Exploring Gut Microbiota Composition as an Indicator of Clinical Response to Dietary FODMAP Restriction in Patients with Irritable Bowel Syndrome

• Published in: Digestive diseases and sciences 2018-02, Vol.63 (2), p.429-436
• Main Authors: Valeur, Jørgen, Småstuen, Milada Cvancarova, Knudsen, Torunn, Lied, Gülen Arslan, Røseth, Arne Gustav
• Format: Article
• Language: English
• Subjects: Biochemistry; Care and treatment; Diet; Digestive system; Gastroenterology; Hepatology; Irritable bowel syndrome; Medicine; Medicine & Public Health; Microbiota; Microbiota (Symbiotic organisms); Monosaccharides; Oncology; Original Article; Polyols; Sugars; Transplant Surgery
• ISSN: 0163-2116; 1573-2568
• DOI: 10.1007/s10620-017-4893-3

Background A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) may relieve symptoms of irritable bowel syndrome (IBS). However, nutritional counseling is resource-demanding and not all patients will benefit. Aims To explore whether gut microbial composition may identify symptom response to a low-FODMAP diet in patients with IBS. Methods Patients were recruited consecutively to participate in a 4-week FODMAP-restricted diet. Response to diet was defined as ≥ 50% decrease in IBS symptom severity scores (IBS-SSS) compared to baseline. Fecal microbiota were analyzed by a commercially available method (the GA-map™ Dysbiosis Test), assessing 54 bacterial markers targeting more than 300 bacteria at different taxonomic levels. Results Sixty-one patients (54 F; 7 M) were included: 32 (29 F; 3 M) classified as responders and 29 (25 F; 4 M) as non-responders. Ten of the 54 bacterial markers differed significantly between responders and non-responders. Based on median values (used as cutoff) of responders for these 10 bacterial markers, we constructed a Response Index (RI): Each patient was given a point when the value for each selected bacterial marker differed from the cutoff. These points were summed up, giving an RI from 0 to 10. Patients with RI > 3 were 5 times more likely to respond (OR = 5.05, 95% CI [1.58; 16.10]), and the probability to respond was 83.4%, 95% CI [61.2–94%]. Conclusions Gut microbial composition, assessed by using a new RI, may constitute a tool to identify patients that are likely to respond to dietary FODMAP restriction.