A study by researchers at Israel’s Weizmann Institute shows intestinal microbes can have a direct effect on the course of amyotrophic lateral sclerosis (ALS / Lou Gehrig’s disease). Certain strains of gut microbes (or their secretions) slowed ALS-like diseases in the lab.
https://www.israel21c.org/major-study-shows-gut-microbes-may-impact-course-of-als/
https://www.timesofisrael.com/treatment-with-gut-microbes-may-slow-progression-of-als-israeli-study/