title: Systematic review and meta-analysis: the effects of fermented milk withBifidobacterium lactisCNCM I-2494 and lactic acid bacteria on gastrointestinal discomfort in the general adult population.
abstract: BACKGROUND
  It has been suggested that probiotics may improve gastrointestinal discomfort. Not all probiotics exhibit the same effects and consequently meta-analyses on probiotics should be confined to well-defined strains or strain combinations. The aim of this study was to evaluate the effectiveness of a probiotic fermented milk (PFM) that includesBifidobacterium lactis(B. lactis) CNCM I-2494 and lactic acid bacteria on gastrointestinal discomfort in the general adult population.
  
  
  METHODS
  Double-blind randomized controlled trials in the general adult population comparing PFM with a control dairy product for at least 4 weeks were searched from multiple literature databases (up to February 2015). Meta-analyses using random-effects models, with individual participant data were undertaken to calculate an odds ratio (OR) or standard mean difference (SMD), with a 95% confidence interval (CI).
  
  
  RESULTS
  The search strategy identified 12,439 documents. Overall, three trials with a total of 598 adults (female = 96.5%) met the inclusion criteria. Consumption of the PFM product was associated with a significant improvement in overall gastrointestinal discomfort compared with the control product (OR = 1.48; 95% CI 1.07-2.05), with a number needed to treat (NNT) of 10.24 (95% CI 5.64-55.93). PFM was also superior to the control in reducing digestive symptoms, as measured using a composite score (SMD = -0.21; 95% CI -0.37 to -0.05). Sensitivity analyses produced similar results, and the heterogeneity between studies was minimal.
  
  
  CONCLUSIONS
  This meta-analysis shows that the consumption of PFM withB. lactisCNCM I-2494 and lactic acid bacteria is associated with a modest but consistent and significant improvement of outcomes related to gastrointestinal discomfort in healthy adults.
authors.affiliation: York Health Economics Consortium, University of York, Heslington, York, UK.
authors.forename: Jacqui
authors.initials: J
authors.lastname: Eales
authors.affiliation: Monash University, Alfred Hospital, Melbourne, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Gibson
authors.affiliation: Wythenshawe Hospital, Manchester, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Whorwell
authors.affiliation: University of Sydney, Royal North Shore Hospital, Sydney, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Kellow
authors.affiliation: Quantics Consulting Ltd, Edinburgh, Scotland.
authors.forename: Ann
authors.initials: A
authors.lastname: Yellowlees
authors.affiliation: Quantics Consulting Ltd, Edinburgh, Scotland.
authors.forename: Richard H J
authors.initials: RH
authors.lastname: Perry
authors.affiliation: York Health Economics Consortium, University of York, Heslington, York, UK.
authors.forename: Mary
authors.initials: M
authors.lastname: Edwards
authors.affiliation: York Health Economics Consortium, University of York, Heslington, York, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: King
authors.affiliation: York Health Economics Consortium, University of York, Heslington, York, UK.
authors.forename: Hannah
authors.initials: H
authors.lastname: Wood
authors.affiliation: York Health Economics Consortium, Enterprise House, Innovation Way, University of York, Heslington, York YO10 5NQ, UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Glanville
keywords: Bifidobacterium lactis; digestive symptoms; gastrointestinal discomfort; meta-analysis; probiotic; systematic review