Chronic Obstructive Pulmonary DiseaseSCFANCT03327181
Short Chain Fatty Acid Metabolism in COPD
A study testing short chain fatty acid tracers in people with Chronic Obstructive Pulmonary Disease, run by Texas A&M University at 1 site in United States.
Trial summary
The short chain fatty acid (SCFA) metabolism has not been studied in subjects suffering from COPD. The purpose of this study is to compare the SCFA metabolism in COPD patients to healthy matched controls. Read more about this study
- Who is it for?
- Ages 45 to 100 yearsHealthy volunteers can take part
- Conditions the study is for
- Chronic Obstructive Pulmonary Disease
- What is being tested?
- short chain fatty acid tracers
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 63 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Apr 2017to 14 Feb 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 to 100 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Ability to walk, sit down and stand up independently
- Age 45 years - 100 years
- Ability to lie in supine or elevated position for 1.5 hours
- Diagnosis of moderate to very severe chronic airflow limitation and compliant to the following criteria: FEV1 < 70% of reference FEV1
- Clinically stable condition and not suffering from a respiratory tract infection or exacerbation of their disease (defined as a combination of increased cough, sputum purulence, shortness of breath, systemic symptoms such as fever, and a decrease in FEV1 > 10% compared with values when clinically stable in the preceding year) at least 4 weeks prior to the first test day
- Shortness of breath on exertion
Show all 13Show fewer
- Willingness and ability to comply with the protocol
- Healthy male or female according to the investigator's or appointed staff's judgment
- Ability to walk, sit down and stand up independently
- Age 45 years - 100 years
- Ability to lay in supine or elevated position for 1.5 hours
- No diagnosis of COPD
- Willingness and ability to comply with the protocol
Who cannot join
- Any condition that may interfere with the definition 'healthy subject' according to the investigator's judgment (healthy subjects only)
- Subjects 86 years and older that fail to get physician eligibility confirmation
- Insulin dependent diabetes mellitus
- Established diagnosis of malignancy
- History of untreated metabolic diseases including hepatic or renal disorder
- Presence of acute illness or metabolically unstable chronic illness
Show all 14Show fewer
- Presence of fever within the last 3 days
- Any other condition according to the PI or nurse that was found during the screening visit, that would interfere with the study or safety of the patient
- Use of protein or amino acid containing nutritional supplements within 5 days of first study day
- Use of short course of oral corticosteroids within 4 weeks preceding first study day
- Failure to give informed consent or Investigator's uncertainty about the willingness or ability of the subject to comply with the protocol requirements
- (Possible) pregnancy
- Already enrolled in another clinical trial and that clinical trial interferes with participating in this study
- When during the period from enrollment to the test day any condition causing the subject to not meet inclusion criteria or to meet exclusion criteria, the subject will be excluded from the study.
Trial locations and contacts
1 site in 1 country.
United States1 site
Texas A&M University
College Station, Texas, 77843-4253
About this study
Official title: Short-chain Fatty Acid Metabolism in Chronic Obstructive Pulmonary Disease
The short chain fatty acid (SCFA) metabolism has not been studied in subjects suffering from COPD. The purpose of this study is to compare the SCFA metabolism in COPD patients to healthy matched controls. This protocol is an extension of recent studies about protein digestion and absorption abnormalities in COPD patients. The investigators hypothesize that SCFA production might be lower in COPD patients than in healthy subjects.
Read the detailed description
Short-chain fatty acids (SCFAs) are straight or branched-chain fatty acids produced by the intestinal microbiota mainly through fermentation of undigested carbohydrates, but also through degradation of dietary and endogenous proteins. With a share of 90 to 95 %, acetate (C2), propionate (C3), and butyrate (C4) are the most common SCFAs in the colon (3). The molar ratios of acetate to propionate to butyrate are on average approximately 60:20:20 throughout the whole colon. Several human studies tried to determine the in situ production of SCFAs by measuring their content in feces (5-8). But fecal SCFA concentrations do not accurately represent the concentrations in more proximal regions of the colon, because colonocytes absorb more than 95 % of SCFAs to use them as an energy source. Further, the measurement of plasma SCFA concentrations is inaccurate because SCFA plasma levels are low due to high metabolism in colonocytes and liver. Thus, stable isotope studies are needed to examine the colonic production and metabolic fate of SCFAs in healthy and diseased subjects.
SCFAs seem to have anti-inflammatory and immune modulating effects. In COPD an enhanced pulmonary inflammatory response causes a combination of small airways disease (e.g., obstructive bronchiolitis) and/or a destruction of lung parenchyma (emphysema). This leads to a progressive and persistent airflow limitation. Smoking and the exposure to polluted air are main risk factors causing COPD. In a mouse model, a diet rich in whey proteins attenuated emphysema through the suppression of respiratory inflammation. This might have been related to a high colonic SCFA concentration due to the diet. Young et al. proposed that in smokers SCFAs might mitigate both the innate-mediated systemic inflammation controlled by the liver and the inflammatory responses in the lung.
Moreover, Nielsen et al. found that gastrointestinal diseases are significantly more prevalent in COPD patients (15 %) than in patients with other diseases (9%). This might have an influence on the SCFA production in the colon. Gastrointestinal problems may also be assessed through the usage of validated questionnaires.
- Conditions
- Chronic Obstructive Pulmonary Disease
- Being tested
- short chain fatty acid tracers
- Keywords
- short chain fatty acid metabolism
- Medical subject headings
- Pulmonary Disease, Chronic Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
short chain fatty acid tracersDietary supplement
stable tracer infusion of acetate, propionate, and butyrate
| Study group | Role | What they receive |
|---|---|---|
| COPD | Experimental | The subject will arrive fasted. A catheter will be inserted in the arm for stable tracer SCFA infusion and blood sampling. The hand of the arm used for blood sampling will be placed in a thermostatically controlled warmed box that heats the air. Immediately after a baseline blood sample is taken, an infusion with stable tracers will be administered by the research nurse. Stable tracers are given to measure SCFA metabolism. Blood samples will be collected before and/or after infusion. Subjects will be asked to complete a list of questions regarding quality of life, mood and depression, diet, and a variety of functional measurements. Receives: Dietary Supplement: short chain fatty acid tracers |
| Healthy older adults | Active comparator | The subject will arrive fasted. A catheter will be inserted in the arm for stable tracer SCFA infusion and blood sampling. The hand of the arm used for blood sampling will be placed in a thermostatically controlled warmed box that heats the air. Immediately after a baseline blood sample is taken, an infusion with stable tracers will be administered by the research nurse. Stable tracers are given to measure SCFA metabolism. Blood samples will be collected before and/or after infusion. Subjects will be asked to complete a list of questions regarding quality of life, mood and depression, diet, and a variety of functional measurements. Receives: Dietary Supplement: short chain fatty acid tracers |
What is being measured
The primary outcome is the main question the study is designed to answer.
whole body short-chain fatty acid metabolism
change in whole body scfa metabolism
Measured: -10, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60 min
Secondary outcomes (12)
Fat free mass measured using dual-energy x-ray absorptiometry
Difference in muscle mass between COPD patients and healthy older adults
Measured: 1 day
Fat mass measured using dual-energy x-ray absorptiometry
Difference in fat mass between COPD patients and healthy older adults
Measured: 1 day
Bone density measured using dual-energy x-ray absorptiometry
Difference in bone density between COPD patients and healthy older adults
Measured: 1 day
handgrip strength dynamometry
Difference in handgrip strength between COPD patients and healthy older adults
Measured: 1 day
Micro-respiratory pressure meter measurement
Difference in maximum inspiratory and expiratory pressure between COPD patients and healthy older adults
Measured: 1 day
moving balance platform measurement
Changes in ability to maintain balance after perturbation of moving platform between COPD patients and healthy older adults. The maximum platform displacement the participant could withstand without stepping will be determined.
Measured: 1 day
Group differences in attention and executive functions as measured by Trail Making Test (TMT),
In Part A, the examinee is instructed to connect a set of 25 circles with numbers as quickly as possible while maintaining accuracy. In Part B, the examinee is instructed to connect a set of 25 circles, alternating between numbers and letters, as quickly as possible while maintaining accuracy. Measures attentional resources and is a measure of the frontal lobe "executive" functions of visual search, set-switching and mental flexibility. The total time in seconds was reported for each measure.
Measured: 1 day
Group differences in attention and executive functions as measured by Stroop Color-Word Test (SCWT),
a word page with words printed in black ink, a color page with blocks printed in color, and a color-word page where the color and the word do not match. The examinee reads the words or names the ink colors as quickly as possible within a time limit. Measures selective attention and inhibitory control. The total time in seconds was reported for each trial.
Measured: 1 day
Group differences in somatosensory functions as measured by vibrotactile behavioral battery
The vibrotactile behavioral battery consists of a non-invasive set of brief tasks targeting sensory processes and inhibition. It can be used to detect neurobiological abnormalities in sensory processing. The battery of vibrotactile tasks involves the use of a small device that is designed to administer calibrated vibratory stimuli to the glabrous skin of digits 3 and 4 of the left hand and is connected to a laptop computer.
Measured: 1 day
Group differences in gut function as reported by "The Gastrointestinal Symptom Rating Scale"
self-administered questionnaire regarding gut function and associated symptoms
Measured: 1 day
Group differences in physical activity as reported by "International Physical Activity Questionnaire"
self-administered questionnaire regarding physical activity
Measured: 1 day
COPD Assessment Test
self-administered questionnaire regarding impact of COPD on daily life
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Oct 2017
- Study start19 Apr 2017
- Primary completion14 Feb 2019
- Study completion14 Feb 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Chronic Obstructive Pulmonary DiseaseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 63 participants (actual)
Sponsor and investigators
- Lead sponsor
- Texas A&M University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Marielle PKJ Engelen, PhD, Texas A&M University
- Investigators
- Marielle Engelen, PhD, Principal investigator, Texas A&M University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03327181
- Sponsor's protocol ID
- 2017-0112
- Acronym
- SCFA
- Status last verified
- Sep 2025
- First submitted
- 10 Oct 2017
- Last updated
- 30 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Huttl VN, Deutz N, Wierzchowska-McNew RA, Ruebush LE, Engelen M. Whole-body and intracellular arginine metabolism in hypertension: role of disease severity and sex. Am J Hypertens. 2026 May 18:hpag047. doi: 10.1093/ajh/hpag047. Online ahead of print.
PubMed 42149813Kang MC, Deutz NEP, Kirschner SK, Engelen MPKJ. Metabolic kinetics and muscle and brain health markers in older adults, and the role of age and presence of chronic morbidities: A large cross-sectional cohort study. Clin Nutr. 2024 Dec;43(12):36-47. doi: 10.1016/j.clnu.2024.10.015. Epub 2024 Oct 11.
PubMed 39423760Engelen MPKJ, Kirschner SK, Coyle KS, Argyelan D, Neal G, Dasarathy S, Deutz NEP. Sex related differences in muscle health and metabolism in chronic obstructive pulmonary disease. Clin Nutr. 2023 Sep;42(9):1737-1746. doi: 10.1016/j.clnu.2023.06.031. Epub 2023 Jul 26.
PubMed 37542951
Study at a glance
From the registry record, last updated by the sponsor on 30 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Short-chain Fatty Acid Metabolism in Chronic Obstructive Pulmonary Disease
- ClinicalTrials.gov ID
- NCT03327181
- Acronym / sponsor ID
- SCFA / 2017-0112
- Conditions
- Chronic Obstructive Pulmonary Disease
- Keywords
- short chain fatty acid metabolism
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 63 participants (actual)
- Lead sponsor
- Texas A&M UniversityUniversity, hospital or other
- Study start
- 19 Apr 2017 (actual)
- Primary completion
- 14 Feb 2019 (actual)
- Study completion
- 14 Feb 2019 (actual)
- First posted
- 31 Oct 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The short chain fatty acid (SCFA) metabolism has not been studied in subjects suffering from COPD. The purpose of this study is to compare the SCFA metabolism in COPD patients to healthy matched controls. This protocol is an extension of recent studies about protein digestion and absorption abnormalities in COPD patients. The investigators hypothesize that SCFA production might be lower in COPD patients than in healthy subjects.
Detailed description
Short-chain fatty acids (SCFAs) are straight or branched-chain fatty acids produced by the intestinal microbiota mainly through fermentation of undigested carbohydrates, but also through degradation of dietary and endogenous proteins. With a share of 90 to 95 %, acetate (C2), propionate (C3), and butyrate (C4) are the most common SCFAs in the colon (3). The molar ratios of acetate to propionate to butyrate are on average approximately 60:20:20 throughout the whole colon. Several human studies tried to determine the in situ production of SCFAs by measuring their content in feces (5-8). But fecal SCFA concentrations do not accurately represent the concentrations in more proximal regions of the colon, because colonocytes absorb more than 95 % of SCFAs to use them as an energy source. Further, the measurement of plasma SCFA concentrations is inaccurate because SCFA plasma levels are low due to high metabolism in colonocytes and liver. Thus, stable isotope studies are needed to examine the colonic production and metabolic fate of SCFAs in healthy and diseased subjects.
SCFAs seem to have anti-inflammatory and immune modulating effects. In COPD an enhanced pulmonary inflammatory response causes a combination of small airways disease (e.g., obstructive bronchiolitis) and/or a destruction of lung parenchyma (emphysema). This leads to a progressive and persistent airflow limitation. Smoking and the exposure to polluted air are main risk factors causing COPD. In a mouse model, a diet rich in whey proteins attenuated emphysema through the suppression of respiratory inflammation. This might have been related to a high colonic SCFA concentration due to the diet. Young et al. proposed that in smokers SCFAs might mitigate both the innate-mediated systemic inflammation controlled by the liver and the inflammatory responses in the lung.
Moreover, Nielsen et al. found that gastrointestinal diseases are significantly more prevalent in COPD patients (15 %) than in patients with other diseases (9%). This might have an influence on the SCFA production in the colon. Gastrointestinal problems may also be assessed through the usage of validated questionnaires.
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| COPD | Experimental | Dietary Supplement: short chain fatty acid tracersThe subject will arrive fasted. A catheter will be inserted in the arm for stable tracer SCFA infusion and blood sampling. The hand of the arm used for blood sampling will be placed in a thermostatically controlled warmed box that heats the air. Immediately after a baseline blood sample is taken, an infusion with stable tracers will be administered by the research nurse. Stable tracers are given to measure SCFA metabolism. Blood samples will be collected before and/or after infusion. Subjects will be asked to complete a list of questions regarding quality of life, mood and depression, diet, and a variety of functional measurements. |
| Healthy older adults | Active comparator | Dietary Supplement: short chain fatty acid tracersThe subject will arrive fasted. A catheter will be inserted in the arm for stable tracer SCFA infusion and blood sampling. The hand of the arm used for blood sampling will be placed in a thermostatically controlled warmed box that heats the air. Immediately after a baseline blood sample is taken, an infusion with stable tracers will be administered by the research nurse. Stable tracers are given to measure SCFA metabolism. Blood samples will be collected before and/or after infusion. Subjects will be asked to complete a list of questions regarding quality of life, mood and depression, diet, and a variety of functional measurements. |
Who may qualify
- Ages
- 45 to 100 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (13 listed)
- Ability to walk, sit down and stand up independently
- Age 45 years - 100 years
- Ability to lie in supine or elevated position for 1.5 hours
- Diagnosis of moderate to very severe chronic airflow limitation and compliant to the following criteria: FEV1 < 70% of reference FEV1
- Clinically stable condition and not suffering from a respiratory tract infection or exacerbation of their disease (defined as a combination of increased cough, sputum purulence, shortness of breath, systemic symptoms such as fever, and a decrease in FEV1 > 10% compared with values when clinically stable in the preceding year) at least 4 weeks prior to the first test day
Key exclusion criteria (14 listed)
- Any condition that may interfere with the definition 'healthy subject' according to the investigator's judgment (healthy subjects only)
- Subjects 86 years and older that fail to get physician eligibility confirmation
- Insulin dependent diabetes mellitus
- Established diagnosis of malignancy
- History of untreated metabolic diseases including hepatic or renal disorder
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| short chain fatty acid tracersstable tracer infusion of acetate, propionate, and butyrate | Dietary supplement | COPD, Healthy older adults |
Primary outcome
whole body short-chain fatty acid metabolism
Time frame: -10, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60 min
change in whole body scfa metabolism
12 secondary outcomes
Fat free mass measured using dual-energy x-ray absorptiometry
Time frame: 1 day
Fat mass measured using dual-energy x-ray absorptiometry
Time frame: 1 day
Bone density measured using dual-energy x-ray absorptiometry
Time frame: 1 day
handgrip strength dynamometry
Time frame: 1 day
Micro-respiratory pressure meter measurement
Time frame: 1 day
moving balance platform measurement
Time frame: 1 day
Group differences in attention and executive functions as measured by Trail Making Test (TMT),
Time frame: 1 day
Group differences in attention and executive functions as measured by Stroop Color-Word Test (SCWT),
Time frame: 1 day
Group differences in somatosensory functions as measured by vibrotactile behavioral battery
Time frame: 1 day
Group differences in gut function as reported by "The Gastrointestinal Symptom Rating Scale"
Time frame: 1 day
Group differences in physical activity as reported by "International Physical Activity Questionnaire"
Time frame: 1 day
COPD Assessment Test
Time frame: 1 day
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Sep 2025.
- Derived from this study: PubMed 42149813Huttl VN, Deutz N, Wierzchowska-McNew RA, Ruebush LE, Engelen M. Whole-body and intracellular arginine metabolism in hypertension: role of disease severity and sex. Am J Hypertens. 2026 May 18:hpag047. doi: 10.1093/ajh/hpag047. Online ahead of print.
- Derived from this study: PubMed 39423760Kang MC, Deutz NEP, Kirschner SK, Engelen MPKJ. Metabolic kinetics and muscle and brain health markers in older adults, and the role of age and presence of chronic morbidities: A large cross-sectional cohort study. Clin Nutr. 2024 Dec;43(12):36-47. doi: 10.1016/j.clnu.2024.10.015. Epub 2024 Oct 11.
- Derived from this study: PubMed 37542951Engelen MPKJ, Kirschner SK, Coyle KS, Argyelan D, Neal G, Dasarathy S, Deutz NEP. Sex related differences in muscle health and metabolism in chronic obstructive pulmonary disease. Clin Nutr. 2023 Sep;42(9):1737-1746. doi: 10.1016/j.clnu.2023.06.031. Epub 2023 Jul 26.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Marielle Engelen, PhD principal investigator
Texas A&M University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing short chain fatty acid tracers in people with Chronic Obstructive Pulmonary Disease, run by Texas A&M University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 13 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 30 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
whole body short-chain fatty acid metabolism (time frame: -10, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60 min). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03327181, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Sep 2025.