Gut bacteria regulate the pathogenesis of Huntington’s disease in Drosophila model

Abstract

Changes in the composition of gut microbiota are implicated in the pathogenesis of several neurodegenerative disorders. Here, we investigated whether gut bacteria affect the hallmarks of Huntington's disease (HD) in transgenic Drosophila melanogaster (fruit fly) models expressing human full-length or N-terminal fragments of mutant huntingtin (HTT) protein, here referred to as HD flies. We find that elimination of commensal gut bacteria by antibiotics reduces the aggregation of amyloidogenic N-terminal fragments of HTT and delays the development of motor defects. Conversely, colonization of HD flies with Escherichia coli (E. coli), a known pathobiont of human gut, accelerates HTT aggregation, aggravates immobility and shortens life span. Similar to antibiotics, treatment of HD flies with compounds such as luteolin, a flavone, or crocin a beta-carotenoid, ameliorates disease phenotypes and promotes survival. Crocin prevents colonization of E. coli in the HD flies gut and alters the levels of commensal bacteria, which may be linked to its protective effects. The opposing effects of E. coli and crocin on HTT aggregation, motor defects and survival in transgenic Drosophila support the involvement of gut-brain networks in the pathogenesis of HD.

Paradigms and Success Stories of Natural Products in Drug Discovery Against Neurodegenerative Disorders (NDDs)

“…Interestingly, the spectrum of neuroprotective effects of crocin is further extended toward HD. In Drosphilia melanogaster HD flies, crocin has been reported to prevent Escherichia coli colonization, which is implicated in HTT aggregation and HD-associated immobility [ 169 ].…”