Low fermentable, oligo-, di-, mono-saccharides and polyol diet in the treatment of irritable bowel syndrome: A systematic review and meta-analysis.

OBJECTIVESThe aim of this review was to systematically assess and meta-analyze the effects of a low fermentable, oligo-, di-, mono-saccharides and polyol (FODMAP) diet (LFD) on the severity of symptoms, quality of life, and safety in patients with irritable bowel syndrome (IBS).

METHODSThe MEDLINE/PubMed, Scopus, and Cochrane Library databases were screened through January 19, 2016. Randomized controlled trials (RCTs) that compared LFD to other diets were included if they assessed symptoms of IBS or abdominal pain in patients with IBS. Safety, quality of life, anxiety, depression, and effect on gut microbiota were defined as secondary outcomes. Standardized mean difference (SMD) and 95% confidence interval (CI) were calculated.

RESULTSNine RCTs with a total of 596 subjects were included. Three RCTs compared LFD with a habitual diet, two RCTs provided all meals and compared LFD with a western diet, one RCT each compared LFD with a diet high in FODMAPs or a sham diet, and two RCTs compared with other diet recommendations for IBS. A meta-analysis revealed significant group differences for LFD compared with other diets with regard to gastrointestinal symptoms (SMD = -0.62; 95% CI = -0.93 to -0.31; P = 0.0001), abdominal pain (SMD = -0.50; 95% CI = -0.77 to -0.22; P = 0.008), and health-related quality of life (SMD = 0.36; 95% CI = 0.10-0.62; P = 0.007). Three studies reported a significant reduction in luminal bifidobacteria after LFD. Adverse events were assessed in three RCTs only and no intervention-related adverse events were reported.

CONCLUSIONSThis meta-analysis found evidence of the short-term efficacy and safety of LFD in patients with IBS. However, only a preliminary recommendation for LFD can be made until long-term effects are investigated.