Nose injuries may let bacteria reach the brain, hinting at Alzheimer’s link in mice

Australian researchers in Griffith University show, in mice, that Chlamydia pneumoniae can travel from the nasal cavity to the brain via the olfactory and trigeminal nerves, with amyloid-beta deposits forming within days. Nasal epithelial injury increased bacterial load and brain involvement, but there are no human data yet and the causal role for Alzheimer's remains unproven; a human study is planned.