Colorectal adenoma recurrence: an analysis of risk factors and gut microbiota characteristics

Colorectal adenoma (CRA) is precancerous lesion of colorectal cancer (CRC). Early detection and endoscopic resection of CRA are the most effective methods for preventing CRC, yet there is a significant recurrence risk. We aim to analyze the risk factors for CRA recurrence and explore the gut microbiota characteristics in individuals with recurrent CRA, in order to provide new insights for risk stratification and intervention.

We recruited 30 participants with recurrent CRA and 15 participants without CRA recurrence. Demographic information, baseline characteristics of adenomas, and other clinical data were collected from each participant. Univariate analysis and Firth Logistic regression analysis were used to analyze the risk factors for CRA recurrence. Meanwhile, fecal samples were collected from all participants and 16s rRNA sequencing was performed to analyze the composition, structure, and taxonomic differences of the gut microbiota, as well as to predict potential functional capacities. Correlation analysis is employed to explore the associations between differential gut microbiota and functional pathways.

Univariate analysis revealed that there were statistically significant differences (p < 0.05) between the two groups in terms of age, body mass index (BMI), diabetes, smoking history, adenoma size, adenoma number, and advanced adenomas. Firth Logistic analysis indicated that adenoma number and smoking history were independent clinical risk factors for CRA recurrence. Microbiomic analysis showed no significant difference (p > 0.05) in the α-diversity and β-diversity of the gut microbiota between the two groups. Taxonomic analysis revealed the abundances of potential pathogenic bacteria such as Escherichia-Shigella and Klebsiella were significantly increased in the recurrence group, while the abundances of Bacteroides and Faecalibacterium were significantly reduced. Furthermore, Linear Discriminant Analysis Effect Size (LEfSe) analysis indicated that the non-recurrence group was enriched with genera such as Megasphaera. Functional prediction analysis suggested that pathways related to fatty acid metabolic and biosynthetic process were more active in the non-recurrence group. Correlation analysis uncovered the genera enriched in the recurrence group were positively correlated with the functional pathways of styrene degradation and fat digestion and absorption, whereas the genera with reduced abundance were positively correlated with fat digestion and absorption and MicroRNAs in cance pathways.

This study not only elucidates the clinical risk factors for CRA recurrence but also reveals that CRA recurrence may be closely associated with the gut microbiota dysbiosis. Combining clinical risk factors with gut microbial biomarkers is expected to construct a more precise predictive model for adenoma recurrence and provide crucial theoretical support for future intervention strategies targeting the gut microbiota.