Effects of lactoferrin-enriched dairy product on iron status in women with gestational diabetes mellitus.

Lactoferrin (LF) is an iron-binding glycoprotein with anti-inflammatory and microbiota-modulating properties, but its effects in gestational diabetes mellitus (GDM) remain unclear. In this double-blind randomized pilot trial (NCT07287384, registered on 11 December 2025), 50 women with GDM (24-30 weeks' gestation) were assigned to receive either an LF-enriched yogurt (100 mg LF/125 g, two servings/day; n = 25) or a control yogurt (n = 25) for eight weeks, alongside 30 mg/day elemental iron. The primary outcome was ferritin change; secondary outcomes included hematologic, metabolic, microbiota, and maternal-neonatal parameters. Forty-six participants completed the study (24 LF, 22 control), with comparable baseline characteristics. Transferrin levels and red blood cell counts increased in both arms. However, ferritin decreased in controls but remained stable in the LF arm, with a significant between-group difference (p = 0.011). Fasting glucose, hemoglobin, and hematocrit were unchanged. Insulin and homeostasis-model-assessment insulin-resistance (HOMA-IR) levels increased modestly within groups without between-group differences. Anemia incidence was similar (20.8% LF vs 27.3% control; p = 0.609). No adverse events occurred. Microbiota diversity was unchanged; LF supplementation increased Lactilactobacillus, Anaerovoracaceae, and was associated with higher Lactobacillus and lower Eggerthella and Actinomyces compared to controls. LF-enriched yogurt was safe, prevented ferritin decline, and modulated selected gut taxa in women with GDM.