title: Effect of multispecies probiotics on irritable bowel syndrome: a randomized, double-blind, placebo-controlled trial.
abstract: OBJECTIVE
  The efficacy of treatment with multispecies probiotics on irritable bowel syndrome (IBS) symptoms and the alterations of gut microbiota in patients who have taken probiotics were investigated.
  
  
  METHODS
  This randomized, double-blind, placebo-controlled trial involved 49 IBS patients (probiotics: 25, placebo: 24) diagnosed according to the Rome III criteria. Patients were randomly assigned to two groups: either to receive multispecies probiotics (a mixture of Bifidobacterium longum, B. bifidum, B. lactis, Lactobacillus acidophilus, L. rhamnosus, and Streptococcus thermophilus) twice a day for 4 weeks or to receive a placebo twice a day for 4 weeks. The primary efficacy end-point was the proportion of participants whose IBS symptoms were substantially relieved at week 4. Secondary end-points were the intensity of abdominal pain/discomfort, bloating, stool frequency/consistency, alterations in fecal microflora over the 4 weeks. Fecal microflora were analyzed in 34 patients (probiotics: 17, placebo: 17) by quantitative real-time polymerase chain reaction assays.
  
  
  RESULTS
  The proportion of patients whose IBS symptoms were substantially relieved at week 4 was significantly higher in the probiotics group than in the placebo group: 68.0% (17/25) versus 37.5% (9/24) (P < 0.05). Secondary end-points such as improvement in abdominal pain/discomfort and bloating occurred in the probiotics group but not in the placebo group. Fecal analysis revealed that B. lactis, L. rhamnosus, and S. thermophilus had increased significantly in the probiotics group after 4 weeks and that B. lactis had increased in the placebo group.
  
  
  CONCLUSIONS
  Multispecies probiotics are effective in IBS patients and induce the alterations in the composition of intestinal microbiota.
authors.affiliation: Department of Gastroenterology, Hanyang University School of Medicine, Seoul, Republic of Korea.
authors.forename: Jun Sik
authors.initials: JS
authors.lastname: Yoon
authors.forename: Won
authors.initials: W
authors.lastname: Sohn
authors.forename: Oh Young
authors.initials: OY
authors.lastname: Lee
authors.forename: Sang Pyo
authors.initials: SP
authors.lastname: Lee
authors.forename: Kang Nyeong
authors.initials: KN
authors.lastname: Lee
authors.forename: Dae Won
authors.initials: DW
authors.lastname: Jun
authors.forename: Hang Lak
authors.initials: HL
authors.lastname: Lee
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Yoon
authors.forename: Ho Soon
authors.initials: HS
authors.lastname: Choi
authors.forename: Won-Seok
authors.initials: WS
authors.lastname: Chung
authors.forename: Jae-Gu
authors.initials: JG
authors.lastname: Seo
mesh_terms: D000328:Adult; D000368:Aged; D001644:Bifidobacterium / Q000302:isolation & purification; D004311:Double-Blind Method; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000188:drug therapy* / Q000382:microbiology; D007778:Lactobacillus / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D015990:Placebo Effect; D019936:Probiotics / Q000008:administration & dosage*; D048249:Streptococcus thermophilus / Q000302:isolation & purification; D055815:Young Adult
keywords: irritable bowel syndrome; microbiota; probiotics