Fibre-rich Foods to Treat Obesity and Prevent Colon Cancer trial study protocol: a randomised clinical trial of fibre-rich legumes targeting the gut microbiome, metabolome and gut transit time of overweight and obese patients with a history of noncancerous adenomatous polyps

BMJ Open. 2024 Feb 5;14(2):e081379. doi: 10.1136/bmjopen-2023-081379.

Abstract

Introduction: Recently published studies support the beneficial effects of consuming fibre-rich legumes, such as cooked dry beans, to improve metabolic health and reduce cancer risk. In participants with overweight/obesity and a history of colorectal polyps, the Fibre-rich Foods to Treat Obesity and Prevent Colon Cancer randomised clinical trial will test whether a high-fibre diet featuring legumes will simultaneously facilitate weight reduction and suppress colonic mucosal biomarkers of colorectal cancer (CRC).

Methods/design: This study is designed to characterise changes in (1) body weight; (2) biomarkers of insulin resistance and systemic inflammation; (3) compositional and functional profiles of the faecal microbiome and metabolome; (4) mucosal biomarkers of CRC risk and (5) gut transit. Approximately 60 overweight or obese adults with a history of noncancerous adenomatous polyps within the previous 3 years will be recruited and randomised to one of two weight-loss diets. Following a 1-week run-in, participants in the intervention arm will receive preportioned high-fibre legume-rich entrées for two meals/day in months 1-3 and one meal/day in months 4-6. In the control arm, entrées will replace legumes with lean protein sources (eg, chicken). Both groups will receive in-person and written guidance to include nutritionally balanced sides with energy intake to lose 1-2 pounds per week.

Ethics and dissemination: The National Institutes of Health fund this ongoing 5-year study through a National Cancer Institute grant (5R01CA245063) awarded to Emory University with a subaward to the University of Pittsburgh. The study protocol was approved by the Emory Institutional Review Board (IRB approval number: 00000563).

Trial registration number: NCT04780477.

Keywords: GASTROENTEROLOGY; NUTRITION & DIETETICS; ONCOLOGY; Obesity.

Publication types

  • Clinical Trial Protocol
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenomatous Polyps* / complications
  • Adult
  • Biomarkers
  • Colonic Neoplasms* / prevention & control
  • Fabaceae*
  • Gastrointestinal Microbiome*
  • Humans
  • Metabolome
  • Obesity / complications
  • Obesity / therapy
  • Overweight / complications
  • Overweight / therapy
  • Randomized Controlled Trials as Topic
  • Vegetables

Substances

  • Biomarkers

Associated data

  • ClinicalTrials.gov/NCT04780477