Researchers at Cedars-Sinai have discovered a potential link between Chlamydia pneumoniae, a common respiratory bacterium, and Alzheimer’s disease. The research, published January 22nd in Nature Communications, suggests this bacterium, typically associated with pneumonia and sinus infections, may play a significant role in the development of Alzheimer’s.
The team found that Chlamydia pneumoniae can survive in the retina for extended periods, offering a new avenue for Alzheimer’s research. The retina, as part of the central nervous system, allows for non-invasive examination of neurological changes. When the bacteria enter the retina, increased immune activity is observed, correlating with inflammation, neuronal death, and cognitive decline.
Dr. Maya Koronyo-Hamaoui, the lead author, stated that the presence of Chlamydia pneumoniae was consistently observed in human tissues, cell cultures, and animal models, revealing previously unknown associations between bacterial infection, inflammation, and neurodegeneration.
Concentrations of Chlamydia pneumoniae were notably higher in the retinas and brains of Alzheimer’s patients compared to individuals with normal cognition. Increased bacterial load correlated with more severe brain pathology and cognitive impairment. Genetic factors also appear to play a role, with higher bacterial concentrations observed in individuals carrying the APOE4 gene variant.
Laboratory studies using human neurons and Alzheimer’s mice revealed that Chlamydia pneumoniae infection increased inflammation, neuronal death, and cognitive decline, indicating the bacteria may accelerate disease progression. This finding offers new possibilities for Alzheimer’s treatment targeting the infection-inflammation axis.
Researchers suggest that chronic bacterial infections and the resulting inflammation may represent a new therapeutic strategy. The study also supports the retina as a potential pathway for non-invasive diagnosis and monitoring of Alzheimer’s disease.
（首圖來源：Unsplash）
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