Bioinformatic identification of CD8+ T cell activation mediated by key genes in fecal microbiota transplantation for irritable bowel syndrome

Abstract

Background The effect of fecal microbiota transplantation (FMT) in treating irritable bowel syndrome (IBS) may be attributed to the modulation of CD8 + T cells. This study aims to identify FMT-mediated key genes to explore the underlying mechanism. Methods Transcriptomic datasets GSE138297 (colonic biopsies from 8 IBS patients pre- and post-FMT) and GSE134649 (single-cell data from 3 healthy colon tissues) were obtained from GEO during December 2023–December 2024. Key genes were identified by intersecting differentially expressed genes (DEGs) and the most relevant co-expression module derived from weighted correlation network analysis. Functional enrichment, gene set enrichment analysis, immune infiltration profiling via TIMER 2.0, single-cell annotation using PanglaoDB and Seurat, and drug–gene interaction screening from DrugBank were conducted to decipher the regulatory mechanisms. Results Ten key genes were identified through integration of DEGs and the MEgreen module. Functional analyses revealed significant involvement in the positive regulation of CD8 + T cells activation. Immune infiltration assessment demonstrated a marked increase in CD8 + T cells abundance post-FMT. Single-cell data indicated predominant expression of LILRB1, P2RY13, CLEC10A, and CLEC12A in dendritic cells, and LILRB1, PIPOX, and CLEC11A were annotated within CD8 + T cells clusters in healthy colonic tissue. Nine (database-derived and speculative) drugs targeting seven key genes were identified, most implicated in the management of IBS symptoms or immunomodulation. Conclusion An association between key gene regulation and CD8 + T cell-related immunoregulation is correlated with the therapeutic effect of FMT in IBS.