Gestational Diabetes Mellitus (GDM)DIGESTNCT07682077
Diabetes, Insulin, Gut, Enteric Supplementation Trial
A study testing Kefir in people with Gestational Diabetes Mellitus (GDM) and Blood Glucose, run by University of New Brunswick at 1 site in Canada.
Trial summary
Pregnancy is a critical window for metabolic health, and early changes in blood sugar regulation can increase the risk of gestational diabetes mellitus (GDM), which affects both maternal and infant health. Read more about this study
- Who is it for?
- Ages 19 years and older, women onlyHealthy volunteers can take part
- Conditions the study is for
- Gestational Diabetes Mellitus (GDM), Blood Glucose, Insulin Resistance, Diabetes
- What is being tested?
- Kefir
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteCanada
- Study dates
- 1 Jun 2026to 1 Jun 2029
- Phase
- Interventional
- 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 19 years and older
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Pregnant individual with a singleton pregnancy
- 19 years and older of age
- Gestational age 14,3 weeks or less at enrolment
- Able and willing to attend four in-person study visits at the PEADS Laboratory: baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, and 1 month postpartum
- Willing and able to comply with study group assignment, including daily consumption of 250 mL of kefir if assigned to the intervention group
- Willing to avoid kefir consumption until completion of the 26-28-week study visit if assigned to the control group
Show all 15Show fewer
- Willing to provide required biological and clinical samples, including stool samples and glucose/insulin data, according to the study protocol
- No probiotic, prebiotic, synbiotic, or antibiotic use during the first trimester or at enrollment
- Not currently consuming probiotic, prebiotic, synbiotic, or antiobiotic supplements
- Willing to avoid probiotic, prebiotic, and synbiotic supplements until completion of the 26-28-week study visit.
- Does not engage in regular moderate-to-vigorous physical activity
- No recent or active infectious illness or significant gastrointestinal symptoms, including diarrhea or constipation in the first trimester of pregnancy.
- No history of bariatric surgery
- Able to communicate in English or French
- Currently living in Fredericton, New Brunswick, and not planning to relocate before the 1-month postpartum visit
Who cannot join
- Pre-existing metabolic disease affecting glucose regulation, including type 1 diabetes or type 2 diabetes
- Current use or first trimester use of medications known to alter glucose metabolism, such as metformin or semaglutide
- Gastrointestinal or inflammatory disease, including Crohn's disease, ulcerative colitis, celiac disease, or diagnosed irritable bowel syndrome
- Allergy, intolerance, or other contraindication to dairy or components of kefir
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
University Of New Brunswick
Fredericton, New Brunswick, E3B 5A3
Maryam Kebbe, PhD, CLC, CMSS, 15064516872, maryam.kebbe@unb.ca
About this study
Official title: Effects of a Kefir Intervention in Pregnancy on Glucose, Insulin, Gestational Diabetes Mellitus, and the Gut Microbiome and Metabolites: A Randomized Controlled Trial
Pregnancy is a critical window for metabolic health, and early changes in blood sugar regulation can increase the risk of gestational diabetes mellitus (GDM), which affects both maternal and infant health. At the same time, the maternal gut microbiome changes throughout pregnancy and may play a role in glucose metabolism and insulin resistance. Kefir, a fermented milk drink containing beneficial bacteria and yeasts, may be a simple dietary strategy to support metabolic health during pregnancy, but its role in preventing GDM has not been well studied.
This study will test whether drinking kefir daily from mid-pregnancy until routine GDM screening can improve glucose and insulin regulation, reduce the incidence of GDM, and modulate the maternal gut microbiome and metabolites, among other outcomes.
Read more
Pregnant individuals will be randomly assigned to either a kefir group or a control group receiving usual prenatal care. Researchers will collect blood glucose and insulin measures, dietary information, stool samples, and body composition data across pregnancy and postpartum to evaluate metabolic and microbiome-related changes.
As one of the first studies to examine kefir as an early pregnancy intervention for GDM prevention, this study will help clarify whether a practical, food-based approach can improve maternal metabolic health. The findings may support future nutrition strategies aimed at reducing GDM risk and improving pregnancy outcomes.
Read the detailed description
Pregnancy is characterized by progressive metabolic and hormonal changes, including increasing insulin resistance, particularly in the second trimester. At the same time, the maternal gut microbiome undergoes substantial shifts across gestation and may contribute to glucose metabolism, insulin resistance, and inflammation. Dietary strategies that can favorably influence the gut microbiome and metabolic health during pregnancy may represent a promising approach to reduce GDM risk. Kefir, a fermented dairy beverage containing a complex consortium of beneficial bacteria and yeasts, has shown potential for improving glycemic control and modulating the gut microbiome in non-pregnant populations, but its preventive role for GDM has not been well established.
The primary aims of this study are to determine whether daily kefir consumption initiated in mid-pregnancy can improve maternal glucose and insulin regulation. Secondary aims will examine whether kefir consumption reduces the incidence of GDM, beneficially modulates maternal gut microbiome and metabolite profiles, and alters postpartum health measures such as breastmilk composition and infant anthropometrics.
This randomized controlled trial in the PEADS Lab at the University of New Brunswick will assign pregnant participants to either a daily kefir intervention group or a control group receiving usual prenatal care. Participants in the intervention group will consume 250 mL of kefir daily beginning at approximately 14 weeks' gestation and continuing until the routine GDM screening window at 26-28 weeks' gestation. Those in the control group will continue with their usual care and habitual diet, but will be asked not to consume kefir for the duration of the study. Participants will attend study visits across pregnancy and postpartum, during which researchers will collect dietary recalls, anthropometric and body composition measurements, blood pressure, and stool and breastmilk samples. Fasted clinical bloodwork will be used to assess glucose and insulin-related outcomes, including screening for GDM.
The primary outcomes are between-group differences in maternal glycemic and insulinemic measures. Secondary outcomes include the incidence of GDM, changes in gut microbial diversity, composition, and metabolites such as short-chain fatty acid concentrations, maternal body composition, breastmilk composition, and infant anthropometrics. Assessments will occur at baseline (~14 weeks gestation), at the GDM screening windows (18-20 weeks for high-risk and 26-28 weeks for low-risk), and one month postpartum.
Pregnancy represents a critical opportunity for early prevention of metabolic complications that can affect lifelong maternal and child health. This study is the first to evaluate kefir as a practical, food-based intervention for GDM prevention, while also exploring the role of the gut microbiome as a potential modifiable mechanism. By integrating clinical, dietary, and microbiome data, this trial will help generate evidence to support accessible nutrition strategies that may improve pregnancy outcomes and inform future maternal health recommendations.
- Conditions
- Gestational Diabetes Mellitus (GDM), Blood Glucose, Insulin Resistance, Diabetes, Gut Microbiome, Gut Metabolites
- Being tested
- Kefir
- Keywords
- Gestational diabetes mellitus, Pregnancy, Probiotics, Kefir, Gut microbiome, Gut metabolites, Glucose, Insulin
- Medical subject headings
- Diabetes, Gestational, Insulin Resistance, Diabetes Mellitus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
KefirDietary supplement
Kefir is a fermented dairy beverage containing a complex host of live bacteria and yeasts. In this study, participants assigned to the intervention group will consume 250 mL of kefir daily from approximately 14 weeks' gestation until the routine GDM screening window at 26-28 weeks' gestation. Participants will otherwise continue their usual prenatal care and habitual diet.
| Study group | Role | What they receive |
|---|---|---|
| Daily Kefir Intake | Experimental | Participants assigned to this group will consume 250 mL of kefir daily beginning at approximately 14 weeks' gestation through the routine GDM screening window at 26-28 weeks' gestation. Participants will otherwise continue their usual prenatal care and habitual diet. Receives: Dietary Supplement: Kefir |
| Control Group | No intervention | Participants assigned to this group will continue their usual prenatal care and habitual diet beginning at approximately 14 weeks' gestation through the routine GDM screening window at 26-28 weeks' gestation. Participants will not consume the study kefir. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Maternal Fasting Glucose Concentrations
Between-group difference in maternal fasting glucose concentrations measured at baseline (14 weeks' gestation) and during pregnancy via glucose challenge testing conducted within the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation
Maternal hbA1c Concentrations
Between-group difference in maternal hbA1c concentrations measured at baseline (14 weeks' gestation) and during pregnancy conducted within the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation
Maternal Fasting Insulin Concentrations
Between-group difference in maternal fasting insulin concentrations measured during pregnancy at the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Measured: 18-20 weeks' gestation, 26-28 weeks' gestation
Maternal Insulin Area Under the Curve
Between-group difference in maternal insulin area under the curve measured during pregnancy at the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Measured: 18-20 weeks' gestation, 26-28 weeks' gestation
Maternal Whole-Body Insulin Sensitivity
Between-group difference in maternal whole-body insulin sensitivity measured during pregnancy at the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Measured: 18-20 weeks' gestation, 26-28 weeks' gestation
Secondary outcomes (17)
Gut Microbiome Diversity and Composition
Gut microbiome diversity and taxa will be assessed using metagenomic sequencing of stool samples collected from participants. Alpha diversity metrics (e.g., Shannon index, Chao1) and beta diversity metrics (Bray-Curtis dissimilarity) will quantify within- and between-sample microbial diversity. Taxonomic composition at phylum, family, and genus levels will be examined.
Measured: At baseline, 18-20 weeks' gestation, and 26-28 weeks' gestation
Gut Microbiome Metabolites
Microbial metabolite profiles relevant to inflammation and metabolic regulation such as short-chain fatty acids will be examined.
Measured: At baseline, 18-20 weeks' gestation, and 26-28 weeks' gestation
Maternal Weight
Maternal weight will be measured at each study visit.
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Maternal Height
Maternal height will be measured at baseline.
Measured: Baseline
Maternal Body Composition (BOD POD)
Maternal body composition will be assessed at each visit using air-displacement plethysmography to estimate fat mass and fat-free mass.
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Maternal Blood Pressure
Maternal blood pressure will be measured to provide additional information on maternal cardiovascular and metabolic health.
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Maternal Breastmilk Composition (Miris HMA)
Breastmilk will be collected 1 month postpartum.
Measured: 1 month postpartum
Infant Length
Infant length will be assessed using standardized procedures 1 month postpartum.
Measured: 1 month postpartum
Infant Weight
Infant weight will be assessed using standardized procedures 1 month postpartum.
Measured: 1 month postpartum
Infant Head and Abdominal Circumferences
Infant circumferences will be assessed using standardized procedures 1 month postpartum.
Measured: 1 month postpartum
Infant Body Composition
Infant body composition will be assessed using air-displacement plethysmography 1 month postpartum.
Measured: 1 month postpartum
Dietary intake
Participants will complete the Automated Self-Administered 24-hour dietary assessment tool (ASA-24) at two time points (one weekday and one weekend).
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Pregnancy Physical Activity Questionnaire
Participants will complete the Pregnancy Physical Activity Questionnaire (PPAQ).
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Postpartum Physical Activity Questionnaire
Participants will complete the Postpartum Physical Activity Questionnaire.
Measured: 1 month postpartum
Edinburgh Postnatal Depression Scale
Participants will complete the Edinburgh Postnatal Depression Scale (EPDS).
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Anxiety subscale of the Symptom Checklist-90
Participants will complete the Anxiety subscale of the Symptom Checklist-90 (SCL-90).
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Weight Control Strategies Scale
Participants will complete the Weight Control Strategies Scale (WCSS).
Measured: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jul 2026
- Study start1 Jun 2026
- Primary completion1 Jun 2028 (estimated)
- Study completion1 Jun 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (21)Papers the sponsor has linked to this study.
- Other trials for Gestational Diabetes Mellitus (GDM)Studies 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Care provider, Investigator, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of New Brunswick
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Maryam Kebbe, University of New Brunswick
- Investigators
- Maryam Kebbe, PhD, CLC, Principal investigator, University of New Brunswick
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07682077
- Sponsor's protocol ID
- 2026-633
- Acronym
- DIGEST
- Status last verified
- Sep 2026
- First submitted
- 11 May 2026
- Last updated
- 28 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Salari A, Ghodrat S, Gheflati A, Jarahi L, Hashemi M, Afshari A. Effect of kefir beverage consumption on glycemic control: A systematic review and meta-analysis of randomized controlled clinical trials. Complement Ther Clin Pract. 2021 Aug;44:101443. doi: 10.1016/j.ctcp.2021.101443. Epub 2021 Jul 13.
PubMed 34280689van Raaij JM, Peek ME, Vermaat-Miedema SH, Schonk CM, Hautvast JG. New equations for estimating body fat mass in pregnancy from body density or total body water. Am J Clin Nutr. 1988 Jul;48(1):24-9. doi: 10.1093/ajcn/48.1.24.
PubMed 3389327Plows JF, Stanley JL, Baker PN, Reynolds CM, Vickers MH. The Pathophysiology of Gestational Diabetes Mellitus. Int J Mol Sci. 2018 Oct 26;19(11):3342. doi: 10.3390/ijms19113342.
PubMed 30373146Pakmehr A, Ejtahed HS, Shirzad N, Hemmatabadi M, Farhat S, Larijani B. Preventive effect of probiotics supplementation on occurrence of gestational diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials. Front Med (Lausanne). 2022 Dec 1;9:1031915. doi: 10.3389/fmed.2022.1031915. eCollection 2022.
PubMed 36530883O'Malley EG, Reynolds CME, O'Kelly R, McMahon L, Sheehan SR, Turner MJ. The diagnosis of gestational diabetes mellitus (GDM) using a 75 g oral glucose tolerance test: A prospective observational study. Diabetes Res Clin Pract. 2020 May;163:108144. doi: 10.1016/j.diabres.2020.108144. Epub 2020 Apr 13.
PubMed 32298706Nakshine VS, Jogdand SD. A Comprehensive Review of Gestational Diabetes Mellitus: Impacts on Maternal Health, Fetal Development, Childhood Outcomes, and Long-Term Treatment Strategies. Cureus. 2023 Oct 23;15(10):e47500. doi: 10.7759/cureus.47500. eCollection 2023 Oct.
PubMed 38021940Johns EC, Denison FC, Norman JE, Reynolds RM. Gestational Diabetes Mellitus: Mechanisms, Treatment, and Complications. Trends Endocrinol Metab. 2018 Nov;29(11):743-754. doi: 10.1016/j.tem.2018.09.004. Epub 2018 Oct 5.
PubMed 30297319Hivert MF, Backman H, Benhalima K, Catalano P, Desoye G, Immanuel J, McKinlay CJD, Meek CL, Nolan CJ, Ram U, Sweeting A, Simmons D, Jawerbaum A. Pathophysiology from preconception, during pregnancy, and beyond. Lancet. 2024 Jul 13;404(10448):158-174. doi: 10.1016/S0140-6736(24)00827-4. Epub 2024 Jun 20.
PubMed 38909619Hamsho M, Hawari R, Yesil Z, Dakhel Z, Dursun Saydam D, Terzi M, Ranneh Y. Effect of different kefir dosages on inflammation status, metabolic profile, and anthropometric measurements in adults: A systematic review and meta-analysis. Nutr Metab Cardiovasc Dis. 2026 May;36(5):104364. doi: 10.1016/j.numecd.2025.104364. Epub 2025 Sep 11.
PubMed 41076330Fisher PM, Sutherland HW, Bewsher PD. The insulin response to glucose infusion in normal human pregnancy. Diabetologia. 1980 Jul;19(1):15-20. doi: 10.1007/BF00258304.
PubMed 6993263Crusell MKW, Hansen TH, Nielsen T, Allin KH, Ruhlemann MC, Damm P, Vestergaard H, Rorbye C, Jorgensen NR, Christiansen OB, Heinsen FA, Franke A, Hansen T, Lauenborg J, Pedersen O. Gestational diabetes is associated with change in the gut microbiota composition in third trimester of pregnancy and postpartum. Microbiome. 2018 May 15;6(1):89. doi: 10.1186/s40168-018-0472-x.
PubMed 29764499Choi Y, Keum GB, Kang J, Doo H, Kwak J, Kim H, Chae Y, Lee S, Yang H, Kim S, Sun X, Kim HB, Yoo SJ. Evaluation of kefir consumption on gut microbial diversity in a healthy young population using full-length 16S rRNA sequencing. Front Microbiol. 2025 May 21;16:1587831. doi: 10.3389/fmicb.2025.1587831. eCollection 2025.
PubMed 40469719Bianchi C, de Gennaro G, Romano M, Battini L, Aragona M, Corfini M, Del Prato S, Bertolotto A. Early vs. standard screening and treatment of gestational diabetes in high-risk women - An attempt to determine relative advantages and disadvantages. Nutr Metab Cardiovasc Dis. 2019 Jun;29(6):598-603. doi: 10.1016/j.numecd.2019.02.007. Epub 2019 Mar 1.
PubMed 30954416Asgharian H, Homayouni-Rad A, Mirghafourvand M, Mohammad-Alizadeh-Charandabi S. Effect of probiotic yoghurt on plasma glucose in overweight and obese pregnant women: a randomized controlled clinical trial. Eur J Nutr. 2020 Feb;59(1):205-215. doi: 10.1007/s00394-019-01900-1. Epub 2019 May 8.
PubMed 31069459Song S, Duo Y, Zhang Y, Qiao X, Xu J, Zhang J, Peng Z, Chen Y, Nie X, Sun Q, Yang X, Wang A, Sun W, Fu Y, Dong Y, Lu Z, Yuan T, Zhao W. The Predictive Ability of Hepatic Steatosis Index for Gestational Diabetes Mellitus and Large for Gestational Age Infant Compared with Other Noninvasive Indices Among Chinese Pregnancies: A Preliminary Double-center Cohort Study. Diabetes Metab Syndr Obes. 2021 Dec 16;14:4791-4800. doi: 10.2147/DMSO.S335364. eCollection 2021.
PubMed 34938090
Study at a glance
From the registry record, last updated by the sponsor on 28 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of a Kefir Intervention in Pregnancy on Glucose, Insulin, Gestational Diabetes Mellitus, and the Gut Microbiome and Metabolites: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07682077
- Acronym / sponsor ID
- DIGEST / 2026-633
- Conditions
- Gestational Diabetes Mellitus (GDM), Blood Glucose, Insulin Resistance, Diabetes, Gut Microbiome, Gut Metabolites
- Keywords
- Gestational diabetes mellitus, Pregnancy, Probiotics, Kefir, Gut microbiome, Gut metabolites, Glucose, Insulin
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- University of New BrunswickUniversity, hospital or other
- Study start
- 1 Jun 2026 (actual)
- Primary completion
- 1 Jun 2028 (estimated)
- Study completion
- 1 Jun 2029 (estimated)
- First posted
- 2 Jul 2026 (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.
Pregnancy is a critical window for metabolic health, and early changes in blood sugar regulation can increase the risk of gestational diabetes mellitus (GDM), which affects both maternal and infant health. At the same time, the maternal gut microbiome changes throughout pregnancy and may play a role in glucose metabolism and insulin resistance. Kefir, a fermented milk drink containing beneficial bacteria and yeasts, may be a simple dietary strategy to support metabolic health during pregnancy, but its role in preventing GDM has not been well studied.
This study will test whether drinking kefir daily from mid-pregnancy until routine GDM screening can improve glucose and insulin regulation, reduce the incidence of GDM, and modulate the maternal gut microbiome and metabolites, among other outcomes.
Pregnant individuals will be randomly assigned to either a kefir group or a control group receiving usual prenatal care. Researchers will collect blood glucose and insulin measures, dietary information, stool samples, and body composition data across pregnancy and postpartum to evaluate metabolic and microbiome-related changes.
As one of the first studies to examine kefir as an early pregnancy intervention for GDM prevention, this study will help clarify whether a practical, food-based approach can improve maternal metabolic health. The findings may support future nutrition strategies aimed at reducing GDM risk and improving pregnancy outcomes.
Detailed description
Pregnancy is characterized by progressive metabolic and hormonal changes, including increasing insulin resistance, particularly in the second trimester. At the same time, the maternal gut microbiome undergoes substantial shifts across gestation and may contribute to glucose metabolism, insulin resistance, and inflammation. Dietary strategies that can favorably influence the gut microbiome and metabolic health during pregnancy may represent a promising approach to reduce GDM risk. Kefir, a fermented dairy beverage containing a complex consortium of beneficial bacteria and yeasts, has shown potential for improving glycemic control and modulating the gut microbiome in non-pregnant populations, but its preventive role for GDM has not been well established.
The primary aims of this study are to determine whether daily kefir consumption initiated in mid-pregnancy can improve maternal glucose and insulin regulation. Secondary aims will examine whether kefir consumption reduces the incidence of GDM, beneficially modulates maternal gut microbiome and metabolite profiles, and alters postpartum health measures such as breastmilk composition and infant anthropometrics.
This randomized controlled trial in the PEADS Lab at the University of New Brunswick will assign pregnant participants to either a daily kefir intervention group or a control group receiving usual prenatal care. Participants in the intervention group will consume 250 mL of kefir daily beginning at approximately 14 weeks' gestation and continuing until the routine GDM screening window at 26-28 weeks' gestation. Those in the control group will continue with their usual care and habitual diet, but will be asked not to consume kefir for the duration of the study. Participants will attend study visits across pregnancy and postpartum, during which researchers will collect dietary recalls, anthropometric and body composition measurements, blood pressure, and stool and breastmilk samples. Fasted clinical bloodwork will be used to assess glucose and insulin-related outcomes, including screening for GDM.
The primary outcomes are between-group differences in maternal glycemic and insulinemic measures. Secondary outcomes include the incidence of GDM, changes in gut microbial diversity, composition, and metabolites such as short-chain fatty acid concentrations, maternal body composition, breastmilk composition, and infant anthropometrics. Assessments will occur at baseline (~14 weeks gestation), at the GDM screening windows (18-20 weeks for high-risk and 26-28 weeks for low-risk), and one month postpartum.
Pregnancy represents a critical opportunity for early prevention of metabolic complications that can affect lifelong maternal and child health. This study is the first to evaluate kefir as a practical, food-based intervention for GDM prevention, while also exploring the role of the gut microbiome as a potential modifiable mechanism. By integrating clinical, dietary, and microbiome data, this trial will help generate evidence to support accessible nutrition strategies that may improve pregnancy outcomes and inform future maternal health recommendations.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Daily Kefir Intake | Experimental | Dietary Supplement: KefirParticipants assigned to this group will consume 250 mL of kefir daily beginning at approximately 14 weeks' gestation through the routine GDM screening window at 26-28 weeks' gestation. Participants will otherwise continue their usual prenatal care and habitual diet. |
| Control Group | No intervention | –Participants assigned to this group will continue their usual prenatal care and habitual diet beginning at approximately 14 weeks' gestation through the routine GDM screening window at 26-28 weeks' gestation. Participants will not consume the study kefir. |
Who may qualify
- Ages
- 19 years and older
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (15 listed)
- Pregnant individual with a singleton pregnancy
- 19 years and older of age
- Gestational age 14,3 weeks or less at enrolment
- Able and willing to attend four in-person study visits at the PEADS Laboratory: baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, and 1 month postpartum
- Willing and able to comply with study group assignment, including daily consumption of 250 mL of kefir if assigned to the intervention group
Key exclusion criteria (4 listed)
- Pre-existing metabolic disease affecting glucose regulation, including type 1 diabetes or type 2 diabetes
- Current use or first trimester use of medications known to alter glucose metabolism, such as metformin or semaglutide
- Gastrointestinal or inflammatory disease, including Crohn's disease, ulcerative colitis, celiac disease, or diagnosed irritable bowel syndrome
- Allergy, intolerance, or other contraindication to dairy or components of kefir
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 |
|---|---|---|
| KefirKefir is a fermented dairy beverage containing a complex host of live bacteria and yeasts. In this study, participants assigned to the intervention group will consume 250 mL of kefir daily from approximately 14 weeks' gestation until the routine GDM screening window at 26-28 weeks' gestation. Participants will otherwise continue their usual prenatal care and habitual diet. | Dietary supplement | Daily Kefir Intake |
Primary outcome
Maternal Fasting Glucose Concentrations
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation
Between-group difference in maternal fasting glucose concentrations measured at baseline (14 weeks' gestation) and during pregnancy via glucose challenge testing conducted within the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Maternal hbA1c Concentrations
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation
Between-group difference in maternal hbA1c concentrations measured at baseline (14 weeks' gestation) and during pregnancy conducted within the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Maternal Fasting Insulin Concentrations
Time frame: 18-20 weeks' gestation, 26-28 weeks' gestation
Between-group difference in maternal fasting insulin concentrations measured during pregnancy at the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Maternal Insulin Area Under the Curve
Time frame: 18-20 weeks' gestation, 26-28 weeks' gestation
Between-group difference in maternal insulin area under the curve measured during pregnancy at the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
Maternal Whole-Body Insulin Sensitivity
Time frame: 18-20 weeks' gestation, 26-28 weeks' gestation
Between-group difference in maternal whole-body insulin sensitivity measured during pregnancy at the respective screening window (18-20 weeks' gestation for high-risk or 24-28 weeks' gestation for high-risk and/or low-risk).
17 secondary outcomes
Gut Microbiome Diversity and Composition
Time frame: At baseline, 18-20 weeks' gestation, and 26-28 weeks' gestation
Gut Microbiome Metabolites
Time frame: At baseline, 18-20 weeks' gestation, and 26-28 weeks' gestation
Maternal Weight
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Maternal Height
Time frame: Baseline
Maternal Body Composition (BOD POD)
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Maternal Blood Pressure
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Maternal Breastmilk Composition (Miris HMA)
Time frame: 1 month postpartum
Infant Length
Time frame: 1 month postpartum
Infant Weight
Time frame: 1 month postpartum
Infant Head and Abdominal Circumferences
Time frame: 1 month postpartum
Infant Body Composition
Time frame: 1 month postpartum
Dietary intake
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Pregnancy Physical Activity Questionnaire
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Postpartum Physical Activity Questionnaire
Time frame: 1 month postpartum
Edinburgh Postnatal Depression Scale
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Anxiety subscale of the Symptom Checklist-90
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
Weight Control Strategies Scale
Time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation, 1 month postpartum
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 28 Sep 2026.
- Background: PubMed 34280689Salari A, Ghodrat S, Gheflati A, Jarahi L, Hashemi M, Afshari A. Effect of kefir beverage consumption on glycemic control: A systematic review and meta-analysis of randomized controlled clinical trials. Complement Ther Clin Pract. 2021 Aug;44:101443. doi: 10.1016/j.ctcp.2021.101443. Epub 2021 Jul 13.
- Background: PubMed 3389327van Raaij JM, Peek ME, Vermaat-Miedema SH, Schonk CM, Hautvast JG. New equations for estimating body fat mass in pregnancy from body density or total body water. Am J Clin Nutr. 1988 Jul;48(1):24-9. doi: 10.1093/ajcn/48.1.24.
- Background: PubMed 30373146Plows JF, Stanley JL, Baker PN, Reynolds CM, Vickers MH. The Pathophysiology of Gestational Diabetes Mellitus. Int J Mol Sci. 2018 Oct 26;19(11):3342. doi: 10.3390/ijms19113342.
- Background: PubMed 36530883Pakmehr A, Ejtahed HS, Shirzad N, Hemmatabadi M, Farhat S, Larijani B. Preventive effect of probiotics supplementation on occurrence of gestational diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials. Front Med (Lausanne). 2022 Dec 1;9:1031915. doi: 10.3389/fmed.2022.1031915. eCollection 2022.
- Background: PubMed 32298706O'Malley EG, Reynolds CME, O'Kelly R, McMahon L, Sheehan SR, Turner MJ. The diagnosis of gestational diabetes mellitus (GDM) using a 75 g oral glucose tolerance test: A prospective observational study. Diabetes Res Clin Pract. 2020 May;163:108144. doi: 10.1016/j.diabres.2020.108144. Epub 2020 Apr 13.
- Background: PubMed 38021940Nakshine VS, Jogdand SD. A Comprehensive Review of Gestational Diabetes Mellitus: Impacts on Maternal Health, Fetal Development, Childhood Outcomes, and Long-Term Treatment Strategies. Cureus. 2023 Oct 23;15(10):e47500. doi: 10.7759/cureus.47500. eCollection 2023 Oct.
- Background: PubMed 30297319Johns EC, Denison FC, Norman JE, Reynolds RM. Gestational Diabetes Mellitus: Mechanisms, Treatment, and Complications. Trends Endocrinol Metab. 2018 Nov;29(11):743-754. doi: 10.1016/j.tem.2018.09.004. Epub 2018 Oct 5.
- Background: PubMed 38909619Hivert MF, Backman H, Benhalima K, Catalano P, Desoye G, Immanuel J, McKinlay CJD, Meek CL, Nolan CJ, Ram U, Sweeting A, Simmons D, Jawerbaum A. Pathophysiology from preconception, during pregnancy, and beyond. Lancet. 2024 Jul 13;404(10448):158-174. doi: 10.1016/S0140-6736(24)00827-4. Epub 2024 Jun 20.
- Background: PubMed 41076330Hamsho M, Hawari R, Yesil Z, Dakhel Z, Dursun Saydam D, Terzi M, Ranneh Y. Effect of different kefir dosages on inflammation status, metabolic profile, and anthropometric measurements in adults: A systematic review and meta-analysis. Nutr Metab Cardiovasc Dis. 2026 May;36(5):104364. doi: 10.1016/j.numecd.2025.104364. Epub 2025 Sep 11.
- Background: PubMed 6993263Fisher PM, Sutherland HW, Bewsher PD. The insulin response to glucose infusion in normal human pregnancy. Diabetologia. 1980 Jul;19(1):15-20. doi: 10.1007/BF00258304.
- Background: PubMed 29764499Crusell MKW, Hansen TH, Nielsen T, Allin KH, Ruhlemann MC, Damm P, Vestergaard H, Rorbye C, Jorgensen NR, Christiansen OB, Heinsen FA, Franke A, Hansen T, Lauenborg J, Pedersen O. Gestational diabetes is associated with change in the gut microbiota composition in third trimester of pregnancy and postpartum. Microbiome. 2018 May 15;6(1):89. doi: 10.1186/s40168-018-0472-x.
- Background: PubMed 40469719Choi Y, Keum GB, Kang J, Doo H, Kwak J, Kim H, Chae Y, Lee S, Yang H, Kim S, Sun X, Kim HB, Yoo SJ. Evaluation of kefir consumption on gut microbial diversity in a healthy young population using full-length 16S rRNA sequencing. Front Microbiol. 2025 May 21;16:1587831. doi: 10.3389/fmicb.2025.1587831. eCollection 2025.
- Individual participant dataSharing planned: Undecided
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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.
Maryam Kebbe, PhD, CLC principal investigator
University of New Brunswick
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Kefir in people with Gestational Diabetes Mellitus (GDM) and Blood Glucose, run by University of New Brunswick at 1 site in Canada.
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 15 inclusion and 4 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: looking for participants now, as of the sponsor's last update on 28 Sep 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 Canada. 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?
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 Maryam Kebbe, PhD, CLC, CMSS (15064516872, maryam.kebbe@unb.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Maternal Fasting Glucose Concentrations (time frame: Baseline, 18-20 weeks' gestation, 26-28 weeks' gestation). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07682077, which also lists 21 linked publications.
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 28 Sep 2026.