Intra‐abdominal pressure and intestinal microbiome are associated with clinical outcomes in sepsis patients receiving early enteral nutrition: A prospective observational study

Abstract Introduction Intra‐abdominal pressure (IAP) and gut microbiota have been associated with the prognosis of patients with sepsis receiving early enteral nutrition (EEN). In this study, we investigated this association and its prognostic value. Methods In this prospective observational study, we enrolled patients with sepsis receiving EEN. Firth's penalized logistic regression and restricted cubic spline (RCS) analyses were used to assess the association between IAP, Chao1 index, and prognosis. The gut microbiota composition and functional potential were analyzed using 16S ribosomal RNA gene sequencing and phylogenetic investigation of communities by reconstruction of unobserved states 2. Results Among the 52 patients, exploratory regression analyses showed that elevated IAP and a decreased Chao1 index were associated with a higher intensive care unit and 28‐d mortality, with no significant interaction ( p > 0.05). RCS analysis revealed an “L‐shaped” nonlinear relationship between the Chao1 index and mortality. RNA sequencing confirmed significant differences in the community structure between the high‐ and low‐IAP groups (analysis of similarity R = 0.197, p = 0.001; Adonis R 2 = 0.042, p = 0.005). Taxonomically, the low‐IAP group was significantly enriched with obligate anaerobic commensals (e.g., Blautia and Faecalibacterium), whereas the high‐IAP group was enriched with the absolute dominance of facultative pathogens, notably Enterococcus. Functional prediction showed significant upregulation of membrane transport and carbohydrate metabolism pathways in the high‐IAP group. Conclusion Elevated IAP and reduced microbiota diversity were associated with poor outcomes in patients with sepsis receiving EEN. A high‐IAP phenotype was also associated with significant taxonomic dysbiosis and predicted metabolic functional alterations.