Lactobacillus reuteri and Reduced Bleeding on Probing (BOP)

Research synthesisModerate evidenceMixed effect size5 studies · 3 beneficial · 2 neutral · 0 harmful

Across 5 studies, 3 reported beneficial effects on reducing bleeding on probing (BOP) and 2 found no benefit over placebo. Effect sizes among beneficial studies ranged from small to large (mixed), with two RCTs showing moderate-to-large significant reductions and one observational study showing a small effect. The predominant population studied was adults with periodontitis (stages III/IV, grades B/C), including those with diabetes or betel quid chewing habits. Only 2 studies reported duration (median 101 days, about 14 weeks), but no consistent dose or form emerged across trials.

Studied populations: Patients with periodontitis (stages III/IV, grades B/C), including those with diabetes mellitus or betel quid chewing habits

Caveats: Two recent RCTs (2024, 2025) found no additional benefit of L. reuteri over placebo, while older RCTs (2015, 2019) and an observational study (2026) reported positive results. This temporal pattern suggests possible publication bias or diminishing effect over time. Sample sizes are small (20–30 per group in the RCTs), and the only beneficial RCT with large effect had a small sample (n=30). The 2026 observational study is low quality (evidence score 1). Overall, the evidence is inconsistent and the clinical significance remains uncertain.

Generated Jul 9, 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: 3.4 months · IQR 8.7 weeks–4.7 months · Range 3 weeks–6 months — Reported in 2 of 5 studies

5 of 5 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)
Effect of adjuvant probiotic therapy (Lactobacillus reuteri) in the treatment of periodontitis associated with diabetes mellitus: clinical, controlled, and randomized study.
- 2024-01-06
- RCT · n = 20
- Clinical oral investigations 28(1)
- - Maria Aparecida Neves Jardini
  - Juliana Fatima Pedroso
  - Camila Lopes Ferreira
  - Camilla Magnoni Moretto Nunes
  - Cadiele Oliana Reichert
  - Marlene Nunez Aldin
  - Antonio Martins Figueiredo Neto
  - Debora Levy
  - Nagila Raquel Teixeira Damasceno
- PubMed: 38183505
- DOI: 10.1007/s00784-023-05441-0
15 Insights on
- Reduced Bleeding on Probing (BOP)
- High evidence
- Clinical
The use of L. reuteri probiotics had no additional effects compared with the placebo
Effect
Neutral
Effect size
Small
Significant
No
Dose
not specified
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
- Clinical
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.

Effect of adjuvant probiotic therapy (Lactobacillus reuteri) in the treatment of periodontitis associated with diabetes mellitus: clinical, controlled, and randomized study.

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.