Lactobacillus plantarum 299v: Evidence, Trial Doses & Interactions

About Lactobacillus plantarum 299v

A well-characterised plant-derived lactic acid bacterium, deposited as DSM 9843, studied mainly for irritable bowel symptoms and — unusually for a probiotic — for its effect on iron absorption.

Lp299v is one of the few strains where the label reliably matches the research, because it is a single proprietary organism sold under its strain designation. The irritable bowel evidence is real but modest: trials report reductions in bloating and abdominal pain against placebo, in studies that are mostly small and several of which were funded by the strain owner. The more interesting finding is the iron one — controlled studies show that taking Lp299v with a meal increases non-heme iron absorption, apparently by producing lactic acid and modifying the meal matrix. That is a specific, measurable, unexpected effect and it is still early work.

Sold as

Capsule, Fermented oat or fruit drink, Sachet

Standardised to

CFU of strain DSM 9843 per dose, typically 10 billion — a product without this marker may not resemble what was studied.

Also known as

Lp299v, L. plantarum 299v

Regulation: Sold as a food supplement with no pre-market efficacy review; EFSA has not authorised probiotic health claims in the EU. The strain is proprietary, which in this case has the side effect that products naming it usually do contain it.

What the research used

The amounts, forms and durations published trials of Lactobacillus plantarum 299v actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

Studied for Irritable bowel syndrome symptoms
10 billion CFU
Moderate
Capsule, once daily · 4–12 weeks
The dose used in the main randomised trials, several of which were supported by the company that owns the strain. Reported effects are on bloating and pain scores rather than on any objective measure.
Studied for Non-heme iron absorption
10 billion CFU
Limited
Taken together with an iron-containing meal or supplement · Single meal in absorption studies; up to several weeks in status studies
Isotope studies report increased iron absorption from a meal when Lp299v is taken with it. This is early work in small groups and has not yet been shown to change ferritin meaningfully in most populations.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

Each timing below was actually compared against an alternative in a trial, which is unusual.

With food
Limited
For the iron effect, taking it with the iron-containing meal is the point of the intervention rather than a convenience — the mechanism operates on the meal itself. This has been directly tested in absorption studies.
Timing was tested. A trial compared this window against another and reported a difference.

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Digestive comfort

Gut & Digestive Health

Moderate evidence

Randomised trials in irritable bowel syndrome report reductions in bloating and abdominal pain with Lp299v compared with placebo, and meta-analyses of the strain find a consistent direction of effect. Trials are small and several were funded by the strain owner, which is why this sits at moderate rather than higher.

Moderate evidence. Several human studies point the same way, with real caveats.

View the 3 sources

Clinical trial: Lactobacillus plantarum 299v (DSM 9843) improves symptoms of irritable bowel syndrome.(opens in a new tab)
Randomised controlled trial · World journal of gastroenterology · 2012 · PMID 22912552
Role of Lactobacillus plantarum 299v versus Placebo in symptomatic improvement of irritable bowel syndrome patients.(opens in a new tab)
Randomised controlled trial · JPMA. The Journal of the Pakistan Medical Association · 2022 · PMID 35320214
Efficacy and Safety of Lactobacillus plantarum DSM 9843 (LP299V) in the Prevention of Antibiotic-Associated Gastrointestinal Symptoms in Children-Randomized, Double-Blind, Placebo-Controlled Study.(opens in a new tab)
Randomised controlled trial · The Journal of pediatrics · 2017 · PMID 28438377

Deep research mode adds each paper’s own conclusion and stated limitations.

Gut microbiome

Gut & Digestive Health

Limited evidence

Lp299v colonises the intestinal mucosa transiently and can be recovered from biopsies during supplementation, but it disappears after stopping. Durable change to the resident microbial community has not been demonstrated.

Limited evidence. Early human work, or mostly lab and animal research.

View the 2 sources

Probiotic Lactobacillus Plantarum 299v decreases kynurenine concentration and improves cognitive functions in patients with major depression: A double-blind, randomized, placebo controlled study.(opens in a new tab)
Randomised controlled trial · Psychoneuroendocrinology · 2019 · PMID 30388595
Probiotic Lactobacillus plantarum 299v supplementation in patients with major depression in a double-blind, randomized, placebo-controlled trial: A metabolomics study.(opens in a new tab)
Randomised controlled trial · Journal of affective disorders · 2025 · PMID 39271063

Deep research mode adds each paper’s own conclusion and stated limitations.

Iron status

Women's Health

Limited evidence

Isotope-labelled absorption studies report that Lp299v taken with a meal increases non-heme iron absorption, with some trials suggesting improved iron status in women. The work is early, the groups are small and the effect on clinically relevant iron measures is not established.

What may be going on: Lactic acid production and effects on the food matrix are proposed to keep iron in a more absorbable form in the upper intestine.

Limited evidence. Early human work, or mostly lab and animal research.

View the 4 sources

The effect of Lactiplantibacillus plantarum 299v together with a low dose of iron on iron status in healthy pregnant women: A randomized clinical trial.(opens in a new tab)
Randomised controlled trial · Acta obstetricia et gynecologica Scandinavica · 2021 · PMID 33880752
Feasibility Study of Lactobacillus Plantarum 299v Probiotic Supplementation in an Urban Academic Facility among Diverse Pregnant Individuals.(opens in a new tab)
Randomised controlled trial · Nutrients · 2023 · PMID 36839232
The Effect of Lactobacillus plantarum 299v on Iron Status and Physical Performance in Female Iron-Deficient Athletes: A Randomized Controlled Trial.(opens in a new tab)
Randomised controlled trial · Nutrients · 2020 · PMID 32365981
Use of a Probiotic to Enhance Iron Absorption in a Randomized Trial of Pediatric Patients Presenting with Iron Deficiency.(opens in a new tab)
Randomised controlled trial · The Journal of pediatrics · 2019 · PMID 30732996

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

Avoid
Immunocompromise, central lines and critical illness
As with any live culture, people who are severely immunosuppressed, critically ill or have a central venous catheter should not start a probiotic without specialist advice. Lactobacillus bacteraemia is documented in these groups.
Worth knowing
Symptom endpoints and manufacturer funding
The irritable bowel evidence rests on self-reported symptom scores in trials largely supported by the strain owner. Both features push effect sizes upward, and neither invalidates the result — they just mean it should be read as moderate rather than settled.
Too much
Initial gas and bloating
Common in the first days, particularly in people whose symptoms are already bloating-dominant, and usually transient.

Lactobacillus plantarum 299v

What lactobacillus plantarum 299v may help with

About Lactobacillus plantarum 299v

What the research used

When it was taken

With food

The evidence in depth

Digestive comfort

Gut microbiome

Iron status

Things to know

Immunocompromise, central lines and critical illness

Symptom endpoints and manufacturer funding

Initial gas and bloating

What lactobacillus plantarum 299v may help with

About Lactobacillus plantarum 299v

What the research used

When it was taken

🍽️With food

The evidence in depth

Digestive comfort

Gut microbiome

Iron status

Things to know

Immunocompromise, central lines and critical illness

Symptom endpoints and manufacturer funding

Initial gas and bloating

With food