# Can Brain Infections Mimic Alzheimer’s?
Researchers have discovered that certain brain infections can trigger changes in the brain that closely resemble Alzheimer’s disease. A groundbreaking study from Griffith University in Australia demonstrated that a bacterium called Chlamydia pneumoniae can travel directly from the nose into the brain through the olfactory nerve, causing pathological changes that look like Alzheimer’s disease in mouse models.
The connection between infections and Alzheimer’s-like symptoms involves a protein called amyloid-beta. When the brain detects an infection, it releases this protein as part of its immune response. The same amyloid-beta protein accumulates in clumps or plaques in the brains of people with Alzheimer’s disease. In the Australian study, when mice had damage to the nasal tissue lining, bacterial infections worsened and the brain deposited even more amyloid-beta protein. The infection happened remarkably fast, with bacteria reaching the central nervous system within 24 to 72 hours.
Chlamydia pneumoniae is not the only infectious agent linked to Alzheimer’s pathology. This bacterium has been found in the majority of human brains affected by late-onset dementia. Additionally, another bacterium called Porphyromonas gingivalis and its toxins have been discovered in the brains of Alzheimer’s patients, with the severity of Alzheimer’s diagnosis correlating with the amount of bacterial toxins present.
The research raises important questions about how infections might contribute to Alzheimer’s disease development. One key question scientists are investigating is whether the increased amyloid-beta deposits represent a natural immune response that can be reversed once the infection is cleared, or whether they cause permanent damage.
The implications are significant for prevention. Researchers warn that damaging the nasal tissue through nose picking can increase the number of bacteria that travel into the brain. Protecting the delicate lining of the nasal cavity may help reduce the risk of bacterial infections reaching the brain.
While these findings come from animal studies, the evidence suggests that infections could be an important factor in Alzheimer’s disease development. This opens new avenues for understanding why some people develop Alzheimer’s and potentially for developing treatments that target infectious causes of dementia.
Recent research has also shown promise in reversing Alzheimer’s-like pathology in animal models. Scientists have demonstrated that restoring the brain’s energy balance through NAD+ restoration can not only prevent Alzheimer’s development but also reverse advanced disease pathology and restore cognitive function in mice. This suggests that even if infections do trigger Alzheimer’s-like changes, therapeutic interventions might be able to reverse the damage.
The relationship between brain infections and Alzheimer’s disease remains an active area of research, with scientists working to understand whether treating infections early could prevent or slow cognitive decline in humans.
Sources
https://www.sciencealert.com/mouse-study-suggests-nose-picking-has-a-surprising-link-with-alzheimers
