Probiotic Supplementation and Micronutrient Status in Healthy Subjects: A Systematic Review of Clinical Trials
What this study found
Probiotic intake in healthy subjects may improve micronutrient status, notably vitamin B12 and folate, calcium, zinc and iron. Two of three folate/B12 trials reported improvements; calcium status improved in multiple pediatric and postmenopausal studies; zinc status improved in some trials, particularly with zinc co-supplementation; iron status improvements were variable, with some ferritin and Hb changes and evidence for increased non‑heme iron absorption with certain Lactobacillus strains; vitamin D status improved in some cases (e.g., L. reuteri NCIMB30242 and multi-strain regimens in…
- Study & population
- Healthy humans across age groups including children and adults; sexes mixed; some subgroups included iron-deficient athletes and vegan subjects; study designs included randomized double-blind placebo-controlled trials, cross-over trials, open-label randomized multicenter trials, randomized trials without blinding, and non-randomized trials.
- Intervention
- Regimens varied across 14 trials: probiotic or synbiotic supplements delivered via yogurt/fermented milk, fortified beverages, capsules or tablets, or powders; single- and multi-strain products used.
- Key limitation
- High heterogeneity across studies (age, strains, doses, durations, administration form) and predominantly moderate-to-high risk of bias; only one study had low risk of bias; several trials nonrandomized or lacking blinding; small to moderate sample sizes; limited dietary control; many studies conducted in Europe;…
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Open PDFOriginal abstract
Micronutrient deficiencies are a worldwide public health concern. Emerging evidence supports the ability of probiotics to enhance micronutrient status, which could aid in the prevention of non-communicable disease-associated malnutrition. This systematic review evaluated evidence of the efficacy of probiotic supplementation to improve micronutrient status in healthy subjects. The authors searched for published English language peer-reviewed journal articles in PubMed, Scopus, Embase, and Google Scholar databases from inception to July 2020 using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of eligible studies was assessed using the Revised Cochrane Risk-of-Bias tool (RoB)2 and Risk of Bias in Non-Randomized Studies of Interventions tool (ROBINS-I tool). Fourteen original studies out of 2790 met the inclusion criteria. The results indicated that, despite varying degrees of efficacy, the intake of certain probiotics in healthy subjects was associated with a positive impact on the status of certain micronutrients (vitamin B12, calcium, folate, iron and zinc). A limitation was that studies were widely heterogeneous in terms of participant age, probiotic strain, species, dosage, intervention duration, and form of administration. Additional clinical trials are warranted to determine the most effective strains of probiotics, doses and durations of interventions.