Impact of Fructose-Enhanced Solid and Soft Drink Diets on Metabolism, Physiology, and Gut Microbiome in Pregnant Rats

Introduction: High fructose consumption is linked to hypertension and metabolic disorders. We hypothesize fructose (solid and/or liquid) may further influence dietary patterns. To investigate potential effects, we compared eating behaviors, physiological and metabolic measures, and gut microbiome in pregnant rats fed solid or liquid fructose-enhanced (soft drink) diets to those fed standard chow. Methods: Pregnant rats were assigned to three dietary groups: (1) standard chow and water (CW), (2) standard chow and decarbonated soft drink (CS, decarbonated Sprite with 5.89% fructose w/v), and (3) 60% fructose chow and water (FW). Body weight, blood pressure, food and liquid intake, fasting blood glucose, plasma insulin, and lipid profiles were measured weekly. Fecal samples were collected before and during pregnancy. At euthanasia, livers and kidneys were analyzed for pathological changes. Results: Data from five rats per group were analyzed. The CS group showed nearly a twofold increase in fluid intake and urinary output at midpregnancy. Both solid and liquid fructose groups had increased carbohydrate calorie intake per kilogram of body weight, while protein and fat intake decreased. Although all rats showed pregnancy-related dyslipidemia, the FW group experienced a more pronounced increase. Pregnancy and the FW diet also led to distinct shifts in the fecal gut microbiome. Conclusions: This pregnant rat model highlights the impact of varying fructose diets during physiological stress. Pregnant rats on high-fructose diets (CS, FW) increased their carbohydrate intake at the expense of protein and fat intake when compared with pregnant rats on a routine diet. CS rats showed a marked increase in soft drink intake and urine. These findings have potential nutritional and health implications for pregnancy and long-term health and warrant further investigation and confirmation.