Yogurt IntakeNCT05931471
Yogurt and GI Health
A study testing Yogurt Intervention in people with Yogurt Intake and Gastrointestinal Immune Function, run by USDA, Western Human Nutrition Research Center at 1 site in United States.
Trial summary
The purpose of this research is to assess mucosal immune function responses in the gastrointestinal (GI) tract to twice-daily yogurt consumption. Previous research has shown that dairy yogurt intake can benefit gastrointestinal health. Read more about this study
- Who is it for?
- Ages 50 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Yogurt Intake, Gastrointestinal Immune Function, Gut Microbiome
- What is being tested?
- Yogurt Intervention
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Sep 2023to 21 Jun 2024
- 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 50 to 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 50 - 75 years
- BMI 18.5 - 39.9 kg/m2
Who cannot join
- BMI less than 18.5 or greater than 39.9
- Consumption of fermented foods or probiotics in the past two weeks
- Unwillingness to abstain from non-study fermented foods and probiotics during the trial
- Allergy to cow milk
- Lactose intolerance
- Any dietary restriction limiting or prohibiting consumption of lightly sweetened, vanilla flavored, whole milk yogurt
Show all 37Show fewer
- Uncomfortable with or unwilling to complete stool sample collections
- Current participation in another research study
- If female,
- Currently pregnant or lactating
- Have had menstrual bleeding in the past 12 months
- Having fewer than 3 bowel movements per week
- Unmanaged hypertension, defined as blood pressure greater than or equal to 140/90 mmHg
- Current diagnosis of:
- Disease that affects the immune system, including HIV/AIDS
- Cancer
- Diabetes
- Asthma with daily medication
- Primary immune deficiency
- Auto-immune disease
- Chronic gastrointestinal disorder (e.g. Crohn's disease, irritable bowel syndrome, colitis, gastric ulcer)
- Current use for 2 weeks or longer of:
- Any drug that affects the immune system, such as immunosuppressants, immune modifying drugs, or corticosteroids (e.g. cortisone, prednisone, methylprednisolone)
- Biologics (e.g. Lantus, Remicade, Rituxan, Humira, Herceptin, Avastin, Lucentis, Enbrel)
- Use of sulfonamides or antibiotics in the past 3 months
- Use of laxatives in the past 2 weeks
- Currently undergoing cancer treatment with radiation or drugs
- History of gastrointestinal surgery that would impact study outcomes, such as gastric bypass, intestinal resection, surgeries of the liver or pancreas, or removal of part or all of any organ of the GI tract
- Having within the past 2 weeks:
- Diarrheal illness, defined as passing 3 or more abnormally loose or watery stools in a 24-hour period
- Persistent vomiting
- Fever
- Having within the past 3 months:
- Surgery
- Hospitalization
- Having within the past 1 month:
- Colonoscopy
Trial locations and contacts
1 site in 1 country.
United States1 site
USDA Western Human Nutrition Research Center
Davis, California, 95616
About this study
Official title: Effect of Yogurt on Mucosal Immunity in the Gastrointestinal Tract
The purpose of this research is to assess mucosal immune function responses in the gastrointestinal (GI) tract to twice-daily yogurt consumption. Previous research has shown that dairy yogurt intake can benefit gastrointestinal health. The current study will determine whether a dietary intervention with dairy yogurt will improve mucosal immunity and the gut microbiome.
Read the detailed description
The gastrointestinal (GI) tract has the difficult task of absorbing nutrients while excluding microorganisms and non-nutritive foreign agents. The GI tract is protected by components of GI mucosal immunity, such as the mucin layer, anti-microbial peptides, secretory IgA (sIgA), and more, which collectively maintain gut homeostasis. When mucosal immunity fails, the result can be gastrointestinal infection, allergic inflammation, or inflammatory bowel disease. Mechanistic knowledge from in vitro studies suggests that sIgA increases in response to lactic acid bacteria and mucin-2 expression increases in response to milk peptides in yogurt. Yogurt consumption may also reduce constipation and increase the production of short-chain fatty acids (SCFAs). SCFAs promote the health of intestinal cells by acting as an energy source, influencing gene expression, and exerting anti-inflammatory effects. When SCFAs increase, fecal pH decreases.
This research will expand the limited existing literature on how GI mucosal immunity changes in response to yogurt consumption, the time frame over which effects occur and how long the effects persist after yogurt is discontinued. Participants will undergo a two-week baseline period without yogurt intake, followed by a three-week intervention of two daily 6-oz servings of dairy yogurt, and a follow-up period with no yogurt consumption. Stool samples will be collected at the end of the 2-week baseline period, after 1, 2, and 3 weeks of intervention, and at the end of the 2 weeks post-intervention period for measurement of fecal sIgA, fecal mucin-2 mRNA, fecal pH, and fecal SCFAs, and analysis of the fecal microbiome. 24-hour dietary recalls will be collected with the Automated Self-Administered Dietary Assessment Tool (ASA24) during the baseline and intervention phases of the trial.
Specific knowledge will be produced regarding the effect of regular yogurt consumption on sIgA levels, mucin-2 gene expression and fecal pH in older adults (age 50 - 75 years). The study will also produce knowledge on the intervention length needed for maximal response in these outcome measures and how long these responses persist when the yogurt intervention is discontinued. The outcomes of this study will 1) provide preliminary data to inform design of future, larger studies on how dairy yogurt or similar cultured products influence GI mucosal immune function, and 2) contribute to growing knowledge on the potential health benefits of consuming fermented, particularly yogurt.
- Being tested
- Yogurt Intervention
- Keywords
- Yogurt, Adults, Gut microbiome, Gut health, Immune function, GI tract
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Yogurt InterventionOther
Participants will be provided with a commercial yogurt that contains only cultured dairy, traditional live active cultures (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, and possibly other non-brand-specific strains), sugar, and, optionally, vanilla flavor. The yogurt will contain no starches or pectin, gums, fiber or other added ingredients. Participants will be asked to consume two 6-ounce portions of yogurt each day, and to log their consumption in a provided booklet. They will be advised to incorporate the yogurt into their diet however they choose (as part of meals or as snacks), to avoid other fermented foods, and to otherwise maintain their habitual diet.
| Study group | Role | What they receive |
|---|---|---|
| Yogurt Consumption | Experimental | Participants will complete a 2-week baseline with no yogurt intake, followed by a three-week yogurt intervention, and then a 2-week follow-up period with no yogurt intake. Receives: Other: Yogurt Intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in fecal secretory immunoglobulin A
Fecal secretory immunoglobulin A (sIgA) will be extracted then measured in duplicate by enzyme-linked immunosorbent assay (ELISA)
Measured: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Secondary outcomes (4)
Changes in fecal mucin-2 mRNA expression
Pre-amplification and quantitative reverse transcription polymerase chair reaction (RT-qPCR) for mucin 2 (MUC2) and GAPDH will be conducted using validated TaqMan assays, and fold MUC2 gene expression of samples will be calculated relative to a commercial total human colon RNA standard using GAPDH as the housekeeping gene.
Measured: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Changes in fecal pH
Fecal pH will be measured with a glass electrode pH meter.
Measured: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Changes in fecal short-chain fatty acids
The most abundant fecal SCFAs, such as acetate, propionate, butyrate, will be analyzed via gas chromatography-mass spectrometry.
Measured: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Fecal microbiome
Gut microbiota composition will be assessed with PCR amplification and 16S sequencing
Measured: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jul 2023
- Study start19 Sep 2023
- Primary completion21 Jun 2024
- Study completion21 Jun 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Yogurt IntakeStudies 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 32 participants (actual)
Sponsor and investigators
- Lead sponsor
- USDA, Western Human Nutrition Research Center
- Sponsor type
- US federal agency
- Responsible party
- Sponsor
- Investigators
- Danielle G Lemay, PhD, Principal investigator, USDA, Western Human Nutrition Research CenterBess L Caswell, PhD, Principal investigator, USDA, Western Human Nutrition Research Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05931471
- Sponsor's protocol ID
- FL119
- Status last verified
- Mar 2025
- First submitted
- 26 Jun 2023
- Last updated
- 18 Mar 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified data will be shared at the time of study publication in accordance with US Department of Agriculture (USDA) policy.
Study at a glance
From the registry record, last updated by the sponsor on 18 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Yogurt on Mucosal Immunity in the Gastrointestinal Tract
- ClinicalTrials.gov ID
- NCT05931471
- Acronym / sponsor ID
- FL119
- Keywords
- Yogurt, Adults, Gut microbiome, Gut health, Immune function, GI tract
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 32 participants (actual)
- Lead sponsor
- USDA, Western Human Nutrition Research CenterUS federal agency
- Study start
- 19 Sep 2023 (actual)
- Primary completion
- 21 Jun 2024 (actual)
- Study completion
- 21 Jun 2024 (actual)
- First posted
- 5 Jul 2023 (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 purpose of this research is to assess mucosal immune function responses in the gastrointestinal (GI) tract to twice-daily yogurt consumption. Previous research has shown that dairy yogurt intake can benefit gastrointestinal health. The current study will determine whether a dietary intervention with dairy yogurt will improve mucosal immunity and the gut microbiome.
Detailed description
The gastrointestinal (GI) tract has the difficult task of absorbing nutrients while excluding microorganisms and non-nutritive foreign agents. The GI tract is protected by components of GI mucosal immunity, such as the mucin layer, anti-microbial peptides, secretory IgA (sIgA), and more, which collectively maintain gut homeostasis. When mucosal immunity fails, the result can be gastrointestinal infection, allergic inflammation, or inflammatory bowel disease. Mechanistic knowledge from in vitro studies suggests that sIgA increases in response to lactic acid bacteria and mucin-2 expression increases in response to milk peptides in yogurt. Yogurt consumption may also reduce constipation and increase the production of short-chain fatty acids (SCFAs). SCFAs promote the health of intestinal cells by acting as an energy source, influencing gene expression, and exerting anti-inflammatory effects. When SCFAs increase, fecal pH decreases.
This research will expand the limited existing literature on how GI mucosal immunity changes in response to yogurt consumption, the time frame over which effects occur and how long the effects persist after yogurt is discontinued. Participants will undergo a two-week baseline period without yogurt intake, followed by a three-week intervention of two daily 6-oz servings of dairy yogurt, and a follow-up period with no yogurt consumption. Stool samples will be collected at the end of the 2-week baseline period, after 1, 2, and 3 weeks of intervention, and at the end of the 2 weeks post-intervention period for measurement of fecal sIgA, fecal mucin-2 mRNA, fecal pH, and fecal SCFAs, and analysis of the fecal microbiome. 24-hour dietary recalls will be collected with the Automated Self-Administered Dietary Assessment Tool (ASA24) during the baseline and intervention phases of the trial.
Specific knowledge will be produced regarding the effect of regular yogurt consumption on sIgA levels, mucin-2 gene expression and fecal pH in older adults (age 50 - 75 years). The study will also produce knowledge on the intervention length needed for maximal response in these outcome measures and how long these responses persist when the yogurt intervention is discontinued. The outcomes of this study will 1) provide preliminary data to inform design of future, larger studies on how dairy yogurt or similar cultured products influence GI mucosal immune function, and 2) contribute to growing knowledge on the potential health benefits of consuming fermented, particularly yogurt.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Yogurt Consumption | Experimental | Other: Yogurt InterventionParticipants will complete a 2-week baseline with no yogurt intake, followed by a three-week yogurt intervention, and then a 2-week follow-up period with no yogurt intake. |
Who may qualify
- Ages
- 50 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Age 50 - 75 years
- BMI 18.5 - 39.9 kg/m2
Key exclusion criteria (37 listed)
- BMI less than 18.5 or greater than 39.9
- Consumption of fermented foods or probiotics in the past two weeks
- Unwillingness to abstain from non-study fermented foods and probiotics during the trial
- Allergy to cow milk
- Lactose intolerance
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 |
|---|---|---|
| Yogurt InterventionParticipants will be provided with a commercial yogurt that contains only cultured dairy, traditional live active cultures (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, and possibly other non-brand-specific strains), sugar, and, optionally, vanilla flavor. The yogurt will contain no starches or pectin, gums, fiber or other added ingredients. Participants will be asked to consume two 6-ounce portions of yogurt each day, and to log their consumption in a provided booklet. They will be advised to incorporate the yogurt into their diet however they choose (as part of meals or as snacks), to avoid other fermented foods, and to otherwise maintain their habitual diet. | Other | Yogurt Consumption |
Primary outcome
Changes in fecal secretory immunoglobulin A
Time frame: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Fecal secretory immunoglobulin A (sIgA) will be extracted then measured in duplicate by enzyme-linked immunosorbent assay (ELISA)
4 secondary outcomes
Changes in fecal mucin-2 mRNA expression
Time frame: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Changes in fecal pH
Time frame: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Changes in fecal short-chain fatty acids
Time frame: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
Fecal microbiome
Time frame: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period
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 Mar 2025.
- Individual participant dataSharing planned: Yes. De-identified data will be shared at the time of study publication in accordance with US Department of Agriculture (USDA) policy.
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.
Danielle G Lemay, PhD principal investigator
USDA, Western Human Nutrition Research Center
Bess L Caswell, PhD principal investigator
USDA, Western Human Nutrition Research Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Yogurt Intervention in people with Yogurt Intake and Gastrointestinal Immune Function, run by USDA, Western Human Nutrition Research Center 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 2 inclusion and 37 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 Mar 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?
Changes in fecal secretory immunoglobulin A (time frame: At end of 2-week baseline period; at 1, 2 and 3 weeks of intervention; and at end of 2-week follow-up period). 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 Mar 2025; AzTrials last refreshed its copy on 1 Nov 2026.