Lactobacillus plantarum 299v and Improved Bowel Movement Frequency

Research synthesisLow evidenceSmall effect3 studies · 1 beneficial · 2 neutral · 0 harmful

Across 3 studies on Lactobacillus plantarum 299v for improved bowel movement frequency, 1 reported a beneficial effect (small magnitude) and 2 reported neutral effects. The evidence is mixed, with the only significant finding coming from an observational study in IBS patients (n=221), while two RCTs (n=190 and n=20) found no significant benefit. Most studies involved IBS patients, and the median study duration was 28 days, though effects are not consistently observed at that timeframe.

Studied populations: irritable bowel syndrome patients

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. The only significant finding was from an observational study; the two RCTs both showed neutral effects, highlighting a potential discrepancy between study designs.

Generated Jun 17, 2026

Doses used in studies

CFU/day: 10 billion (median 10 billion, IQR 10 billion–10 billion) — 1 study

Time to effect

Median: 4 weeks · IQR 4 weeks–4 weeks · Range 4 weeks–4 weeks — Reported in 1 of 3 studies

Safety in these studies

Overall tolerabilityReported
Self-assessment identified that long-term treatment with LP299V was tolerated well by 94 % of patients.
from: [Treatment of IBS with Lactobacillus plantarum 299v: Therapeutic success increases with le

3 of 3 papersPopulation:

Role of Lactobacillus plantarum 299v versus Placebo in symptomatic improvement of irritable bowel syndrome patients.
- 2022-02-03
- RCT · n = 190
- JPMA. The Journal of the Pakistan Medical Association 72(3)
- - Ahmad Nawaz Babar
  - Muhammad Kamran Hassan
  - Fazl Ullah
  - Anwar Ullah
- PubMed: 35320214
- DOI: 10.47391/jpma.0758
7 Insights on
- Improved Bowel Movement Frequency
- High evidence
- Large Human Trial
There was no significant difference in terms of relieving abdominal pain, bloating and rectal emptying between the groups (p>0.05).
Effect
Neutral
Effect size
Small
Significant
No
A controlled, double-blind, randomized study on the efficacy of Lactobacillus plantarum 299V in patients with irritable bowel syndrome.
- 2001-10
- RCT · n = 20
- European journal of gastroenterology & hepatology 13(10)
- - K Niedzielin
  - H Kordecki
  - B Birkenfeld
- PubMed: 11711768
- DOI: 10.1097/00042737-200110000-00004
3 Insights on
- Improved Bowel Movement Frequency
- High evidence
- Highly Cited
- Clinical
There was also a trend towards normalization of stools frequency in constipated patients in six out of 10 patients treated with LP299V compared with two out of 11 treated with placebo (P = 0.17).
Effect
Neutral
Effect size
Small
Significant
No
[Treatment of IBS with Lactobacillus plantarum 299v: Therapeutic success increases with length of treatment - real-life data of a non-interventional study in Germany].
- 2021-02
- Observational · n = 221
- Zeitschrift fur Gastroenterologie 59(02)
- - Heiner Krammer
  - Martin Storr
  - Ahmed Madisch
  - Julia Riffel
- PubMed: 33556972
- DOI: 10.1055/a-1340-0204
20 Insights on
- Improved Bowel Movement Frequency
- High evidence
significant reduction of severity (S) and frequency (H) of individual symptoms, such as abdominal pain (S: -67%, H: -51%), flatulence (S: -61%, H: -63%), diarrhea (S: -70%, H: -32%) and constipation (S: -79%, H: -6%) was observed.
Effect
Beneficial
Effect size
Small
Significant
Yes
Dose
1 capsule/day (1 × 10^10 CFU)

Lactobacillus plantarum 299v and Improved Bowel Movement Frequency

Role of Lactobacillus plantarum 299v versus Placebo in symptomatic improvement of irritable bowel syndrome patients.

A controlled, double-blind, randomized study on the efficacy of Lactobacillus plantarum 299V in patients with irritable bowel syndrome.

[Treatment of IBS with Lactobacillus plantarum 299v: Therapeutic success increases with length of treatment - real-life data of a non-interventional study in Germany].