Peptostreptococcales is an order of Gram-positive, endospore-forming, and predominantly strictly anaerobic bacteria within the class Clostridia.
The order Peptostreptococcales encompasses three validly published families:
These families contain diverse anaerobic species widely distributed in animal-associated and environmental microbiomes.
Peptostreptococcales members are anaerobic fermenters of carbohydrates and amino acids, often producing short-chain fatty acids such as acetate, butyrate, and propionate. Spore formation enables survival in challenging environments and facilitates transmission.
Several species within the order are medically significant, notably Clostridioides difficile, an important human pathogen responsible for severe gastrointestinal infections associated with antibiotic usage.