The Application of a Fasting- Mimicking Diet in Periodontitis: A Feasibility Study

The aim of the present study is to test if a fasting mimicking diet (FMD) can influence the systemic and periodontal response following non-surgical periodontal therapy. The null hypothesis is that a FMD does not modify the local and systemic inflammatory post-treatment response.

The test group will have periodontal treatment followed by fasting mimicking diet while the control group will have the same periodontal treatment and continue with their normal diet.

Full-mouth clinical periodontal measurements including probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival index (GI) and plaque index (PI) will be recorded.Blood and GCF samples will be taken.Enzyme-linked immunosorbent assay (ELISA) will be used to determine biochemical parameters in the biological samples.

This is a multi-center randomized controlled trial with internal pilot.The study protocol was approved by the Ethics Committee for the Use of Human Subjects in Research of Hatay Mustafa Kemal University. Participants will be selected from the patients who consult to the Periodontology Clinic of Akdeniz University Faculty of Dentistry. (Antalya, TURKEY).Participants will be screened by clinical staff/ investigator. We expect 20 eligible participants available per year.

The FMD program is a plant-based diet program and consists of a 5-days regimen. Test group will be assigned to follow one cycle of a fasting mimicking diet (FMD) the same day after receiving the full-mouth non-surgical periodontal treatment (NSPT). In contrast, control group after receiving the NSPT will continue with their current diet.

Patients in the test group will need 5 visits and patients in the control group will also need 5 visits.

At the screening visit, consent will be sought by the trained applicant which will be recorded through a written participant consent form detailing the complete trial procedure and an agreement checklist for each data collection method.

Visit 1 (Day -7/-10): Informed consent will be given and signed, blood and GCF samples will be collected, medical history will be checked and oral examination will be carried out including recording number of teeth and at 6 sites per tooth probing depth,recession (mm) and bleeding after probing.A very superficial prophylaxis , motivation and oral hygiene instructions will be provided.

On day 0 Morning (Visit 2) : Patients will undergo full-mouth subgingival instrumentation procedures and more detailed hygiene instruction will be reinforced. In the afternoon patients of the test group will start the FMD for 5 consecutive days.

On day 1(Visit 3) :Blood and GCF samples will be taken. Medical history, adverse events and concomitant medications will be checked.

On day 7 (Visit 4 ): Blood and GCF samples will be taken. Medical history, adverse events and concomitant medications will be checked.

On day 90±5 (visit 5): Full mouth periodontal charting measurements will be recorded. Blood and GCF sample swill be taken. Periodontal re-evaluation will be done.

The samples will be collected during the study visit from the patient by investigator, who will participate in this study. GCF Periopaper Strips will be used in the gingival crevice of the teeth. They will then be immediately measured on a calibrated Periotron 8000 electronic transducer. Once measured gcf strips for that visit will all be stored in a single 2 ml tube and pooled for further analysis.

4 ml of venous blood will be collected from the participant's arm into hemogard sterile vacutainers. The samples for serum will be centrifuged for 5 mins at 40,000 rpm then immediately divided into 1 ml aliquots and stored in a freezer at - 80°C, until required for analysis. After their initial storage, the sample will be transferred to the Microbiome and Salivary laboratories of Guy's Hospital.

Blood samples will be tested for cytokines, acute phase proteins and inflammtory markers. Gingival Crevicular Fluid will be analyzed for inflammatory mediators, antibodies, peptides and cytokines using techniques such as ELISA.

Circulating levels of IGF-1, fasting blood glucose level will be assessed to monitor the compliance of FMD.

Eligibility Criteria:
Inclusion Criteria:

* 18-70 years old patients
* Periodontitis stage III-IV, grade B-C
* Systemically healthy
* Normal weight to overweight. Body mass index: 18-30
* Minimum of 24 teeth present
* Be willing and physically able to carry out all study procedures.
* Absence of hopeless teeth, acute dental conditions, teeth with endo-periodontal lesions and necrotising periodontal diseases.

Exclusion Criteria:

* Age\> 70 years old
* Smokers
* Systemically compromised
* Underweight/Obese
* Pregnant
* Alcoholism
* Systemic antibiotics intake within 3 months
* Periodontal treatment in the last 12 months
* Mental illness, depression, dementia.
* Denture wearer/ presence of dental implants
* Unable or unwilling to participate in baseline or follow up examinations
* Unable or unwilling to complete the dietary intervention
* Significant food allergies