[t-3]

Probiotics at this point are mostly snake oil AFAICT. We just don't have the tech or knowledge to properly culture most relevant microbiota, and pills aren't a very effective way to supply them. "Prebiotics" AKA forming good eating habits looks to be far more effective for gut health, but it doesn't offer the opportunity to sell yeast pills for $/mg.

[elmerfud]

I agree with this entirely. Until more is known about the gut microbiome and how to properly seed and replace it the most effective home thing to do is prebiotic fiber and medium chain triglyceride oils. These have both been shown to sustain known healthy bacteria of the gut and reduce known unhealthy bacteria.

The best sources to get these from is not supplements either it's from a natural foods that they come from.