An enterotype is a classification of living organisms based on its bacteriological ecosystem in the gut microbiome. Humans can be roughly divided into three enterotypes depending on which genus of bacteria dominates their gut: Bacteroides, Ruminococcus, or Prevotella. 

• People who eat a lot of meat and saturated fat tended to have more Bacteroides in their flora. 
• Ruminococcus prevailed in people who consumed lots of alcohol and polyunsaturated fats. 
• Prevotella favored a diet rich in carbohydrates.

Long-term diet is strongly associated with the gut microbiome composition. If switching gut enterotype is possible, it may take a long-term dietary intervention. 

Chimpanzees have enterotypes that are compositionally analogous to those found in humans.