Herpes virus in the gut could trigger Alzheimer's disease

In a recent study from researchers at Arizona University in the United States, a chronic gut infection linked to the cytomegalovirus (HCMV) has been identified as potentially affecting the progression of Alzheimer’s disease. The research published in the journal Alzheimer's & Dementia suggests that once HCMV is established in the gut, it can travel to the brain via the vagus nerve, which connects the two areas. This mechanism could explain a biologically unique subtype of Alzheimer’s that may impact a significant percentage of those affected by the disease. The study identifies specific immune system reactions associated with Alzheimer’s disease that are triggered after the herpes virus reaches the brain. Through the activation of immune cells known as microglia, HCMV reinforces the expression of a gene called CD83. Sustained activity from these immune cells could lead to chronic inflammation, which is a known contributor to neuronal damage and disease progression. Further investigations into the spinal fluid of participants diagnosed with Alzheimer’s indicated a higher propensity for antibodies against HCMV, implicating the virus in the disease's pathology. Notably, researchers found evidence of HCMV in the vagus nerve, supporting the theory that this pathway is crucial in understanding how gastrointestinal infections may exacerbate neurological conditions. The implications of this study are significant, as they suggest that antiviral medications currently used for the cytomegalovirus could be potentially repurposed to treat or prevent this unique form of Alzheimer’s. Researchers are also working on developing a blood test that could detect an active HCMV infection, aiding in the diagnosis of patients susceptible to this subtype of the disease.