Gut-Bacteria Sugar Could Trigger ALS and FTD, Study Finds

A Case Western Reserve University–led study links a gut bacteria–produced inflammatory glycogen to ALS and FTD. In mouse models, certain gut bacteria produce glycogen that provokes brain inflammation and blood-brain barrier breakdown, with the C9ORF72 gene variant acting as a brake on glycogen’s harmful effects. Introducing bacteria like Parabacteroides merdae worsened inflammation, while the enzyme alpha-amylase reduced inflammation and extended lifespan in mice. Human stool samples showed elevated inflammatory glycogen in most ALS patients and in one FTD patient, suggesting a potential gut-targeted avenue for therapy, pending larger human studies and early clinical trials.