For the concept-level interpretation, see Foundations: Enterotypes.

Limitation
This study only addresses whether gut microbiome 'types' are real as discrete categories — it does not mean that the ratio of certain gut bacteria (like Prevotella vs Bacteroides) is useless. Those ratios may still turn out to be meaningful markers for health and diet, even if the hard boundaries between 'types' are not.
Tags
gut-microbiome, enterotypes, dimensionality-reduction, clustering, 16s-rrna, metagenomics, american-gut-project, human-microbiome-project