Observations placeholder

J Pediatr Gastroenterol Nutr. 2009 Apr;48 Suppl 2:S95-7. doi: 10.1097/MPG.0b013e3181a15e2e.  Postinfectious irritable bowel syndrome. Barbara G, Cremon C, Pallotti F, De Giorgio R, Stanghellini V, Corinaldesi R. Department of Internal Medicine and Gastroenterology and CRBA, University of Bologna, Bologna, Italy. giovanni.barbara@unibo.it

Irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by abdominal pain and changes in bowel habits, not sustained by structural changes.

There is now consistent evidence indicating that IBS may be the adverse outcome of an acute episode of infectious gastroenteritis, the so-called postinfectious (PI) IBS. The infectious agents involved in the development of PI-IBS include pathogenic bacteria, parasites, and viruses.

Abdominal pain and diarrhea are the most common symptoms of PI-IBS. Several studies identified a number of risk factors increasing the susceptibility for PI-IBS development. These include the virulence of the pathogen, the severity, and duration of the acute enteritis, younger age, female sex, and psychological disturbances.

Several mucosal abnormalities in the colon or ileum of patients who develop PI-IBS have been described. These changes include increased mucosal permeability, an increased amount of intraepithelial lymphocytes, lamina propria T cells, and mast cells, as well as serotonin-containing enteroendocrine cells.

The mediators released by these activated cells may evoke enteric nervous system responses, excite sensory afferent pathways, and induce visceral hyperalgesia. Little is known about the prognosis of PI-IBS, although it is likely better than that of nonspecific IBS.

There is little evidence about a specific treatment for PI-IBS. Although probiotics ..may be promising in the prevention of PI-IBS, the efficacy of these treatments should be assessed in an ad hoc designed study.

PMID: 19300138

Rev Esp Enferm Dig. 2013 Jan;105(1):19-36. Effect of probiotic species on irritable bowel syndrome symptoms: A bring up to date meta-analysis. Ortiz-Lucas M, Tobías A, Saz P, Sebastián JJ.

Background and objectives: immune system alteration in irritable bowel syndrome (IBS) patients may be modulated by probiotics. We assessed the efficacy of some probiotic species in alleviating characteristic IBS symptoms.

Material and methods: a meta-analysis of all identified randomized controlled trials comparing probiotics with placebo in treating IBS symptoms was performed with continuous data summarized using standardized mean differences (SMDs) with 95% confidence intervals (95% CIs), where appropriate. The random-effects model was employed in cases of heterogeneity; otherwise, fixed-effects models were used.

Results: meta-analysis was performed with 10 of 24 studies identified as suitable for inclusion. Probiotics improved pain scores if they contained

• Bifidobacterium breve (SMD, - 0.34; 95% CI, - 0.66; -0.02),
• Bifidobacterium longum (SMD, -0.48; 95% CI, - 0.91; -0.06),
• Lactobacillus acidophilus (SMD, -0.31; 95% CI, -0.61; -0.01) species.

Distension scores were improved by probiotics containing

• B. breve (SMD, -0.45; 95% CI, -0.77; -0.13),
• Bifidobacterium infantis,
• Lactobacillus casei, or
• Lactobacillus plantarum (SMD, -0.53; 95% CI, -1.00; -0.06) species.

All probiotic species tested improved flatulence:

• B. breve (SMD, -0.42; 95% CI, -0.75;- 0.10),
• B. infantis,
• L. casei,
• L. plantarum (SMD, -0.60; 95% CI, -1.07; -0.13),
• B. longum,
• L. acidophilus,
• Lactobacillus bulgaricus, and
• Streptococcus salivarius ssp. thermophilus (SMD, -0.61; 95% CI, -1.01; -0.21).

There was not a clear positive effect of probiotics concerning the quality of life.

Conclusions: some probiotics are an effective therapeutic option for IBS patients, and the effects on each IBS symptom are likely species-specific. Future studies must focus on the role of probiotics in modulating intestinal microbiota and the immune system while considering individual patient symptom profiles.

PMID: 23548007