title: Are there any different effects of Bifidobacterium, Lactobacillus and Streptococcus on intestinal sensation, barrier function and intestinal immunity in PI-IBS mouse model?
abstract: OBJECTIVE
  Research has increasingly suggested that gut flora plays an important role in the development of post-infectious irritable bowel syndrome (PI-IBS). Studies of the curative effect of probiotics for IBS have usually been positive but not always. However, the differences of treatment effects and mechanisms among probiotic stains, or mixture of them, are not clear. In this study, we compared the effects of different probiotics (Befidobacterium, Lactobacillus, Streptococcus or mixture of the three) on intestinal sensation, barrier function and intestinal immunity in PI-IBS mouse model.
  
  
  METHODS
  PI-IBS model was induced by Trichinella spiralis infection in mice. Different probiotics were administered to mice after 8 weeks infection. Visceral sensitivity was measured by scores of abdominal withdrawal reflex (AWR) and the threshold intensity of colorectal distention. Colonic smooth muscle contractile response was assessed by contraction of the longitudinal muscle strips. Plasma diamine oxidase (DAO) and d-lactate were determined by an enzymatic spectrophotometry. Expression of tight junction proteins and cytokines in ileum were measured by Western blotting.
  
  
  RESULTS
  Compared to control mice, PI-IBS mice treated either alone with Befidobacterium or Lactobacillus (but not Streptococcus), or the mixture of the three exhibited not only decreased AWR score and contractile response, but also reduced plasma DAO and D-lactate. These probiotic treatments also suppressed the expression of proinflammatory cytokine IL-6 and IL-17 and promoted the expression of major tight junction proteins claudin-1 and occludin. The mixture of the three probiotic strains performed better than the individual in up-regulating these tight junction proteins and suppressing IL-17 expression.
  
  
  CONCLUSIONS
  Bifidobacterium and Lactobacillus, but not Streptococcus, alleviated visceral hypersensitivity and recovered intestinal barrier function as well as inflammation in PI-IBS mouse model, which correlated with an increase of major tight junction proteins. In addition, Mixture of three species was indicated to be superior to a single one.
authors.affiliation: Division of Gastroenterology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Division of Gastroenterology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Gong
authors.affiliation: Division of Gastroenterology, Hospital of Dongfeng Motor Company of Hubei University of Medicine, Shiyan, Hubei, China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Wang
authors.affiliation: Division of Gastroenterology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Yanqin
authors.initials: Y
authors.lastname: Long
authors.affiliation: Division of Culture Collection, Hubei Center of Industrial Culture Collection and Research, Wuhan, Hubei, China.
authors.forename: Xiaochao
authors.initials: X
authors.lastname: Fu
authors.affiliation: Division of Gastroenterology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Division of Gastroenterology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qian
authors.affiliation: Division of Gastroenterology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Hou
mesh_terms: D000818:Animals; D001644:Bifidobacterium; D015153:Blotting, Western; D016207:Cytokines / Q000378:metabolism; D007413:Intestinal Mucosa / Q000502:physiology; D007422:Intestines / Q000276:immunology / Q000502:physiology*; D007778:Lactobacillus; D051379:Mice; D010539:Permeability; D019936:Probiotics; D013045:Species Specificity; D013291:Streptococcus
chemical_list: D016207:Cytokines