Childhood antibiotics as a risk factor for Crohn's disease: Cohort study
I had really bad IBS from consuming water on a tropical island in Panama one time and suffered for a few years with even my doctor friend telling me "Damn that sucks, not much you can do except manage". Pretty horrible symptoms until I discovered L. Reuteri. [1]  I read that it's been a bacteria that was more commonly found in samples until around the 1950s when people started consuming more garbage processed food and was sold. Simply stated, it changed my life. It emits a substance called Reuterin which inhibits the growth of other more harmful bacterial species. [2] I can't speak personally for suffering on the level of Crohn's disease, but there's positive research out there regarding it. [3] [4][1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5917019/[2] https://en.wikipedia.org/wiki/Reuterin[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7270012/[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7468961/