Lactobacillus reuteri and Reduced Bleeding on Probing (BOP)

Research synthesisLow evidenceMixed effect size4 studies · 3 beneficial · 1 neutral · 0 harmful

Across 4 studies, 3 reported beneficial effects of Lactobacillus reuteri on reducing bleeding on probing (BOP), with effect sizes ranging from small to moderate, while 1 study found no benefit. The predominant effect size is mixed (small to moderate). The most-studied dose was lozenges taken twice daily, though CFU counts were inconsistently reported. Effects were observed primarily in patients with periodontitis, and the median study duration across the 1 study reporting duration was 21 days, which is relatively short for periodontal outcomes.

Effective dose range: 2 lozenges/day (specific CFU not consistently reported)
Studied populations: Patients with periodontitis (stage III/IV, grade B/C) and adolescents with betel quid chewing habits

Caveats: Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Evidence base is small (only 4 studies) — conclusions should be considered preliminary. The only study with neutral findings was a 2025 RCT with a higher evidence score, suggesting the effect may be modest or context-dependent. Most trials were short (≤21 days), limiting generalizability to longer-term periodontal outcomes.

Generated May 25, 2026

Doses used in studies

day: 2 (median 2, IQR 2–2) — 1 study
lozenges/day: 2 (median 2, IQR 2–2) — 1 study

Time to effect

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

4 of 4 papersPopulation:

Clinical and microbiological effectiveness of limosilactobacillus reuteri in supportive periodontal therapy: randomized clinical trial.
- 2025-08-26
- RCT
- Clinical oral investigations 29(9)
- - Magda Mensi
  - Eleonora Scotti
  - Silvia Marchetti
  - Annamaria Sordillo
  - Gianluca Garzetti
  - Stefano Calza
  - Mark J Buijs
  - Egija Zaura
  - Bernd W Brandt
- PubMed: 40856866
- DOI: 10.1007/s00784-025-06508-w
6 Insights on
- Reduced Bleeding on Probing (BOP)
- High evidence
- Clinical
Both groups showed a significant decrease in PPD, BOP, CAL, and number/percentage of residual pockets compared to baseline. However, no inter-group differences were noted.
Effect
Neutral
Effect size
Small
Significant
No
Dose
3 weeks of bi-daily supplementation with lozenges containing probiotic (specific CFU not stated in abstract)
Clinical efficacy of Lactobacillus reuteri-containing lozenges in the supportive therapy of generalized periodontitis stage III and IV, grade C: 1-year results of a double-blind randomized placebo-controlled pilot study
- 2019-10-16
- RCT · n = 20
- Clinical Oral Investigations 24(6)
- - M. G. Grusovin
  - S. Bossini
  - S. Calza
  - V. Cappa
  - G. Garzetti
  - E. Scotti
  - E. Gherlone
  - M. Mensi
- PubMed: 31620939
- DOI: 10.1007/s00784-019-03065-x
5 Insights on
- Reduced Bleeding on Probing (BOP)
- High evidence
more BOP reduction at 6 and 9 months (p < 0.05)
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Dose
2 lozenges/day
Clinical and Biochemical Evaluation of Lozenges Containing Lactobacillus reuteri as an Adjunct to Non-Surgical Periodontal Therapy in Chronic Periodontitis.
- 2015-06
- RCT · n = 30
- Journal of Periodontology 86(6)
- - G. Ince
  - Hare Gürsoy
  - Ş. Ipçi
  - G. Cakar
  - E. Emekli-Alturfan
  - S. Yılmaz
- PubMed: 25741580
- DOI: 10.1902/jop.2015.140612
7 Insights on
- Reduced Bleeding on Probing (BOP)
- High evidence
- Highly Cited
Differences in intergroup comparisons of BOP were found to be significant (P <0.05) in favor of the test group at all time points.
Effect
Beneficial
Effect size
Large
Significant
Yes
Effectiveness of Lactobacillus reuteri Probiotics on Plaque Index, Gingival Index, and Bleeding on Probing in Adolescents with Betel Quid Chewing Habit: Study in Children Aged 13-15 Years in Alor Regency, East Nusa Tenggara.
- 2026-02-12
- Observational
- International journal of clinical pediatric dentistry 19(2)
- - Labiba Idzni Marjani
  - Margaretha Suharsini
  - Eva Fauziah
- PubMed: 41800014
- DOI: 10.5005/jp-journals-10005-3411
4 Insights on
- Reduced Bleeding on Probing (BOP)
- Low evidence
There was a significant difference in PI, GI, and BOP scores before and after consuming L. reuteri for 7 and 14 days (p < 0.05).
Effect
Beneficial
Effect size
Small
Significant
Yes
Dose
twice a day for 14 days

Lactobacillus reuteri and Reduced Bleeding on Probing (BOP)

Clinical and microbiological effectiveness of limosilactobacillus reuteri in supportive periodontal therapy: randomized clinical trial.

Clinical efficacy of Lactobacillus reuteri-containing lozenges in the supportive therapy of generalized periodontitis stage III and IV, grade C: 1-year results of a double-blind randomized placebo-controlled pilot study

Clinical and Biochemical Evaluation of Lozenges Containing Lactobacillus reuteri as an Adjunct to Non-Surgical Periodontal Therapy in Chronic Periodontitis.

Effectiveness of Lactobacillus reuteri Probiotics on Plaque Index, Gingival Index, and Bleeding on Probing in Adolescents with Betel Quid Chewing Habit: Study in Children Aged 13-15 Years in Alor Regency, East Nusa Tenggara.