Abstract
OBJECTIVE: We aimed to investigate the relationship between fecal bile acid (BA) profile and intestinal microbiota in patients with chronic radiation enteritis (CRE). METHODS: Altogether 60 patients with cervical cancer (CC) who visited Xijing Hospital between December 2022 and September 2023 were enrolled, including 20 patients who did not undergo any treatment (the CC group), 20 patients who developed CRE after radical radiotherapy (the CRE group), and 20 patients who did not experience CRE after radical radiotherapy (the non-CRE [NRE] group). Patients' characteristics and fecal samples were collected. Fecal BA profiles were quantified, and intestinal microbiota were analyzed by using the 16S rRNA gene sequencing. Differentially expressed BAs and microorganisms were identified across groups, and their correlations were assessed using Spearman's correlation analysis. RESULTS: In patients with CRE, BA metabolism was characterized by increased proportions of primary BAs and decreased proportions of secondary BAs, particularly lithocholic acid and its isomers. In addition, the abundance of beneficial bacterial genera, such as Bifidobacterium and Megasphaera, was reduced, whereas that of potentially pathogenic genera, including Megamonas and Dorea, was increased. Furthermore, a bidirectional relationship between BA metabolism and intestinal microbiota was observed. CONCLUSIONS: Patients with CRE present notable alterations in BA metabolism and intestinal microbiota. CRE may trigger a harmful feedback mechanism driven by the interaction between these two factors. Targeted regulation of BA metabolism and intestinal microbiota may be a promising therapeutic approach for the management of CRE. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05728060.