Lactobacillus plantarum 299v and Improved Iron Levels

Research synthesisModerate evidenceMixed effect size4 studies · 4 beneficial · 0 neutral · 0 harmful

Across 4 studies (3 statistically significant), all reported beneficial effects of L. plantarum 299v on iron status. The predominant effect size was mixed (small to large across studies), and the most frequently studied population was pregnant women. Dosing was only specified in one trial (10^10 CFU/day).

Studied populations: pregnant women, adults with iron deficiency anemia

Caveats: Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). The evidence base is small (only 4 studies), and study durations were often unreported. Effect sizes varied widely from small to large, and most research focused on pregnant women or patients with existing iron deficiency, limiting generalizability.

Generated Jul 17, 2026

Doses used in studies

CFU/day: 10 billion (median 10 billion, IQR 10 billion–10 billion) — 1 study

Time to effect

Median: 3 months · IQR 3 months–3 months · Range 3 months–3 months — Reported in 1 of 4 studies

Safety in these studies

gastrointestinal intoleranceReported
IRT-Pro group, when compared with IRT-only group, experienced significantly lower rates of gastrointestinal intolerance over the course of IRT (13·0 % v. 46·5 %, P < 0·001)
from: Improved gastrointestinal tolerance and iron status via probiotic use in iron deficiency a
treatment discontinuationReported
treatment discontinuation within the first 30 d (3·6 % v. 15·9 %, P < 0·001)
from: Improved gastrointestinal tolerance and iron status via probiotic use in iron deficiency a

4 of 4 papersPopulation:

A Systematic Review and Meta-Analysis on the Effects of Probiotic Species on Iron Absorption and Iron Status.
- 2019-12-03
- Meta-Analysis · n = 950
- Nutrients 11(12)
- - Susan C Vonderheid
  - Lisa Tussing-Humphreys
  - Chang Park
  - Heather Pauls
  - Nefertiti OjiNjideka Hemphill
  - Bazil LaBomascus
  - Andrew McLeod
  - Mary Dawn Koenig
- PubMed: 31816981
- DOI: 10.3390/nu11122938
3 Insights on
- Improved Iron Levels
- High evidence
- Rigorous Journal
- Adults
only one study supplementing with Lp299v showed improvement in serum iron
Effect
Beneficial
Effect size
Small
Significant
Yes
Improved gastrointestinal tolerance and iron status via probiotic use in iron deficiency anaemia patients initiating oral iron replacement: a randomised controlled trial.
- 2024-11-04
- RCT · n = 295
- The British journal of nutrition 132(10)
- - Gokhan Koker
  - Yasin Sahinturk
  - Gulhan Ozcelik Koker
  - Muhammed Ali Coskuner
  - Merve Eren Durmus
  - Mehmet Mutlu Catli
  - Ayhan Hilmi Cekin
- PubMed: 39494607
- DOI: 10.1017/s0007114524002757
5 Insights on
- Improved Iron Levels
- High evidence
- Large Human Trial
- Clinical
IRT-Pro v. IRT-only group had significantly higher serum levels for iron (76·0 (51·0-96·0) v. 60·0(43·0-70·0) µg/dl, P < 0·001)
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Dose
not specified
The effect of Lactiplantibacillus plantarum 299v together with a low dose of iron on iron status in healthy pregnant women: A randomized clinical trial
- 2021-04-21
- RCT
- Acta Obstetricia et Gynecologica Scandinavica 100(9)
- - U. Axling
  - G. Önning
  - Titti Martinsson Niskanen
  - N. Larsson
  - S. Hansson
  - L. Hulthén
- PubMed: 33880752
- DOI: 10.1111/aogs.14153
17 Insights on
- Improved Iron Levels
- High evidence
- Pregnant Women
Intake of Lp attenuated the decrease in serum ferritin from baseline to week 28 (p = 0.003) and week 35 (p ˂ 0.001) and resulted in reduced prevalence of iron deficiency (59% vs 78%, p = 0.017) and iron deficiency anemia (7.4% vs 21%, p = 0.023) at week 35.
Effect
Beneficial
Effect size
Large
Significant
Yes
Dose
1010 colony forming units twice daily
Feasibility Study of Lactobacillus Plantarum 299v Probiotic Supplementation in an Urban Academic Facility among Diverse Pregnant Individuals
- 2023-02-09
- RCT · n = 20
- Nutrients 15(4)
- - Nefertiti OjiNjideka Hemphill
  - Lacey Pezley
  - Alana D. Steffen
  - G. Elam
  - M. Kominiarek
  - A. Odoms-Young
  - Nicollette Kessee
  - Alyshia Hamm
  - L. Tussing-Humphreys
  - M. D. Koenig
- PubMed: 36839232
- DOI: 10.3390/nu15040875
2 Insights on
- Improved Iron Levels
- High evidence
- Pregnant Women
A slower decline in maternal hematological and iron parameters across pregnancy was observed in the Lp299v® group compared to placebo.
Effect
Beneficial
Effect size
Small

Lactobacillus plantarum 299v and Improved Iron Levels

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

Improved gastrointestinal tolerance and iron status via probiotic use in iron deficiency anaemia patients initiating oral iron replacement: a randomised controlled trial.

The effect of Lactiplantibacillus plantarum 299v together with a low dose of iron on iron status in healthy pregnant women: A randomized clinical trial

Feasibility Study of Lactobacillus Plantarum 299v Probiotic Supplementation in an Urban Academic Facility among Diverse Pregnant Individuals