TLR2 and Parkinson disease: When the gut reacts, Toll-like receptor 2 and Toll-like receptor 4 are activated by recognizing bacterial DNA in the gut, the expression of Toll-like receptor 2 and Toll-like receptor 4 in the gut is significantly higher than in healthy people (82), and abnormal expression of their receptors can accelerate the occurrence of Parkinson’s disease (83).