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Completed

NCT Number: NCT05449249

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

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.

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Key information

Conditions

Healthy Halitosis Mouth Diseases Pathological Conditions, Signs and Symptoms Periodontal Diseases Periodontitis Signs and Symptoms Signs and Symptoms, Digestive Stomatognathic Diseases

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Buchinger Wilhelmi clinic

Überlingen, 88662, Germany

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Long-term fasting

Procedure

The participants will undergo a fasting program that includes the daily intake of 250 kcal under medical supervision.

Primary outcomes

  1. Changes in halitosis

    Time frame: daily from baseline to the 3rd day of food reintroduction

    Concentration of volatile sulfide compounds (hydrogen sulfide, methylmercaptan and dimethyl sulphide) using the OralChrome devise

  2. Changes in microbiota compositions of subgingival microbial and plaque sampling

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Parvimonas micra (Pm) and Prevotella intermedia (Pi) analysed by RT-q-PCR

  3. Changes in microbiota composition in saliva

    Time frame: Baseline, fasting day 10, food reintroduction day 3, 1 and 3 months afterwards

    16 rRNA gene amplicon sequencing

  4. Changes in microbiota composition in faeces

    Time frame: Baseline, first spontaneous stool after food reintroduction (up to day 3), 1 and 3 months afterwards

    16 rRNA gene amplicon sequencing

  5. Changes in total antioxidant capacity (TAC)

    Time frame: Baseline, fasting day 3, 5, 10

    (mmol DPPH/L)

  6. Changes in hydrogen sulfide production capacity

    Time frame: at the beginning and the end of fasting, on day 3 and 5, as well as at the food reintroduction

    measured in serum and urine using the lead acetate assay

Secondary outcomes

  1. Changes in glutathione (GSH)

    Time frame: Baseline, fasting day 3, 5, 10

    (µmol/g Hb)

  2. Changes in thiobarbituric acid reactive substances (TBARS)

    Time frame: Baseline, fasting day 3, 5, 10

    (µmol/L)

  3. Changes in malondialdehyde (MDA)

    Time frame: Baseline, fasting day 3, 5, 10

    nM/L

  4. Changes in protein carbonyls

    Time frame: Baseline, fasting day 3, 5, 10

    (nmol/mg protein)

  5. Changes in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase

    Time frame: Baseline, fasting day 3, 5, 10

    (µL)

  6. Changes in glutathione reductase (GR) activity

    Time frame: Baseline, fasting day 3, 5, 10

    (U/g Hb)

  7. Changes in glutathione peroxidase (GPx) activity

    Time frame: Baseline, fasting day 3, 5, 10

    (U/g Hb)

  8. Changes in peroxiredoxin activity

    Time frame: Baseline, fasting day 3, 5, 10

    (U/g Hb)

  9. Changes in catalase (CAT) activity

    Time frame: Baseline, fasting day 3, 5, 10

    (U/mg Hb)

  10. Changes in superoxide dismutase (SOD) activity

    Time frame: Baseline, fasting day 3, 5, 10

    (U/g Hb)

  11. Changes in hydroxyl radical scavenging

    Time frame: Baseline, fasting day 3, 5, 10

    (mmol deoxyribose/ml)

  12. Changes in superoxydradical scavenging

    Time frame: Baseline, fasting day 3, 5, 10

    (mmol NBT/L plasma)

  13. Changes in ABTS scavenging

    Time frame: Baseline, fasting day 3, 5, 10

    (mmol/L)

  14. Changes in reducing power

    Time frame: Baseline, fasting day 3, 5, 10

    (mmol/L plasma)

  15. Changes in thiosulfate

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    measured using the monobromobimane method using HPLC and LC-MS/MS

  16. Changes in persulfidation

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    persulfidation in serum and urine

  17. Changes in cystein

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    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

  18. Changes in amino acid metabolites

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    using a targeted approach in serum and urine

  19. Changes in IL-10 in blood

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in blood with Bio-Plex 200 Suspension array System

  20. Changes in G-CSF in blood

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in blood with Bio-Plex 200 Suspension array System

  21. Changes in IFN-γ in blood

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in blood with Bio-Plex 200 Suspension array System

  22. Changes in TNF-α in blood

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in blood with Bio-Plex 200 Suspension array System

  23. Changes in IL-1β in blood

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in blood with Bio-Plex 200 Suspension array System

  24. Changes in IL-6 in blood

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in blood with Bio-Plex 200 Suspension array System

  25. Changes in IL-8 in blood

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in blood with Bio-Plex 200 Suspension array System

  26. Changes in IL-17 in blood

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in blood with Bio-Plex 200 Suspension array System

  27. Changes in IL-10 in gingival crevicular fluid

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System

  28. Changes in G-CSF in gingival crevicular fluid

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System

  29. Changes in IFN-γ in gingival crevicular fluid

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System

  30. Changes in TNF-α in gingival crevicular fluid

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System

  31. Changes in IL-1β in gingival crevicular fluid

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System

  32. Changes in IL-6 in gingival crevicular fluid

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System

  33. Changes in IL-8 in gingival crevicular fluid

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System

  34. Changes in IL-17 in gingival crevicular fluid

    Time frame: Baseline, fasting day 10, food reintroduction day 3

    analysed in gingival crevicular fluid with Bio-Plex 200 Suspension array System

Other outcomes

  1. Changes in Rosenberg scale

    Time frame: daily from baseline to the 3rd day of food reintroduction

    organoleptic intensity scale for measuring oral malodor: 0 = no odor to 5 = intense odor

  2. Changes in Seemann scale

    Time frame: daily from baseline to the 3rd day of food reintroduction

    organoleptic assessment: 1 = odor noticable from 10 cm to 3 = odor noticeable from 1m

  3. Changes in Ayurvedic diagnosis of the tongue

    Time frame: daily from baseline to the 3rd day of food reintroduction

    examination of the tongue

  4. Changes in urinary ketone bodies

    Time frame: daily from baseline to the 3rd day of food reintroduction

    using ketostix

  5. Changes in capillary blood ketones

    Time frame: daily from baseline to the 3rd day of food reintroduction

    using GlucoMen areo 2k

  6. Changes in capillary blood glucose

    Time frame: daily from baseline to the 3rd day of food reintroduction

    using GlucoMen areo 2k

  7. Changes in ph value of the urin

    Time frame: daily from baseline to the 3rd day of food reintroduction

    using test strips

  8. Changes in weight

    Time frame: daily from baseline to the 3rd day of food reintroduction as well as 1 and 3 months after

    kg

  9. Changes in blood pressure

    Time frame: daily from baseline to the 3rd day of food reintroduction as well as 1 and 3 months after

    systolic and diastolic in mmHg

  10. Changes in pulse

    Time frame: daily from baseline to the 3rd day of food reintroduction as well as 1 and 3 months after

    beats per minute

  11. Plaque Index score

    Time frame: baseline

    Sillness & Loe, 1964: from 0 = no plaque to 3 = abundant plaque along the gingival margin, interdental spaces filled with plaque

  12. Gingival index score

    Time frame: baseline

    Löe & Sillness, 1963: from 0 = normal gingiva to 3 = severe inflammation

  13. Probing pocket depth

    Time frame: baseline

    Bleeding on probing, recorded as present within 30 sec (1) or absent (0)

  14. clinical attachment level

    Time frame: baseline

    distance between the cemento-enamel junction and the tip of the graduated steel

  15. recession

    Time frame: baseline

    distance between CEJ and marginal edge of the free gingiva

  16. Changes in leucocytes

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (thousands/µl)

  17. Changes in erythrocytes

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (millions/µl)

  18. Changes in haemoglobin

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (g/dl)

  19. Changes in haematocrit

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (in %)

  20. Changes in MCV

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (fl)

  21. Changes in MCH

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (pg)

  22. Changes in MCHC

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (g/dl)

  23. Changes in thrombocytes

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (thousands/µl)

  24. Changes in international normalized ratio

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    ratio

  25. Changes in Quick

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (in %)

  26. Changes in partial thromboplastin time

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (sec)

  27. Changes in aspartate aminotransferase (AST/GOT)

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (U/l)

  28. Changes in alanine aminotransferase (ALT/GPT)

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (U/l)

  29. Changes in gamma-glutamyl transferase (GGT)

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (U/l)

  30. Changes in alkaline phosphatase

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (U/l)

  31. Changes in uric acid

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/dl)

  32. Changes in urea

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/dl)

  33. Changes in glomerular Filtration Rate (GFR)

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (ml/min/1.73m2KOF)

  34. Changes in creatinine

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/dl)

  35. Changes in thyroid-stimulating hormone (TSH)

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mE/l)

  36. Changes in total cholesterol

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/dl)

  37. Changes in triglyceride

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/dl)

  38. Changes in high-density lipoprotein (HDL)

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/dl)

  39. Changes in low-density lipoprotein (LDL)

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/dl)

  40. Changes in LDL / HDL - ratio

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    ratio

  41. Changes in glucose

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/dl)

  42. Changes in HbA1c

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mmol/mol)

  43. Changes in sodium

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mmol/l)

  44. Changes in potassium

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mmol/l)

  45. Changes in calcium

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mmol/l)

  46. Changes in magnesium

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mmol/l)

  47. Changes in erythrocyte sedimentation rate

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mm/h)

  48. Changes in C - reactive protein

    Time frame: Baseline, fasting day 10, and food reintroduction day 3

    (mg/l)

  49. Changes in pH value of saliva

    Time frame: Baseline, fasting day 10, food reintroduction day 3, 1 and 3 months afterwards

    (mol/l)

Sponsors and collaborators

Lead sponsor

Buchinger Wilhelmi Development & Holding GmbH

Other

Collaborators

  • ETH Zurich (Switzerland)
  • King's College London
  • University of Geneva, Switzerland

Registry information

Acronym: OralFast

Important dates

Study start
2022
Primary completion
2022
Study completion
2023
First posted
Jul 8, 2022
Registry last updated
Jan 13, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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