Gemella morbillorum promotes colorectal tumorigenesis through barrier disruption and invasion-dependent DNA damage.

Gemella morbillorum is enriched in colorectal cancer tissues and promotes tumorigenesis by disrupting the intestinal barrier and causing DNA damage through invasion-dependent lipid peroxidation.

• Why it matters: Understanding how bacteria contribute to colorectal cancer can reveal new targets for prevention and therapy, as the mechanisms for many species remain unclear.
• What they did: Researchers analyzed feces and tumor tissues from CRC patients and used mouse models to investigate Gm's role, focusing on its effects on immune response, barrier integrity, invasion pathways, and lipid metabolism.
• The result: Gm suppresses IL-22 production, impairs barrier function, invades CRC cells via an ANXA2-dependent pathway, and induces lipid peroxidation that leads to DNA damage, highlighting its potential as an onco-pathogen.