The influence of maternal diet on offspring development and liver metabolism

Altering maternal nutrition affects fetal development and can have long-lasting effects on the offspring, potentially predisposing them to later metabolic disease. These effects can occur without affecting birth weight, although small for date offspring appear to be at increased risk. One mechanism linking changes in the maternal environment to an increased risk of later disease is enhanced exposure to glucocorticoids (GC). Tissue sensitivity to cortisol is regulated, in part, by the GC receptor (GR) and 11-beta-hydroxysteroid dehydrogenase (11βHSD) types 1 and 2. Several studies have shown the effects of maternal nutrient restriction on the programming of GC action in the offspring, however, dietary excess is far more characteristic of the diets consumed by contemporary pregnant women. The aim of this thesis was to provide a novel insight into the effects of moderate changes in the macronutrient ratio, within the maternal diet fed to pigs (whilst maintaining energy content), on offspring growth, development and liver metabolism until adolescence. Fat supplementation (Fat supplemented (FS): 9 %; Control (C): 2.5 %) from day 0 until 110 of gestation, reduced maternal glucose tolerance at term and decreased the survival rate of piglets after birth, possibly due to hypoglycaemia. In addition, supplementing the maternal diet with protein (Protein supplemented (PS): 16.3 %; C: 12.3 %) also increased the incidence of postnatal mortality, with surviving offspring demonstrating an up-regulation of mRNA transcripts involved in GC sensitivity i.e. GC receptor and 11βHSD-1, in the liver. Furthermore, this thesis demonstrated no negative effects of accelerated postnatal growth on low-birth weight piglets as others have suggested. In conclusion, this thesis has demonstrated a detrimental effect of fat and protein supplementation until day 110 of gestation on postnatal mortality. These findings could have profound consequences for the pig industry where reducing piglet mortality is of economic importance. In addition, an increased level of protein in the diet during gestation increases GC sensitivity in the offspring which may be indicative of excess GC exposure in utero. These types of adaptations could have significant implications in determining the programming effects of maternal diet on adult disease risk.EThOS - Electronic Theses Online ServiceGBUnited Kingdo