Lactiplantibacillus plantarum

What it is

Lactiplantibacillus plantarum is a lactic acid bacterium. Until 2020 it was named Lactobacillus plantarum; a reclassification proposed in 2020 split the old Lactobacillus genus into 25 genera, one of which is Lactiplantibacillus. It is very common in vegetable fermentations and has a long history as a starter culture for many fermented foods. Strain 299v (also listed as DSM 9843) is the strain used in the trials described here.

What the research says

The evidence is strain-specific and mixed. For irritable bowel syndrome (IBS), one 214-patient trial of 299v reported less pain and bloating over 4 weeks, but an 8-week South African trial and a small 12-patient crossover trial found no significant difference from placebo. For iron, a meta-analysis of 8 studies found that 299v increased iron absorption from a meal or supplement. Most studies did not find better iron status (the body's iron stores), and a small trial in female athletes, two of whose authors were employed by a probiotics company, found differences that were not statistically significant. Lactobacillus bacteria, including L. plantarum, have been found in rare published cases of heart valve infection.

Evidence grade: Disputed.

What goes wrong

A narrative review of 82 published cases of Lactobacillus heart valve infection (infective endocarditis) found L. plantarum in 8 of them. (Source 1)

• Expert review, not systematic, Very low certainty.
• Size: 82 patients from 77 studies.
• Who: Published case reports of Lactobacillus endocarditis.
• How long: Case reports up to September 2023.
• Result: L. plantarum in 9.8% (8 of 82 patients). The review counts species in published cases and does not say which cases came from supplements.
• Funding: not stated in the passage we fetched.

Limit of this finding: A review that pooled 82 published case reports. It shows the infection happens, not how often.

The isolated species from the 82 patients with IE were L. rhamnosus in 23.2% (19 patients), L. casei in 13.4% (11), L. jensenii in 13.4% (11), L. acidophilus in 13.4% (11), L. plantarum in 9.8% (8)

The US Office of Dietary Supplements states that probiotic use has been linked to bloodstream and other infections, mostly in people who were severely ill or immunocompromised. (Source 2)

• Official position, Certainty not rated.
• Size: not applicable.
• Who: People taking probiotics generally.
• How long: not applicable.
• Result: No numbers given in the passage.
• Funding: government (NIH)

The use of probiotics has been linked to bacteremia, fungemia (fungi in the blood), or infections that have resulted in severe illness in some cases, most of which involved individuals who were severely ill or immunocompromised

What the evidence supports

A 4-week randomised placebo-controlled trial reported that L. plantarum 299v relieved IBS symptoms, particularly abdominal pain and bloating. (Source 3)

• Randomized trial, Low certainty.
• Size: 214 IBS patients.
• Who: Adults with IBS meeting Rome III criteria (India)
• How long: 4 weeks.
• Result: After 4 weeks, pain severity and daily pain frequency were lower with 299v than placebo (P < 0.05); 78.1% vs 8.1% rated the effect excellent or good (P < 0.01).
• Funding: not stated in the passage we fetched.

A 4-wk treatment with L. plantarum 299v (DSM 9843) provided effective symptom relief, particularly of abdominal pain and bloating, in IBS patients fulfilling the Rome III criteria.

A meta-analysis of eight studies found that L. plantarum 299v increased iron absorption. (Source 4)

• Meta-analysis, Certainty not rated.
• Size: 8 studies in the iron-absorption meta-analysis; 15 studies (N = 950) in the review overall.
• Who: Humans in iron absorption studies, mostly meal studies.
• How long: Single meals to short courses.
• Result: Pooled standardized mean difference 0.55 (95% CI 0.22-0.88, p = 0.001).
• Funding: not stated in the passage we fetched.

demonstrated a significant increase in iron absorption following administration of the probiotic Lp299v with a pooled standardized mean difference (an average intervention effect size) of 0.55 (95% CI 0.22–0.88, p = 0.001).

What the evidence does not support

An 8-week randomised placebo-controlled trial found no significant difference between L. plantarum 299v and placebo in IBS abdominal pain or quality of life. (Source 5)

• Randomized trial, Low certainty.
• Size: not given in the passage we fetched.
• Who: Adults with IBS meeting Rome II criteria (South Africa)
• How long: 8 weeks.
• Result: Abdominal pain relief P = 0.800; QoL-IBS P = 0.687; both groups improved.
• Funding: not stated in the passage we fetched.

There was no significant difference in abdominal pain relief between the study and placebo groups (P = 0.800).

A small double-blind crossover trial found that L. plantarum 299V did not change colonic fermentation or improve IBS symptoms. (Source 6)

• Randomized trial, Very low certainty.
• Size: 12 patients.
• Who: Previously untreated patients with IBS (UK)
• How long: 4 weeks per arm.
• Result: Median symptom score 8.5 on placebo vs 8 on 299V, no significant difference; breath hydrogen after lactulose was lower on the probiotic (P = 0.019).
• Funding: not stated in the passage we fetched.

In conclusion, Lactobacillus plantarum 299V in this study did not appear to alter colonic fermentation or improve symptoms in patients with the irritable bowel syndrome.

In the same review, most trials of probiotics on iron status markers did not find improvement; one Lp299v study showed higher serum iron. (Source 4)

• Systematic review, Certainty not rated.
• Size: 7 clinical trials on iron status.
• Who: Humans in randomised and non-randomised trials.
• How long: Varied.
• Result: Only one study (Lp299v) showed better serum iron; no other study showed better iron status indices.
• Funding: not stated in the passage we fetched.

only one study supplementing with Lp299v showed improvement in serum iron; no other studies reported improvement in iron status-related indices with probiotic treatment.

Where the evidence is mixed

In a trial in iron-deficient female athletes, adding 299v to 20 mg iron raised ferritin more than iron alone, but the difference was not statistically significant; two authors were employed by a probiotics company. (Source 7)

• Randomized trial, Low certainty.
• Size: 53 randomised, 39 completed.
• Who: Healthy non-anaemic female athletes with low iron stores.
• How long: 12 weeks.
• Result: Ferritin rose 13.6 vs 8.2 µg/L at 4 weeks (p = 0.056); reticulocyte haemoglobin 1.5 vs 0.82 pg at 12 weeks (p = 0.083).
• Funding: Funding statement not checked. Conflict-of-interest statement: two authors (UA, GÖ) employed by Probi AB, a probiotics company; the verifier reports two further authors employed by The Nature's Bounty Co.

Intake of Lp299v with iron for four weeks increased ferritin levels more than iron alone (13.6 vs. 8.2 µg/L), but the difference between the groups was not significant (p = 0.056).

Where the research disagrees

Whether L. plantarum 299v relieves IBS symptoms

• Ducrotté, Sawant, Jayanthi 2012, RCT, 214 patients, 4 weeks: "A 4-wk treatment with L. plantarum 299v (DSM 9843) provided effective symptom relief, particularly of abdominal pain and bloating, in IBS patients fulfilling the Rome III criteria." (Source 3)
• Stevenson et al. 2014, RCT, 8 weeks: "An 8-wk treatment with L. plantarum 299 v did not provide symptomatic relief, particularly of abdominal pain and bloating, in patients fulfilling the Rome II criteria." (Source 8)

How much

• Reference intake: No RDA, AI or other reference intake exists for L. plantarum or any probiotic organism, because it is not an essential nutrient. The NIH Office of Dietary Supplements describes product amounts in colony forming units (CFU) instead. (Source 9)
• Upper limit: No tolerable upper intake level has been set for any probiotic organism. The ODS notes that higher CFU counts are not necessarily more effective. (Source 9)
• Studied: IBS trial (Ducrotté 2012): one capsule of L. plantarum 299v (DSM 9843) daily for 4 weeks versus placebo. (Source 10)
• Studied: IBS trial (Sen 2002): L. plantarum 299V for 4 weeks in a crossover design, 12 patients. (Source 11)
• Studied: Iron trial (Axling 2020): 20 mg of iron with or without Lp299v, in female athletes. (Source 12)

A common belief, and what the research shows

The belief: Any product with 'L. plantarum' on the label will do what the 299v studies found.

What the research shows: Effects are reported by strain and by condition. A systematic review of 228 trials concluded: "Strong evidence was found supporting the hypothesis that the efficacy of probiotics is both strain-specific and disease-specific." Even for 299v, IBS trials disagree, and the iron-absorption benefit has not been matched by consistent gains in iron status.

Questions and answers

What is it?

Lactiplantibacillus plantarum is the current name for the bacterium formerly called Lactobacillus plantarum. In 2020, taxonomists proposed splitting the old genus Lactobacillus into 25 genera, and Lactiplantibacillus is one of the new genera named in that proposal. (Source 13)

What does it do in the body?

A meta-analysis of eight studies found that L. plantarum 299v increased iron absorption. However, of seven trials looking at iron status, only one (with 299v) showed an improvement, in serum iron; no others found better iron status. Its effects on IBS are covered in the findings. (Source 4)

Is it good or bad for you?

Lactobacillus bacteria can, rarely, cause heart valve infection (infective endocarditis). In a narrative review of 82 published cases, L. plantarum was the species found in 8 (9.8%). The evidence on benefits is set out in the findings. (Source 1)

How do you get more of it?

A review of probiotic studies in healthy adults found that taking probiotic supplements can lead to a transient increase in the gut of the specific bacteria in the supplement. (Source 14)

If it is harmful, what reduces it?

It is not normally considered harmful, so this usually does not apply. A narrative review of published case reports of Lactobacillus heart valve infection found that aminoglycosides and penicillin were the antibiotics most often used for treatment, and 53.7% of patients had surgery. (Source 15)

Why might someone be low in it or missing it?

The literature we searched does not describe a deficiency of L. plantarum or explain why someone might be low in it. (Source 14)

We searched: Web searches for L. plantarum deficiency, low levels and loss; reviews of L. plantarum in fermented foods (Garcia-Gonzalez 2021, Paramithiotis 2025) and of probiotics in healthy adults (Khalesi 2019). None describes a deficiency state or its causes.

Which whole foods contain it or feed it?

L. plantarum is found throughout vegetable fermentations, such as fermented vegetables, and in many cases it dominates and drives the fermentation. (Source 16)

What happens if you do not have it?

No study we found shows harm from not carrying L. plantarum. (Source 14)

We searched: Web searches for L. plantarum deficiency, absence and health outcomes; reviews of L. plantarum in fermented foods (Garcia-Gonzalez 2021) and of probiotics in healthy adults (Khalesi 2019). None describes a deficiency state.

How can you test for it?

Consumer stool tests exist, but a 2026 evaluation of direct-to-consumer gut microbiome testing services found major discrepancies, both within and across the different providers. (Source 17)

References

1. Antibiotics (MDPI). Infective Endocarditis by Lactobacillus Species—A Narrative Review. 2024. DOI 10.3390/antibiotics13010053. Read the source
2. NIH Office of Dietary Supplements. Probiotics: Fact Sheet for Health Professionals. 2025. Read the source
3. World Journal of Gastroenterology. Clinical trial: Lactobacillus plantarum 299v (DSM 9843) improves symptoms of irritable bowel syndrome. 2012. PMID 22912552, DOI 10.3748/wjg.v18.i30.4012. Read the source
4. Nutrients. A Systematic Review and Meta-Analysis on the Effects of Probiotic Species on Iron Absorption and Iron Status. 2019. PMID 31816981, DOI 10.3390/nu11122938. Read the source
5. Nutrition. Randomized clinical trial: Effect of Lactobacillus plantarum 299 v on symptoms of irritable bowel syndrome. 2014. PMID 25194614. Read the source
6. Digestive Diseases and Sciences. Effect of Lactobacillus plantarum 299v on Colonic Fermentation and Symptoms of Irritable Bowel Syndrome. 2002. PMID 12452404, DOI 10.1023/A:1020597001460. Read the source
7. Nutrients. The Effect of Lactobacillus plantarum 299v on Iron Status and Physical Performance in Female Iron-Deficient Athletes: A Randomized Controlled Trial. 2020. DOI 10.3390/nu12051279. Read the source
8. Nutrition. Randomized clinical trial: Effect of Lactobacillus plantarum 299 v on symptoms of irritable bowel syndrome. 2014. PMID 25194614. Read the source
9. NIH Office of Dietary Supplements. Probiotics: Fact Sheet for Health Professionals. 2025. Read the source
10. World Journal of Gastroenterology. Clinical trial: Lactobacillus plantarum 299v (DSM 9843) improves symptoms of irritable bowel syndrome. 2012. PMID 22912552, DOI 10.3748/wjg.v18.i30.4012. Read the source
11. Digestive Diseases and Sciences. Effect of Lactobacillus plantarum 299v on Colonic Fermentation and Symptoms of Irritable Bowel Syndrome. 2002. PMID 12452404, DOI 10.1023/A:1020597001460. Read the source
12. Nutrients. The Effect of Lactobacillus plantarum 299v on Iron Status and Physical Performance in Female Iron-Deficient Athletes: A Randomized Controlled Trial. 2020. DOI 10.3390/nu12051279. Read the source
13. International Journal of Systematic and Evolutionary Microbiology. A taxonomic note on the genus Lactobacillus: Description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae. 2020. DOI 10.1099/ijsem.0.004107. Read the source
14. European Journal of Clinical Nutrition. A review of probiotic supplementation in healthy adults: helpful or hype?. 2019. PMID 29581563, DOI 10.1038/s41430-018-0135-9. Read the source
15. Antibiotics (MDPI). Infective Endocarditis by Lactobacillus Species—A Narrative Review. 2024. DOI 10.3390/antibiotics13010053. Read the source
16. Applied Biosciences (MDPI). Lactiplantibacillus plantarum, the Integral Member of Vegetable Fermentations. 2025. DOI 10.3390/applbiosci4010007. Read the source
17. Communications Biology. Evaluating the analytical performance of direct-to-consumer gut microbiome testing services. 2026. DOI 10.1038/s42003-025-09301-3. Read the source