An interventional study of TRE: Time-restricted eating in Vaccination, Immunosenescence and Metabolism, sponsored by Charite University, Berlin, Germany. Recruiting at 1 site in Germany. Open to participants aged 60 Years to 85 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-09-18.
Sponsored by Charite University, Berlin, Germany · Not applicable, Interventional, and Basic science
The aim of this study is to investigate the effects of a four-week time-restricted eating (TRE) intervention on autophagy, immune function, and vaccine response to a seasonal influenza and COVID-19 vaccines in older healthy subjects.
Aging impairs immune cell autophagy and reduces vaccine efficacy, leaving older adults highly vulnerable to influenza and other infectious diseases. Time-Restricted Eating (TRE), by limiting daily food intake to an 8-hour window without detailed calorie counting, modulates nutrient-sensing pathways (e.g., mTOR inhibition, AMPK activation) and boosts autophagic flux in preclinical models. In a randomized, controlled trial, healthy volunteers aged 60-85 will follow either four weeks of TRE or their usual eating pattern. After that, all will receive a standard seasonal vaccines against influenza and COVID-19 outside of the trial at their general practitioner (min. 2 days and max. 14 days after the stop of intervention). Blood and physiologic measurements at baseline, after four weeks of study intervention will quantify autophagy in immune cells, metabolome/proteome shifts, body composition, blood pressure, and arterial stiffness, among others. At two additional visits after the vaccination (2 weeks and 12-14 weeks after the vaccination), immune responses to the vaccination will be monitored in the blood. The investigators hypothesize that TRE-induced restoration of autophagy and amelioration of immunosenescence will correlate with stronger vaccine responses, offering a simple, low-cost strategy to rejuvenate immunity and improve preventive care in the elderly.
333 studies on the registry are indexed under Intermittent Fasting; 99 are open to participants now.
This study's planned enrollment of 24 is below the median of 50 across 320 interventional studies indexed under Intermittent Fasting.
Browse Intermittent Fasting studies →Charite University, Berlin, Germany is the lead sponsor of 857 studies on the registry; 129 are open to participants now.
Compared within Intermittent Fasting, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Fasting. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Four weeks of ad libitum eating pattern with eating time window \>11 h/day. No change of the regular eating pattern.
Four weeks of TRE, where the daily eating pattern is reduced to 8 h/day. The first meal will be before 10:00 AM.
Behavioral: TRE: Time-restricted eating
The daily eating pattern is reduced to 8 h/day. The first meal will be before 10:00 AM.
Autophagic flux in PBMCs
Change in autophagic flux in peripheral immune cells from baseline (V1) to four weeks (V2), comparing the TRE group versus control, as measured by flow cytometry detection of LC3-II accumulation via antibody staining.
Time frame: Change from baseline to 4 weeks
Change in body weight
Change in body weight
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in body composition (BodPod)
Change in body composition (e.g., fat and lean body mass), assessed via Air Displacement Plethysmography (ADP, BodPod).
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in body composition (BIA)
Change in body composition (e.g., fat and lean body mass), assessed via bioimpedance analysis (BIA).
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in the differential blood count
Change in the differential blood count, assessed with Hematology analyzers.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in blood glucose levels
Change in blood glucose levels, assessed via routine blood diagnostic tests
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in insulin metabolism
Changes in insulin metabolism parameters, including insulin, IGF-1, C-peptide, ghrelin, leptin, adiponectin, and glucagon, assessed via ELISAs
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Changes in blood ketone body levels
Changes in blood ketone body levels (3-hydroxybutyrate, acetoacetate, acetone), assessed using commercially available assay kits
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in blood lipid profile
Changes in blood lipids assessed via metabolomics and routine blood diagnostic tests
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in liver or renal function
Changes in blood parameters of liver and renal function assessed via routine blood diagnostic tests
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in blood electrolyte levels
Changes in blood electrolyte levels assessed via routine blood diagnostic tests
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in the incidence of clinically diagnosable infections during the study period
Change in the incidence of clinically diagnosable infections during the study period, assessed at study visits by the study physician
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in continuous blood glucose levels
Change in continuous blood glucose levels, assessed with continuous glucose monitors (CGM). CGMs will be applied at V1 and V2 and record continuous glucose levels for 14 days each.
Time frame: CGMs will be applied at V1 and V2 and record continuous glucose levels for 14 days each.
Change in grip strength
Change in grip strength, assessed with a dynamometer. Handgrip strength will be measured using a dynamometer three times sequentially and repeated after 1 hour.
Time frame: Change from baseline to 4 weeks (end of TRE).
Change in metabolic rate
Change in metabolic rate via indirect calorimetry. Indirect calorimetry will be performed to assess energy expenditure as well as carbohydrate and fat oxidation rates. During the procedure, the subject will rest quietly in bed while wearing a ventilated hood. The hood is equipped with an inlet and an outlet valve. Through the inlet valve, the subject receives a constant supply of fresh air, while exhaled air is collected via the outlet valve. Sampling at the rear of the calorimetry device allows determination of gas concentrations in the ambient room air. By calculating the difference, oxygen consumption (VO₂) and carbon dioxide production (VCO₂) in ml/min are determined. These volumes enable the calculation of energy expenditure and substrate oxidation rates. This measurement is performed after a rest period of 30 minutes to determine resting fasting energy expenditure (duration approximately 30 minutes).
Time frame: Change from baseline to 4 weeks (end of TRE).
Change in Sleep Quality
Change in Sleep Quality assessed using a questionnaire for the Pittsburgh Sleep Quality Index \[PSQI\].
Time frame: Change from baseline to 4 weeks (end of TRE)
Change in health-related quality of life
Change in EQ-5D-5L assessed using questionnaires.
Time frame: Change from baseline to 4 weeks (end of TRE)
Change in ChronoType
Change in ChronoType assessed using the Munich ChronoType Questionnaire \[MCTQ\]
Time frame: Change from baseline to 4 weeks (end of TRE)
Change in the Multidimensional Prognostic Index (MPI).
Change in the MPI for geriatric assessment. MPI assessments will be conducted, including documentation of medication and dietary supplement use, medication allergies, nutritional therapies, a range of disease symptoms, social history, activities of daily living (ADL), instrumental activities of daily living (IADL), malnutrition screening, the Short Portable Mental Status Questionnaire (SPMSQ), and the Exton Smith Scale (assessment of decubitus risk), all administered via standardized questionnaires.
Time frame: Change from baseline to 4 weeks
Change in the walking speed.
A 10-meter walk test will be performed to determine walking speed in m/s. For this purpose, the subject will walk from a 0-meter mark to a 10-meter mark upon command. Timing will begin at the 2-meter mark. The procedure will be repeated three times, and the times will be averaged. If the subject's fitness level permits, the procedure will be repeated with the instruction to complete the 10 meters 'as fast as possible while still feeling safe'.
Time frame: Change from baseline to 4 weeks
Change in proteome profiles in plasma and PBMCs.
Change in proteome profiles in plasma and PBMCs, measured by LC-MS mass spectrometry or Olink proteomics.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in metabolite patterns in plasma.
Change in metabolite patterns in plasma, assessed by untargeted (¹H-NMR) and/or targeted (LC-MS) metabolomics.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in metabolite patterns in stool.
Change in metabolite patterns in stool, assessed by untargeted (¹H-NMR) and/or targeted (LC-MS) metabolomics.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in metabolite patterns in urine.
Change in metabolite patterns in urine, assessed by untargeted (¹H-NMR) and/or targeted (LC-MS) metabolomics.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in gut microbiome composition.
Change in gut microbiome composition by metagenomic sequencing of stool.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in immune-cell subset distribution and activation.
Change in immune-cell subset distribution and activation, assessed by scRNA-seq and flow cytometry.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in body fat percentage.
Change in body fat percentage, measured by air-displacement plethysmography.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in office systolic and diastolic blood pressure.
Change in office systolic and diastolic blood pressure (mmHg), measured by non-invasive blood pressure cuff.
Time frame: Change from baseline to 4 weeks
Change in pulse-wave velocity.
Change in pulse-wave velocity (m/s), measured by PulsePen.
Time frame: Change from baseline to 4 weeks
Change in frequency of pro- and anti-inflammatory immune cells.
Change in frequency of pro- and anti-inflammatory immune cells in PBMCs, by flow cytometric immunophenotyping.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in immune-cell function.
Change in immune-cell function (cytokine production, proliferation) after in vitro stimulation of PBMC subsets, by flow cytometry.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in circulating pro- and anti-inflammatory cytokine concentrations in plasma.
Change in circulating pro- and anti-inflammatory cytokine concentrations in plasma, by multiplex cytokine assay.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in expression of senescence markers in immune-cell subsets.
Change in expression of senescence markers in immune-cell subsets, by flow cytometry.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in the hypusination status of eIF5A in PBMCs
Change in the hypusination status of eIF5A in PBMCs by flow cytometry.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in mTOR activity status in PBMCs
Change in mTOR activity status in PBMCs by flow cytometry.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in expression of key autophagy-regulatory genes.
Change in expression of key autophagy-regulatory genes in specific immune-cell types or bulk PBMCs, by qPCR, scRNA-seq, or bulk RNA-seq.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in energy metabolism in immune-cell subsets.
Change in cellular energy metabolism in immune-cell subsets, measured by Seahorse extracellular flux analysis and/or Scenith Assay in isolated immune cells ex vivo.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in coagulation.
Change in coagulation, assessed via e.g., thrombin generation, d-dimers from plasma
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in influenza-specific B- and T-cell responses.
Change in influenza-specific B- and T-cell responses in serum and PBMCs (e.g., ELISpot).
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in SARS-CoV-2 specific B- and T-cell responses.
Change in SARS-CoV-2 specific B- and T-cell responses in serum and PBMCs (e.g., ELISpot).
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in concentration of influenza-specific IgG antibodies.
Change in concentration of influenza-specific IgG antibodies, by ELISA.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in concentration of SARS-CoV-2 specific IgG antibodies.
Change in concentration of SARS-CoV-2 specific IgG antibodies, by ELISA.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in concentration of influenza-neutralizing antibodies.
Change in concentration of influenza-neutralizing antibodies.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in concentration of SARS-CoV-2 neutralizing antibodies.
Change in concentration of SARS-CoV-2 neutralizing antibodies.
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Change in DNA-break profiles in primary B cells.
Change in DNA-break profiles in primary B cells, assessed by SWIBRID (Switch-joint Breakpoint Repertoire Identification).
Time frame: Change from baseline to 4 weeks (end of TRE), 2 weeks and 12-14 weeks after vaccination
Plan to share: Yes — Individual participant data that underlie the results of reported articles (text, tables, figures, supplemental data) will be shared after deidentification.
Supporting information: Study protocol
Time frame: Beginning 9 months and ending 36 months following article publication.
Access criteria: Researchers who provide a methodologically and scientifically sound proposal.
No publications or documents are linked to this record.
Started Sep 2025 (actual). Primary completion is estimated for Sep 2026, 12 months after the start.
Of 257 non-industry interventional studies with no phase under Intermittent Fasting, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 34. This study's planned 12 months is below that.
Counting every sponsor, half of 263 studies reached it within 17 months; a quarter within 8 and three quarters within 34.
How these figures are worked out, and which studies are left out of them.
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Charite University, Berlin, Germany →