No one has ever explained to me the difference between "antibiotics" (which defeat the "bad" bacteria and promote the "good") and "probiotics" (which promote the "good" and defeat the "bad"), so its almost like the WC Fields carnival barker joke where he displays identical twins as "the world's tallest midget and the world's shortest giant". I guess the simple answer would be that antibiotics are the "broad-leaf weed killer" that promotes grass, and probiotics the selective "narrow-leaf fertilizer" that promotes grass. Of course probiotics less regulated, but I'd sure like to know more about how all "biotics" work!

I did some research on antibiotics, and learned that scientists may know that certain antibiotics work, but are not sure exactly why or how. In addition, there is evidence that different people may benefit from different gut biomes, not exactly a "one size fits all". Certainly an interesting and ongoing mystery. Lactobacillus and Bifidobacteria definitely good ones, but in what amounts? We've raised many calves over the years, and have noticed that a calf partially on his Mom for >3 months (instead of the 1 week supply of claustrum you usually get) are MUCH healthier, so my opinion is your best chance of getting great gut flora/immunity comes at that time (from Mom's immunities), later we may have sorta "missed the boat". My own article:

https://scottvern.medium.com/an-imagined-interview-with-the-gut-brain-bb52d2af3d45

Anyway, thanks for further elaborating on this intriguing issue!