Meta-analysis of probiotics for the treatment of irritable bowel syndrome. World J Gastroenterol

Department of Health Services Research and Development, VA Puget Sound Health Care System, Seattle WA 98101, United States.
World Journal of Gastroenterology (Impact Factor: 2.37). 06/2008; 14(17):2650-61. DOI: 10.3748/wjg.14.2650
Source: PubMed


Irritable bowel syndrome (IBS) is a chronic condition affecting 3%-25% of the general population. As no curative treatment is available, therapy is aimed at reducing symptoms, often with little success. Because alteration of the normal intestinal microflora has been observed in IBS, probiotics (beneficial microbes taken to improve health) may be useful in reducing symptoms. This paper systematically reviews randomized, controlled, blinded trials of probiotics for the treatment of IBS and synthesizes data on efficacy across trials of adequate quality. PubMed, Medline, Google Scholar, NIH registry of clinical trials, metaRegister, and the Cochrane Central Register of Controlled Trials were searched from 1982-2007. We also conducted secondary searches of reference lists, reviews, commentaries, relevant articles on associated diseases, books and meeting abstracts. Twenty trials with 23 probiotic treatment arms and a total of 1404 subjects met inclusion criteria. Probiotic use was associated with improvement in global IBS symptoms compared to placebo [pooled relative risk (RR pooled) 0.77, 95% confidence interval (95% CI) 0.62-0.94]. Probiotics were also associated with less abdominal pain compared to placebo [RR pooled = 0.78 (0.69-0.88)]. Too few studies reported data on other IBS symptoms or on specific probiotic strains to allow estimation of a pooled RR. While our analyses suggest that probiotic use may be associated with improvement in IBS symptoms compared to placebo, these results should be interpreted with caution, given the methodological limitations of contributing studies. Probiotics warrant further study as a potential therapy for IBS.

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    • "Based on this latter possibility, therapeutic approaches designed to manipulate gut flora with the replenishment of probiotics have been tested in both of patients and animal models with IBS. Several systematic reviews and meta-analyses report that probiotics have a statistically significant effect in improving overall and individual symptoms of IBS patients[11], [12], [13], [14], [15], [16]. Unfortunately, studies of the curative effect of probiotics in IBS have usually, but not always, been positive. "
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    ABSTRACT: Research has increasingly suggested that gut flora plays an important role in the development of post-infectious irritable bowel syndrome (PI-IBS). Studies of the curative effect of probiotics for IBS have usually been positive but not always. However, the differences of treatment effects and mechanisms among probiotic stains, or mixture of them, are not clear. In this study, we compared the effects of different probiotics (Befidobacterium, Lactobacillus, Streptococcus or mixture of the three) on intestinal sensation, barrier function and intestinal immunity in PI-IBS mouse model. PI-IBS model was induced by Trichinella spiralis infection in mice. Different probiotics were administered to mice after 8 weeks infection. Visceral sensitivity was measured by scores of abdominal withdrawal reflex (AWR) and the threshold intensity of colorectal distention. Colonic smooth muscle contractile response was assessed by contraction of the longitudinal muscle strips. Plasma diamine oxidase (DAO) and d-lactate were determined by an enzymatic spectrophotometry. Expression of tight junction proteins and cytokines in ileum were measured by Western blotting. Compared to control mice, PI-IBS mice treated either alone with Befidobacterium or Lactobacillus (but not Streptococcus), or the mixture of the three exhibited not only decreased AWR score and contractile response, but also reduced plasma DAO and D-lactate. These probiotic treatments also suppressed the expression of proinflammatory cytokine IL-6 and IL-17 and promoted the expression of major tight junction proteins claudin-1 and occludin. The mixture of the three probiotic strains performed better than the individual in up-regulating these tight junction proteins and suppressing IL-17 expression. Bifidobacterium and Lactobacillus, but not Streptococcus, alleviated visceral hypersensitivity and recovered intestinal barrier function as well as inflammation in PI-IBS mouse model, which correlated with an increase of major tight junction proteins. In addition, Mixture of three species was indicated to be superior to a single one.
    PLoS ONE 03/2014; 9(3):e90153. DOI:10.1371/journal.pone.0090153 · 3.23 Impact Factor
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    • "It has been shown that factors related to IBD include acquired factors (e.g., smoking and diet), pathogens, genetic factors, and irregular immune system [2]. Over the past decades, the homeostatic functions of microflora on host GI tract have attracted much attention because growing numbers of clinical studies have suggested that probiotics exhibit anti-inflammatory effects on IBD patients [3,4]. Arseneau et al. [5] suggested that innate immune responses play an equally significant, even more primary character compared with adaptive immune responses in IBD initiation and progression due to the observation that probiotics elicit anti- inflammatory effects in the GI tract by means of mucosal innate immune system stimulation, instead of suppression. "
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    ABSTRACT: Crohn's disease and ulcerative colitis are the major types of chronic inflammatory bowel disease occurring in the colon and small intestine. A growing body of research has proposed that probiotics are able to attenuate the inflammatory symptoms of these diseases in vitro and in vivo. However, the mechanism of probiotic actions remains unclear. Our results suggested Lactobacillus plantarum MYL26 inhibited inflammation in Caco-2 cells through regulation of gene expressions of TOLLIP, SOCS1, SOCS3, and IkappaBalpha, rather than SHIP-1 and IRAK-3. We proposed that live/ heat-killed Lactobacillus plantarum MYL26 and bacterial cell wall extract treatments impaired TLR4-NFkappab signal transduction through Tollip, SOCS-1 and SOCS-3 activation, thus inducing LPS tolerance. Our findings suggest that either heat-killed probiotics or probiotic cell wall extracts are able to attenuate inflammation through pathways similar to that of live bacteria.
    BMC Microbiology 08/2013; 13(1):190. DOI:10.1186/1471-2180-13-190 · 2.73 Impact Factor
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    • "They should have the ability to survive in sufficient numbers as well as to pass through the gut (bile and acid tolerant), be safe for consumption, and be adhesive to the intestinal mucosa. They should exert an antagonistic effect against pathogens, and interfere with the translocation of the pathogenic bacteria and modulate the immune system [14, 27,28,29,30, 33]. However, none of the probiotic strains meet these criteria in full or the studies showing this are not convincing. "
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    ABSTRACT: The review is devoted to the problems of microbiota and the ways of it correction employing beneficial life bacteria- probiotics. It covers the issues related to the functioning of human microbiota and its importance for the health, individual variability of microbial content, functioning of the probiotics in the human organism and the history of probiotic studies with particular focus on the microbiological investigations in the USSR. The article discusses the safety issues related to probiotics and the problems with probiotic therapy, trying to explain the reasons for the side effects caused by probiotics. The necessity of personified selection of the probiotic strain or individual microbial therapy autoprobiotics is also discussed.
    07/2013; 32(3):81-91. DOI:10.12938/bmfh.32.81
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