It was revealed in the Naturethe latest evidence suggesting that bacteria and infections play a significant and little-understood role in destroying the brain as we age.
In a new study, the results of which were published at the end of January in Nature Communicationsscientists discovered an intriguing link between infection and brain health, finding that a common bacteria in the eye appears to be associated with cognitive decline and Alzheimer’s disease.
Investigators from Cedars-Sinai (USA) found traces of Chlamydia pneumoniae — a bacterium best known for causing respiratory infections — in the retinal tissue of the eye.
Higher levels of this agent pathogen correlated with advanced degeneration in patients with Alzheimer.
While this does not demonstrate causality in any way, the results add to a growing body of evidence suggesting that chronic infections play some role in neurodegenerative diseases over time.
“Seeing Chlamydia pneumoniae consistently in human tissues, cell cultures and animal models allowed us identify a hitherto unrecognized link between bacterial infection, inflammation and neurodegeneration”, praised the corresponding author, Maya Koronyo-Hamaoui.
“The eye is a substitute for the brain, and this study shows that retinal bacterial infection and chronic inflammation may reflect brain pathology and predict disease statussupporting retinal imaging as a non-invasive way to identify people at risk for Alzheimer’s,” he added.
It remains, however, to be clarified whether the bacteria plays a direct role in the progression of the disease or whether it is simply more likely to appear as the brain and immune system become compromised with age. It is important to note that these results continue to be debated and do not confirm an origin of cognitive decline.
Still, the eye can now be a useful focus for monitoring brain-related disease riskpotentially offering a less invasive way of monitoring early changes associated with cognitive decline – says New Atlas.
