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Head-to-head evidence comparison — which supplement is right for you?
L. plantarum 299v vs L. rhamnosus GG: L. rhamnosus GG has the stronger overall evidence (6 vs 5/10); they're alternatives for improve digestion — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
L. rhamnosus GG wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Mostly mechanism / observational
Top outcomes
Verdict
Mostly mechanism / observational
Top outcomes
Shared outcomes (1)
Outcomes where both L. plantarum 299v and L. rhamnosus GG have evidence — compare verdict strength side-by-side.
1 x 10^9 CFU (1 billion) daily taken WITH the iron-containing meal is sufficient for the iron effect — in the dual-isotope crossover trial 10^9 was significant (28.6% vs 18.5%, p<0.028) while 10^10 was NOT (29.1% vs 20.1%, p=0.080). The freeze-dried capsule and IBS trials used 1 x 10^10 CFU daily, and the pregnancy trial used 1 x 10^10 CFU twice daily (2 x 10^10 CFU/day)
with-meals
Freeze-dried capsule standardized to 299v (DSM 9843)
10-20 billion CFU (1-2 x 10^10) daily; 10 billion CFU/day is the effective floor
any
Capsule standardized to ATCC 53103
Immediate, per meal
12-25 weeks
4 weeks
n/a
During the antibiotic course
During hospital stay
n/a
n/a
A Systematic Review and Meta-Analysis on the Effects of Probiotic Species on Iron Absorption and Iron Status.
Nutrients (2019) · Meta analysis
Pooled SMD 0.55 (95% CI 0.22-0.88, p=0.001) for increased iron absorption across 8 studies
The effect of Lactiplantibacillus plantarum 299v together with a low dose of iron on iron status in healthy pregnant women: A randomized clinical trial.
Acta Obstet Gynecol Scand (2021) · Rct · n=326
Iron deficiency at week 35: 59% vs 78% (p=0.017); iron-deficiency anaemia 7.4% vs 21% (p=0.023)
Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis.
Gastroenterology (2023) · Meta analysis
For global IBS symptoms, certainty of evidence was LOW for this strain (moderate only for Escherichia strains)
Lactobacillus rhamnosus GG versus Placebo for Acute Gastroenteritis in Children.
N Engl J Med (2018) · Rct · n=971
Primary outcome (modified Vesikari score >=9 within 14 days): 11.8% with LGG vs 12.6% placebo; RR 0.96 (0.68-1.35), P=0.83
Systematic review with meta-analysis: Lactobacillus rhamnosus GG in the prevention of antibiotic-associated diarrhoea in children and adults.
Aliment Pharmacol Ther (2015) · Meta analysis
Antibiotic-associated diarrhea fell from 22.4% to 12.3%; RR 0.49 (0.29-0.83) pooled across 11 RCTs, n=1,308 (12 RCTs, n=1,499 included overall)
Probiotics for treating acute infectious diarrhoea.
Cochrane Database Syst Rev (2020) · Meta analysis
In studies at low risk of bias, no difference in diarrhea lasting >=48 hours (RR 1.00, 0.91-1.09; moderate certainty)
L. rhamnosus GG has a higher evidence score (6/10 vs 5/10) and wins in 2 of 3 categories.
For improve digestion, L. rhamnosus GG has a higher relevance score (72 vs 50).
No known interactions between L. plantarum 299v and L. rhamnosus GG have been documented in our database. However, always consult a healthcare provider before combining supplements.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.