Partial Replacement of Maltodextrin With Galactose in Post‐Weaning Diets of Mice Alters Body Composition and Energy Metabolism in Early‐Life and Programs Hepatic Igf1 Expression in Later‐Life

Galactose, a component of lactose, has nutritional programming power in mice. Lactose-free formulae contain maltodextrin, but no galactose. Here, partly replacing maltodextrin with galactose in the post-weaning diet was investigated for its metabolic and nutritional programming effects. Female and male mice were fed 39 energy% (en%) maltodextrin and 8 en% glucose (CON), or 31 en% maltodextrin with 16 en% galactose (GAL), or 15 en% maltodextrin and 16 en% galactose plus 16 en% glucose (lactose-mimic, LM) from postnatal week (PW) 3 to PW6. Body weight, fat mass, lean mass, energy expenditure (EE), and respiratory exchange ratio (RER) were lower at PW6 in female GAL and LM mice (p < 0.05). After receiving 9 weeks of the same obesogenic high-fat diet, the expression of hepatic insulin-like growth factor 1 (Igf1) appeared lower in both galactose-fed groups in females (p < 0.05). Partly replacing maltodextrin with galactose or galactose plus glucose in a post-weaning diet in mice resulted in significantly lower body weight, fat and lean mass, EE, and RER in early-life, and had no obvious nutritional programming effects except on liver Igf1 mRNA in females in later-life. The implications of this programming effect remain to be investigated further.