Microbial and Environmental Factors Associated With Polyps Development in Familial Adenomatous Polyposis (MicrobEnvironment in FAP)

Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disorder linked to a mutation in the APC gene, associated with the development of multiple colonic and duodenal adenomas, which in 100% of cases progress to colorectal cancer (CRC) if left untreated. Management of affected patients is usually based on prophylactic total colectomy with or without rectal preservation, followed by regular endoscopic surveillance of the duodenum and rectum or ileal reservoir. However, there is considerable inter- and intra-familial variability in the rate of adenoma appearance and development for identical mutations. This strongly suggests the additional role of environmental factors. Recently, the gut microbiota has been identified as a co-factor of carcinogenesis in patients with FAP, but no prospective evaluation of the association between the incidence and severity of adenomatous proliferations and a microbiological signature has been studied, particularly at duodenal level in operated patient.

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Key information

Conditions

Familial Adenomatous Polyposis Adenoma Adenomatous Polyposis Coli Adenomatous Polyps Colonic Diseases Colorectal Neoplasms Congenital, Hereditary, and Neonatal Diseases and Abnormalities Digestive System Diseases Digestive System Neoplasms Gastrointestinal Diseases Gastrointestinal Neoplasms Genetic Diseases, Inborn Intestinal Diseases Intestinal Neoplasms Intestinal Polyposis Neoplasms Neoplasms by Histologic Type Neoplasms by Site Neoplasms, Glandular and Epithelial Neoplastic Syndromes, Hereditary Rectal Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Hôpital Edouard Herriot, Lyon, France

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

≥18 years
Non-opposition obtained
Prophylactic colectomy for at least 2 years in the context of APC-related familial adenomatous polyposis with ileorectal or ileoanal anastomosis
Included in the national POLYPOSE database
Regular endoscopic follow-up with upper and lower GI endoscopy at Hôpital Edouard Herriot or Hôpital de la Croix-Rousse
Having performed at least 2 endoscopies as part of follow-up

Exclusion criteria

Antibiotic therapy within 2 months prior to stool sampling
Taking probiotics for less than 1 month
Person deprived of liberty by judicial or administrative decision

Treatment and study plan

Sampling of feces and duodenal fluids

Other

Blood sampling (plasmotheque and serotheque): 2 tubes (EDTA (5mL) and dry (5mL)) during hospitalization
Fecal sampling (fecal library): A stool sample (approx. 2g) will be taken 48 hours before the endoscopy at home for outpatient or during hospitalization
Duodenal aspiration fluid (6-10 mL in total): before and after mucosal lavage with sterile isotonic saline on the day of endoscopy.
Food and Lifestyle Questionnaire (FFQ) during inclusion

Primary outcomes

Fecal microbiota composition

Time frame: Within 48 hours of endoscopy

Analysis of fecal microbiota composition as a function of the cumulative number of reservoir (rectum or ileal) adenomas treated over 3 consecutive endoscopies

Study contacts

Contact information is provided by the study sponsor or research team.

Nicolas BENECH, MD PhD

CONTACT

[email protected]

+33426109435 ext. +33

Sponsors and collaborators

Lead sponsor

Hospices Civils de Lyon

Other

Registry information

Official study title

Microbial and Environmental Factors Associated With Polyps Development in Familial Adenomatous Polyposis

Important dates

Study start: 2024
Primary completion: 2028
Study completion: 2029
First posted: Sep 26, 2024
Registry last updated: May 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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