Researchers studied the link between gut bacteria & neurodegenerative disease in C. elegans.
Colonization of the worms with human enteric bacterial pathogens led to proteostasis disruption that was rescued by butyrate.
Photo below shows normal C. elegans (left) compared with worms infected with pathogenic bacteria.
https://www.sciencefocus.com/news/scientists-identify-gut-bacteria-linked-to-neurodegenerative-conditions/