Causal Relationship Between Gut Microbiota and Gastrointestinal Polyps: A Mendelian Randomization Study.

Area of Science:

• Genetics and Microbiology
• Gastroenterology
• Human Health and Disease

Background:

• Intestinal flora is recognized for its association with gastrointestinal polyp development.
• The precise causal relationship between gut microbiota and polyps remains unclear.
• Gastrointestinal polyps include gastric, duodenal, colon, and rectal types.

Purpose of the Study:

• To investigate the causal relationship between gut microbiota and polyps in the stomach, duodenum, colon, and rectum.
• To utilize Mendelian randomization (MR) analysis for assessing causality.
• To identify specific bacterial taxa associated with increased or decreased risk of gastrointestinal polyps.

Main Methods:

• Mendelian randomization (MR) analysis was performed using publicly available genome-wide association study summary data.
• Gut microbiota data were sourced from the International MiBioGen Consortium; gastrointestinal polyp data from the MRC-IEU Consortium.
• Causality was assessed using MR-Egger, weighted median, inverse variance weighting, simple mode, and weighted mode techniques, with heterogeneity and pleiotropy evaluated.

Main Results:

• Specific bacteria like Lachnospiraceae UCG004, Erysipelotrichaceae UCG003, and Veillonella were linked to increased colon polyp risk.
• Dorea and Clostridium innocuum group showed a protective effect against colon polyps.
• Allisonella was associated with increased rectal polyp risk, while Christensenellaceae R.7 group, Parasutterella, and Intestinimonas were protective. Lachnospiraceae FCS020 group, Intestinibacter, Ruminococcaceae UCG003, and Parasutterella were risk factors for stomach and duodenal polyps.

Conclusions:

• The study establishes a causal link between gut microbiota dysbiosis and gastrointestinal polyp formation.
• Specific bacterial taxa play significant roles in the risk and protection against various gastrointestinal polyps.
• Further research is needed to elucidate the precise mechanisms by which these bacteria influence polyp development.