Elevated colonic microbiota-associated paucimannosidic and truncated N-glycans in pediatric ulcerative colitis

Pediatric ulcerative colitis (UC) is a distinct type of inflammatory bowel disease with severe disease activity and rapid progression, which can lead to detrimental life-long consequences. The pathogenesis of pediatric UC remains unclear, although dysbiosis of the gut microbiota has been considered an important factor. In this study, we collected intestinal mucosal-luminal interface microbiota samples from a cohort of treatment-naïve pediatric UC or control patients and used two different mass spectrometry-based glycomic approaches to examine the N-glycans that were associated with the microbiota. We observed abundant small N-glycans that were associated with the microbiota and found that the pediatric UC microbiota samples contained significantly higher levels of these atypical N-glycans compared to those of controls. Four paucimannosidic or other truncated N-glycans were identified to successfully segregate UC from control patients with an area under the ROC curve of ≥0.9. This study indicates that the aberrant metabolism of glycans in the intestinal by gut microbiota may be involved in the pathogenesis of UC and intestinal N-glycans, including small glycans, can act as novel biomarker candidates for pediatric UC.