The predominant genera in the human colonic microbiota are Bacteroides and Prevotella, which belong to the major phyla Bacteroidetes. Their composition and metabolic activities are largely modulated by diet and, in addition, they can also affect the metabolism of food. Prevotella is associated with plant-rich diets (high levels of complex carbohydrates and fruit and vegetable intake), whereas Bacteroides is linked to a high intake of fat and protein. Bacteroides and Prevotella species have their own specific habitats in the human body as they are antagonistic.
References:
HealthMatters.io - Lab results explained 