This 2018 report from the Journal of Parkinson’s Disease examines the association between the gut bacteria Helicobacter pylori and PD. H. pylori is a common gut bacterium that causes ulcers, gastritis, and can lead to stomach cancer. The majority of PD cases are caused by unknown environmental factors, and bacterial infections could be one of them. This has led doctors to look at the link between H. pylori and PD. After reviewing past studies on the subject four important points were noted: H. pylori-infected PD patients experience worse motor function issues than those not infected; people with PD are more prone to be infected by H. pylori and eradication of H. pylori could improve motor function and levodopa absorption in people with PD.