[Question] Where should I look for information on gut health?

I’ve been on a gut health kick, reading Brain Maker, adding more kale for the insoluble fiber, and cutting seed oils and sugar.

The author recommends probiotic enemas and fecal transplant, but I’ve seen mixed information on effectiveness of such treatments, and I also read a concerning article by a professor that seemed to indicate that bacteria from probiotic foods doesn’t stick around in the intestine, which makes it seem like oral probiotics in general might just all be temporary.

Where can I find more detailed information about this? What can I do besides diet that actually works to improve your gut health/​microbiota diversity?