Metatranscriptomic analysis of colonic mucosal samples exploring the functional role of active microbial consortia in complicated diverticulitis

In this study, we investigated complicated diverticulitis, an inflammatory condition associated with abscesses, fistulas, intestinal obstructions, perforations, and primarily affects adults over the age of 60. Although the exact etiology remains unclear, the gut microbiome has been suggested as a contributing factor. Previous studies have used 16S rRNA gene analysis from patient fecal samples, which is limited to identifying the bacterial communities present. Herein, we employed shotgun metatranscriptomics on 40 patient-matched samples of diseased and adjacent normal colonic mucosal tissues from 20 patients with complicated diverticulitis to gain a more comprehensive understanding of active microbial taxa and gene expression patterns that may be involved in this disease state. Our findings revealed distinct beta diversity and a conglomerate of pathogenic microbiota in the diseased tissues, including Staphylococcus cohnii, Corynebacterium jeikeium, Kineococcus, Talaromyces rugulosus, Campylobacteraceae, and Ottowia, among others. The adjacent normal tissues were a stark contrast, harboring anti-inflammatory taxa such as Streptococcus salivarius and housekeeping genes and pathways such as the ABC-2 type transport system ATP-binding protein. These results align with previous amplicon sequencing studies and provide novel functional insights that may be crucial for understanding the etiology of complicated diverticulitis.