Microbial butyrate capacity is reduced in inflamed mucosa in patients with ulcerative colitis.

Reduced butyrate-production capacity has been reported in fecal microbial communities in patients with active ulcerative colitis. However, the butyrate-production capacity of the mucosal microbiome from active vs quiescent mucosa in ulcerative colitis has been unexplored. We sought to determine the diversity and relative abundance of mucosal bacterial and fungal communities from endoscopically active vs quiescent mucosa in patients with UC, and aimed to predict contributions of mucosal microbial communities to butyrate synthesis. Systematic, segmental right- and left-sided biopsies were obtained from endoscopically active (n = 13) or quiescent (n = 17) colonic mucosa, among 15 patients with pan-colonic ulcerative colitis. Dietary fiber intake of patients was performed using the validated five-item FiberScreen questionnaire. Amplicon sequencing of mucosal bacteria and fungi was performed. The diversity and relative abundance of mucosal bacterial and fungal taxa were quantified, and predicted contributions to butyrate synthesis were ascertained. Bacterial alpha and beta diversity were similar between active vs quiescent mucosa. Butyrogenic taxa were significantly increased in quiescence, including Butyricimonas, Subdoligranulum, and Alistipes. Predicted butyrate kinase activity was significantly and concomitantly increased in quiescent mucosa. Fiber intake was positively correlated with butyrogenic microbes. Compared to mucosal bacterial prevalence, mucosal fungi were detected in low prevalence. Butyrogenic microbes are relatively increased in quiescent mucosa in ulcerative colitis, and may be related to increased fiber intake during quiescence. Manipulation of the mucosal microbiome towards butyrate-producing bacteria may be associated with endoscopic quiescence.

Ozanimod-Associated Iatrogenic Kaposi Sarcoma in a Patient With Ulcerative Colitis.

Ozanimod is an oral sphingosine-1-phosphate receptor modulator. Although it can be an effective drug for the induction and maintenance of remission in patients with moderately to severely active ulcerative colitis, there have been a few reported cases of various malignancies after exposure to this small molecule. We describe a unique case of biopsy-proven Kaposi sarcoma of the skin and colon in a patient with biologic-resistant ulcerative colitis after treatment with ozanimod for 2 months. Given the potential risk of malignancy associated with this agent, physicians should be aware of this rare adverse event.