Meta-analysis of probiotics for the treatment of irritable bowel syndrome

Gut microbiota is not modified by Randomized, Double-blind, Placebo-controlled Trial of VSL#3 in Diarrhea-predominant Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is a common condition that negatively impacts the quality of life for many individuals. The exact etiology of this disorder is largely unknown; however, emerging studies suggest that the gut microbiota is a contributing factor. Several clinical trials show that probiotics, such as VSL#3, can have a favorable effect on IBS. This double-blind, randomized placebo-controlled study has been conducted in diarrhea-predominant IBS subjects in order to investigate the effect of VSL#3 on the fecal microbiota. The bacterial composition of the fecal microbiota was investigated using high-throughput microarray technology to detect 16S RNA. Twenty four subjects were randomized to receive VSL#3 or placebo for 8 weeks. IBS symptoms were monitored using GSRS and quality of life questionnaires. A favorable change in Satiety subscale was noted in the VSL #3 groups. However, the consumption of the probiotic did not change the gut microbiota. There were no adverse events or any safety concerns encountered during this study. To summarize, the use of VSL#3 in this pilot study was safe and showed improvement in specific GSRS-IBS scores in diarrhea-predominant IBS subjects. The gut microbiota was not affected by VSL#3 consumption suggesting that the mechanism of action is not directly linked to the microbiota.

Inflammation and microflora

Irritable bowel syndrome (IBS) is the most common gastrointestinal condition, affecting 10% to 20% of adults in developed countries. Over the last few years, growing evidence has supported a new hypothesis for IBS based on alterations in intestinal bacterial composition. This article reviews the evidence for a bacterial concept in IBS and begins to formulate a hypothesis of how these bacterial systems could integrate in a new pathophysiologic mechanism in the development of IBS. Data suggesting an interaction between this gut flora and inflammation in the context of IBS is also presented.

Therapies aimed at the gut microbiota and inflammation: antibiotics, prebiotics, probiotics, synbiotics, anti-inflammatory therapies

Several recent observations have raised the possibility that disturbances in the gut microbiota and/or a low-grade inflammatory state may contribute to symptomatology and the etiology of irritable bowel syndrome (IBS). Consequent on these hypotheses, several therapeutic categories have found their way into the armamentarium of those who care for IBS sufferers. These agents include probiotics, prebiotics, antibiotics, and anti-inflammatory agents.

Therapy options in irritable bowel syndrome

BACKGROUND

Numerous meta-analyses have recently assessed the overall clinical benefit of single therapy options and groups of therapies in the irritable bowel syndrome (IBS). By large, this should enable physicians to select from a number of therapy options available.

METHODS

We entered dichotomous outcome data from 121 IBS trials published over the last 35 years with different groups and subgroups of drugs (antispasmodics, motility-affecting agents, antidepressants, peppermint oil), dietary interventions (bran, probiotics), and psychotherapy (cognitive behavioral, psychodynamic, hypnotherapy, relaxation techniques) into meta-analytic tools and estimate the overall efficacy (odds ratio, number needed to treat).

RESULTS

Highest efficacy is currently found for peppermint oil, followed by psychotherapeutic and psychopharmacological interventions and probiotics. Traditional antispasmodic therapy has a moderate efficacy, whereas the list of (partially failed or cancelled) motility affecting drugs yielded weak clinical results, and therapies by bran and fibers are of no value in IBS.

CONCLUSION

Evidence-based therapy in IBS provides a number of effective treatment options beyond the fact that many novel compounds under development have failed to reach the market. An algorithm for clinical therapy decision is proposed.

Probiotics: from bench to market

"Probiotics: From Bench to Market" was a one-day conference convened by the New York Academy of Sciences on June 11, 2010, with the goal of stimulating discussion of the physiological effects of probiotics on the gastrointestinal, nervous, and immune systems. The program included speakers from academia, industry, and government to give conference participants a full understanding of the state of the field of probiotics. The overall goal of the program was to increase communication and collaboration among these groups to advance probiotic research and probiotic contributions to public health. The conference was divided into three sessions and included both oral and visual presentations as well as panel discussions.

Probiotics in gastrointestinal disorders

A new era in medical science has dawned with the realization of the critical role of the "forgotten organ," the enteric flora, in health and disease. Central to this beneficial interaction between the flora and humans is the manner in which the bacteria contained within the gut "talk" to the immune system and, in particular, the immune system that is widespread within the gut itself, the gut- (or mucosa-) associated lymphoid tissue (GALT or MALT). Into this landscape comes a new player: the probiotic. While many products have masqueraded as probiotics, only those that truly and reproducibly contain live organisms and have been shown, in high-quality human studies, to confer a health benefit can actually claim this title. Several human disease states have benefited from the use of probiotics, most notably diarrheal illnesses, some inflammatory bowel diseases, and certain infectious disorders. Irritable bowel syndrome can now be added to this list. Although this area holds much promise, more high-quality trials of probiotics in digestive disorders, as well as laboratory investigations of their mechanisms of action, are required.

Food & health forum meeting: evidence-based nutrition

The present report summarises a meeting held by the Food & Health Forum at the Royal Society of Medicine, London, on 27 May 2010. The objective of the meeting was to review the problems associated with the use of evidence-based nutrition and to discuss what constitutes the efficacy for foods and food constituents and how the strength and consistency of the evidence can be assessed and adapted to circumstances in which health claims are to be used on food products. The meeting highlighted the limitations with the present evidence-based nutrition models with the prospect that this may have long-term consequences for nutrition science and ultimately the consumer who may not benefit from new science that could have an impact on health.

Effect of a multispecies probiotic supplement on quantity of irritable bowel syndrome-related intestinal microbial phylotypes

BACKGROUND

Probiotics can alleviate the symptoms of irritable bowel syndrome (IBS), possibly by stabilizing the intestinal microbiota. Our aim was to determine whether IBS-associated bacterial alterations were reduced during multispecies probiotic intervention consisting of Lactobacillus rhamnosus GG, L. rhamnosus Lc705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium breve Bb99. The intervention has previously been shown to successfully alleviate gastrointestinal symptoms of IBS.

METHODS

The faecal microbiotas of 42 IBS subjects participating in a placebo-controlled double-blind multispecies probiotic intervention were analysed using quantitative real-time polymerase chain reaction (qPCR). Eight bacterial targets within the gastrointestinal microbiota with a putative IBS association were measured.

RESULTS

A phylotype with 94% similarity to Ruminococcus torques remained abundant in the placebo group, but was decreased in the probiotic group during the intervention (P = 0.02 at 6 months). In addition, the clostridial phylotype, Clostridium thermosuccinogenes 85%, was stably elevated during the intervention (P = 0.00 and P = 0.02 at 3 and 6 months, respectively). The bacterial alterations detected were in accordance with previously discovered alleviation of symptoms.

CONCLUSIONS

The probiotic supplement was thus shown to exert specific alterations in the IBS-associated microbiota towards the bacterial 16S rDNA phylotype quantities described previously for subjects free of IBS. These changes may have value as non-invasive biomarkers in probiotic intervention studies.

Integrative medicine and gastrointestinal disease

Common disorders of the gastrointestinal (GI) tract account for about 50 million visits per year to physicians trained in traditional allopathic or osteopathic medicine. Sometimes patients turn to more alternative treatments because standard medical therapy is either not producing the most desired result or may have side effects, or patients may see complementary or alternative therapies as more natural. In the United States, the overall expenditure for complementary and alternative medicine (CAM) is in the tens of billions of dollars per year. Because physicians need to be aware of the latest evidence for different complementary and alternative therapies used for gastrointestinal disorders, this article focuses on the most common and most studied CAM therapies for selected common gastrointestinal disorders.

VSL#3 improves symptoms in children with irritable bowel syndrome: a multicenter, randomized, placebo-controlled, double-blind, crossover study

BACKGROUND AND OBJECTIVES

: Irritable bowel syndrome (IBS) is a common problem in pediatrics, for which no safe and effective treatment is available. Probiotics have shown some promising results in adult studies, but no positive study has been published on pediatric age. We aimed at investigating the efficacy of VSL#3 in a population of children and teenagers affected by IBS, in a randomized, double-blind, placebo-controlled, crossover study conducted in 7 pediatric gastroenterology divisions.

PATIENTS AND METHODS

: Children 4 to 18 years of age, meeting eligibility criteria, were enrolled. The patients were assessed by a questionnaire for a 2-week baseline period. They were then randomized to receive either VSL#3 or a placebo for 6 weeks, with controls every 2 weeks. At the end, after a "wash-out" period of 2 weeks, each patient was switched to the other group and followed for a further 6 weeks.

RESULTS

: A total of 59 children completed the study. Although placebo was effective in some of the parameters and in as many as half of the patients, VSL#3 was significantly superior to it (P < 0.05) in the primary endpoint, the subjective assessment of relief of symptoms; as well as in 3 of 4 secondary endpoints: abdominal pain/discomfort (P < 0.05), abdominal bloating/gassiness (P < 0.05), and family assessment of life disruption (P < 0.01). No significant difference was found (P = 0.06) in the stool pattern. No untoward adverse effect was recorded in any of the patients.

CONCLUSIONS

: VSL#3 is safe and more effective than placebo in ameliorating symptoms and improving the quality of life in children affected by IBS.

Dose-response efficacy of a proprietary probiotic formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for antibiotic-associated diarrhea and Clostridium difficile-associated diarrhea prophylaxis in adult patients

OBJECTIVES

Standard therapies for antibiotic-associated diarrhea (AAD) and Clostridium difficile-associated diarrhea (CDAD) have limited efficacy. Probiotic prophylaxis is a promising alternative for reduction of AAD and CDAD incidence.

METHODS

In this single-center, randomized, double-blind, placebo-controlled dose-ranging study, we randomized 255 adult inpatients to one of three groups: two probiotic capsules per day (Pro-2, n=86), one probiotic capsule and one placebo capsule per day (Pro-1, n=85), or two placebo capsules per day (n=84). Each probiotic capsule contained 50 billion c.f.u. of live organisms (Lactobacillus acidophilus CL1285 +Lactobacillus casei LBC80R Bio-K+ CL1285). Probiotic prophylaxis began within 36 h of initial antibiotic administration, continued for 5 days after the last antibiotic dose, and patients were followed for an additional 21 days.

RESULTS

Pro-2 (15.5%) had a lower AAD incidence vs. Pro-1 (28.2%). Each probiotic group had a lower AAD incidence vs. placebo (44.1%). In patients who acquired AAD, Pro-2 (2.8 days) and Pro-1 (4.1 days) had shorter symptom duration vs. placebo (6.4 days). Similarly, Pro-2 (1.2%) had a lower CDAD incidence vs. Pro-1 (9.4%). Each treatment group had a lower CDAD incidence vs. placebo (23.8%). Gastrointestinal symptoms were less common in the treatment groups vs. placebo and in Pro-2 vs. Pro-1.

CONCLUSIONS

The proprietary probiotic blend used in this study was well tolerated and effective for reducing risk of AAD and, in particular, CDAD in hospitalized patients on antibiotics. A dose-ranging effect was shown with 100 billion c.f.u., yielding superior outcomes and fewer gastrointestinal events compared to 50 billion c.f.u. (ClinicalTrials.gov number NCT00958308).

Immune-stimulating effects of lactic acid bacteria in vivo and in vitro

The health-promoting effects of lactic acid bacteria (LAB) are well recognised, making them a popular functional food ingredient. Commercially available probiotic products are often promoted as capable of improving immune defences also in healthy subjects. However, while strain-specific differences exist in the effects of LAB, conventional yoghurt bacteria have proved beneficial as well. For comparing the immunological effects of conventional and probiotic LAB, young healthy women received either a commercially available probiotic fermented milk product or a conventional yoghurt for four weeks. Both treatments showed comparable effects resulting in a stronger immunological reaction to stimuli (natural cytotoxicity against cancer cells, mitogen-induced T-lymphocyte activation and stimulated cytokine production). To study the mechanisms behind these effects, conventional (Lactobacillus delbrueckii) and probiotic (Lactobacillus rhamnosus GG), LAB were compared in vitro at the cellular level. Interestingly, L. rhamnosus GG was more potent in inducing maturation of dendritic cells (DC) that play a substantial role in directing the immune response to stimuli. In turn, L. delbrueckii provoked a higher secretion of proinflammatory cytokines as well as IL-10. These effects were, however, observed only after direct incubation of DC and LAB, not when both were separated by a layer of enterocyte-like Caco-2 cells. LAB also induced cytokine secretion in peripheral blood mononuclear cells in a similar manner and this effect was reduced in a Caco-2 cell model, suggesting a modulating influence of gut epithelial cells. While both conventional and probiotic strains modulate the immune response, specific properties may offer therapeutic options in the treatment of certain diseases.

Probiotics

PURPOSE

The pharmacology, uses, dosages, safety, drug interactions, and contraindications of probiotics are reviewed.

SUMMARY

Probiotics are live nonpathogenic microorganisms administered to improve microbial balance, particularly in the gastrointestinal tract. They consist of Saccharomyces boulardii yeast or lactic acid bacteria, such as Lactobacillus and Bifidobacterium species, and are regulated as dietary supplements and foods. Probiotics exert their beneficial effects through various mechanisms, including lowering intestinal pH, decreasing colonization and invasion by pathogenic organisms, and modifying the host immune response. Probiotic benefits associated with one species or strain do not necessarily hold true for others. The strongest evidence for the clinical effectiveness of probiotics has been in the treatment of acute diarrhea, most commonly due to rotavirus, and pouchitis. More research is needed to clarify the role of probiotics for preventing antibiotic-associated diarrhea, Clostridium difficile infection, travelers' diarrhea, irritable bowel syndrome, ulcerative colitis, Crohn's disease, and vulvovaginal candidiasis. There is no consensus about the minimum number of microorganisms that must be ingested to obtain a beneficial effect; however, a probiotic should typically contain several billion microorganisms to increase the chance that adequate gut colonization will occur. Probiotics are generally considered safe and well tolerated, with bloating and flatulence occurring most frequently. They should be used cautiously in patients who are critically ill or severely immunocompromised or those with central venous catheters since systemic infections may rarely occur. Bacteria-derived probiotics should be separated from antibiotics by at least two hours.

CONCLUSION

Probiotics have demonstrated efficacy in preventing and treating various medical conditions, particularly those involving the gastrointestinal tract. Data supporting their role in other conditions are often conflicting.

Probiotic bacteria and intestinal epithelial barrier function

The intestinal tract is a diverse microenvironment where more than 500 species of bacteria thrive. A single layer of epithelium is all that separates these commensal microorganisms and pathogens from the underlying immune cells, and thus epithelial barrier function is a key component in the arsenal of defense mechanisms required to prevent infection and inflammation. The epithelial barrier consists of a dense mucous layer containing secretory IgA and antimicrobial peptides as well as dynamic junctional complexes that regulate permeability between cells. Probiotics are live microorganisms that confer benefit to the host and that have been suggested to ameliorate or prevent diseases including antibiotic-associated diarrhea, irritable bowel syndrome, and inflammatory bowel disease. Probiotics likely function through enhancement of barrier function, immunomodulation, and competitive adherence to the mucus and epithelium. This review summarizes the evidence about effects of the many available probiotics with an emphasis on intestinal barrier function and the mechanisms affected by probiotics.

Systematic review and meta-analysis of Saccharomyces boulardii in adult patients

This article reviews the evidence for efficacy and safety of Saccharomyces boulardii (S. boulardii) for various disease indications in adults based on the peer-reviewed, randomized clinical trials and pre-clinical studies from the published medical literature (Medline, Clinical Trial websites and meeting abstracts) between 1976 and 2009. For meta-analysis, only randomized, blinded controlled trials unrestricted by language were included. Pre-clinical studies, volunteer studies and uncontrolled studies were excluded from the review of efficacy and meta-analysis, but included in the systematic review. Of 31 randomized, placebo-controlled treatment arms in 27 trials (encompassing 5029 study patients), S. boulardii was found to be significantly efficacious and safe in 84% of those treatment arms. A meta-analysis found a significant therapeutic efficacy for S. boulardii in the prevention of antibiotic-associated diarrhea (AAD) (RR = 0.47, 95% CI: 0.35-0.63, P < 0.001). In adults, S. boulardii can be strongly recommended for the prevention of AAD and the traveler's diarrhea. Randomized trials also support the use of this yeast probiotic for prevention of enteral nutrition-related diarrhea and reduction of Helicobacter pylori treatment-related symptoms. S. boulardii shows promise for the prevention of C. difficile disease recurrences; treatment of irritable bowel syndrome, acute adult diarrhea, Crohn's disease, giardiasis, human immunodeficiency virus-related diarrhea; but more supporting evidence is recommended for these indications. The use of S. boulardii as a therapeutic probiotic is evidence-based for both efficacy and safety for several types of diarrhea.

Novel perspectives in probiotic treatment: the efficacy and unveiled mechanisms of the physiological functions

Probiotics are defined as "live microorganisms which confer a health benefit on the host" when administered in adequate amounts, and have potential effects for maintaining intestinal development, nutrition, and treating intestinal inflammations, functional disorders, and other extra-intestinal diseases. Although the benefits of probiotics for human health were first noted over 100 years ago, the analysis of probiotic functions began in earnest only 20 years ago. Probiotics, such as some strains of Lactobacillus, Bifidobacterium, Escherichia coli, and Bacillus subtilis, inhibit the growth of pathogenic bacteria, induce competitive effects for the adherent of pathogenic bacteria and their toxins to intestinal epithelia, induce cytoprotective heat shock proteins, enhance the intestinal barrier function, and modulate the host immune responses. The crosstalk between the host and the probiotics appears to be mediated by bacteria-derived effectors, which can be sensed with multiple systems, including the Toll-like receptors and cell membrane transporters. Future analyses will identify more probiotic-derived effectors, the recognition mechanisms of these effectors, and the subsequent changes of the intestinal epithelia and immune cells for each probiotic treatment. For clinical use, a procedure that objectively evaluates the ability of each probiotic effect will help establish a standard for choosing the most valuable strain and its proper dose for each individual patient.

Irritable bowel syndrome: epidemiology, diagnosis and treatment: an update for health-care practitioners

Irritable bowel syndrome (IBS), a chronic gastrointestinal disorder, affects from 3-20% of the US population, depending on sociocultural and comorbid factors. IBS is characterized by a symptom complex of abdominal pain and abnormal bowel habits that present as diarrhea or constipation, and general physical weakness in the absence of abnormal morphological, histological or inflammatory markers. The main diagnostic Rome III criteria as established by international professional organizations are based on exclusion criteria and the occurrence and rate of symptoms. Because the pathophysiology and causes of IBS are poorly understood, treatment approaches are mainly focused on symptom management to maintain everyday functioning and improve quality of life for persons with IBS. The mainstay of intervention is pharmacological treatment with antispasmodics and antidiarrheals for diarrhea, prokinetics and high-fiber diets for constipation, and supportive therapy with low-dose antidepressants to normalize gastrointestinal motility. Other interventions include lifestyle and dietary changes, psychotherapy, herbal therapies and acupuncture. The purpose of this review is to critically assess benefits and risks of current treatment approaches as well as promising complementary and alternative therapies.

Treating irritable bowel syndrome with probiotics: the evidence

Irritable bowel syndrome (IBS) is a disorder of chronic abdominal pain, altered bowel habit and abdominal distension. It is the commonest cause of referral to gastroenterologists in the developed world and yet current therapeutic strategies are often unsatisfactory. There is now increasing evidence linking alterations in the gastrointestinal (GI) microbiota and IBS. Changes in faecal and mucosa-associated microbiota, post-infectious IBS, a link with small intestinal bacterial overgrowth and an up-regulation of the GI mucosal immune system all suggest a role for the GI microbiota in the pathogenesis of IBS. Given this evidence, therapeutic alteration of the GI microbiota by probiotic bacteria could be beneficial. The present paper establishes an aetiological framework for the use of probiotics in IBS and comprehensively reviews randomised placebo-controlled trials of probiotics in IBS using multiple electronic databases. It highlights safety concerns over the use of probiotics and attempts to establish guidelines for their use in IBS in both primary and secondary care.

Probiotic treatment of irritable bowel syndrome in children

Treatment of functional bowel disorders of irritable bowel-type (IBS) in children remains a difficult task because of a lack of drugs with low adverse event profile. We here report the results of a treatment study in 203 children (66 boys and 137 girls) age 4 to 18 years (mean: 10.5+/-4.5 years) with typical IBS symptoms with abdominal pain and either predominant diarrhea (n=50), constipation (n=56), alternating stool frequency (n=28) or unspecific pain (n=69). The average duration of symptoms prior to therapy was 175 days. Most (95%) patients up to age 11 were treated with a daily dose of 10 drops of Symbioflor 2 (SF2) (SymbioPharm, Herborn) (cells and autolysate of 1.5-4.5x10(7) CFU of bacteria of Escherichia coli type), in the elder children 77% received this dosage, while the remaining received a higher dose up to 30 drops/day. Treatment lasted 43 days on average.

RESULTS

All patients tolerated the treatment well and without adverse events. The key IBS symptoms (abdominal pain, stool frequency) as well as the other symptoms (bloating, mucous and blood in stool, need for straining at stools, urge to defecate) improved significantly during treatment. Global assessment of therapy by parents and doctors was altogether positive. In summary these data confirm efficacy and tolerability of this probiotic compound in children and adolescents and supplement published data of probiotic IBS therapy in adults.

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.

Bugs and irritable bowel syndrome: The good, the bad and the ugly

Recently, there has been strong interest in the therapeutic potential of probiotics for irritable bowel syndrome (IBS). At the same time, there is a rapidly growing body of evidence to support an etiological role for gastrointestinal infection and the associated immune activation in the development of post-infectious IBS. In a more controversial area, small intestinal bacterial overgrowth has been associated with a subset of patients with IBS; the issue of whether it is appropriate to treat a subset of IBS patients with antibiotics and probiotics is currently a matter for debate. Thus, it appears that the gastrointestinal microbial flora may exert beneficial effects for symptoms of IBS under some circumstances, while in other situations gut microbes could give rise to symptoms of IBS. How do we make sense of the apparently diverse roles that 'bugs' may play in IBS? To address this question, we have conducted an in-depth review, attempting where possible to draw lessons from Asian studies.

Probiotics and gut health: A special focus on liver diseases

Probiotic bacteria have well-established beneficial effects in the management of diarrhoeal diseases. Newer evidence suggests that probiotics have the potential to reduce the risk of developing inflammatory bowel diseases and intestinal bacterial overgrowth after gut surgery. In liver health, the main benefits of probiotics might occur through preventing the production and/or uptake of lipopolysaccharides in the gut, and therefore reducing levels of low-grade inflammation. Specific immune stimulation by probiotics through processes involving dendritic cells might also be beneficial to the host immunological status and help prevent pathogen translocation. Hepatic fat metabolism also seems to be influenced by the presence of commensal bacteria, and potentially by probiotics; although the mechanisms by which probiotic might act on the liver are still unclear. However, this might be of major importance in the future because low-grade inflammation, hepatic fat infiltration, and hepatitis might become more prevalent as a result of high fat intake and the increased prevalence of obesity.

Irritable bowel syndrome: role of food in pathogenesis and management

Patients with the irritable bowel syndrome (IBS) commonly report the precipitation of symptoms on food ingestion. Though the role of dietary constituents in IBS has not been extensively studied, food could contribute to symptom onset or even the causation of IBS through a number of mechanisms. First, the physiological response of the intestine to food ingestion could precipitate symptoms in predisposed individuals; second, there is some evidence that allergy or intolerance to a particular food can produce IBS-like symptoms, third, certain foods may alter the composition of the luminal milieu, either directly or indirectly through effects on bacterial metabolism, and thus induce symptoms and, finally, IBS may develop following exposure to food-borne pathogens. Anticipatory, psychological factors generated by previous negative experiences with food ingestion or other factors may also contribute though their contribution has been scarcely quantified. Not surprisingly, there is considerable interest in the potential roles of diet and food supplements in the therapy of IBS; for the most part, the evidence base for such recommendations remains slim though certain probiotics show considerable promise.

The effects of maturation on the colonic microflora in infancy and childhood

The composition of colonic mircoflora and its changes with maturation have rarely been investigated in large samples. Methods. We used conventional microbiological testing to analyse the colonic flora (Kyberstatus, Institut forMicroecology, Herborn, Germany) of stool samples from 12 484 children with different intestinal and nonintestinal diagnoses. Stool samples were analysed for total colony forming units (CFU) (per g stool) and the abundance of Bifidobacteria, Bacteroides sp., Escherichia coli, Enterococcus sp., and Lactobacillus sp. with respect to age, gender. A subset of 1089 infants was analysed for monthly changes within the first year of life. Results. Total CFU and individual microbial species were highest during the first year of life, decreased within the first 2 years, and then stabilized for the remaining childhood. In infants, the total CFU rose until month 5, declined with weaning, and peaked at 9–10 months. Significant effects of age, but not of gender, were found in Bacteroides sp. and Lactobacilli. However Bacterioids sp. and Lactobacilli increased with age, while Enterococci and E. coli decreased, and Bifidobacteria remained stable. Conclusion. Colonic microflora show both a bacteria-specific and general pattern of maturation which is most profound within the first year.

[Abdominal bloating: an up-to-date]

Bloating is a common symptom, especially in women. In the clinical practice, it remains a therapeutic challenge. Since recently, its pathophysiology is better understood: an impaired transit of gas (particularly in the small bowel) or a visceral hypersensitivity leading to the induction of an abdominal discomfort despite a normal volume of gas are two of the main causes, far more frequent than an excessive production of gas. Moreover, bloating can be related to abnormal viscera-somatic reflexes promoting both an abdomino-phrenic dyssynergia and the relaxation of the muscles of the abdominal wall. From a therapeutic point of view, the efficacy of the gas absorbants remains to be more documented. Besides the treatment of a constipation and the avoidance of nutrients either highly fermentable or rich in fructose, other therapeutic options include prokinetics and drugs acting on visceral sensitivity. Probiotics are another promising option. In some centers, a non pharmacological therapeutic approach, mainly based on hypnosis, is discussed.

Fermented milk containing Bifidobacterium lactis DN-173 010 improves gastrointestinal well-being and digestive symptoms in women reporting minor digestive symptoms: a randomised, double-blind, parallel, controlled study

The ability of probiotics to improve bowel habits or transit time has been shown in healthy populations. Additional data are required to support the use of specific probiotics to improve gastrointestinal (GI) well-being. The present study was designed to investigate the effect of consuming fermented milk (FM) on GI well-being, digestive symptoms and health-related quality of life (HRQoL) amongst women without diagnosed GI disorders. In this double-blind, controlled, parallel-design study, subjects were randomised to ingest daily either 2 x 125 g FM containing Bifidobacterium lactis DN-173 010 and yoghurt strains or a control non-fermented dairy product for 4 weeks followed by a 4-week wash-out period. GI well-being and digestive symptoms were assessed weekly. HRQoL was measured every 4 weeks. Data were analysed using analysis of covariance and logistic regression, correcting for baseline values on the full analysis set population of 197 women (aged 18-60 years). The percentage of women reporting an improvement in their GI well-being was significantly (P < 0.01) higher in the FM group v. the control group (OR 1.69; 95 % CI 1.17, 2.45). A significantly (P < 0.05) more pronounced decrease in the composite score of digestive symptoms was observed in the FM group when comparing with the control group (least squares mean - 0.57; 95 % CI - 1.12, - 0.02). Among HRQoL dimensions, the digestive comfort score was significantly (P < 0.05) improved in the FM group compared with the control group. The present study showed that the daily consumption of a specific FM is able to improve GI well-being and digestive symptoms in adult women without GI disorders.

The role of diet in symptoms of irritable bowel syndrome in adults: a narrative review

This review summarizes what is known about the effect of diet on irritable bowel syndrome (IBS) symptoms emphasizing data from randomized, controlled clinical trials. Studies suggest that IBS symptoms in one quarter of patients may be caused or exacerbated by one or more dietary components. Recent studies indicate that a diet restricted in fermentable, poorly absorbed carbohydrates, including fructose, fructans (present in wheat and onions), sorbitol, and other sugar alcohols is beneficial, but confirmatory studies are needed. Despite a long history of enthusiastic use, fiber is marginally beneficial. Insoluble fiber may worsen symptoms. Some patients with IBS, especially those with constipation, will improve with increased intake of soluble fiber. Prebiotic fibers have not been adequately tested. Daily use of peppermint oil is effective in relieving IBS symptoms. The usefulness of probiotics in the form of foods such as live-culture yogurt and buttermilk for IBS symptoms is not established. In clinical practice, it is very difficult to establish that a patient's symptoms result from an adverse reaction to food. A double blind placebo-controlled food challenge is the most reliable method, but it is not suitable for routine clinical use. A modified exclusion diet and stepwise reintroduction of foods or trials of eliminating classes of food may be useful.

Safety assessment of Lactobacillus brevis KB290 as a probiotic strain

Lactobacillus brevis KB290 (KB290), a plant-derived probiotic lactic acid bacterium, reportedly improves gut health and stimulates immune function. Here we extensively investigated the geno-, acute, subacute, and subchronic toxicity of KB290 and its bacterial translocation potential. KB290 was non-mutagenic in the bacterial reverse mutation assay by the preincubation method. In the single oral dose toxicity test, KB290 at 10(9) cfu/ml was nontoxic at maximum capacity (20 ml/kg). When 10(8), 10(9), or 10(10) cfu/kg was administered daily to rats by gavage for 2 weeks (subacute assay), we observed no clear treatment-related effect and no evidence of bacterial translocation from the gastrointestinal tract. When it was administered for 13 weeks (subchronic assay), we again observed no clear treatment-related effect and no significant toxicological effect. Based on those results, we consider 10(10) cfu/kg per day, the highest dose tested, to be the no observed adverse effect level (NOAEL). These results suggest that KB290 is safe for human consumption.

Altering the gastrointestinal flora in patients with functional bowel disorders: a way ahead?

Functional gastrointestinal disorders are very common in the Western world, but unfortunately the underlying mechanisms behind these disorders are incompletely understood. Treatment options are limited and the economic consequences for society are profound. Recent data suggest an involvement of bacteria in the pathogenesis of functional gastrointestinal disorders. Probiotics are promising new treatment alternatives, which will be reviewed in this supplement.

Targeting the human microbiome with antibiotics, probiotics, and prebiotics: gastroenterology enters the metagenomics era

Studies of metagenomics and the human microbiome will tremendously expand our knowledge of the composition of microbial communities in the human body. As our understanding of microbial variation and corresponding genetic parameters is refined, this information can be applied to rational remodeling or "tailoring" of human-associated microbial communities and their associated functions. Physiologic features such as the development of innate and adaptive immunity, relative susceptibilities to infections, immune tolerance, bioavailability of nutrients, and intestinal barrier function may be modified by changing the composition and functions of the microbial communities. The specialty of gastroenterology will be affected profoundly by the ability to modify the gastrointestinal microbiota through the rational deployment of antibiotics, probiotics, and prebiotics. Antibiotics might be used to remove or suppress undesirable components of the human microbiome. Probiotics can introduce missing microbial components with known beneficial functions for the human host. Prebiotics can enhance the proliferation of beneficial microbes or probiotics, to maximize sustainable changes in the human microbiome. Combinations of these approaches might provide synergistic and effective therapies for specific disorders. The human microbiome could be manipulated by such "smart" strategies to prevent and treat acute gastroenteritis, antibiotic-associated diarrhea and colitis, inflammatory bowel disease, irritable bowel syndrome, necrotizing enterocolitis, and a variety of other disorders.

Bacillus coagulans significantly improved abdominal pain and bloating in patients with IBS

BACKGROUND

Symptoms of irritable bowel syndrome (IBS) can have a profound impact on emotional health and quality of life, and current treatments are sometimes unsatisfactory for patients facing this lifelong disease. Probiotics, which can normalize gastrointestinal microflora, may alleviate symptoms of IBS.

OBJECTIVE

This preliminary controlled study was conducted to evaluate the effects of the probiotic Bacillus coagulans GBI-30, 6086 on IBS symptoms.

METHODS

This was a randomized, double-blind, parallel-group, placebo-controlled clinical trial involving 44 subjects who received either placebo or B coagulans GBI-30, 6086 once a day for 8 weeks. Self-assessments of the severity of IBS symptoms (abdominal pain and bloating) were recorded every day for 8 weeks. Because baseline values were significantly different between the 2 study groups, within-group analysis was conducted.

RESULTS

Improvements from baseline abdominal pain and bloating scores in the B coagulans GBI-30, 6086 group were statistically significant for all 7 weekly comparisons (P < 0.01). In the placebo group, only changes in abdominal pain scores at weeks 6 and 8 achieved statistical significance (P < 0.05). No treatment-related adverse events or serious adverse events were reported during the 8-week study period.

CONCLUSIONS

Preliminary data suggest that the patented B coagulans GBI-30, 6086 probiotic may be a safe and effective option for the relief of abdominal pain and bloating for patients with IBS. Larger, extended trials are needed to verify these results.

Clostridium difficile associated infection, diarrhea and colitis

A new, hypervirulent strain of Clostridium difficile, called NAP1/BI/027, has been implicated in C. difficile outbreaks associated with increased morbidity and mortality since the early 2000s. The epidemic strain is resistant to fluoroquinolones in vitro, which was infrequent prior to 2001. The name of this strain reflects its characteristics, demonstrated by different typing methods: pulsed-field gel electrophoresis (NAP1), restriction endonuclease analysis (BI) and polymerase chain reaction (027). In 2004 and 2005, the US Centers for Disease Control and Prevention (CDC) emphasized that the risk of C. difficile-associated diarrhea (CDAD) is increased, not only by the usual factors, including antibiotic exposure, but also gastrointestinal surgery/manipulation, prolonged length of stay in a healthcare setting, serious underlying illness, immune-compromising conditions, and aging. Patients on proton pump inhibitors (PPIs) have an elevated risk, as do peripartum women and heart transplant recipients. Before 2002, toxic megacolon in C. difficile-associated colitis (CDAC), was rare, but its incidence has increased dramatically. Up to two-thirds of hospitalized patients may be infected with C. difficile. Asymptomatic carriers admitted to healthcare facilities can transmit the organism to other susceptible patients, thereby becoming vectors. Fulminant colitis is reported more frequently during outbreaks of C. difficile infection in patients with inflammatory bowel disease (IBD). C. difficile infection with IBD carries a higher mortality than without underlying IBD. This article reviews the latest information on C. difficile infection, including presentation, vulnerable hosts and choice of antibiotics, alternative therapies, and probiotics and immunotherapy. We review contact precautions for patients with known or suspected C. difficile-associated disease. Healthcare institutions require accurate and rapid diagnosis for early detection of possible outbreaks, to initiate specific therapy and implement effective control measures. A comprehensive C. difficile infection control management rapid response team (RRT) is recommended for each health care facility. A communication network between RRTs is recommended, in coordination with each country’s department of health. Our aim is to convey a comprehensive source of information and to guide healthcare professionals in the difficult decisions that they face when caring for these oftentimes very ill patients.

Safety assessment of a proprietary preparation of a novel Probiotic, Bacillus coagulans, as a food ingredient

It has been demonstrated that some strains of Bacillus coagulans can survive extremes of heat, acidity of the stomach, and bile acids, to which commonly consumed probiotics are susceptible. A toxicological safety assessment was performed on a proprietary preparation of B. coagulans – GanedenBC^30™ – a novel probiotic. Seven toxicologic studies were conducted and included: in vitro bacterial reverse mutation assay; in vitro chromosomal aberration assay; micronucleus assay in mice; acute and 90 day subchronic repeated oral toxicity studies were conducted in Wistar Crl:(WI) BR rats; acute eye and skin irritation studies were conducted in rabbits.

The results of this toxicological safety assessment indicate that GanedenBC^30™B. coagulans does not demonstrate mutagenic, clastogenic, or genotoxic effects. Furthermore, the results of the acute and 90-day subchronic oral toxicity studies in rats resulted in the conclusion of a NOAEL greater than 1000 mg/kg per day. Since the concentration of the cell mass used in the 90-day study was 1.36 × 10¹¹ CFUs/g, this corresponds to 95.2 × 10¹¹ CFUs for a 70 kg human and since the suggested human dose is in the range of 100 × 10⁶ to 3 × 10⁹ CFUs, this gives a safety factor ranging from 3173 to 95,200 times. Based upon scientific procedures and supported by history of use, GanedenBC^30™ is considered safe for chronic human consumption.

[Alterations of intestinal epithelial barrier and flora in the irritable bowel syndrome]

The irritable bowel syndrome (IBS) is a common bowel disorder that markedly impairs quality of life of patients. The causes of IBS symptoms are not well known. Motility and sensibility disorders, a genetic susceptibility, stress, previous GI infections and food intolerance have been involved in the pathogenesis of IBS. Recent investigations suggest that alterations of the intestinal epithelial barrier integrity, in particular increased permeability, could modify the cross-talk between bacterial microflora and the host, thus leading to persitent "low-grade" inflammation and alterated GI motility and sensitivity.

Complementary and alternative medicine for treatment of irritable bowel syndrome

OBJECTIVE

To review the evidence supporting selected complementary and alternative medicine approaches used in the treatment of irritable bowel syndrome (IBS).

QUALITY OF EVIDENCE

MEDLINE (from January 1966), EMBASE (from January 1980), and the Cochrane Database of Systematic Reviews were searched until March 2008, combining the terms irritable bowel syndrome or irritable colon with complementary therapies, alternative medicine, acupuncture, fiber, peppermint oil, herbal, traditional, yoga, massage, meditation, mind, relaxation, probiotic, hypnotherapy, psychotherapy, cognitive therapy, or behavior therapy. Results were screened to include only clinical trials, systematic reviews, and meta-analyses. Level I evidence was available for most interventions.

MAIN MESSAGE

Soluble fibre improves constipation and global IBS symptoms. Peppermint oil alleviates IBS symptoms, including abdominal pain. Probiotic trials show overall benefit for IBS but there is little evidence supporting the use of any specific strain. Hypnotherapy and cognitive-behavioural therapy are also effective therapeutic options for appropriate patients. Certain herbal formulas are supported by limited evidence, but safety is a potential concern. All interventions are supported by systematic reviews or meta-analyses.

CONCLUSION

Several complementary and alternative therapies can be recommended as part of an evidence-based approach to the treatment of IBS; these might provide patients with satisfactory relief and improve the therapeutic alliance.

State-of-the-art of irritable bowel syndrome and inflammatory bowel disease research in 2008

Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) are two of the leading causes of chronic intestinal conditions in the world. This issue of World Journal of Gastroenterology (WJG) presents a series of papers from world experts who discuss the current knowledge and opinions on these important conditions. Although great strides have been made in the diagnosis, treatment and pathology of IBS and IBD; much has yet to be explained. The etiologies and risk factors of these multifactorial conditions remain elusive. Specific diagnostic biomarkers need to be developed and safer treatments developed. The burden of IBS and IBD on the healthcare system is felt with repeated medical care visits and high costs. IBS and IBD patients can account for 30%-50% of office visits at gastroenterology services/clinics. Over one million people have IBD in the United States, with 30 000 new cases being diagnosed every year. One-quarter million people in the UK are afflicted with IBD. The cost of medical care in the United States for IBD is estimated to be $1.8 billion/year.

The prevalence and antibiotic resistance of Shigella sp. recovered from patients admitted to Bouali Hospital, Tehran, Iran during 1999-2001

The present study was conducted to determine the prevalence of serotypes and antibiotic resistance in Shigella spp. isolated from patients admitted to Bouali hospital, Tehran, Iran during 1999 to 2001. All cases of shigellosis that were diagnosed according to their clinical pictures and microbial cultures were included in current study. Patients' age ranged from 12 to 89 years. Overall, 52 patients (56%) and 41(44%) were males and female, respectively. From a total of 90 Shigella isolates, 40 strains were identified as S. sonnei (45%), 26 as S. flexneri (27.9%), 3 as S. boydii (3%) and 21 as S. dysenteriae (24%). More than 95% of the isolates were susceptible to ciprofloxacin, ceftriaxone and ceftizoxim, 70% to nalidixic acid and less than 50% to co-trimoxazole, tetracycline, ampicillin and fourazolodon.