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Causal Relationship Between Gut Microbiota and Gastrointestinal Polyps: A Mendelian Randomization Study
Yang Xie1, Sheng Chen1, Yiling Xiong1
1Department of Gastroenterology, Jiangxi Provincial Key Laboratory of Digestive Diseases, Jiangxi Clinical Research Center for Gastroenterology, Digestive Disease Hospital, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, China.
Background/Aims:
Numerous studies have confirmed that intestinal flora is closely linked to the development of gastrointestinal polyps. However, the precise causal link between them has yet to be clarified. This study sought to determine the causal relationship between gut microbiota and gastric, duodenal, colon, and rectal polyps by Mendelian randomization (MR).
Materials And Methods:
We employed publicly available genome-wide association study summary data to conduct MR analysis. Gut microbiota data were sourced from the International MiBioGen Consortium, and gastrointestinal polyp data were obtained from the MRC-IEU Consortium. Instrumental variables were selected based on eligible single-nucleotide polymorphisms. To assess causality, we utilized MR-Egger, weighted median, inverse variance weighting, simple mode, and weighted mode techniques. Heterogeneity and pleiotropy were evaluated through Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis.
Results:
We determined that Lachnospiraceae UCG004, Erysipelotrichaceae UCG003, and Veillonella increased the risk of colon polyps. However, Dorea and Clostridium innocuum group act as protective factors for colon polyps. Allisonella increases the risk of rectal polyps. In contrast, Christensenellaceae R.7 group, Parasutterella, and Intestinimonas are protective factors for rectal polyps. Lachnospiraceae FCS020 group, Intestinibacter, Ruminococcaceae UCG003, and Parasutterella act as risk factors for stomach and duodenum polyps.
Conclusions:
Our research establishes a causal link between gut microbiota dysbiosis and the formation of gastrointestinal polyps. Nonetheless, additional studies are necessary to explore the mechanisms through which bacterial taxa influence the development of these polyps.
Insights
Gut bacteria influence gastrointestinal polyp development. Specific microbes increase colon and rectal polyp risk, while others offer protection. This study used Mendelian randomization to establish these causal links.
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.
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