The idea of "enterotypes," the notion that everyone's gut microbiome sorts neatly into one of a few distinct types, was proposed in 2011. It's usually described as dominance by either Prevotella or Bacteroides bacteria, and it quickly spread into popular gut health content. A more recent, larger analysis of 747 samples across five continents found the underlying science considerably messier than the tidy category system suggests.
When researchers removed Prevotella and Bacteroides from the analysis entirely, the original "enterotype" groupings stopped separating the samples at all. That suggests the apparent clustering was an artifact of these two dominant bacteria overshadowing everything else, not evidence of truly distinct community types.[1] No other bacteria reliably traveled alongside either Prevotella or Bacteroides dominance across the different populations studied; associations that showed up in one study frequently didn't replicate in another.
What to do with this
If you've seen your gut described as a "Prevotella type" or "Bacteroides type" from a test or quiz, treat that as one data point about your current diet pattern, plant-forward versus animal-protein-forward. It isn't a fixed identity that determines what you should eat going forward. The bacteria levels themselves respond to what you eat, a personalized pattern covered in how different people respond to the same meal, so shifting your diet will shift these numbers over time; they're not a stable category you're locked into. Skip any product or plan that treats "your enterotype" as a rigid, unchanging classification requiring a specific matched diet.
