Ruairi Robertson (https://twitter.com/ruairirobertson) has a pretty good TEDx overview of Elie's work and how it seemed to be an early harbinger of the gut-brain axis https://www.youtube.com/watch?v=awtmTJW9ic8 from a bout a year earlier than that article.

Understanding this space of ideas and how things unfolded in the early 1900s puts a lot of weird ideas into perspective. Kellogg's weird fascination with cleaning out people's rectums with colonic yogurt pumps, for example.