A common bacterium, Chlamydia pneumoniae, prevalent in sinus infections and pneumonia, has been detected in the eyes of deceased Alzheimer's patients. Researchers from Cedars-Sinai found this bacterium in retinal tissue, which is directly connected to the brain. The findings suggest the bacteria can trigger an inflammatory response potentially leading to nerve cell death and exacerbating Alzheimer's symptoms.
This discovery opens avenues for potential therapies targeting inflammation and early antibiotic treatment for respiratory infections. The study analyzed retinal samples from over 100 individuals, finding higher bacterial levels in those with Alzheimer's disease. The presence of Chlamydia pneumoniae was also associated with more severe cognitive decline, particularly in individuals carrying the APOE4 gene variant, a known Alzheimer's risk factor.
Further experiments on human neurons and lab mice indicated that the bacterium accelerates inflammation and nerve cell death, contributing to cognitive decline and prompting the production of amyloid-beta, a protein linked to Alzheimer's. While experts urge caution, noting that the findings indicate an association rather than causation, they acknowledge the potential for new diagnostic and treatment strategies.
Experts emphasize that common infections do not cause Alzheimer's. However, the research highlights inflammation's role in disease progression and may lead to future methods for detecting or treating the condition. Current recommendations for brain health include managing cardiovascular risk factors, staying mentally and socially engaged, and seeking medical attention for cognitive symptoms.