title: Effects of synbiotic fermented milk containing Lactobacillus acidophilus La-5 and Bifidobacterium animalis ssp. lactis BB-12 on the fecal microbiota of adults with irritable bowel syndrome: A randomized double-blind, placebo-controlled trial.
abstract: We conducted a randomized double-blind, placebo-controlled multicentric study to investigate the influence of a synbiotic fermented milk on the fecal microbiota composition of 30 adults with irritable bowel syndrome (IBS). The synbiotic product contained Lactobacillus acidophilus La-5, Bifidobacterium animalis ssp. lactis BB-12, Streptococcus thermophilus, and dietary fiber (90% inulin, 10% oligofructose), and a heat-treated fermented milk without probiotic bacteria or dietary fiber served as placebo. Stool samples were collected after a run-in period, a 4-wk consumption period, and a 1-wk follow-up period, and were subjected to real-time PCR and 16S rDNA profiling by next-generation sequencing. After 4wk of synbiotic (11 subjects) or placebo (19 subjects) consumption, a greater increase in DNA specific for L. acidophilus La-5 and Bifidobacterium animalis ssp. lactis was detected in the feces of the synbiotic group compared with the placebo group by quantitative real-time PCR. After 1wk of follow-up, the content of L. acidophilus La-5 and B. animalis ssp. lactis decreased to levels close to initial levels. No significant changes with time or differences between the groups were observed for Lactobacillus, Enterobacteriaceae, Bifidobacterium, or all bacteria. The presence of viable BB-12- and La-5-like bacteria in the feces resulting from the intake of synbiotic product was confirmed by random amplification of polymorphic DNA (RAPD)-PCR. At the end of consumption period, the feces of all subjects assigned to the synbiotic group contained viable bacteria with a BB-12-like RAPD profile, and after 1wk of follow-up, BB-12-like bacteria remained in the feces of 87.5% of these subjects. The presence of La-5-like colonies was observed less frequently (37.5 and 25% of subjects, respectively). Next-generation sequencing of 16S rDNA amplicons revealed that only the percentage of sequences assigned to Strep. thermophilus was temporarily increased in both groups, whereas the global profile of the fecal microbiota of patients was not altered by consumption of the synbiotic or placebo. In conclusion, daily consumption of a synbiotic fermented milk had a short-term effect on the amount and proportion of La-5-like strains and B. animalis ssp. lactis in the fecal microbiome of IBS patients. Furthermore, both synbiotic and placebo products caused a temporary increase in fecal Strep. thermophilus.
authors.affiliation: Institute of Dairy Science and Probiotics, Department of Animal Science, Biotechnical Faculty, University of Ljubljana, SI-1230 Domžale, Slovenia. Electronic address: bojana.bogovic@bf.uni-lj.si.
authors.forename: Bojana
authors.initials: B
authors.lastname: Bogovič Matijašić
authors.affiliation: Institute of Dairy Science and Probiotics, Department of Animal Science, Biotechnical Faculty, University of Ljubljana, SI-1230 Domžale, Slovenia.
authors.forename: Tanja
authors.initials: T
authors.lastname: Obermajer
authors.affiliation: Division of Microbiology and Microbial Biotechnology, Department of Animal Science, Biotechnical Faculty, University of Ljubljana, SI-1230 Domžale, Slovenia.
authors.forename: Luka
authors.initials: L
authors.lastname: Lipoglavšek
authors.affiliation: Institute of Dairy Science and Probiotics, Department of Animal Science, Biotechnical Faculty, University of Ljubljana, SI-1230 Domžale, Slovenia.
authors.forename: Tjaša
authors.initials: T
authors.lastname: Sernel
authors.affiliation: Faculty of Pharmacy, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
authors.forename: Igor
authors.initials: I
authors.lastname: Locatelli
authors.affiliation: Faculty of Pharmacy, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
authors.forename: Mitja
authors.initials: M
authors.lastname: Kos
authors.affiliation: Faculty of Pharmacy, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
authors.forename: Alenka
authors.initials: A
authors.lastname: Šmid
authors.affiliation: Institute of Dairy Science and Probiotics, Department of Animal Science, Biotechnical Faculty, University of Ljubljana, SI-1230 Domžale, Slovenia.
authors.forename: Irena
authors.initials: I
authors.lastname: Rogelj
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000069982:Bifidobacterium animalis / Q000737:chemistry*; D017523:Croatia; D043302:Cultured Milk Products / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D004043:Dietary Fiber / Q000008:administration & dosage*; D004311:Double-Blind Method; D005243:Feces / Q000382:microbiology; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000188:drug therapy*; D007779:Lactobacillus acidophilus / Q000737:chemistry*; D008875:Middle Aged; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D017524:Slovenia; D048249:Streptococcus thermophilus / Q000737:chemistry; D058616:Synbiotics / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial; D004043:Dietary Fiber; D012336:RNA, Ribosomal, 16S
keywords: irritable bowel syndrome; metataxonomics; real-time PCR; synbiotic fermented milk