How might amyloid beta act as a natural antibiotic in the brain?

Research suggests that amyloid beta may function as a natural antibiotic within the brain by acting as a defense mechanism against infection. In this capacity, the protein serves to entrap microorganisms, effectively isolating them to protect surrounding tissue.1

The hypothesis that amyloid beta acts as a natural antibiotic implies a potential link between Alzheimer disease and brain infection. Under this model, the formation of neuritic plaques—which consist of amyloid beta deposits—may be an immune response that becomes excessive or abnormal in individuals who eventually develop the disease. While this provides a functional perspective on the protein's presence, it remains unclear whether these plaques are a primary cause of the disease or a consequence of underlying pathological processes.1