Knee OsteoarthritisPhase 2OA-INULINNCT07189585
Inulin Supplementation for Reducing Inflammation and Knee Pain in Older Adults With Osteoarthritis
A Phase 2 study testing inulin in people with Knee Osteoarthritis, run by Yale University at 1 site in United States.
Trial summary
This study will test whether inulin, a type of dietary fiber, can reduce inflammation in older adults with knee osteoarthritis. Inflammation in the body may contribute to both joint pain and the progression of osteoarthritis. Read more about this study
- Who is it for?
- Ages 40 years and older
- Conditions the study is for
- Knee Osteoarthritis
- What is being tested?
- inulin
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 84 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Nov 2026to 31 Jul 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
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 40 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Provision of signed and dated informed consent form.
- Stated willingness to comply with all study procedures and availability for the duration of the study (8 weeks).
- Male or female, aged ≥ 40 years.
- Established patient in the VA Connecticut Healthcare System
- At least one knee with pain severity in the past week ≥ 4/10 on numerical rating scale (NRS)
- Self-reported knee pain on most days of the prior month.
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- Diagnosed with knee osteoarthritis (Kellgren-Lawrence grade 2-4 on radiographic imaging within the past 2 years).
- Ability to take oral powder supplements and willingness to adhere to the inulin/placebo daily regimen.
- Agreement to adhere to lifestyle considerations (see Section 5.3) throughout study duration, including maintenance of current diet, physical activity, and avoidance of new dietary supplements or complementary therapies.
- English-speaking and able to provide informed consent.
- For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to continue such method during study participation.
Who cannot join
- Current diagnosis of pre-diabetes (impaired glucose tolerance) or diabetes mellitus (Type 1 or Type 2).
- Use of antibiotics within the past 6 months.
- Current use of medications known to significantly impact the gut microbiome (e.g., proton pump inhibitors, disease-modifying antirheumatic drugs, GLP-1 receptor agonists).
- Use of anti-inflammatory dietary supplements (e.g., turmeric, omega-3 fatty acids) within the past 30 days.
- Participation in another interventional study or use of an investigational drug within the past 30 days.
- Current use of complementary or integrative therapies for knee OA including tai chi, acupuncture or yoga.
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- Known allergy or intolerance to components of the study intervention, including inulin or maltodextrin.
- The presence of significant gastrointestinal disease that may interfere with the intervention or outcomes, such as inflammatory bowel disease or active peptic ulcer disease.
- Any medical, psychological, or behavioral condition that, in the opinion of the investigators, would place the participant at undue risk, interfere with study participation or adherence, or compromise data integrity.
- Current diagnosis of alcohol use disorder
- Pregnancy
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
VA Connecticut Healthcare System, West Haven Campus
West Haven, Connecticut, 06516
Evelyn Hsieh, MD, PhD, (203) 785-7092, evelyn.hsieh@yale.edu
About this study
Official title: Change in LPS With Inulin Supplementation and Its Association With Knee Pain Among Older Adults With Osteoarthritis
This study will test whether inulin, a type of dietary fiber, can reduce inflammation in older adults with knee osteoarthritis. Inflammation in the body may contribute to both joint pain and the progression of osteoarthritis. Inulin is a prebiotic fiber that may improve gut health and reduce lipopolysaccharide (LPS), a marker of bacterial products in the blood that is linked to inflammation.
In this trial, participants with knee osteoarthritis will be randomly assigned to receive either inulin or a placebo (maltodextrin) for 8 weeks. The study will measure changes in blood LPS levels, knee pain, and other markers of inflammation. The goal is to determine whether inulin supplementation can improve pain and reduce inflammation in people with knee osteoarthritis.
Read the detailed description
Knee osteoarthritis (OA) is a leading cause of pain and disability among older adults. Low-grade systemic inflammation has been implicated in OA pathogenesis, and bacterial products such as lipopolysaccharide (LPS) translocated from the gut microbiome may contribute to joint inflammation. Inulin-type fructans are non-digestible carbohydrates classified as prebiotic fibers. By modulating the gut microbiome, inulin has been shown to promote the growth of beneficial bacteria and to increase short-chain fatty acid (SCFA) production, which may help reduce systemic LPS levels and inflammation.
This is a single-center, randomized, double-blind, placebo-controlled clinical trial of participants aged 40 years or older with radiographically confirmed knee OA and significant knee pain. Participants will be randomized in a 1:1:1 ratio to receive 10 g/day inulin, 15 g/day inulin, or placebo (maltodextrin) for 8 weeks. The primary outcome is change in serum LPS from baseline to 8 weeks in the combined inulin groups compared to placebo.
The study hypothesis is that inulin supplementation will reduce circulating LPS and improve knee pain outcomes, supporting the role of gut microbiome modulation in the management of OA-related inflammation.
- Conditions
- Knee Osteoarthritis
- Being tested
- inulin, Maltodextrin (Placebo)
- Keywords
- Inulin, Prebiotic, Lipopolysaccharide, Inflammation, Knee pain, Older adults
- Medical subject headings
- Osteoarthritis, Knee, Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
inulinDrug
Also called Orafti® Inulin, BENEO-Orafti
Inulin is a fermentable prebiotic fiber derived from chicory root. For this study, inulin is packaged into single-dose sachets containing 5 g, 10 g, or 15 g of powder. Participants in the 10 g arm escalate from 5 g/day for 3 days to 10 g/day, then continue with sachets containing a 2:1 blend of inulin and maltodextrin to provide a daily 10 g inulin dose. Participants in the 15 g arm escalate from 5 g/day for 3 days, 10 g/day for 4 days, then 15 g/day for the remaining 8 weeks. Sachets are mixed with food or beverage and taken once daily with the largest meal.
Maltodextrin (Placebo)Drug
Also called Placebo
Maltodextrin is a carbohydrate powder widely used as a food additive. For this study, maltodextrin is used as the placebo comparator. It is packaged into single-dose sachets identical in appearance and taste to inulin sachets. Participants receive escalating doses (5 g/day for 3 days, 10 g/day for 4 days, then 15 g/day) for a total of 8 weeks. Sachets are mixed with food or beverage and taken once daily with the largest meal.
| Study group | Role | What they receive |
|---|---|---|
| Placebo (Maltodextrin) | Placebo comparator | Participants receive maltodextrin powder in identical sachets. Dose is escalated over 2 weeks to match the dosing schedule of the inulin arms (5 g daily for 3 days, 10 g daily for 4 days, then 15 g daily). Sachets are mixed with food or beverage and taken once daily with the largest meal, for 8 weeks. Receives: Drug: Maltodextrin (Placebo) |
| Inulin 10 g/day | Experimental | Participants receive inulin powder in identical sachets. Dose is escalated to 10 g daily (5 g daily for 3 days, then 10 g daily for 4 days). After Week 2, participants continue with one 15 g sachet containing a 2:1 blend of inulin and maltodextrin, providing a daily dose of 10 g inulin. Sachets are mixed with food or beverage and taken once daily with the largest meal, for 8 weeks. Receives: Drug: inulin |
| Inulin 15 g/day | Experimental | Participants receive inulin powder in identical sachets. Dose is escalated to 15 g daily (5 g daily for 3 days, 10 g daily for 4 days, then 15 g daily). Sachets are mixed with food or beverage and taken once daily with the largest meal, for 8 weeks. Receives: Drug: inulin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in serum lipopolysaccharide (LPS) concentration from baseline to 8 weeks
Serum LPS levels will be measured at baseline and at 8 weeks to evaluate the effect of inulin supplementation compared to placebo.
Measured: Baseline and 8 weeks
Secondary outcomes (2)
Change in serum LPS concentration between 10 g and 15 g inulin groups
Dose-response effect of inulin supplementation on serum LPS levels.
Measured: Baseline and 8 weeks
Change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
Self-reported knee pain and function will be measured using the WOMAC scale. Higher scores indicate worse pain, stiffness, and functional limitations. Total possible score of 0-96.
Measured: Baseline and 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Sep 2025
- Study start1 Nov 2026 (estimated)
- Primary completion31 Jul 2027 (estimated)
- Study completion31 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Knee OsteoarthritisStudies of the same condition, open and under way.
- More trials run by Yale UniversityThe sponsor's other registered studies.
- 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants are randomized in a 1:1:1 ratio to placebo, 10 g/day inulin, or 15 g/day inulin for 8 weeks.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 84 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yale University
- Sponsor type
- University, hospital or other
- Collaborators
- VA Connecticut Healthcare System, National Center for Complementary and Integrative Health (NCCIH)
- Responsible party
- Principal investigator, Evelyn Hsieh Donroe, Yale University
- Investigators
- Evelyn Hsieh, MD, PhD, Principal investigator, Yale University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07189585
- Sponsor's protocol ID
- 2000040523
- Other IDs
- 174626, 1R61AT013472-01
- Acronym
- OA-INULIN
- Status last verified
- Jul 2026
- First submitted
- 16 Sep 2025
- Last updated
- 7 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared because the study is conducted within the Veterans Affaire system, which prohibits release of participant-level data outside of the VA firewall. However, de-identified aggregate group-level data, study protocol, data collection instruments, and analytic code will be made available to qualified researchers upon request in accordance with NIH Data Management and Sharing policy.
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Change in LPS With Inulin Supplementation and Its Association With Knee Pain Among Older Adults With Osteoarthritis
- ClinicalTrials.gov ID
- NCT07189585
- Acronym / sponsor ID
- OA-INULIN / 2000040523
- Conditions
- Knee Osteoarthritis
- Keywords
- Inulin, Prebiotic, Lipopolysaccharide, Inflammation, Knee pain, Older adults
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 84 participants (estimated)
- Lead sponsor
- Yale UniversityUniversity, hospital or other
- Collaborators
- VA Connecticut Healthcare System, National Center for Complementary and Integrative Health (NCCIH)
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 31 Jul 2027 (estimated)
- Study completion
- 31 Jul 2027 (estimated)
- First posted
- 24 Sep 2025 (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.
This study will test whether inulin, a type of dietary fiber, can reduce inflammation in older adults with knee osteoarthritis. Inflammation in the body may contribute to both joint pain and the progression of osteoarthritis. Inulin is a prebiotic fiber that may improve gut health and reduce lipopolysaccharide (LPS), a marker of bacterial products in the blood that is linked to inflammation.
In this trial, participants with knee osteoarthritis will be randomly assigned to receive either inulin or a placebo (maltodextrin) for 8 weeks. The study will measure changes in blood LPS levels, knee pain, and other markers of inflammation. The goal is to determine whether inulin supplementation can improve pain and reduce inflammation in people with knee osteoarthritis.
Detailed description
Knee osteoarthritis (OA) is a leading cause of pain and disability among older adults. Low-grade systemic inflammation has been implicated in OA pathogenesis, and bacterial products such as lipopolysaccharide (LPS) translocated from the gut microbiome may contribute to joint inflammation. Inulin-type fructans are non-digestible carbohydrates classified as prebiotic fibers. By modulating the gut microbiome, inulin has been shown to promote the growth of beneficial bacteria and to increase short-chain fatty acid (SCFA) production, which may help reduce systemic LPS levels and inflammation.
This is a single-center, randomized, double-blind, placebo-controlled clinical trial of participants aged 40 years or older with radiographically confirmed knee OA and significant knee pain. Participants will be randomized in a 1:1:1 ratio to receive 10 g/day inulin, 15 g/day inulin, or placebo (maltodextrin) for 8 weeks. The primary outcome is change in serum LPS from baseline to 8 weeks in the combined inulin groups compared to placebo.
The study hypothesis is that inulin supplementation will reduce circulating LPS and improve knee pain outcomes, supporting the role of gut microbiome modulation in the management of OA-related inflammation.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
- Model description
- Participants are randomized in a 1:1:1 ratio to placebo, 10 g/day inulin, or 15 g/day inulin for 8 weeks.
| Arm | Type | Receives |
|---|---|---|
| Placebo (Maltodextrin) | Placebo comparator | Drug: Maltodextrin (Placebo)Participants receive maltodextrin powder in identical sachets. Dose is escalated over 2 weeks to match the dosing schedule of the inulin arms (5 g daily for 3 days, 10 g daily for 4 days, then 15 g daily). Sachets are mixed with food or beverage and taken once daily with the largest meal, for 8 weeks. |
| Inulin 10 g/day | Experimental | Drug: inulinParticipants receive inulin powder in identical sachets. Dose is escalated to 10 g daily (5 g daily for 3 days, then 10 g daily for 4 days). After Week 2, participants continue with one 15 g sachet containing a 2:1 blend of inulin and maltodextrin, providing a daily dose of 10 g inulin. Sachets are mixed with food or beverage and taken once daily with the largest meal, for 8 weeks. |
| Inulin 15 g/day | Experimental | Drug: inulinParticipants receive inulin powder in identical sachets. Dose is escalated to 15 g daily (5 g daily for 3 days, 10 g daily for 4 days, then 15 g daily). Sachets are mixed with food or beverage and taken once daily with the largest meal, for 8 weeks. |
Who may qualify
- Ages
- 40 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (11 listed)
- Provision of signed and dated informed consent form.
- Stated willingness to comply with all study procedures and availability for the duration of the study (8 weeks).
- Male or female, aged ≥ 40 years.
- Established patient in the VA Connecticut Healthcare System
- At least one knee with pain severity in the past week ≥ 4/10 on numerical rating scale (NRS)
Key exclusion criteria (11 listed)
- Current diagnosis of pre-diabetes (impaired glucose tolerance) or diabetes mellitus (Type 1 or Type 2).
- Use of antibiotics within the past 6 months.
- Current use of medications known to significantly impact the gut microbiome (e.g., proton pump inhibitors, disease-modifying antirheumatic drugs, GLP-1 receptor agonists).
- Use of anti-inflammatory dietary supplements (e.g., turmeric, omega-3 fatty acids) within the past 30 days.
- Participation in another interventional study or use of an investigational drug within the past 30 days.
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 |
|---|---|---|
| inulinAlso: Orafti® Inulin, BENEO-OraftiInulin is a fermentable prebiotic fiber derived from chicory root. For this study, inulin is packaged into single-dose sachets containing 5 g, 10 g, or 15 g of powder. Participants in the 10 g arm escalate from 5 g/day for 3 days to 10 g/day, then continue with sachets containing a 2:1 blend of inulin and maltodextrin to provide a daily 10 g inulin dose. Participants in the 15 g arm escalate from 5 g/day for 3 days, 10 g/day for 4 days, then 15 g/day for the remaining 8 weeks. Sachets are mixed with food or beverage and taken once daily with the largest meal. | Drug | Inulin 10 g/day, Inulin 15 g/day |
| Maltodextrin (Placebo)Also: PlaceboMaltodextrin is a carbohydrate powder widely used as a food additive. For this study, maltodextrin is used as the placebo comparator. It is packaged into single-dose sachets identical in appearance and taste to inulin sachets. Participants receive escalating doses (5 g/day for 3 days, 10 g/day for 4 days, then 15 g/day) for a total of 8 weeks. Sachets are mixed with food or beverage and taken once daily with the largest meal. | Drug | Placebo (Maltodextrin) |
Primary outcome
Change in serum lipopolysaccharide (LPS) concentration from baseline to 8 weeks
Time frame: Baseline and 8 weeks
Serum LPS levels will be measured at baseline and at 8 weeks to evaluate the effect of inulin supplementation compared to placebo.
2 secondary outcomes
Change in serum LPS concentration between 10 g and 15 g inulin groups
Time frame: Baseline and 8 weeks
Change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
Time frame: Baseline and 8 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared because the study is conducted within the Veterans Affaire system, which prohibits release of participant-level data outside of the VA firewall. However, de-identified aggregate group-level data, study protocol, data collection instruments, and analytic code will be made available to qualified researchers upon request in accordance with NIH Data Management and Sharing policy.
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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.
Evelyn Hsieh, MD, PhD principal investigator
Yale University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing inulin in people with Knee Osteoarthritis, run by Yale 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 11 inclusion and 11 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: opening soon, as of the sponsor's last update on 7 Jul 2026. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Evelyn Hsieh, MD, PhD ((203) 785-7092, evelyn.hsieh@yale.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in serum lipopolysaccharide (LPS) concentration from baseline to 8 weeks (time frame: Baseline and 8 weeks). 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 7 Jul 2026.