title: Consistent Prebiotic Effect on Gut Microbiota With Altered FODMAP Intake in Patients with Crohn's Disease: A Randomised, Controlled Cross-Over Trial of Well-Defined Diets.
abstract: OBJECTIVE
  Altering FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) intake has substantial effects on gut microbiota. This study aimed to investigate effects of altering FODMAP intake on markers of colonic health in patients with Crohn's disease.
  
  
  METHODS
  After evaluation of their habitual diet, 9 patients with clinically quiescent Crohn's disease were randomised to 21 days of provided low or typical ("Australian") FODMAP diets with ≥21-day washout in between. Five-day fecal samples were collected at the end of each diet and analyzed for calprotectin, pH, short-chain fatty acids (SCFA) and bacterial abundance. Gastrointestinal symptoms were recorded daily.
  
  
  RESULTS
  Eight participants collected feces and were adherent to the diets. FODMAP intake differed across the three dietary periods with low<habitual<Australian diet. SCFA, pH and total bacterial abundance remained unaltered, but relative abundance was higher for butyrate-producing Clostridium cluster XIVa (P=0.008) and mucus-associated Akkermansia muciniphila (P=0.016), and lower for Ruminococcus torques (P=0.034) during the Australian compared with low FODMAP diet. Results during habitual diet were similar to the low FODMAP intervention, but significantly different to the Australian diet. The diets had no effects on calprotectin, but symptoms doubled in severity with the Australian diet (n=9; P<0.001).
  
  
  CONCLUSIONS
  In clinically quiescent Crohn's disease, altering dietary FODMAP intake is associated with marked changes in fecal microbiota, most consistent with a prebiotic effect of increasing FODMAPs as shown in an irritable bowel/healthy cohort. This strategy might be favorable for gut health in Crohn's disease, but at the cost of inducing symptoms.
authors.affiliation: Department of Gastroenterology, Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia.|Department of Gastroenterology, Central Clinical School, Monash University, Melbourne, Victoria, Australia.
authors.forename: Emma P
authors.initials: EP
authors.lastname: Halmos
authors.affiliation: Food Futures National Research Flagship, Commonwealth Scientific and Industrial Research Organisation, Food, Animal and Health Sciences, Adelaide, South Australia, Australia.|School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia.
authors.forename: Claus T
authors.initials: CT
authors.lastname: Christophersen
authors.affiliation: Food Futures National Research Flagship, Commonwealth Scientific and Industrial Research Organisation, Food, Animal and Health Sciences, Adelaide, South Australia, Australia.
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Bird
authors.affiliation: Department of Gastroenterology, Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia.|Department of Dietetics and Human Nutrition, La Trobe University, Bundoora, Victoria, Australia.
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Shepherd
authors.affiliation: Department of Gastroenterology, Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia.|Department of Gastroenterology, Central Clinical School, Monash University, Melbourne, Victoria, Australia.
authors.forename: Jane G
authors.initials: JG
authors.lastname: Muir
authors.affiliation: Department of Gastroenterology, Eastern Health Clinical School, Monash University, Box Hill, Victoria, Australia.|Department of Gastroenterology, Central Clinical School, Monash University, Melbourne, Victoria, Australia.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Gibson