A Systematic Review and Meta-Analysis on the Effects of Probiotic Species on Iron Absorption and Iron Status

Strategies to prevent iron deficiency anemia (IDA) have varying effectiveness. The purpose of this systematic review of the literature and meta-analysis was to examine the effects of probiotics on iron absorption and iron status-related markers in humans.

We followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) reporting guidelines. Relevant articles were identified from Embase, Pubmed, Scopus, and CINAHL from inception to February, 2019. We conducted a meta-analysis for eight studies examining the effect of the probiotic Lactobacillus plantarum 299v (Lp299v) on iron absorption.

Fifteen studies reported in 12 articles were identified (N = 950). Our meta-analysis of eight studies using a random-effects model demonstrated a significant increase in iron absorption following administration of the probiotic Lp299v with a pooled standardized mean difference (an average intervention effect size) of 0.55 (95% CI 0.22-0.88, p = 0.001). Of the seven randomized clinical trials (RCTs) and nonrandomized clinical trials examining a range of probiotic species on iron status, only one study supplementing with Lp299v showed improvement in serum iron; no other studies reported improvement in iron status-related indices with probiotic treatment.

Lp299v significantly improved iron absorption in humans. Future research should include the assessment of Lp299v effect on iron absorption and iron status in populations at high risk of IDA, including pregnant women.