Kefir: 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 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. 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.
Eligibility
Sex
FEMALE
Min age
19 Years
Max age
—
Healthy volunteers
Accepted
Inclusion Criteria:
* 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
* 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
Exclusion Criteria:
* 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
Primary outcome measure(s)
Maternal Fasting Glucose Concentrations — 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 — 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 — 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 — 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 — 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).
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
We use cookies to analyse site traffic and improve your experience. With your consent, we may also use cookies for advertising. You can change your choice at any time.
