[Llamamoe]

1. I only read scientific publications. No way to find anything but SEO spam on Google nowadays.

2. Some probiotics might help, not sure which or how much. FMT should help. Healthy diets should shift bacterial composition favourably, though this won't be permanent changes.

3. I don't think there's any food out there that can permanently change the microbiome composition enough to make a big difference. I doubt much if any of the L. Reuteri survived the gastric acid, and if it did, it's just one species among hundreds.