TH and Parkinson disease: The previously constructed next-generation probiotics Lactococcus lactis (L. lactis) MG1363-pMG36e-GLP-1 was confirmed to steadily secrete GLP-1 as well as exerting neurotrophic effect on MPTP-induced PD model mice by derepressing tyrosine hydroxylase (TH) and reducing α-syn aggregation to improve motor functions [20].