TAXONOMY: Bacteria -> Bacteroidetes/Chlorobi group -> Bacteroidetes -> Bacteroidia -> Bacteroidales -> Rikenellaceae -> Alistipes
'Alistipes' is a genus in the phylum Bacteroidetes (Bacteria). Alistipes are bacteria commensal to the gut and, in limited quantities, are indicative of gastrointestinal good-health. However, these microbes shun diets rich in plant-based foods, thrive on high-fat diets, and grow especially well in the gut microbiomes of those suffering from obesity. Fortunately, the bugs all but vanish after a course of antibiotics, so such treatment has potential as an anti-obesity therapeutic. Straight or slightly curved rods 0.2–0.9 µm in diameter × 0.5–4 µm in length, with rounded ends. Swellings may occur, but spores are not formed. Cells usually occur singly or in pairs, occasionally in longer filaments. Nonmotile. Gram negative. Obligately anaerobic. Indole is produced. Gelatin is digested. Nitrate is not reduced to nitrite. Arginine and urea are not hydrolyzed. Produce succinic acid as the major glucose metabolic end product, with minor amounts of acetic acid. The major long-chain fatty acid produced is C15:0 iso.
DNA G+C content (mol%): 55–58.
This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072]