Helicobacter pylori
Helicobacter pylori is a gram-negative, microaerophilic, spiral bacterium usually found in the stomach. Up to 90% of people infected with H. pyleori never experience symptoms or complications. Individuals infected with the bacteria have a 10% to 20% lifetime risk of developing peptic ulcers. It can cause multiple sclerosis, coronary artery disease, periodontitis, Parkinson’s disease, Guillain–Barré syndrome.