C3AR1 and Mental deterioration: Helicobacter pylori-Derived Outer Membrane Vesicles and Cognitive Decline: Outer membrane vesicles (OMVs) derived from Helicobacter pylori (H. pylori) can cross biological barriers and enter the brain. They interact with astrocytes, microglia, and neurons via the complement component 3 (C3) - C3a receptor (C3aR) signaling pathway, inducing glial cell activation and neuronal dysfunction. This interaction contributes to the pathological progression of amyloid beta and cognitive decline.