Oral and Gut Microbiota Changes During Long-term Fasting in Humans

Study Overview
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Brief Summary
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The aim of this longitudinal trial is to investigate the effects of a 10±3-day fasting period in 30 subjects. Changes in the oral and gut microbiota, halitosis, as well as inflammatory and antioxidative parameters and biomarkers of sulfur metabolism will be analysed.

Detailed Description
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Fasting has been linked with changes in gut microbiota as part of the physiological adaptation. Furthermore, associations have been described between oral disease and nutrition (diet rich in carbohydrates). The aim of the present longitudinal clinical study is to explore the effect of a 10±3-day fasting period on the oral and gut microbiota. 30 systemically healthy subjects attending the Buchinger Wilhelmi Clinics for fasting, will participate. Changes in oral microbiota will be assessed in plaque and saliva samples and a number of inflammatory markers will be analyzed in Gingival Crevicular fluid (GCF) and blood obtained before, during and after the fasting period. The changes in the oral microbiota will be associated to the composition of the gut microbiota. Changes in periodontal parameters and halitosis related to the fasting period will be further evaluated. Given the known association between sulfur metabolism and the redox status, parameters from the antioxidant status and oxidative damages will also be assessed.

Official Title
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Oral and Gut Microbiota Changes During Long-term Fasting in Humans

Conditions
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Healthy, Periodontitis

Intervention / Treatment
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* Procedure: Long-term fasting


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Both subjects with periodontitis and healthy periodontium will be included. Signed informed consent Exclusion Criteria: Not able to sign the informed consent diagnosticated with cachexia, anorexia, nervosa, advanced kidney, liver or cerebrovascular insufficiency Smoking the intake of antibiotics within the last 8 weeks, as well as the intake of probiotics within the last 4 weeks periodontal treatment in the last 6 months chronic manifest psychical and psychiatric diseases participation in another study pregnancy or breastfeeding

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Interventional Model Description: single-arm, prospective, monocentric, interventional study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Long-term fasting<br>Long-term fasting according to the Buchinger Wilhelmi fasting program. | Procedure: Long-term fasting<br>* The participants will undergo a fasting program that includes the daily intake of 250 kcal under medical supervision.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in halitosis | Concentration of volatile sulfide compounds (hydrogen sulfide, methylmercaptan and dimethyl sulphide) using the OralChrome devise | daily from baseline to the 3rd day of food reintroduction | 
| Changes in microbiota compositions of subgingival microbial and plaque sampling | Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Parvimonas micra (Pm) and Prevotella intermedia (Pi) analysed by RT-q-PCR | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in microbiota composition in saliva | 16 rRNA gene amplicon sequencing | Baseline, fasting day 10, food reintroduction day 3, 1 and 3 months afterwards | 
| Changes in microbiota composition in faeces | 16 rRNA gene amplicon sequencing | Baseline, first spontaneous stool after food reintroduction (up to day 3), 1 and 3 months afterwards | 
| Changes in total antioxidant capacity (TAC) | (mmol DPPH/L) | Baseline, fasting day 3, 5, 10 | 
| Changes in hydrogen sulfide production capacity | measured in serum and urine using the lead acetate assay | at the beginning and the end of fasting, on day 3 and 5, as well as at the food reintroduction | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in glutathione (GSH) | (µmol/g Hb) | Baseline, fasting day 3, 5, 10 | 
| Changes in thiobarbituric acid reactive substances (TBARS) | (µmol/L) | Baseline, fasting day 3, 5, 10 | 
| Changes in malondialdehyde (MDA) | nM/L | Baseline, fasting day 3, 5, 10 | 
| Changes in protein carbonyls | (nmol/mg protein) | Baseline, fasting day 3, 5, 10 | 
| Changes in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase | (µL) | Baseline, fasting day 3, 5, 10 | 
| Changes in glutathione reductase (GR) activity | (U/g Hb) | Baseline, fasting day 3, 5, 10 | 
| Changes in glutathione peroxidase (GPx) activity | (U/g Hb) | Baseline, fasting day 3, 5, 10 | 
| Changes in peroxiredoxin activity | (U/g Hb) | Baseline, fasting day 3, 5, 10 | 
| Changes in catalase (CAT) activity | (U/mg Hb) | Baseline, fasting day 3, 5, 10 | 
| Changes in superoxide dismutase (SOD) activity | (U/g Hb) | Baseline, fasting day 3, 5, 10 | 
| Changes in hydroxyl radical scavenging | (mmol deoxyribose/ml) | Baseline, fasting day 3, 5, 10 | 
| Changes in superoxydradical scavenging | (mmol NBT/L plasma) | Baseline, fasting day 3, 5, 10 | 
| Changes in ABTS scavenging | (mmol/L) | Baseline, fasting day 3, 5, 10 | 
| Changes in reducing power | (mmol/L plasma) | Baseline, fasting day 3, 5, 10 | 
| Changes in thiosulfate | measured using the monobromobimane method using HPLC and LC-MS/MS | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in persulfidation | persulfidation in serum and urine | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in cystein | using the S-sulfocysteine (SSC) method which is a HPLC-based method using automated precolumn derivatization with OPA and UV detection at 338 nm in serum and urine | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in amino acid metabolites | using a targeted approach in serum and urine | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-10 in blood | analysed in blood with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in G-CSF in blood | analysed in blood with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IFN-γ in blood | analysed in blood with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in TNF-α in blood | analysed in blood with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-1β in blood | analysed in blood with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-6 in blood | analysed in blood with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-8 in blood | analysed in blood with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-17 in blood | analysed in blood with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-10 in gingival crevicular fluid | analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in G-CSF in gingival crevicular fluid | analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IFN-γ in gingival crevicular fluid | analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in TNF-α in gingival crevicular fluid | analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-1β in gingival crevicular fluid | analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-6 in gingival crevicular fluid | analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-8 in gingival crevicular fluid | analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 
| Changes in IL-17 in gingival crevicular fluid | analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System | Baseline, fasting day 10, food reintroduction day 3 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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redox status, oral microbiota, intestinal microbiota, inflammatory status, sulfur metabolism, halitosis