Anaerostipes is a Gram positive and anaerobic bacterial genus from the family of Lachnospiraceae.

Nonsporeforming, nonmotile rods, sometimes in chains of 2–4 cells. Gram positive in exponential phase but not stationary-phase cultures. Nonmotile. Strictly anaerobic and both catalase- and oxidase-negative. Nonhemolytic. Cells produce mainly acetic, lactic, and butyric acids from glucose. Arginine dihydrolase, phosphoamidase, and α-galactosidase are produced. Gelatin and urea are not hydrolyzed; indole is not produced. Positive for nitrate reduction.