiotics a bad name. It is now up to science to deliver the remedies, and to society to make sure that only proven products reach the marketplace and the people in most need.

Probiotics and prebiotics in gastrointestinal disorders

PURPOSE OF REVIEW

This review summarizes the clinical efficacy of probiotics and prebiotics in gastrointestinal disorders and examines the mechanisms of action related to their therapeutic effect.

RECENT FINDINGS

The demonstration that immune and epithelial cells can discriminate between different microbial species has extended the known mechanism(s) of action of probiotics beyond simple barrier and antimicrobial effects. It has also confirmed that probiotic bacteria modulate mucosal and systemic immune activity and epithelial function. The progressive unraveling of these mechanisms of action has led to new credence for the use of probiotics and prebiotics in clinical medicine. Level I evidence now exists for the therapeutic use of probiotics in infectious diarrhea in children, recurrent Clostridium difficile-induced infections and postoperative pouchitis. Level II evidence is emerging for the use of probiotics in other gastrointestinal infections, prevention of postoperative bacterial translocation, irritable bowel syndrome, and in both ulcerative colitis and Crohn disease. Nevertheless, one consistent feature has emerged over the past year: Not all probiotic bacteria have similar therapeutic effects. Future clinical trials will need to incorporate this fact into trial planning and design.

SUMMARY

The use of probiotics and prebiotics as therapeutic agents for gastrointestinal disorders is rapidly moving into the "mainstream." Mechanisms of action explain the therapeutic effects and randomized; controlled trials provide the necessary evidence for their incorporation into the therapeutic armamentarium.