About L. plantarum
Lactobacillus plantarum (reclassified in 2020 as Lactiplantibacillus plantarum) is a versatile lactic acid bacterium found in fermented foods. Clinical evidence is strain-dependent. Strain 299v (DSM 9843, branded as ProViva/IbSium) has the deepest dataset for IBS — Ducrotté 2012 RCT (n=214) showed symptom improvement vs placebo. PS128 has emerging psychobiotic data. Generic 'L. plantarum' on a label without a strain identifier should not be assumed to deliver the clinical effects published for specific strains. No established RDA/UL.
What L. plantarum supports
- Strain 299v may reduce IBS bloating and abdominal pain (Ducrotté 2012; mixed across other trials)
- 299v co-administered with iron may improve non-heme iron absorption (Hoppe 2017)
How much L. plantarum to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
1–50
billion_cfu
Clinical range 1-50 billion CFU/day. Strain-specific evidence: 299v at 10 billion CFU/day (Ducrotté 2012 IBS, Niedzielin 2001); PS128 at 30 billion CFU/day (psychobiotic trials); DR7 at 10 billion CFU/day (stress/cognition). Generic 'L. plantarum' on labels without strain ID is essentially unverifiable for clinical match. Dose is measured in CFU, not mg.
Clinical evidence
Limited clinical evidence. Strain-specific evidence varies widely. 299v has the strongest IBS data; PS128 and DR7 have small psychobiotic/mood trials. Unspecified 'L. plantarum' has no guaranteed clinical effect since outcomes don't generalize across strains.
NIH Fact Sheet