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.
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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
PREVENTION
Masking
NONE
Enrollment
36
The participants will undergo a fasting program that includes the daily intake of 250 kcal under medical supervision.
Buchinger Wilhelmi clinic
Überlingen, Germany
Changes in halitosis
Concentration of volatile sulfide compounds (hydrogen sulfide, methylmercaptan and dimethyl sulphide) using the OralChrome devise
Time frame: 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
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in microbiota composition in saliva
16 rRNA gene amplicon sequencing
Time frame: Baseline, fasting day 10, food reintroduction day 3, 1 and 3 months afterwards
Changes in microbiota composition in faeces
16 rRNA gene amplicon sequencing
Time frame: 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)
Time frame: Baseline, fasting day 3, 5, 10
Changes in hydrogen sulfide production capacity
measured in serum and urine using the lead acetate assay
Time frame: at the beginning and the end of fasting, on day 3 and 5, as well as at the food reintroduction
Changes in glutathione (GSH)
(µmol/g Hb)
Time frame: Baseline, fasting day 3, 5, 10
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Changes in thiobarbituric acid reactive substances (TBARS)
(µmol/L)
Time frame: Baseline, fasting day 3, 5, 10
Changes in malondialdehyde (MDA)
nM/L
Time frame: Baseline, fasting day 3, 5, 10
Changes in protein carbonyls
(nmol/mg protein)
Time frame: Baseline, fasting day 3, 5, 10
Changes in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase
(µL)
Time frame: Baseline, fasting day 3, 5, 10
Changes in glutathione reductase (GR) activity
(U/g Hb)
Time frame: Baseline, fasting day 3, 5, 10
Changes in glutathione peroxidase (GPx) activity
(U/g Hb)
Time frame: Baseline, fasting day 3, 5, 10
Changes in peroxiredoxin activity
(U/g Hb)
Time frame: Baseline, fasting day 3, 5, 10
Changes in catalase (CAT) activity
(U/mg Hb)
Time frame: Baseline, fasting day 3, 5, 10
Changes in superoxide dismutase (SOD) activity
(U/g Hb)
Time frame: Baseline, fasting day 3, 5, 10
Changes in hydroxyl radical scavenging
(mmol deoxyribose/ml)
Time frame: Baseline, fasting day 3, 5, 10
Changes in superoxydradical scavenging
(mmol NBT/L plasma)
Time frame: Baseline, fasting day 3, 5, 10
Changes in ABTS scavenging
(mmol/L)
Time frame: Baseline, fasting day 3, 5, 10
Changes in reducing power
(mmol/L plasma)
Time frame: Baseline, fasting day 3, 5, 10
Changes in thiosulfate
measured using the monobromobimane method using HPLC and LC-MS/MS
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in persulfidation
persulfidation in serum and urine
Time frame: 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
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in amino acid metabolites
using a targeted approach in serum and urine
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in IL-10 in blood
analysed in blood with Bio-Plex 200 Suspension array System
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in G-CSF in blood
analysed in blood with Bio-Plex 200 Suspension array System
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in IFN-γ in blood
analysed in blood with Bio-Plex 200 Suspension array System
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in TNF-α in blood
analysed in blood with Bio-Plex 200 Suspension array System
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in IL-1β in blood
analysed in blood with Bio-Plex 200 Suspension array System
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in IL-6 in blood
analysed in blood with Bio-Plex 200 Suspension array System
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in IL-8 in blood
analysed in blood with Bio-Plex 200 Suspension array System
Time frame: Baseline, fasting day 10, food reintroduction day 3
Changes in IL-17 in blood
analysed in blood with Bio-Plex 200 Suspension array System
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: Baseline, fasting day 10, food reintroduction day 3