Pathogenic bacteria exploit intestinal mucus sugar to infect the gut.

A new study by researchers at the University of British Columbia (UBC) and BC Children's Hospital shows the sugar sialic acid, which makes up part of the protective intestinal mucus layer, fuels disease-causing bacteria in the gut.

The findings suggest a potential treatment target for intestinal bacterial infections and a range of chronic diseases linked to gut bacteria, including inflammatory bowel disease (IBD), celiac disease, irritable bowel syndrome, and short bowel syndrome.

For the study, the researchers examined Citrobacter rodentium, an intestinal bacterial pathogen of mice that are used to model infections with human E. coli. The team discovered that the bacteria have genes involved in sialic acid consumption, and when these genes are removed, the bacteria’s growth is impaired.

Further investigation revealed that upon consuming the sugars, the bacteria produced two special virulence proteins that help the bacteria cross the colonic mucus layer and stick to the underlying epithelial cells. The findings reveal how the bacteria can change over time and actually worsen the disease.

Reference: Sialic acid plays a pivotal role in licensing Citrobacter rodentium's transition from the intestinal lumen to a mucosal adherent niche, Proceedings of the National Academy of Sciences DOI 10.1073/pnas.2301115120