Probiotic Ingestion and Isoagglutinin Titers
Public ClinicalTrials.gov record NCT00891787. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Background: * Probiotics are oral food supplements containing live bacteria that may be beneficial to a person s digestion or general health. Probiotics are available as tablets, powder, or liquid supplements and are frequently used to supplement yogurt. They are available for purchase without prescription in most supermarkets. * The bacteria in probiotic supplements commonly express sugar substances on their surface. These sugar substances are similar to group A and B blood group sugars, called antigens. These antigens determine a person s blood group. Researchers are studying the effect of probiotic supplements on the amount of blood group antibodies that are present in a person s blood. Objectives: * To determine whether taking oral probiotic supplements increases anti-A and anti-B isoagglutinins (antibodies that cause red blood cells to clump together) in healthy subjects. * To study the frequency of these effects and determine whether there is a dose-response relationship with probiotics and isoagglutinin titers. Eligibility: * Healthy adults, 18 years or older, with type A, B, or O blood. * Female participants need to have undergone menopause or have had a hysterectomy. * Individuals are ineligible if they currently donate platelets; have a history of ulcerative colitis or Crohn s disease; have had major bowel surgery; are pregnant or capable of becoming pregnant; have a bleeding or clotting disorder; have a history of a blood disorder or immune deficiency; have a history of high-risk behaviors for exposure to HIV or hepatitis B or C; have diabetes; have received vaccinations in the past 2 months, with the exception of the flu vaccine; are currently taking immunosuppressive medications; are currently taking antibiotics; or have taken probiotic supplements within the last 12 months. Design: * Researchers will conduct the following tests throughout the 28-week study: * Blood samples will be drawn every 2 weeks to measure the quantity of isoagglutinin titers. * Depending on individual results, continued blood testing may be done every 3 months for 1 year, then every 6 to 12 months for up to 5 years. * Study subjects will take a probiotic supplement at a dose of 1 to 3 caplets per day for 18 consecutive weeks according to the following schedule: * During the first 6-week period, the subject will take one probiotic tablet daily. * During the second 6-week period, the subject will take one probiotic tablet twice daily. * During the third 6-week period, the subject will take one probiotic tablet three times daily. * Control group subjects will be followed in a similar manner but will not take probiotic supplements. * The outcome measure is the percent of probiotic ingestors (the study subjects) versus control group subjects who experience a fourfold or greater rise in isoagglutinin titer. * Study subjects will receive the following financial compensation: $10 per blood sample, for a maximum of $240 if all 24 samples are collected; $100 after completing the first 6-week period; $150 after completing the second 6-week period; and $200 after completing the third 6-week period. * Control subjects will receive $10 per blood sample, for a maximum of $150 if all 15 samples are collected.
Study identification
- NCT ID
- NCT00891787
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 1
- Enrollment
- 36 participants
Conditions and interventions
Eligibility (public fields only)
- Age range
- 18 Years to 70 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Apr 28, 2009 (Type not available)
- Primary completion
- Apr 6, 2011 (Actual)
- Completion
- Apr 6, 2011 (Actual)
- Last update posted
- Oct 6, 2017
2009 – 2011
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| National Institutes of Health Clinical Center, 9000 Rockville Pike | Bethesda | Maryland | 20892 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT00891787, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Oct 6, 2017 · Synced Oct 6, 2026
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Open the official record
The complete public registry record, listed eligibility criteria, and available contact information for NCT00891787 live on ClinicalTrials.gov.