"Genus Bacteroides" is a group of Gram-negative bacteria commonly found in the human gut. Some synonyms for this genus include Bacteroides fragilis group, Prevotella, and Porphyromonas. The Bacteroides fragilis group includes several species such as B. ovatus, B. thetaiotaomicron, and B. uniformis. Prevotella is a genus that includes anaerobic bacteria found in various human body sites such as the oral cavity and respiratory tract. Porphyromonas is another genus of anaerobic bacteria commonly found in the mouth, but some species are also found in the gut and respiratory tract. Despite having different synonyms, these bacteria are closely related and play important roles in human health and disease.