Patient-Reported Probiotic Use During Periodontal Therapy in Periodontitis

This study included 130 stage 3 grade b periodontitis patients, classified as self-reported probiotic product users or non-users (n = 65 each). Periodontitis was defined by detectable interdental CAL at two or more non-adjacent teeth. Stage III Grade B periodontitis was defined by interdental CAL ≥5 mm at the site of greatest loss, with grading based on a bone loss/age ratio of 0.25-1.00.

All patients received routine non surgical periodontal therapy, including individualized oral hygiene instruction and supra- and subgingival mechanical debridement/root surface instrumentation where indicated.

The study did not include an investigator-assigned probiotic intervention. No probiotic strain, dose, formulation, frequency, duration or adherence protocol was prescribed as part of the study. Group classification was based on self-reported use of probiotic supplements or commercially labelled probiotic products during active periodontal treatment and post-treatment follow-up. Patients who reported such use were classified as probiotic product users, whereas those reporting no probiotic supplement or commercially labelled probiotic product use during the same interval were classified as non-users. Traditional homemade fermented foods, including homemade yogurt, kefir, pickles, vinegar, sourdough products and boza, were recorded as dietary fermented-food habits when reported but were not used to define probiotic exposure because strain composition, colony-forming unit content, microbial viability, dose and consistency of intake could not be verified (FAO/WHO, 2002; Hill et al., 2014; Sahin, 2026). Therefore, the exposure represented self-reported real-world probiotic-labelled product use rather than standardized probiotic intake.

Plaque index (PI), probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), sites with PPD ≥5 mm and the 14-item Oral Health Impact Profile (OHIP-14) were recorded at baseline, 1 month and 3 months. Probiotic-related knowledge,attitudes and acceptance were assessed using questionnaires.

Inclusion criteria

Adults aged 18-70 years. Presence of at least 20 natural teeth. Diagnosis of Stage III Grade B periodontitis. Periodontitis defined as detectable interdental clinical attachment loss at two or more non-adjacent teeth.

Stage III periodontitis defined as interdental clinical attachment loss ≥5 mm at the site of greatest loss.

Grade B periodontitis defined by a bone loss/age ratio of 0.25-1.00. Availability for baseline, 1-month, and 3-month clinical and questionnaire evaluations.

Exclusion criteria

Use of systemic antibiotics within the previous 3 months. Periodontal treatment within the previous 6 months. Presence of systemic disease. Pregnancy or lactation. Severe cognitive or psychiatric conditions that could interfere with questionnaire completion or follow-up.