Effect of Colon Delivered Vitamin C on Gut Microbiota and Related Health Biomarkers in Healthy Older Adults

September 6, 2023 updated by: DSM Nutritional Products, Inc.
Recent studies have shown that many vitamins, if consumed in high daily dosages or delivered to the colon, can modulate the gut microbiota and their metabolites. In parallel, gut microbiota imbalances are linked to diseases, e.g., obesity, type 2 diabetes, cardiovascular disease, autoimmune diseases, and intestinal inflammatory diseases. Therefore, vitamin administration could offer health benefits beyond those traditionally considered for these nutrients. Earlier, our group investigated the effect of colon-delivered vitamins A, B2, C, D, and E on the gut microbiota using a human clinical trial and showed that vitamin C, B2, and D modulates the human gut microbiome in terms of metabolic activity and bacterial composition. The most distinct effect was that of vitamin C, which significantly increased microbial alpha diversity and fecal short-chain fatty acids compared to the placebo. However, the dose-dependent and combined effect of colon-delivered vitamins on the microbial community and its subsequent impact on host health is unknown. This study will investigate the effect of colon-delivered vitamin C (three dosages) on the gut microbiome.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

264

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Participants must be willing and able to give written informed consent and to understand, to participate, and to comply with the clinical study requirements.
  2. Between 50 and 70 years of age.
  3. Has a BMI of between 18.5 - 30 Kg/m2.
  4. Participants have had a stable body weight (≤5 % change) over the past 3-months.
  5. Is in general good health, as determined by interview and vital signs (blood pressure, heart rate, pulse) by the investigator.
  6. Willing to avoid consuming gut microbiome modulating dietary supplements, prebiotic, probiotic, or fibre-rich supplements, and, within 4 weeks prior to the baseline visit, until the end of the study.
  7. Maintain current level of physical activity.
  8. Willing to consume the investigational product daily for the duration of the study.
  9. Female participants in menopause for at least the last one year.

Exclusion Criteria:

  1. Are hypersensitive to any of the components of the test product.
  2. Has taken antibiotics within the previous 3 months prior to Baseline (Visit 2).
  3. Is currently using systemic steroids, systemic antibiotics, proton pump inhibitors, H2 blocker, antacid, metformin, or immunosuppressant medication.
  4. Participant has a history of drug and/or alcohol abuse at the time of enrolment (Drinks more than nationally recommended units per week (>11 units for women; >17 units for men); Is currently in treatment for alcohol/substance abuse; Has been diagnosed with alcohol/substance abuse disorder).
  5. Is a smoker or vaper.
  6. Vegetarian or vegan.
  7. Has made any major dietary changes in the past 3 months prior to Baseline (Visit 2).
  8. Planned major changes in the lifestyle (i.e., diet, dieting, exercise level, significant travel) during the duration of the study.
  9. Has a currently active eating disorder.
  10. Has food allergies or other issues with foods that would preclude the intake of the study products, as determined by the study investigator.
  11. Is having a typical fibre intake >30 g fibre/day.
  12. Has an active gastrointestinal disorder or previous gastrointestinal surgery, which in the opinion of the investigator would impact the study outcomes.
  13. If taking chronic medications (e.g., anti-hypertensive medications), they must have been taking the product for at least two months to screening and agree to maintain the same dosage throughout the study.
  14. Has severe or uncontrolled type 2 diabetes, psychiatric disorder, gastrointestinal disease (i.e., diarrhoea, Crohn's disease, ulcerative colitis, IBS, diverticulosis, stomach or duodenal ulcers respiratory or cardiac illness or any other condition which in the opinion of the investigator would impact the study outcomes.
  15. Has a current or history of any gastrointestinal cancer
  16. Are severely immunocompromised (HIV positive, transplant patient, on anti-rejection medications, on a steroid for >30 days, or chemotherapy or radiotherapy with the last year).
  17. Experiences alarm features such as weight loss, rectal bleeding, a recent change in bowel habit (<3 months).
  18. Have a current malignant disease or any concomitant end-stage organ disease.
  19. Individuals who, in the opinion of the investigator are considered to be poor attendees or unlikely for any reason to be able to comply with the trial.
  20. Participants may not be receiving treatment involving experimental drugs. If the participant has been in a recent experimental trial, these must have been completed not less than 60 days prior to this study.
  21. Participants who have undergone intensive skin treatments (e.g. laser treatment or skin related surgery) in the last 3 months.
  22. If taking any dietary supplements or medications known to affect skin health or other trial measures (resveratrol, ginkgo biloba, ginseng, fruit powder extracts and DHA).

  23. Has a skin condition likely to interfere with skin assessments (e.g., eczema, dermatitis, any open skin wounds, reactive and sensitive skin).

    -

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Low dose
Daily dose of 80 mg Vitamin C (Ascorbic acid) once a day for 12 weeks
Dietary supplement: Vitamin C
Colon delivered vitamin C (ascorbic acid) for 12 weeks
Other Names:
  • Ascorbic acid
Experimental: Mid dose
Daily dose of 200 mg Vitamin C (Ascorbic acid) once a day for 12 weeks
Dietary supplement: Vitamin C
Colon delivered vitamin C (ascorbic acid) for 12 weeks
Other Names:
  • Ascorbic acid
Experimental: High dose
Daily dose of 500 mg Vitamin C (Ascorbic acid) once a day for 12 weeks
Dietary supplement: Vitamin C
Colon delivered vitamin C (ascorbic acid) for 12 weeks
Other Names:
  • Ascorbic acid
Placebo Comparator: Placebo
One capsule of 570 mg (consisting microcrystalline cellulose) once a day for 12 weeks
Other: placebo
Colon delivered placebo once a day for 12 weeks
Other Names:
  • Microcrystalline cellulose

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Microbial metabolites measured as short-chain fatty acid content in faeces, at baseline and at week 12.
Time Frame: from baseline to 12 weeks
To assess the changes of microbial metabolites from baseline to 12 weeks supplementation of three different doses of colon delivered vitamin C to compare the changes to placebo.
from baseline to 12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Faecal microbial composition and diversity
Time Frame: from baseline to 12 weeks
Faecal microbial composition at phylum, genus, and species levels, and alpha and beta diversity indices at the genus and species level as measured by metagenomic based profiles at baseline and at week 12.
from baseline to 12 weeks
Intestinal inflammation
Time Frame: from baseline to 12 weeks
Intestinal inflammation as assessed by faecal calprotectin at baseline and at week 12.
from baseline to 12 weeks
Intestinal barrier integrity
Time Frame: from baseline to 12 weeks
Intestinal barrier integrity as assessed by sCD14 at baseline and at week 12.
from baseline to 12 weeks
Oxidative stress in blood
Time Frame: from baseline to 12 weeks
Oxidative stress level measured as free thiol content in blood at baseline and at week 12.
from baseline to 12 weeks
Inflammatory status in blood
Time Frame: from baseline to 12 weeks
Systemic inflammation measured as high sensitive C reactive protein (hs-CRP) in blood at baseline and at week 12.
from baseline to 12 weeks
Gastrointestinal symptoms and quality of life
Time Frame: from baseline to 12 weeks
Gastrointestinal symptoms and quality of life as assessed by Gastrointestinal Symptom Rating Scale (GSRS) and short form survey-36 (SF-36) questionnaires at baseline and at week 12.
from baseline to 12 weeks
Stool consistency
Time Frame: from baseline to 12 weeks
Stool consistency (Bristol Stool Scale), as reported in the daily eDiary app (at baseline and week 12).
from baseline to 12 weeks
Stool frequency
Time Frame: from baseline to 12 weeks
Stool frequency, as reported in the daily eDiary app (at baseline and week 12).
from baseline to 12 weeks
Systemic vitamin status
Time Frame: from baseline to 12 weeks
The concentration of vitamin C in blood at baseline and at week 12.
from baseline to 12 weeks
Faecal pH
Time Frame: from baseline to 12 weeks
Faecal pH at baseline and at week 12.
from baseline to 12 weeks
Faecal microbial composition and diversity
Time Frame: from baseline to 4 weeks
Faecal microbial composition at phylum, genus, and species levels, and alpha and beta diversity indices at the genus and species level as measured by metagenomic based profiles at baseline and at week 4.
from baseline to 4 weeks
Microbial metabolites
Time Frame: from baseline to 4 weeks
Faecal microbial metabolites measured as short-chain fatty acid content at baseline and week 4.
from baseline to 4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

DSM Nutritional Products, Inc.

Collaborators

Atlantia Food Clinical Trials

Investigators

  • Principal Investigator: Prof Timothy Dinan, Cork University Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 1, 2022

Primary Completion (Estimated)

November 30, 2023

Study Completion (Estimated)

June 30, 2024

Study Registration Dates

First Submitted

October 25, 2022

First Submitted That Met QC Criteria

October 27, 2022

First Posted (Actual)

October 28, 2022

Study Record Updates

Last Update Posted (Actual)

September 7, 2023

Last Update Submitted That Met QC Criteria

September 6, 2023

Last Verified

September 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 020-11-11-VITC

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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