Neuroprotective effects of an engineered Escherichia coli Nissle 1917 on Parkinson's disease in mice by delivering GLP‐1 and modulating gut microbiota

Considerable evidence suggests that insulin resistance is closely linked to Parkinson's disease (PD), leading to agents aiming at treating diabetes can be regarded as new neuroprotective strategies in PD, notably glucagon‐like peptide‐1 (GLP‐1). However, the extremely short half‐life of GLP‐1 due to degradation by the ubiquitous proteolytic enzyme limits its clinical application. In this study, we engineered the recombinant integrant probiotic strain Escherichia coli Nissle 1917 (EcN) to create a strain EcN‐GLP‐1 that effectively delivers the heterologous GLP‐1 molecule. Subsequently, we assessed its neuroprotective effects on 1‐methyl‐4‐phenyl‐1, 2, 3, 6‐tetrahydropyridine (MPTP)‐induced PD mice. We demonstrated that EcN‐GLP‐1 treatment could improve motor deficits, increase tyrosine hydroxylase‐positive neurons, suppress microglia and astrocyte activation, reduce brain and colon inflammation, and ameliorate colonic barrier function damaged by MPTP induction. Meanwhile, we confirmed that the oral administration of EcN‐GLP‐1 could restore the disturbance of gut microbiota in the MPTP‐induced PD mice, by reducing the relative abundances of Akkermansia and Oscillospira, and increasing the level of Prevotella in the gut. These results support further development of an engineered probiotic platform in which production of GLP‐1 for gut‐brain disorders, such as PD.