Similarly to HD, in Parkinson’s disease (PD), gastrointestinal (GI) impairment is a frequently reported early symptom of the disease and its involvement in disease progression is a growing topic of research7. Clinical research studies have indicated a significantly lower expression of occludin, but not ZO-1, in colonic samples from PD patients as compared to controls8. This evidence concerns the gene OCLN and Parkinson disease.