title: Health benefits of probiotics: are mixtures more effective than single strains?
abstract: OBJECTIVE
  Most studies on probiotics utilise single strains, sometimes incorporated into yoghurts. There are fewer studies on efficacy of mixtures of probiotic strains. This review examines the evidence that (a) probiotic mixtures are beneficial for a range of health-related outcomes and (b) mixtures are more or less effective than their component strains administered separately.
  
  
  RESULTS
  Mixtures of probiotics had beneficial effects on the end points including irritable bowel syndrome and gut function, diarrhoea, atopic disease, immune function and respiratory tract infections, gut microbiota modulation, inflammatory bowel disease and treatment of Helicobacter pylori infection. However, only 16 studies compared the effect of a mixture with that of its component strains separately, although in 12 cases (75%), the mixture was more effective.
  
  
  CONCLUSIONS
  Probiotic mixtures appear to be effective against a wide range of end points. Based on a limited number of studies, multi-strain probiotics appear to show greater efficacy than single strains, including strains that are components of the mixtures themselves. However, whether this is due to synergistic interactions between strains or a consequence of the higher probiotic dose used in some studies is at present unclear.
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Whiteknights, PO Box 226, Reading RG6 6AP, UK. c.m.c.chapman@pgr.reading.ac.uk
authors.forename: C M C
authors.initials: CM
authors.lastname: Chapman
authors.forename: G R
authors.initials: GR
authors.lastname: Gibson
authors.forename: I
authors.initials: I
authors.lastname: Rowland
mesh_terms: D000818:Animals; D003876:Dermatitis, Atopic / Q000178:diet therapy / Q000503:physiopathology / Q000517:prevention & control; D005767:Gastrointestinal Diseases / Q000178:diet therapy / Q000503:physiopathology / Q000517:prevention & control; D041981:Gastrointestinal Tract / Q000382:microbiology / Q000502:physiology / Q000503:physiopathology; D006304:Health Status; D006801:Humans; D019936:Probiotics / Q000008:administration & dosage / Q000627:therapeutic use*; D012141:Respiratory Tract Infections / Q000178:diet therapy / Q000503:physiopathology / Q000517:prevention & control