Ruminococcus
Ruminococcus is a genus of bacteria in the class Clostridia. They are anaerobic, Gram-positive gut microbes. One or more species in this genus are found in significant numbers in the human gut microbiota. The type species is "R. flavefaciens". As usual, bacteria taxonomy is in flux, with Clostridia being paraphyletic, and some erroneous members of "Ruminococcus" being reassigned to a new genus "Blautia" on the basis of 16S rRNA gene sequences. One of the most highly cited papers involving the genus "Ruminococcus" is a paper describing interspecies hydrogen transfer between "Ruminococcus albus" and "Wolinella succinogenes". In 1972, "Ruminococcus  bromii" was reportedly found in the human gut, which was the first of several species discovered. They may play a role in plant cell wall breakdown in the colon. One study found that "R. albus", "R. callidus", and "R. bromii" are less abundant in people with inflammatory bowel disease. "Ruminococcus" are also less abundant in patients with Parkinson's disease. "R. gnavus" is associated with Crohn's disease. Species. Species belonging to the Lachnospiraceae family and therefore in need of reclassification: