inflammation<\/a>, nerve cell death and cognitive decline.<\/p>\n
<\/p>\n
Seeing Chlamydia pneumoniae consistently across human tissues, cell cultures and animal models allowed us to identify a previously unrecognized link between bacterial infection, inflammation and neurodegeneration. The eye is a surrogate for the brain, and this study shows that retinal bacterial infection and chronic inflammation can reflect brain pathology and predict disease status, supporting retinal imaging as a noninvasive way to identify people at risk for Alzheimer\u2019s.\u201d<\/p>\n
\n
<\/p>\n
Maya Koronyo-Hamaoui, PhD, professor of\u00a0Neurosurgery,\u00a0Neurology, and\u00a0Biomedical Sciences\u00a0at Cedars-Sinai Health Sciences University and the leading, senior author of the study<\/p>\n
<\/p>\n
To conduct the study, researchers used advanced imaging, genetic testing and protein analysis to examine retinal tissue from 104 individuals, some with normal cognition, some with mild cognitive impairment and some with Alzheimer\u2019s disease.<\/p>\n
They found significantly higher levels of Chlamydia pneumoniae in the retinas and brains of people with Alzheimer\u2019s disease than they found in people with normal cognition. The higher the bacterial levels detected, the more severe the brain changes and cognitive decline investigators found.<\/p>\n
Higher levels of the bacterium were more common in people who carried the APOE4 gene variant, a known risk factor for Alzheimer\u2019s disease.<\/p>\n
Investigators also studied human neurons in the lab and in laboratory mice with Alzheimer\u2019s disease. In both, infection with\u00a0Chlamydia pneumoniae\u00a0increased inflammation, nerve cell death and cognitive decline, showing the bacterium can accelerate disease processes. The infection also triggered production of amyloid-beta, the protein that accumulates in the brains of people with Alzheimer\u2019s.<\/p>\n
The findings were driven by co-first authors Bhakta Gaire, PhD, and Yosef Koronyo, MSc.<\/p>\n
\u201cThis discovery raises the possibility of targeting the infection-inflammation axis to treat Alzheimer\u2019s,\u201d said\u00a0Timothy Crother, PhD, co-corresponding author of the study and research professor at\u00a0Cedars-Sinai Guerin Children’s\u00a0and the Department of Biomedical Sciences at Cedars\u2011Sinai.<\/p>\n
The findings suggest that targeting chronic bacterial infection\u2014and the inflammation it triggers\u2014could represent a new treatment strategy. The research also supports potential use of the retina as a noninvasive way to help diagnose and monitor the disease.<\/p>\n
Source:<\/p>\n
Journal reference:<\/p>\n
Gaire, B. P., et al. (2026). Identification of Chlamydia pneumoniae and NLRP3 inflammasome activation in Alzheimer\u2019s disease retina.\u00a0Nature Communications. doi: 10.1038\/s41467-026-68580-4.\u00a0https:\/\/www.nature.com\/articles\/s41467-026-68580-4<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Chlamydia pneumoniae\u2014a common bacterium that causes pneumonia and sinus infections\u2014can linger in the eye and brain for years…\n","protected":false},"author":2,"featured_media":1972,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[12590,21211,1596,3033,20786,15025,13448,3029,134,13695,13346,21696,111,139,69,43662,2859,1518],"class_list":{"0":"post-263376","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-health","8":"tag-antibiotic","9":"tag-bacterial","10":"tag-brain","11":"tag-cell","12":"tag-cell-death","13":"tag-chlamydia","14":"tag-chronic","15":"tag-eye","16":"tag-health","17":"tag-imaging","18":"tag-inflammation","19":"tag-nerve","20":"tag-new-zealand","21":"tag-newzealand","22":"tag-nz","23":"tag-pneumonia","24":"tag-protein","25":"tag-research"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/263376","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=263376"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/263376\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/1972"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=263376"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=263376"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=263376"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}