Chris: I think I may have answered this last time, but I’ll mention it again. It’s a good question, and I don’t have a ton of faith in the culture section of the Doctor’s Data report for this, among other reasons. When you do a culture, it’s not necessarily representative of what’s going on in the rest of the microbiome because you end up amplifying certain species that were found in the culture, and then that doesn’t necessarily represent the quantity of that species in the microbiome.
I think now, particularly with the recent update of the GI-MAP test and uBiome, there are some better options for assessing the normal microbiota. I am going to be making some updates to the stool testing section of the course, including adding a module on uBiome, and adding some material on the GI-MAP test. You get access to all of the updates that I make even after the course has ended, so you’ll be able to take a look at those once they’re finished.
There’s is a bigger question here that’s regardless of what method of testing is used, which is how do we know what a normal microbiome is for a given individual? And unfortunately, the answer is we don’t really. We’ve been able to discern some patterns that are consistent within populations, and we, I think, also we can detect certain things that are on the extremes that are probably problematic for everybody or beneficial for everybody, or at least most people.
Examples would be overgrowth of or excessive presence of methanogens will probably lead to the excess methane production and methane-predominant SIBO for most people, which might be detected on a uBiome stool sample, or excessive abundance of certain pathogenic species of E. coli would probably be harmful for most people, that could come up on the GI-Map panel or the uBiome. There are certain things that are probably an issue for most people, but outside of those things there’s still a really big range of what might be normal within given individuals and also even within certain populations.
I think I mentioned last time that in the Hadza hunter–gatherer population in Africa, I believe that their levels of Bifidobacteria are actually quite low, which was a surprise to the researchers who were assessing their microbiome because in Western populations, low Bifidobacteria is correlated with poor gut health, and in the Hadza population, that’s not the case at all. In fact, they have remarkably good gut health, but their Bifidobacteria is low. That’s just one example, but there are many others. I think now with the quantitative PCR, or qPCR, technology that’s available and also increased ability to crunch data with AI, transcriptomics, and proteomics, and metabolomics, our understanding of what’s normal in the microbiome is going to increase pretty significantly in the coming years, so that’s exciting.