title: Effect of probiotics and synbiotics on blood glucose: a systematic review and meta-analysis of controlled trials.
abstract: OBJECTIVE
  High fasting blood glucose (FBG) can lead to chronic diseases such as diabetes mellitus, cardiovascular and kidney diseases. Consuming probiotics or synbiotics may improve FBG. A systematic review and meta-analysis of controlled trials was conducted to clarify the effect of probiotic and synbiotic consumption on FBG levels.
  
  
  METHODS
  PubMed, Scopus, Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature databases were searched for relevant studies based on eligibility criteria. Randomized or non-randomized controlled trials which investigated the efficacy of probiotics or synbiotics on the FBG of adults were included. Studies were excluded if they were review articles and study protocols, or if the supplement dosage was not clearly mentioned.
  
  
  RESULTS
  A total of fourteen studies (eighteen trials) were included in the analysis. Random-effects meta-analyses were conducted for the mean difference in FBG. Overall reduction in FBG observed from consumption of probiotics and synbiotics was borderline statistically significant (-0.18 mmol/L 95 % CI -0.37, 0.00; p = 0.05). Neither probiotic nor synbiotic subgroup analysis revealed a significant reduction in FBG. The result of subgroup analysis for baseline FBG level ≥7 mmol/L showed a reduction in FBG of 0.68 mmol/L (-1.07, -0.29; ρ < 0.01), while trials with multiple species of probiotics showed a more pronounced reduction of 0.31 mmol/L (-0.58, -0.03; ρ = 0.03) compared to single species trials.
  
  
  CONCLUSIONS
  This meta-analysis suggests that probiotic and synbiotic supplementation may be beneficial in lowering FBG in adults with high baseline FBG (≥7 mmol/L) and that multispecies probiotics may have more impact on FBG than single species.
authors: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.|School of Medicine, Griffith University, Gold Coast, Australia.
authors: Elham
authors: E
authors: Nikbakht
authors: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia. s.khalesi@cqu.edu.au.|School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia. s.khalesi@cqu.edu.au.
authors: Saman
authors: http://orcid.org/0000-0002-8208-2518
authors: S
authors: Khalesi
authors: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.|School of Medicine, Griffith University, Gold Coast, Australia.
authors: Indu
authors: I
authors: Singh
authors: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
authors: Lauren Therese
authors: LT
authors: Williams
authors: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
authors: Nicholas P
authors: NP
authors: West
authors: Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.|School of Medicine, Griffith University, Gold Coast, Australia.
authors: Natalie
authors: N
authors: Colson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D018849:Controlled Clinical Trials as Topic; D005215:Fasting; D006801:Humans; D006943:Hyperglycemia / Q000517:prevention & control; D016239:MEDLINE; D008875:Middle Aged; D019936:Probiotics / Q000008:administration & dosage*; D016032:Randomized Controlled Trials as Topic; D058616:Synbiotics / Q000008:administration & dosage*
chemical_list: D001786:Blood Glucose
keywords: Fasting blood glucose; Hyperglycemia; Probiotics; Synbiotics