Association between gut microbiota composition and ischemic colitis: a comparative analysis

This study aimed to examine the association between gut microbiota composition and ischemic colitis (IC) by comparing the microbial diversity and abundance in individuals diagnosed with IC and healthy controls.

A comparative analysis of gut microbiota was conducted in 18 individuals with IC and 11 healthy controls. Microbial community structure was assessed at both the phylum and genus levels.

At the phylum level, individuals with IC exhibited a predominance of Proteobacteria, Bacteroidetes, and Firmicutes, whereas the control group primarily harbored Phylum Firmicutes, Proteobacteria, and Actinobacteria. At the genus level, the IC group showed enrichment in Bacteroides, Halomonas, and Escherichia-Shigella while the control group primarily included Akkermansia, Bacteroides, and Bifidobacterium. Beta diversity analysis demonstrated significantly greater operational taxonomic unit richness and community diversity in the IC group compared to controls. Analysis of similarities demonstrated significant inter-group differences in microbial community composition (r = 0.223, p = 0.002). Analysis of molecular variance analysis further confirmed significant differences in microbial abundance and diversity between groups (p < 0.05). Linear discriminant analysis effect size identified a significant enrichment of Proteobacteria in the IC group, particularly Gammaproteobacteria, Pseudomonadales, Moraxellaceae, and Enhydrobacter. In contrast, the control group exhibited significant enrichment in Firmicutes, notably Rothia, Peptostreptococcaceae, Clostridium sensu stricto, Clostridiaceae, and Erysipelotrichales.

The gut microbiota of individuals with IC was characterized by increased microbial diversity and notable alterations in community composition. Specifically, there was an enrichment of Proteobacteria and several potentially pathogenic taxa, including the genera Bacteroides, Halomonas, and Escherichia-Shigella, as well as members of the order Pseudomonadales. Meanwhile, we observed reductions in Firmicutes, Actinobacteria, and health-associated genera, including Akkermansia, Bifidobacterium, and Rothia. These microbial shifts are associated with IC, which may be related to the disruption of gut homeostasis, promotion of inflammation, and impairment of mucosal barrier function. Due to the observational and cross-sectional nature of this study, no causal relationship between microbial changes and IC can be established, and further research is needed to explore the specific mechanisms involved.