Microbial and Transcriptomic Landscape Associated With Neutrophil Extracellular Traps in Perianal Fistulizing Crohn's Disease

Perianal fistulizing Crohn's disease (pfCD) poses significant healing challenges, closely associated with neutrophil extracellular traps (NETs). This study aimed to investigate the microbe-host interactions influencing NETs in pfCD. From January 2019 to July 2022, patients with pfCD were screened at Ren Ji Hospital. Patients in remission following comprehensive treatment were recruited. We documented clinical characteristics, medication regimens, healing outcomes, and infliximab levels in fistula tissues. NET positivity was confirmed by positive results in citrullinated histone H3 (CitH3) enzyme-linked immunosorbent assay (ELISA) and dual immunofluorescence staining for myeloperoxidase and CitH3. Microbial and transcriptomic profiles from fistula tissues, obtained during surgery, were analyzed using 16S rRNA gene sequencing and RNA sequencing. Differences in microbiome and transcriptomic profiles were evaluated, and their relationships were assessed using Mantel's and Spearman's coefficients. Significant differences in microbial communities were found between groups (P = .007). Representatively differential microbes such as Prevotella bivia, Streptococcus gordonii, and Bacteroides dorei were enriched in NETs-positive fistulas (P