SarcopeniaNCT05549622
Impact of Diet on the Gut-Muscle Axis in Older Adults
A study testing Low-soluble fiber diet and High-soluble fiber diet in people with Sarcopenia and Dietary Exposure, run by Tufts University at 1 site in United States.
Trial summary
Muscle health declines during aging. One factor that may impact muscle health is the community of bacteria that live in our intestines, but studies aimed at improving muscle health by targeting the gut in older adults are sparse. Read more about this study
- Who is it for?
- Ages 65 years and olderHealthy volunteers can take part
- Conditions the study is for
- Sarcopenia, Dietary Exposure, Microbial Colonization
- What is being tested?
- Low-soluble fiber diet and High-soluble fiber diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 31 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Mar 2023to 30 Apr 2025
- 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 65 years and older
- All sexes
- Healthy volunteers accepted
- Older adult
Who may be able to join
- Independently living older adults (> 65y)
- Sedentary (Godin-Shepard Leisure Time Physical Activity Questionnaire score < 10)
- Non-smoking
- Not already consuming a high-fiber diet (> 22, 28 g/day for women, men)
- Free of gastrointestinal disease (gastrointestinal cancer, inflammatory bowel disease, bariatric surgery, irritable bowel syndrome)
- Fluent in English
Show all 12Show fewer
- Willing to attend three study visits (enrollment, baseline, and week-13)
- Willing to consume an abundance of fruits, vegetables, nuts/seeds
- Willing to consume an abundance of soluble fiber-rich foods (broccoli, brussels sprouts, flaxseeds sweetened with dates, lima beans, butternut squash, carrots, collard greens)
- Willing to tolerate mild gastrointestinal discomfort (bloating, belly grumbling, flatulence). Note that all attempts will be made to replace foods that may trigger these issues.
- Willing to not consume antibiotics during the 13-week study
- Willing to not schedule a colonoscopy during the 13-week study
Who cannot join
- Unwilling to visit the Tufts Human Nutrition Research Center on Aging (HNRCA) 3x/week to pick up the pre-prepared study diet
- Unwilling to only consume the provided food (unsweetened tea and/or black coffee are allowed)
- Food allergies related to foods that are included in the study
- Chewing problems
- Unwilling to wear a daily step counter (pedometer)
- Unwilling to complete a daily questionnaire that will assess gastrointestinal comfort
Show all 22Show fewer
- Malnutrition (BMI < 18.5 kg/m2)
- Use of supplemental probiotics or antibiotics, participation in an investigational drug evaluation, or a recent change in habitual medication use within the 1 month-period prior to the screening visit
- > 5% weight loss or weight gain within the past 6-months
- A recent history of alcohol abuse (within the past 5 years)
- A history of any significant injury or surgery that currently affects physical functioning and ability to perform physical function testing
- Treatment with immunosuppressive drugs
- A prior diagnosis of organ failure (heart, liver, renal, respiratory)
- Diabetes mellitus (type 1, or type 2 with insulin therapy)
- Chronic kidney disease (eGFR ≤ 30 mL/min/1.73 m2)
- Overt disease (cancer, dementia, cardiovascular disease)
- Chronic use of anti-inflammatory medication (corticosteroids)
- Already enrolled in another research study
- Active infection, including Tuberculosis , HIV, malaria, hepatitis, shingles, Methicillin-Resistant Staphylococcus Aureus (MRSA), SARS-CoV-2
- Any major illness or condition that may interfere with study outcomes at the discretion of the study physician
- Won't remain in Boston for the 13-week study duration
- Unwilling to complete a daily checklist aimed at quantifying the amount of food eaten on the study diet
Trial locations and contacts
1 site in 1 country.
United States1 site
Jean Mayer Human Nutrition Research Center on Aging at Tufts University
Boston, Massachusetts, 02111
About this study
Official title: Impact of a High-Soluble Fiber Diet on the Gut-Muscle Axis in Older Adults
Muscle health declines during aging. One factor that may impact muscle health is the community of bacteria that live in our intestines, but studies aimed at improving muscle health by targeting the gut in older adults are sparse. The primary goal of this study is to use a diet that is enriched in soluble fiber, which is exclusively utilized by gut bacteria to make substances that can impact muscle health, to improve muscle-related measures in older adults.
Read the detailed description
During aging, skeletal muscle mass and physical function decrease, whereas levels of lipids and adipocytes increase within and between muscle cells, thereby worsening muscle composition. As a result of these age-related changes, older adults are at a higher risk for frailty, falls and fracture, disability and hospitalization, and all-cause mortality. Accordingly, elucidation of mechanisms that underlie muscle mass, muscle composition, and physical function, and interventions that positively affect these variables will be important for addressing the public health priority of an improved quality of life and healthy aging in older adults.
The gut microbiome and its metabolic products are involved in mechanisms that impact skeletal muscle mass, muscle composition, and physical function, which has been defined as the gut-muscle axis. For example, muscle mass and physical function are reduced in animals that do not have a microbiome (germ-free mice), and in antibiotic-treated mice, an intervention that reduces gut bacterial content. Investigating further, gut bacteria-derived metabolites affect muscle mass, muscle composition, and physical function in young and aged animals, including positive effects for the short-chain fatty acids (SCFAs) acetate, propionate, and butyrate, and negative effects for indoxyl sulfate (IS) and para-cresol sulfate (PCS). Similarly, phenol sulfate (PS) and phenylacetylglutamine (PAG) are gut microbiome-derived metabolites that were associated with poor muscle composition and worse physical function in studies of older adult humans that were published by our group. Interestingly, higher colonic levels of SCFAs are associated with a lower pH, an important finding because growth of Enterobacteriaceae, a bacterial family that contains genes involved in the production of IS, PCS, PS, and PAG, is limited in an acidic environment and following exposure to physiological levels of SCFAs. Taken together, these data suggest that interventions aimed at increasing bacterial SCFA production may be an important approach for improving muscle-related measures in older adults.
Soluble fiber fermentation by gut bacteria results in the formation of acetate, propionate, and butyrate, and fecal SCFAs proportionally increase, whereas circulating levels of IS and PCS are reduced in response to high-soluble fiber diets. As a proof of concept, fecal and circulating levels of SCFAs, muscle mass, and aerobic exercise capacity were increased in young mice that were fed a relatively higher soluble fiber diet, but few studies have attempted this approach in older adult humans. When considering that fecal levels of SCFAs decrease during aging, whereas plasma levels of IS, PCS, PS, and PAG increase, these data collectively suggest that a high-soluble fiber diet may be an important approach for improving muscle-related measures in older adults humans. To test this hypothesis, older adults will be randomized to consume a high- or low-soluble fiber diet for 12-weeks.
- Conditions
- Sarcopenia, Dietary Exposure, Microbial Colonization
- Being tested
- Low-soluble fiber diet, High-soluble fiber diet
- Keywords
- skeletal muscle, soluble fiber, gut-muscle axis, microbiome, SCFA, Uremic metabolites
- Medical subject headings
- Sarcopenia, Communicable Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low-soluble fiber dietOther
12 older adults (>65y) will be randomized to consume the USDA Guidelines for fiber intake (10g of total fiber/1000 calories), as the low-soluble fiber diet
High-soluble fiber dietOther
12 older adults (>65y) will be randomized to consume 34-35g of total fiber/1000 calories, as the high-soluble fiber diet
| Study group | Role | What they receive |
|---|---|---|
| Low-soluble fiber diet | Other | Not described Receives: Other: Low-soluble fiber diet |
| High-soluble fiber diet | Active comparator | Not described Receives: Other: High-soluble fiber diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Quantification of SCFAs in fecal samples
Fecal levels of bacterial metabolites, including acetate, propionate, and butyrate will be determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
Quantification of whole-body lean mass with DXA
Measurement of whole-body lean mass will be determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
Quantification of hand grip strength
Grip strength will be determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
Chair stand test
The number of chair stands that can be performed in 30 seconds will be determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
Secondary outcomes (5)
Quantification of thigh muscle composition with computed tomography
Determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
6-minute walk test
The distance walked in 6 minutes will be determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
Quantification of gut bacterial metabolites in plasma
Bacterial metabolites, including SCFAs but also indoxyl sulfate, p-cresol sulfate, phenol sulfate, and phenylacetylglutamine will be determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
Quantification of gut bacterial composition in fecal samples
Determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
Quantification of pH in fecal samples
Determined at the baseline and week-13 study visits
Measured: Change from baseline when compared with the Week-13 visit
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Sep 2022
- Study start1 Mar 2023
- Primary completion30 Apr 2025
- Study completion30 Apr 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SarcopeniaStudies 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- 24 older adults (\> 65y) will be randomized to consume a high- or low-soluble fiber diet
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 31 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tufts University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jennifer Lee, Tufts University
- Investigators
- Michael S Lustgarten, PhD, Study director, Scientist II, NEPS Laboratory
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05549622
- Sponsor's protocol ID
- GRANT13386865
- Status last verified
- Aug 2024
- First submitted
- 24 Aug 2022
- Last updated
- 18 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No data from participants will be shared with researchers not affiliated with this project.
Study at a glance
From the registry record, last updated by the sponsor on 18 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of a High-Soluble Fiber Diet on the Gut-Muscle Axis in Older Adults
- ClinicalTrials.gov ID
- NCT05549622
- Acronym / sponsor ID
- GRANT13386865
- Conditions
- Sarcopenia, Dietary Exposure, Microbial Colonization
- Keywords
- skeletal muscle, soluble fiber, gut-muscle axis, microbiome, SCFA, Uremic metabolites
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 31 participants (actual)
- Lead sponsor
- Tufts UniversityUniversity, hospital or other
- Study start
- 1 Mar 2023 (actual)
- Primary completion
- 30 Apr 2025 (actual)
- Study completion
- 30 Apr 2025 (actual)
- First posted
- 22 Sep 2022 (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.
Muscle health declines during aging. One factor that may impact muscle health is the community of bacteria that live in our intestines, but studies aimed at improving muscle health by targeting the gut in older adults are sparse. The primary goal of this study is to use a diet that is enriched in soluble fiber, which is exclusively utilized by gut bacteria to make substances that can impact muscle health, to improve muscle-related measures in older adults.
Detailed description
During aging, skeletal muscle mass and physical function decrease, whereas levels of lipids and adipocytes increase within and between muscle cells, thereby worsening muscle composition. As a result of these age-related changes, older adults are at a higher risk for frailty, falls and fracture, disability and hospitalization, and all-cause mortality. Accordingly, elucidation of mechanisms that underlie muscle mass, muscle composition, and physical function, and interventions that positively affect these variables will be important for addressing the public health priority of an improved quality of life and healthy aging in older adults.
The gut microbiome and its metabolic products are involved in mechanisms that impact skeletal muscle mass, muscle composition, and physical function, which has been defined as the gut-muscle axis. For example, muscle mass and physical function are reduced in animals that do not have a microbiome (germ-free mice), and in antibiotic-treated mice, an intervention that reduces gut bacterial content. Investigating further, gut bacteria-derived metabolites affect muscle mass, muscle composition, and physical function in young and aged animals, including positive effects for the short-chain fatty acids (SCFAs) acetate, propionate, and butyrate, and negative effects for indoxyl sulfate (IS) and para-cresol sulfate (PCS). Similarly, phenol sulfate (PS) and phenylacetylglutamine (PAG) are gut microbiome-derived metabolites that were associated with poor muscle composition and worse physical function in studies of older adult humans that were published by our group. Interestingly, higher colonic levels of SCFAs are associated with a lower pH, an important finding because growth of Enterobacteriaceae, a bacterial family that contains genes involved in the production of IS, PCS, PS, and PAG, is limited in an acidic environment and following exposure to physiological levels of SCFAs. Taken together, these data suggest that interventions aimed at increasing bacterial SCFA production may be an important approach for improving muscle-related measures in older adults.
Soluble fiber fermentation by gut bacteria results in the formation of acetate, propionate, and butyrate, and fecal SCFAs proportionally increase, whereas circulating levels of IS and PCS are reduced in response to high-soluble fiber diets. As a proof of concept, fecal and circulating levels of SCFAs, muscle mass, and aerobic exercise capacity were increased in young mice that were fed a relatively higher soluble fiber diet, but few studies have attempted this approach in older adult humans. When considering that fecal levels of SCFAs decrease during aging, whereas plasma levels of IS, PCS, PS, and PAG increase, these data collectively suggest that a high-soluble fiber diet may be an important approach for improving muscle-related measures in older adults humans. To test this hypothesis, older adults will be randomized to consume a high- or low-soluble fiber diet for 12-weeks.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- 24 older adults (> 65y) will be randomized to consume a high- or low-soluble fiber diet
| Arm | Type | Receives |
|---|---|---|
| Low-soluble fiber diet | Other | Other: Low-soluble fiber diet |
| High-soluble fiber diet | Active comparator | Other: High-soluble fiber diet |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Older adult
Key inclusion criteria (12 listed)
- Independently living older adults (> 65y)
- Sedentary (Godin-Shepard Leisure Time Physical Activity Questionnaire score < 10)
- Non-smoking
- Not already consuming a high-fiber diet (> 22, 28 g/day for women, men)
- Free of gastrointestinal disease (gastrointestinal cancer, inflammatory bowel disease, bariatric surgery, irritable bowel syndrome)
Key exclusion criteria (22 listed)
- Unwilling to visit the Tufts Human Nutrition Research Center on Aging (HNRCA) 3x/week to pick up the pre-prepared study diet
- Unwilling to only consume the provided food (unsweetened tea and/or black coffee are allowed)
- Food allergies related to foods that are included in the study
- Chewing problems
- Unwilling to wear a daily step counter (pedometer)
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 |
|---|---|---|
| Low-soluble fiber diet12 older adults (>65y) will be randomized to consume the USDA Guidelines for fiber intake (10g of total fiber/1000 calories), as the low-soluble fiber diet | Other | Low-soluble fiber diet |
| High-soluble fiber diet12 older adults (>65y) will be randomized to consume 34-35g of total fiber/1000 calories, as the high-soluble fiber diet | Other | High-soluble fiber diet |
Primary outcome
Quantification of SCFAs in fecal samples
Time frame: Change from baseline when compared with the Week-13 visit
Fecal levels of bacterial metabolites, including acetate, propionate, and butyrate will be determined at the baseline and week-13 study visits
Quantification of whole-body lean mass with DXA
Time frame: Change from baseline when compared with the Week-13 visit
Measurement of whole-body lean mass will be determined at the baseline and week-13 study visits
Quantification of hand grip strength
Time frame: Change from baseline when compared with the Week-13 visit
Grip strength will be determined at the baseline and week-13 study visits
Chair stand test
Time frame: Change from baseline when compared with the Week-13 visit
The number of chair stands that can be performed in 30 seconds will be determined at the baseline and week-13 study visits
5 secondary outcomes
Quantification of thigh muscle composition with computed tomography
Time frame: Change from baseline when compared with the Week-13 visit
6-minute walk test
Time frame: Change from baseline when compared with the Week-13 visit
Quantification of gut bacterial metabolites in plasma
Time frame: Change from baseline when compared with the Week-13 visit
Quantification of gut bacterial composition in fecal samples
Time frame: Change from baseline when compared with the Week-13 visit
Quantification of pH in fecal samples
Time frame: Change from baseline when compared with the Week-13 visit
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 18 Jul 2025.
- Individual participant dataSharing planned: No. No data from participants will be shared with researchers not affiliated with this project.
Related trials for Sarcopenia
Enrolling by invitation
Online Exercise Program for Transplant Patients: A Pilot Study
Kidney Transplantation, Physical Function
Not yet recruitingPhase 2
A Study of Bimagrumab in Participants With HFpEF
Heart Failure, Diastolic, Diastolic Heart Failure
Not yet recruiting
The Aim of the Study is to Decipher the Alterations in Signalling Pathways of Skeletal Muscle Stem Cells (Satellite Cells (SCs)) in Individuals With COPD, as Well as to Examine the Effect of Exercise Training on SCs.
COPD (Chronic Obstructive Pulmonary Disease), Sarcopenia in Elderly
Not yet recruitingPhase 2
MF-300 for Treatment of Age-Related Sarcopenia
Sarcopenia in Elderly
Not yet recruitingObservational study
Validation of Uzbek SARC-F and IPAQ-SF Questionnaires in Adults With and Without Hypothyroidism
Hypothyroidism, Psychometrics
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.
Michael S Lustgarten, PhD study director
Scientist II, NEPS Laboratory
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low-soluble fiber diet and High-soluble fiber diet in people with Sarcopenia and Dietary Exposure, run by Tufts 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 12 inclusion and 22 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 18 Jul 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?
Quantification of SCFAs in fecal samples (time frame: Change from baseline when compared with the Week-13 visit). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 18 Jul 2025.