I agree with this. Unless you can make yoghurt with only lactobacilli or bifidobacteria, then the tests are pretty useless.

I think North (one of the yoghurt testers) said Grapefruit-Seed-Extract didn't kill stop yoghurt growing. The implication being that Grapefruit-Seed-Extract therefore doesn't kill good bacteria. I think this would be an entirely erroneous assumption. Grapefruit-Seed-Extract is a very powerful antibacteria agent. I would be amazed if it didn't kill most 'good' bacteria.

I'm not knocking GSE, just using it as an example. I think GSE might just be the best herbal antimicrobial out there. Just making the point that unless yoghurt is grown with only good bacteria, then any tests are virtually meaningless.

Best to assume all herbal antifungals kill good bacteria unless PROVEN otherwise. As far as I know, no herbal antifungals have been PROVEN not to kill good bacteria. Lots of CLAIMS are made though. The only exception is perhaps colostrum/lactoferrin, which is not really an antifungal, more an immune booster.

The one good thing about herbal antifungals killing bacteria though, is that they will tend to kill more in the small intestine, where bacteria often cause problems (e.g. SIBO). This is because the herbs get digested, metabolised and absorbed as they progress down the GI tract. By the time they reach the large bowel they are much weaker, so may not kill too many good bacteria there.