To assess the effects of aging on protein digestion and amino acid absorption in healthy humans.
ID
Source
Brief title
Condition
- Gastrointestinal conditions NEC
- Protein and amino acid metabolism disorders NEC
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The primary study parameter is the mRNA expression of brush border peptidases
and small peptide and amino acid transporters in duodenal mucosal cells.
Secondary outcome
Secondary study parameters include protein expression levels of brush border
peptidases and small peptide and amino acid transporters in duodenal mucosal
cells, fecal microbial fermentation metabolites and duodenal mucosal protein
synthesis rate.
Background summary
Worldwide, the aging population is increasing. Aging is associated with loss of
independence and increased risk of co-morbidity. Sufficient protein intake is
imperative to maintain skeletal muscle mass and overall health, and thereby
stimulates active aging. It has been suggested that age-dependent changes in
gastrointestinal (GI) tract physiology affect the amount of protein digested
and absorbed, as well as impact the intestinal microbiota. However, it is not
clear to what extent actual protein digestion and absorption are altered in
older individuals, and how this is related to the intestinal microbiota. So
far, no human data on the expression and activity of brush border enzymes and
protein-related transporters in small intestinal epithelial cells are
available. Understanding the age-dependent digestion and absorption kinetics of
protein is important for creating specific diets in older individuals to
improve protein intake and thereby stimulate healthy aging.
Study objective
To assess the effects of aging on protein digestion and amino acid absorption
in healthy humans.
Study design
Cross-sectional
Study burden and risks
Participants will come to the laboratory for a total of three visits,
comprising of one screening visit (±1 hour), one visit on the *loading day* (±1
hour), and one visit on the experimental test day (±3 hours).
During the screening visit, participants will fill in a medical questionnaire
and height, weight and blood pressure will be measured.
During the visit on the *loading day* (twodays prior to the experimental test
day) participants will ingest the first dose of 70% deuterium oxide (100 mL)
and blood and saliva samples will be collected. Deuterium oxide dosing to
achieve a body water enrichment of 1 APE is completely safe as it is far below
the threshold for biological toxicity in humans (approximately 20 APE), and
will be returned to baseline enrichments within 30 days.
Two days prior to the test day, participants will ingest another two doses of
70% deuterium oxide (100 mL + 20 mL), collect 2 saliva samples, consume a
standardized diet and they have to record their food intake and physical
activity performed. During these two days, participants are not allowed to
perform heavy physical exercise or drink alcohol. At the experimental test day,
participants have to arrive in a fasted state.
Saliva sampling (4 samples total) and feces collection (2 samples total) is
risk-free. Blood sampling is minimal (20 mL total) and will be conducted using
a single venapuncture method. Duodenal biopsies (8 total) will be obtained by
an experienced gastroenterologist using gastroduodenoscopy, which is considered
a safe routine medical procedure with low risk of complications.
There is no direct benefit for the participants except for their contribution
to the scientific knowledge of protein digestion and amino acid absorption to
optimize protein intervention strategies in the growing aging population.
Universiteitssingel 50
Maastricht 6229ER
NL
Universiteitssingel 50
Maastricht 6229ER
NL
Listed location countries
Age
Inclusion criteria
- Aged 18-35 years or 67+ years
- Body mass index (BMI) 18.5-30 kg/m2
- Regular stool frequency ranging from 1-3 times/day
Exclusion criteria
- History of cardiovascular, respiratory, gastrointestinal, urogenital,
neurological, psychiatric, dermatologic, musculoskeletal, metabolic, endocrine,
haematological, immunologic disorders, allergy, major surgery and/or laboratory
assessments which might limit participation in or completion of the study
protocol, interfere with the execution of the experiment, or potential
influence the study outcomes (to be decided by the principal investigator and
responsible physician)
- Major abdominal surgery interfering with gastrointestinal function (upon
judgement of the principal investigator and responsible physician)
- Use of medication which limit participation in or completion of the study
protocol, interferes with the execution of the experiment, or potential
influences the study outcomes (to be decided by the principal investigator and
responsible physician) including but not limited to chronic use of
anticoagulants, regular use of laxatives 14 days prior to the study or during
the study period, use of antibiotics 3 months prior to the study or during the
study period
- Use of supplementation (i.e. vitamin, pre- and probiotic supplementation,
protein) within 14 days prior to testing
- Administration of investigational drugs or participation in any scientific
intervention study prior to or during the study period, which may interfere
with this study (upon judgement of the principal investigator and responsible
physician)
- Specific diet (e.g. vegetarian, vegan, gluten free, no diary) within the
study period
- Planning to lose weight during the study period
- Excessive alcohol consumption (defined as > 14 alcoholic consumptions per
week)
- Smoking
- Drug use
- Pregnancy
- Donated blood three months prior to the test day
- No given permission to register participation in electronic patient file at
MUMC+ and to add records of gastroduodenoscopy
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL84569.068.23 |
| Other | Volgt, registratie in clinicaltrials.gov |