''Christensenella'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of non- spore-forming,

anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: * Anaerobic adhesive, a bonding a ...

, and nonmotile

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

from the family Christensenellaceae. The species '' C. minuta'' has been published and validated, and '' C. timonensis'' and '' C. massiliensis'' have been proposed as novel species of the genus ''Christensenella'', all isolated from human feces. ''C. minuta'' in the gut has been associated with reduction in body weight and adiposity of mice. In a test on 977 volunteers, humans with higher levels of ''Christensenella'' in their guts were found to be more likely to have a lower body mass index than those with low levels. ''Christensenella'' are better represented in persons who are metabolically healthy. However, there is a link to possible pathogenic qualities of ''C. minuta'' in humans. An 18-year-old male presented with symptoms of appendicitis. Lab work revealed C. Minuta was found in his bloodstream. Upon removal of the appendix, his symptoms and blood levels of ''C. minuta'' disappeared. Alonso, B. L., Irigoyen von Sierakowski, A., Sáez Nieto, J. A., & Rosel, A. B. (2017). First report of human infection by ''Christensenella minuta'', a gram-negative, strickly [sic] anaerobic rod that inhabits the human intestine. Anaerobe, 44, 124–125. https://doi.org/10.1016/j.anaerobe.2017.03.007

References

Clostridiaceae Gram-negative bacteria Bacteria described in 2011 {{Clostridia-stub