Faecal microbial flora and disease activity in rheumatoid arthritis during a vegan diet

Br J Rheumatol. 1997 Jan;36(1):64-8. doi: 10.1093/rheumatology/36.1.64.


To clarify the role of the faecal flora in the diet-induced decrease of rheumatoid arthritis (RA) activity, 43 RA patients were randomized into two groups: the test group to receive living food, a form of uncooked vegan diet rich in lactobacilli, and the control group to continue their ordinary omnivorous diets. Based on clinical assessments before, during and after the intervention period, a disease improvement index was constructed for each patient. According to the index, patients were assigned either to a group with a high improvement index (HI) or to a group with a low improvement index (LO). Stool samples collected from each patient before the intervention and at 1 month were analysed by direct stool sample gas-liquid chromatography of bacterial cellular fatty acids. This method has proved to be a simple and sensitive way to detect changes and differences in the faecal microbial flora between individual stool samples or groups of them. A significant, diet-induced change in the faecal flora (P = 0.001) was observed in the test group, but not in the control group. Further, in the test group, a significant (P = 0.001) difference was detected between the HI and LO categories at 1 month, but not in the pre-test samples. We conclude that a vegan diet changes the faecal microbial flora in RA patients, and changes in the faecal flora are associated with improvement in RA activity.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arthritis, Rheumatoid / diet therapy*
  • Arthritis, Rheumatoid / microbiology*
  • Bacteria / chemistry
  • Bacterial Physiological Phenomena
  • Chromatography, Gas
  • Colon / microbiology
  • Diet, Vegetarian*
  • Fatty Acids / analysis
  • Feces / microbiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Random Allocation


  • Fatty Acids