title: Butyrate modulates bacterial adherence on LS174T human colorectal cells by stimulating mucin secretion and MAPK signaling pathway.
abstract: OBJECTIVE
  Fermentation of dietary fiber results in production of various short chain fatty acids in the colon. In particular, butyrate is reported to regulate the physical and functional integrity of the normal colonic mucosa by altering mucin gene expression or the number of goblet cells. The objective of this study was to investigate whether butyrate modulates mucin secretion in LS174T human colorectal cells, thereby influencing the adhesion of probiotics such as Lactobacillus and Bifidobacterium strains and subsequently inhibiting pathogenic bacteria such as E. coli. In addition, possible signaling pathways involved in mucin gene regulation induced by butyrate treatment were also investigated.
  
  
  METHODS
  Mucin protein content assay and periodic acid-Schiff (PAS) staining were performed in LS174T cells treated with butyrate at various concentrations. Effects of butyrate on the ability of probiotics to adhere to LS174T cells and their competition with E. coli strains were examined. Real time polymerase chain reaction for mucin gene expression and Taqman array 96-well fast plate-based pathway analysis were performed on butyrate-treated LS174T cells.
  
  
  RESULTS
  Treatment with butyrate resulted in a dose-dependent increase in mucin protein contents in LS174T cells with peak effects at 6 or 9 mM, which was further confirmed by PAS staining. Increase in mucin protein contents resulted in elevated adherence of probiotics, which subsequently reduced the adherent ability of E. coli. Treatment with butyrate also increased transcriptional levels of MUC3, MUC4, and MUC12, which was accompanied by higher gene expressions of signaling kinases and transcription factors involved in mitogen-activated protein kinase (MAPK) signaling pathways.
  
  
  CONCLUSIONS
  Based on our results, butyrate is an effective regulator of modulation of mucin protein production at the transcriptional and translational levels, resulting in changes in the adherence of gut microflora. Butyrate potentially stimulates the MAPK signaling pathway in intestinal cells, which is positively correlated with gut defense.
authors.affiliation: Department of Animal Biotechnology and Resource, Sahmyook University, Hwarangro 815, Nowon-gu, Seoul 139-742, Korea.
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Jung
authors.affiliation: Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
authors.forename: Jeong Hyeon
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Animal Biotechnology and Resource, Sahmyook University, Hwarangro 815, Nowon-gu, Seoul 139-742, Korea.
authors.forename: Woo-Min
authors.initials: WM
authors.lastname: Jeon
authors.affiliation: Department of Animal Biotechnology and Resource, Sahmyook University, Hwarangro 815, Nowon-gu, Seoul 139-742, Korea.
authors.forename: Kyoung-Sik
authors.initials: KS
authors.lastname: Han
keywords: Butyrate; LS174T cell; MAPK; MUC gene; mucin protein