Predictors of Symptom-Specific Treatment Response to Dietary Interventions in Irritable Bowel Syndrome

Nutrients. 2022 Jan 17;14(2):397. doi: 10.3390/nu14020397.


(1) Background: Predictors of dietary treatment response in irritable bowel syndrome (IBS) remain understudied. We aimed to investigate predictors of symptom improvement during the low FODMAP and the traditional IBS diet for four weeks. (2) Methods: Baseline measures included faecal Dysbiosis Index, food diaries with daily energy and FODMAP intake, non-gastrointestinal (GI) somatic symptoms, GI-specific anxiety, and psychological distress. Outcomes were bloating, constipation, diarrhea, and pain symptom scores treated as continuous variables in linear mixed models. (3) Results: We included 33 and 34 patients on the low FODMAP and traditional IBS diet, respectively. Less severe dysbiosis and higher energy intake predicted better pain response to both diets. Less severe dysbiosis also predicted better constipation response to both diets. More severe psychological distress predicted worse bloating response to both diets. For the different outcomes, several differential predictors were identified, indicating that baseline factors could predict better improvement in one treatment arm, but worse improvement in the other treatment arm. (4) Conclusions: Psychological, nutritional, and microbial factors predict symptom improvement when following the low FODMAP and traditional IBS diet. Findings may help individualize dietary treatment in IBS.

Keywords: NICE guidelines; diet; disorders of the gut brain interaction; dysbiosis; functional gastrointestinal disorders; gastrointestinal symptoms; irritable bowel syndrome; low FODMAP diet; prediction; treatment response.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Abdominal Pain / therapy
  • Adult
  • Anxiety Disorders / physiopathology
  • Brain-Gut Axis / physiology
  • Constipation / therapy
  • Diarrhea / therapy
  • Diet
  • Diet Records
  • Dietary Carbohydrates / administration & dosage
  • Dysbiosis
  • Energy Intake
  • Feces / microbiology
  • Fermentation
  • Humans
  • Irritable Bowel Syndrome / diet therapy*
  • Irritable Bowel Syndrome / physiopathology*
  • Irritable Bowel Syndrome / psychology
  • Male
  • Meals
  • Middle Aged
  • Nutrition Therapy / methods
  • Nutritional Status
  • Treatment Outcome*


  • Dietary Carbohydrates