title: A specific Streptococcus mutans strain aggravates  non-alcoholic fatty liver disease.
abstract: OBJECTIVE
  Streptococcus mutans, a major dental caries pathogen, has shown to be associated with the aggravation of cerebral hemorrhage and inflammatory bowel diseases. In this study, we evaluated the effects ofS. mutans on the development of non-alcoholic steatohepatitis (NASH) in a mouse model.
  
  
  METHODS
  Streptococcus mutans oral strain MT8148 (serotype c) and a blood isolate TW871 (k) were used. C57BL/6J mice (6 weeks old)were fed a high-fat diet for 4 weeks; the test strains or phosphate-buffered saline was then intravenously administered. Mice were euthanized after 8 or 12 weeks. Whole body, extirpated liver, and visceral fat weights were determined, and histopathological evaluations of the liver specimens were performed.
  
  
  RESULTS
  Mice infected with TW871 showed significantly greater body and liver weights than those administered MT8148 or phosphate-buffered saline. Histopathological analyses revealed prominent infiltration of inflammatory cells and adipocellular deposition in livers extirpated 8 weeks after an infection with TW871; fibrosis was also observed in livers extirpated after 12 weeks.
  
  
  CONCLUSIONS
  These results suggest that a specific strain of S. mutans could induce NASH.
authors.forename: S
authors.initials: S
authors.lastname: Naka
authors.forename: R
authors.initials: R
authors.lastname: Nomura
authors.forename: Y
authors.initials: Y
authors.lastname: Takashima
authors.forename: R
authors.initials: R
authors.lastname: Okawa
authors.forename: T
authors.initials: T
authors.lastname: Ooshima
authors.forename: K
authors.initials: K
authors.lastname: Nakano
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D065626:Non-alcoholic Fatty Liver Disease / Q000382:microbiology*; D012720:Severity of Illness Index; D013290:Streptococcal Infections / Q000150:complications*; D013295:Streptococcus mutans