Lacticaseibacillus casei decrease long-chain fatty acids and most substances in an experimental model of intestinal mucositis

PURPOSE: To evaluate the long-chain fatty acid and major compounds levels in the feces after prophylactic oral use of Lacticaseibacillus casei in an experimental model of intestinal mucositis. METHODS: Fifteen Swiss mice were randomly divided into three groups (n=5/group): The negative or positive control groups (n = 5) received saline orally for 18 days and an the intraperitoneal (i.p.) of saline or 5 Fluorouracil (450 mg/kg) in 15(th) day, respectability. L. casei group received oral concentration of L. casei (1x10(9) CFU/mL) for 18 days, the i.p. injection of 5-fluorouracil (450 mg/kg) in 15(th) days. Tissue samples from colon and each small intestine segment were collected for histopathological analysis. Stool samples were collected. Fecal composition of long-chain fatty acids and sterols were analysed by gas chromatography-mass spectrometry on the 15(th) and the 18(th) day. RESULTS: The mucosa layer of all small intestine segments of animals from L. casei showed well preserved epithelium and glands, without necrosis signs, but Goblet cells number decreased. Several long-chain fatty acids and sterols have been identified before and after in the groups. L. casei administration after 5-FU treatment reduced concentrations of linoleic acid (18:2) (p < 0.001) and oleic acid (18:1) (p < 0.001) in feces. CONCLUSIONS: L. casei prevented the mucosal damage associated with 5-FU-induced intestinal mucositis reduced long-chain fatty acid levels in the feces.