TAXONOMY: Bacteria -> Terrabacteria group -> Firmicutes -> Clostridia -> Clostridiales -> Christensenellaceae -> Christensenella
A novel, strictly anaerobic, non-motile, non-spore-forming, Gram-negative, short, straight rod with tapered ends, designated YIT 12065(T), isolated from human faeces. Strain YIT 12065(T) was saccharolytic and negative for catalase, oxidase and urease, hydrolysis of aesculin and gelatin, nitrate reduction and indole production. The end products of glucose fermentation were acetic acid and a small amount of butyric acid. The DNA G+C content was 51.3 mol%. Christensenella also seems to sit at the centre of a large network of microbes; if it’s there, these others are likely to show up too. And it influences our weight: it’s more common in lean people, and it can reduce weight gain in mice.All of these traits suggest that Christensenella might (emphasis on might) be a keystone species: one that wields a disproportionate influence upon the world around it. It doesn’t help that we know so little about this mysterious microbe. It’s there from birth: when Ley looked at an older study involving a single infant, she found that Christensenella made up 20 percent of the microbes in the baby’s stool. It’s much rarer in samples from adults. Its abundance doesn’t depend on our diet, unlike many other gut bacteria. And it is influenced by our genes.
This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072]