Diabetes, Insulin, Gut, Enteric Supplementation Trial

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