title: Oral ingestion of streptococcus thermophilus diminishes severity of small intestinal mucositis in methotrexate treated rats.
abstract: BACKGROUND
  Currently, there are no available effective preventative or adjunctive agents to alleviate symptoms of chemotherapy-induced mucositis. This is compounded by the absence of a recognized and validated noninvasive biomarker to assess gut function. This study investigated the effects of orally ingested Streptococcus thermophilus (TH-4) on chemotherapy-induced small intestinal damage in rats using the noninvasive (13)C-sucrose breath test (SBT).
  
  
  METHODS
  Gastrointestinal damage was induced in 27 female dark agouti rats (148 +/- 1g) with MTX (1.5 mg/kg; i.m.). Rats received MTX or saline at 0 h; with daily treatment of: TH-4 at doses of 10(9) (high), 10(8) (low) cfu/mL, or skim milk (vehicle), 48 h pre and 96 h post-MTX. The noninvasive (13)C-sucrose breath test (SBT) was conducted at -24, 24 and 96 h post-MTX to monitor gut function. At sacrifice, small intestinal tissues were collected for determinations of sucrase activity, myeloperoxidase (MPO) activity and histological assessment.
  
  
  RESULTS
  MTX + vehicle and MTX + low TH-4-treated rats produced significantly lower SBT and sucrase activity results compared to saline controls (p < 0.001). In contrast, MTX + high TH-4 treatment showed no significant differences in the SBT compared to saline controls, and the SBT results were significantly higher compared to MTX + vehicle and MTX + low TH-4 (p < 0.05). MPO levels were significantly elevated (p < 0.05) in MTX + vehicle and MTX + low TH-4, but not following MTX + high TH-4 treatment, compared to saline controls. This was further confirmed by histological analyses.
  
  
  CONCLUSIONS
  Oral ingestion of TH-4 at 10(9) cfu/mL is capable of partially attenuating small bowel damage in rats. The noninvasive SBT is a useful technique to longitudinally assess the efficacy of treatments or interventions for small bowel disease.
authors.affiliation: Centre for Paediatric and Adolescent Gastroenterology, Children, Youth and Women's Health Service, North Adelaide, South Australia.
authors.forename: Katie L
authors.initials: KL
authors.lastname: Tooley
authors.forename: Gordon S
authors.initials: GS
authors.lastname: Howarth
authors.forename: Kerry A
authors.initials: KA
authors.lastname: Lymn
authors.forename: Andrew
authors.initials: A
authors.lastname: Lawrence
authors.forename: Ross N
authors.initials: RN
authors.lastname: Butler
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004327:Drinking Behavior; D005247:Feeding Behavior; D005260:Female; D007421:Intestine, Small / Q000473:pathology*; D008727:Methotrexate / Q000633:toxicity*; D052016:Mucositis / Q000139:chemically induced / Q000382:microbiology / Q000517:prevention & control*; D051381:Rats; D011919:Rats, Inbred Strains; D048249:Streptococcus thermophilus
chemical_list: D008727:Methotrexate