Probiotics, prebiotics, and low FODMAP diet for irritable bowel syndrome - What is the current evidence?

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders worldwide. While the pathogenesis is not clearly understood, current research points to the role of the gut microbiome and alterations in the diversity of the microbiota. Probiotics, prebiotics, and low FODMAP diet are therapeutic means associated with modification of the gut microbiome for the alleviation of IBS symptoms. This narrative review assesses the current evidence on the efficacy of these treatment options based on findings from recent systematic reviews and meta-analyses published from October 2013 to October 2018. There is a general agreement in the 11 included systematic reviews and meta-analyses that probiotic therapy is safe and can be effective in improving overall IBS symptom scores and abdominal pain in the general IBS population. Nonetheless, conflicting findings remain and no recommendation on the specific species/strains or combination can be made. Short-term restriction of FODMAP in the diet can improve IBS symptoms as per the findings of 7 systematic reviews and meta-analyses, even though the quality of the evidence remains questionable. Inappropriate use of the low FODMAP diet can potentially impact health negatively. As such, a low FODMAP diet is only recommended as a second line treatment guided by qualified clinicians with specialized training. Despite preclinical studies of some prebiotics demonstrated the potential use in improving gut microbiome and intestinal inflammatory response, the beneficial effect of prebiotics for IBS remains theoretical. Two systematic reviews found no evidence to support the clinical use of prebiotics for IBS.