Neoadjuvant treatment response and radiation colitis in rectal carcinoma patients correlate with mucosal microbiome diversity

We investigated the relationship of mucosa-associated bacteria to neoadjuvant therapy response and development of radiation colitis in rectal carcinoma. We examined mucosa-associated microbiomes in rectal carcinoma resection specimens from 57 patients with neoadjuvant regimens of no therapy, chemotherapy only, or chemoradiation, with and without radiation colitis requiring therapeutic intervention. Microbiome profiling was 16S rDNA sequencing from formalin fixed paraffin embedded tissue at the proximal margin of resection.