Characterization of Mucosa-Associated Microbiota in Formalin-Fixed, Paraffin-Embedded Tissues From Southern Thai...

Familial adenomatous polyposis (FAP) is an autosomal dominant syndrome associated with germline mutations in the adenomatous polyposis coli (APC) gene. Patients eventually may develop colorectal cancer (CRC) if they are not diagnosed in the early stages. Dysbiosis is an important contributing factor to the complex events in carcinogenesis, which are poorly understood. First, 25 tissue samples from 13 patients with FAP at Songklanagarind Hospital were classified as nontumor (n = 18) or tumor tissues (n = 7). Following isolation, 5 DNA samples of insufficient quantity and quality were excluded. The 16S rRNA gene targeting the V3-V4 region was sequenced, and the sequencing data were analyzed using bioinformatics tools. The abundance of Romboutsia and Clostridium genera and Lachnospiraceae NK4A136 was significantly higher in tumor tissues than that in nonneoplastic samples. Furthermore, several bacterial genera, including Acinetobacter, Paracoccus, Brevundimonas, and Brevibacillus, were predominant or key taxa in nontumor mucosae. We found an alteration in the mucosa-associated microbiota composition of southern Thai patients that may have contributed to the tumorigenesis of FAP. These findings may improve the knowledge of the potential roles of microbes in FAP and aid the development of preventive measures for cancer development and progression through modulation of the gut microbiota.