By Dr. Sanchari Sinha Dutta, Ph.D. Reviewed by Lauren Hardaker Jul 31 2025 By analyzing what’s on the surface of the tongue, scientists uncover powerful clues to detecting Parkinson’s disease: no needles, no scans, just a simple swab. Study:  Microbiome and metabolome integrated analysis: exploring potential diagnostic approaches for Parkinson’s disease using tongue coating samples . Image credit: Andrey_Popov/Shutterstock.com Researchers at the Shanghai Jiao Tong University School of Medicine,