Chris Kresser: There are some studies that talk about which prebiotics feed which types of bacteria. I don’t feel like the research is currently at the point where we really know for certain how to answer this question, Julie, which is why I generally prefer a rotation strategy with different kinds of fermentable fiber that mimics our kind of ancestral intake of a wider variety of plant species. Most of the prebiotics would be expected to increase most of those species that are reported on that Doctor’s Data column, but another thing to realize is that there are differences in terms of what a normal gut microbiota is for each person, and this is one of the reasons why I don’t typically recommend using the uBiome and American Gut profiles as a means of making clinical decisions because we don’t really know what a completely normal microbiome is supposed to look like in each individual.
Let’s say you see someone and they have 4+’s on everything except for Enterococcus, where they have a 1 or even a no growth of Enterococcus. Is that a problem? I don’t really know. It may be that that person has great beneficial flora, and for whatever reason, they just don’t have a lot of Enterococcus, and it’s not a problem for them.
Just keep that in mind. We’re looking at patterns. We’re looking at the overall presentation. We’re not looking at necessarily having every single one of those at 4+ being the end goal that’s necessary for optimal gut health.