H Pylori bacteria can infect the stomach lining, causing low stomach acid, nutrient malabsorption, and chronic inflammation. That inflammation doesn’t just stay local, it travels through the gut-brain axis, impacting neurotransmitters like serotonin, dopamine, and GABA. One study found that H. pylori infection was significantly associated with higher rates of anxiety and depression, likely due to inflammatory cytokines and altered brain chemistry (PMID: 30240439). Functional medicine testing can