Lactobacillus plantarum 299v (Lp299v)

Q: Does L. plantarum 299v help IBS?

Possibly. A 2026 meta-analysis found it improved key IBS symptoms, and a 214-person trial reported less pain and bloating, but an 81-person trial found no benefit over placebo.

Q: Does it help with iron tablets?

One open, non-placebo trial in 295 people starting iron found fewer stomach side effects and better iron markers with L. plantarum 299v added; it needs placebo-controlled confirmation.

Q: How much L. plantarum 299v was used in studies?

IBS trials used 10 billion to 50 billion CFU a day for 4 to 8 weeks, most often 10 billion CFU a day.

Q: Can it be taken with antibiotics?

Health Canada's probiotics monograph directs separating bacterial probiotics from antibiotics by at least 2–3 hours.

Q: Does it stop diarrhoea from antibiotics in children?

Not in the largest trial: in 438 children, loose stools and antibiotic-associated diarrhoea were not significantly lower than with placebo.

Q: Who should avoid it?

People with immune-compromised conditions, including long-term corticosteroid users, per Health Canada, and premature infants, in whom probiotics have caused severe infections (NCCIH, FDA). Pregnancy and breastfeeding data are lacking.

Also called Lactiplantibacillus plantarum 299v, LP299V, Lp299v, DSM 9843, L. plantarum 299v.

Best grade B across 6 graded outcomes Other Last checked Oct 21, 2026

The short answer

From 10 sources

Lactobacillus plantarum 299v (DSM 9843), now classed as Lactiplantibacillus plantarum, is a single probiotic strain studied mainly for IBS. A 2026 meta-analysis of six trials (521 people) found less abdominal pain and better symptoms (grade B), though one 81-person trial found no benefit. A 438-child trial found no effect on antibiotic-associated loose stools.

Every graded outcome on this page

6 rows · line = participants

Grade BIBS symptoms (abdominal pain severity, incomplete evacuation, symptom-improvement rates)IBSn 521
Grade BAbdominal pain and bloating in IBSIBSn 214
Grade CGI tolerance of oral iron and iron statusIron tolerancen 295
Grade CAbdominal pain relief in IBSIBSn 81
Grade DIBS abdominal pain and overall symptomsIBSn 40
No effectLoose stools and GI symptoms during antibiotics in childrenAntibiotic-associated diarrhoean 438
3 more graded outcomes, in the evidence chapter

Key facts

What it is: A single strain (DSM 9843) of Lactiplantibacillus plantarum, formerly Lactobacillus plantarum^8,1
Pooled IBS data: A 2026 strain-specific meta-analysis of six placebo-controlled trials (521 participants) found L. plantarum 299v (DSM 9843) reduced abdominal pain severity and improved key IBS symptoms⁶
Mixed IBS trials: 214 patients: less pain and bloating at 4 weeks; 81 adults: no difference from placebo at 8 weeks^1,2
Children on antibiotics: No reduction in loose or watery stools in 438 children (39% vs 44.5%)⁴
Canada: L. plantarum is listed in Health Canada's probiotics monograph, which directs separating doses from antibiotics by 2–3 hours⁸

What it is

Lactobacillus plantarum 299v (DSM 9843) is a single probiotic bacterial strain, studied mainly for IBS symptoms.

How it works

Proposed

Like other probiotics, L. plantarum 299v is proposed to work by shifting the gut's microbial community, producing beneficial substances and influencing immune responses; NCCIH notes that effects differ between probiotic strains. How it might ease IBS symptoms has not been established.⁷

Forms, side by side

2 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.

Lactobacillus plantarum 299v (Lp299v) forms compared

2 forms

Lactobacillus plantarum 299v (Lp299v) forms compared: 2 forms by 3 attributes. Empty cells are labelled No data yet, or Not graded in the evidence row.
2 forms	Freeze-dried capsules	Liquid suspension or fermented drink
Absorption in people	No head-to-head human data between product formats.¹	No head-to-head human data between product formats.³
GI tolerance	Adverse events not reported as a concern in the IBS or paediatric trials.^1,4	Not reported in the abstract.³
Studied for	IBS in adults; antibiotic-associated symptoms in children; oral iron tolerance	IBS (one small 2001 trial)

Freeze-dried capsules
Absorption in people
No head-to-head human data between product formats.¹
GI tolerance
Adverse events not reported as a concern in the IBS or paediatric trials.^1,4
Studied for
IBS in adults; antibiotic-associated symptoms in children; oral iron tolerance
Liquid suspension or fermented drink
Absorption in people
No head-to-head human data between product formats.³
GI tolerance
Not reported in the abstract.³
Studied for
IBS (one small 2001 trial)

What the human research says

Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.

Trial map

6 graded outcomes, largest study first

6 graded outcomes: 4 improved, 2 no effect. The largest, a 2026 meta-analysis of 521 people on IBS symptoms (abdominal pain severity, incomplete evacuation, symptom-improvement rates), found an improvement.

By sizeTable

1IBS symptoms (abdominal pain severity, incomplete evacuation, symptom-improvement rates)

Improved · Grade B · Meta-analysis, 521 people, 2026

Patients with IBS in 6 placebo-controlled trials of L. plantarum 299v alone (Sweden, Poland, France/India, South Africa, Pakistan)

Dose, result and source

Every graded outcome on this page, largest study first
Outcome	Found	People	Study	Who was studied
IBS symptoms (abdominal pain severity, incomplete evacuation, symptom-improvement rates)	Improved	521	Grade B · Meta-analysis, 2026	Patients with IBS in 6 placebo-controlled trials of L. plantarum 299v alone (Sweden, Poland, France/India, South Africa, Pakistan)
Loose stools and GI symptoms during antibiotics in children	No effect	438	No-effect grade · RCT, 2017	Children aged 1–11 receiving outpatient antibiotics in primary care
GI tolerance of oral iron and iron status	Improved	295	Grade C · RCT, 2024	Patients with newly diagnosed iron deficiency anaemia starting oral iron
Abdominal pain and bloating in IBS	Improved	214	Grade B · RCT, 2012	Patients with IBS (Rome III)
Abdominal pain relief in IBS	No effect	81	Grade C · RCT, 2014	Adults with IBS (Rome II) at a referral hospital in South Africa
IBS abdominal pain and overall symptoms	Improved	40	Grade D · RCT, 2001	Patients with IBS

Every graded row

6 rows

Form tested

Showing 6 of 6 outcomes. Human trials only.

Grade BIBS symptoms (abdominal pain severity, incomplete evacuation, symptom-improvement rates)IBSLess pain, better symptomsMeta-analysis · 6 studies
n 521 · 2026

Improved Pooled results showed less severe abdominal pain and less feeling of incomplete evacuation, and more patients reported significant improvement in pain, flatulence and overall digestive symptoms than with placebo. Bloating severity and constipation resolution did not differ. Adverse effects did not differ from placebo.

Design: Meta-analysis, 6 studies, n = 521, 2026
Population: Patients with IBS in 6 placebo-controlled trials of L. plantarum 299v alone (Sweden, Poland, France/India, South Africa, Pakistan)
Form: L. plantarum 299v (DSM 9843), single strain
Dose: 10–50 billion CFU a day across the included trials (full-text Table 1)
Duration: 4–8 weeks
Source: Reference 6 · PubMed 41682832 (opens PubMed)

Grade BAbdominal pain and bloating in IBSIBSImprovedRCT
n 214 · 2012

Improved Pain severity (0.68 vs 0.92) and daily pain frequency (1.01 vs 1.71) were lower than with placebo (p<0.05), with similar results for bloating; 78.1% vs 8.1% rated the effect excellent or good.

Design: RCT, n = 214, 2012
Population: Patients with IBS (Rome III)
Form: L. plantarum 299v (DSM 9843) capsules
Dose: One capsule daily (10 billion CFU per capsule, per the full text)
Duration: 4 weeks
Source: Reference 1 · PubMed 22912552 (opens PubMed)

Grade CGI tolerance of oral iron and iron statusIron toleranceImprovedRCT
n 295 · 2024

Improved GI intolerance 13.0% vs 46.5% and early discontinuation 3.6% vs 15.9% (both p<0.001); serum iron, transferrin saturation and haemoglobin rise were higher at 3 months.

Design: RCT, n = 295, 2024
Population: Patients with newly diagnosed iron deficiency anaemia starting oral iron
Form: L. plantarum 299v added to oral iron
Dose: Not stated in the abstract
Duration: First 30 days of a 3-month iron course
Source: Reference 5 · PubMed 39494607 (opens PubMed)

Grade CAbdominal pain relief in IBSIBSNo effectRCT
n 81 · 2014

No effect No difference from placebo in abdominal pain relief (p=0.80) or IBS quality of life (p=0.69); pain fell in both groups, indicating a large placebo effect.

Design: RCT, n = 81, 2014
Population: Adults with IBS (Rome II) at a referral hospital in South Africa
Form: L. plantarum 299v capsules
Dose: Two capsules of 5 billion CFU daily (10 billion CFU)
Duration: 8 weeks
Source: Reference 2 · PubMed 25194614 (opens PubMed)

Grade DIBS abdominal pain and overall symptomsIBSImprovedRCT
n 40 · 2001

Improved All 20 on LP299V reported resolution of abdominal pain vs 11 of 20 on placebo (p=0.0012); overall IBS symptoms improved in 95% vs 15%.

Design: RCT, n = 40, 2001
Population: Patients with IBS
Form: LP299V liquid suspension
Dose: Not stated in the abstract
Duration: 4 weeks
Source: Reference 3 · PubMed 11711768 (opens PubMed)

No effectLoose stools and GI symptoms during antibiotics in childrenAntibiotic-associated diarrhoeaNo effectRCT
n 438 · 2017

No effect Loose/watery stools 39% vs 44.5% (p=0.26); antibiotic-associated diarrhoea 2.8% vs 4.1% (p=0.4); abdominal symptoms did not differ. Satisfactory safety profile.

Design: RCT, n = 438, 2017
Population: Children aged 1–11 receiving outpatient antibiotics in primary care
Form: LP299V (DSM 9843)
Dose: Not stated in the abstract
Duration: Antibiotic course plus 1 week
Source: Reference 4 · PubMed 28438377 (opens PubMed)

What the numbers add up to

Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.

Strong first trial, null replication

The 214-person trial reported large benefits, but a smaller 8-week trial at the same daily amount found no difference from placebo, so pooled results carry most weight.^1,2,6

Studied doses

Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.

Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.

Doses studied in human trials

Doses studied in human trials ranged from 10 billion to 50 billion CFU a day for 4 to 8 weeks in adults with IBS; abstracts of the paediatric antibiotic trial and the iron trial did not state the amount.^6,1,2

Interactions and safety

Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.

What Lactobacillus plantarum 299v meets

2 cited rows 1 tested together

Medicines 2

Lactobacillus plantarum 299v2 medicines · 1 supplement

Supplements and foods 1

Drug label or FDA notice
Tested together in a graded trial

Also cited: 1 tested together

Antibiotics
- Drug labelDrug label or FDA notice
  Antibiotics, for example any oral antibiotic course: Health Canada's probiotics monograph directs that bacterial probiotics be taken at least 2–3 hours before or after antibiotics.
  Source 8, Health Canada (NNHPD) (2026)
Immunosuppressive treatment
- Drug labelDrug label or FDA notice
  Immunosuppressive treatment, for example long-term corticosteroids: Health Canada lists an immune-compromised condition, including long-term corticosteroid treatment, as a contraindication for probiotics; NCCIH and ODS say harmful effects are more likely in people with compromised immune systems.
  Source 8, Health Canada (NNHPD) (2026); Source 7, National Center for Complementary and Integrative Health (NCCIH) (2019); Source 9, NIH Office of Dietary Supplements (2025)
IronIron page
- Tested together
  GI tolerance of oral iron and iron status. Graded on the Lactobacillus plantarum 299v page; tested together is not a claim that they work better together.

Interactions

2 agents

Published interactions, grouped by kind
Agent	What the source says	Evidence
Medicines2
Antibioticse.g. any oral antibiotic course	Health Canada's probiotics monograph directs that bacterial probiotics be taken at least 2–3 hours before or after antibiotics.⁸	Drug label
Immunosuppressive treatmente.g. long-term corticosteroids	Health Canada lists an immune-compromised condition, including long-term corticosteroid treatment, as a contraindication for probiotics; NCCIH and ODS say harmful effects are more likely in people with compromised immune systems.^8,7,9	Drug label

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Lactobacillus plantarum 299v and your picks, and between your picks.

Add a supplement or medicine

Most cited:

Add a supplement or medicine you take to check it against Lactobacillus plantarum 299v.

Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.

Who should be careful

5 groups

Weakened immune system or serious illness: Health Canada's probiotics monograph contraindicates use with immune-compromised conditions (e.g. AIDS, lymphoma, long-term corticosteroids), and NCCIH says risks are greater with severe illness.^8,7
Premature infants: Severe or fatal infections have been reported in premature infants given probiotics, and the FDA has warned health care providers about this risk (NCCIH).^7,10
Fever, bloody diarrhoea or severe abdominal pain: Health Canada monograph wording: ask a health care practitioner before use with fever, vomiting, bloody diarrhoea or severe abdominal pain, and stop if digestive upset persists beyond 3 days.⁸
Pregnancy and breastfeeding: The NCCIH and NIH ODS probiotic fact sheets give no pregnancy- or breastfeeding-specific safety data, and no strain-specific data were found; NCCIH advises consulting a health care provider before using any probiotic supplement.^7,9
Product contents: NCCIH notes some probiotic products have contained microorganisms other than those on the label.⁷

How to read the label

What to check on the Supplement Facts panel.

How to read the label

4 checks

Find the strain code

Look for 299v or DSM 9843 after the species name. Probiotics are identified by genus, species and strain designation, and the IBS results belong to this strain, not to L. plantarum in general.^9,8,6

CFU, not just weight

US rules require only the total weight of microorganisms, which counts live and dead cells; a CFU count is voluntary. Check for a CFU figure per serving.⁹

CFU at end of shelf life

Bacteria die during storage, so a CFU count guaranteed through the expiry date is more useful than one at the time of manufacture.⁹

Compare with the trials

The IBS trials used 10 to 50 billion CFU a day, most often 10 billion CFU a day; the label may list CFU per capsule or per serving.^6,1,2

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

6 answers

Does L. plantarum 299v help IBS?

Possibly. A 2026 meta-analysis found it improved key IBS symptoms, and a 214-person trial reported less pain and bloating, but an 81-person trial found no benefit over placebo.^6,1,2

Does it help with iron tablets?

One open, non-placebo trial in 295 people starting iron found fewer stomach side effects and better iron markers with L. plantarum 299v added; it needs placebo-controlled confirmation.⁵

How much L. plantarum 299v was used in studies?

IBS trials used 10 billion to 50 billion CFU a day for 4 to 8 weeks, most often 10 billion CFU a day.^6,1,2

Can it be taken with antibiotics?

Health Canada's probiotics monograph directs separating bacterial probiotics from antibiotics by at least 2–3 hours.⁸

Does it stop diarrhoea from antibiotics in children?

Not in the largest trial: in 438 children, loose stools and antibiotic-associated diarrhoea were not significantly lower than with placebo.⁴

Who should avoid it?

People with immune-compromised conditions, including long-term corticosteroid users, per Health Canada, and premature infants, in whom probiotics have caused severe infections (NCCIH, FDA). Pregnancy and breastfeeding data are lacking.^8,7,10,9

Sources

10 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

10 sources

1Clinical trial: Lactobacillus plantarum 299v (DSM 9843) improves symptoms of irritable bowel syndrome.RCT World J Gastroenterol, 2012 · PMID 22912552
2Randomized clinical trial: effect of Lactobacillus plantarum 299 v on symptoms of irritable bowel syndrome.RCT Nutrition, 2014 · PMID 25194614
3A controlled, double-blind, randomized study on the efficacy of Lactobacillus plantarum 299V in patients with irritable bowel syndrome.RCT Eur J Gastroenterol Hepatol, 2001 · PMID 11711768
4Efficacy and Safety of Lactobacillus plantarum DSM 9843 (LP299V) in the Prevention of Antibiotic-Associated Gastrointestinal Symptoms in Children-Randomized, Double-Blind, Placebo-Controlled Study.RCT J Pediatr, 2017 · PMID 28438377
5Improved gastrointestinal tolerance and iron status via probiotic use in iron deficiency anaemia patients initiating oral iron replacement: a randomised controlled trial.RCT Br J Nutr, 2024 · PMID 39494607
6Strain-Specific Systematic Review with Meta-Analysis of Probiotics Efficacy in the Treatment of Irritable Bowel Syndrome.Meta-analysis J Clin Med, 2026 · PMID 41682832
7Probiotics: Usefulness and Safety (last updated August 2019)Fact sheet National Center for Complementary and Integrative Health (NCCIH), 2019 · nccih.nih.gov
8Natural Health Product Monograph: Probiotics (April 24, 2026)Guideline Health Canada (NNHPD), 2026 · webprod.hc-sc.gc.ca
9Probiotics: Fact Sheet for Health Professionals (updated March 25, 2025)Fact sheet NIH Office of Dietary Supplements, 2025 · ods.od.nih.gov
10Risk of Invasive Disease in Preterm Infants Given Probiotics Formulated to Contain Live Bacteria or YeastSafety communication U.S. Food and Drug Administration, 2023 · fda.gov

What changed

Every dated change to this page: what changed, who made it and why.

Change log

2 entries

Dated changes to this page
Date	Change	Who and why
Oct 21, 2026evidence, studied doses, interactions, who should avoid, label guide, FAQ, key facts, summary, sources	Added the 2026 strain-specific IBS meta-analysis (PMID 41682832, already cited) as a graded row with doses and n from its full-text table; widened studied doses to 10–50 billion CFU; added an immunosuppressant interaction (Health Canada, NCCIH, NIH ODS); new label guide on strain code and CFU labelling (NIH ODS, Health Canada); cited the FDA 2023 preterm-infant safety communication; new dose FAQ.	Writer: Kymata Health EditorialTrigger: A–Z page audit
Oct 14, 2026all	Initial editorial evidence review	Writer: Kymata Health EditorialTrigger: new page

Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.

Lactobacillus plantarum 299v (Lp299v)

Medicines 2

Supplements and foods 1

Antibiotics

Immunosuppressive treatment

IronIron page