Patients with irritable bowel syndrome who adhered to a low fermentable, oligo-, di-, mono-saccharides and polyol diet, known as the low FODMAPs diet, experienced improvement in gastrointestinal symptoms and quality of life, according to a new meta-analysis published in Nutrition.
The review, which included nine randomized controlled trials published between 2012 and 2016, also showed the low FODMAP diet appeared safe in the short-term, but the researchers concluded that long-term data are needed before more than a preliminary recommendation for the diet can be made for patients with IBS.
“The mechanism behind the low FODMAP diet lies in the reduction of the fermentable load and the liquid volume that is delivered to the colon to reduce gas production and luminal distension that is associated with GI symptom relief in patients with IBS,” Dania Schumann, MSc, of the department of internal and integrative medicine at Kliniken Essen-Mitte, and faculty of medicine at the University of Duisburg-Essen in Essen, Germany, and colleagues wrote.
The investigators reviewed nine randomized controlled trials (n = 596) that compared the low FODMAP diet to other diets in patients with IBS.
Three of the trials compared the low FODMAP diet with a habitual diet, two trials provided all meals and compared the low FODMAP diet with a western diet, one trial compared the low FODMAP diet with a diet high in FODMAPs, another compared it to a sham diet, and two compared it with other diet recommendations for IBS.
Patients who adhered to the low FODMAP diet showed significantly greater improvements in gastrointestinal symptoms (standardized mean difference = –0.62; 95% CI, –0.93 to –0.31), abdominal pain (SMD = –0.5; 95% CI, –0.77 to –0.22) and health-related quality of life (SMD = 0.36; 95% CI, 0.1-0.62) compared with other diets.
Additionally, no diet-related adverse events occurred in the three trials analyzed for safety.
Finally, investigators evaluated the effects of the low FODMAP diet on the gut microbiome in four trials, three of which showed a significant reduction in luminal bifidobacteria after the diet intervention.
Despite the positive efficacy findings, the researchers noted that 25% of patients with IBS do not improve on the low FODMAP diet, and that it may only be effective for patients with diarrhea predominant IBS (IBS-D).
“Constipation underlies different intestinal mechanisms and has been associated with a lack of dietary fiber,” they wrote. “The [low FODMAP diet] has been criticized for not providing sufficient sources of fiber, and further research is needed to analyze effects on single subtypes as well as conjunctive therapies that benefit [constipation predominant IBS (IBS-C)].”
The researchers concluded that further research is needed to evaluate the long-term outcomes and safety of the low FODMAP diet, as well as its long-term effects on gut microbiota, cost effectiveness and efficacy compared with alternatives. – by Alex Young
Disclosures: The authors report no relevant financial disclosures.