Proceedings of The Physiological Society

Obesity (2014) Proc Physiol Soc 32, PC026

Poster Communications

Maternal dietary supplementation of fatty acids and its effects on milk composition and adipose tissue development in the offspring

R. M. Woods1, M. Birtwistle1, G. Davies1, V. Perry3, H. Budge1, F. Wiens2, M. E. Symonds1

1. Early Life Nutrition Research Unit, University of Nottingham, Nottingham, United Kingdom. 2. Danone Research Centre for Specialized Nutrition, Nutricia, Utrecht, Netherlands. 3. School of Veterinary Medicine and Science, University of Nottingham, Nottingham, United Kingdom.

Background and Aims: Brown adipose tissue (BAT) is essential in enabling the newborn to effectively adapt to cold exposure of the extra-uterine environment (1). In sheep, during postnatal development BAT is rapidly replaced by white adipose tissue, an adaptation determined in part by the maternal metabolic and endocrine environment (2). One dietary factor that may influence this process is the milk content of conjugated linoleic acid (CLA) which, in vitro, has been shown to promote the abundance of the BAT specific uncoupling protein (UCP) 1. In most mammals, the cis-9, trans-11 isomer is the most abundant CLA isomer in milk (3). The aim of this study was, therefore, to determine whether maternal dietary supplementation to increase milk CLA, in particular the cis-9, trans-11 isomer, would promote the retention of BAT during postnatal development.Methods:From the first day of lactation, sheep were fed daily either a standard diet (n=8) of concentrate (1.5 kg/day) with hay (1.5/kg day) or the same diet plus 3% sunflower oil (SO; n=7). Each mother raised 2 lambs. Milk samples were collected from each mother at 7 and 28 days of lactation, immediately before one lamb was blood sampled, euthanased with an intravenous injection (Pentobarbital Sodium, 200mg/kg body weight) and tissue sampled. Samples of perirenal adipose tissue were weighed and stored at -80°C, then analysed for gene expression for UCP1. This work was carried out under UK Home Office approval. Values are means ±S.E.M. compared by an unpaired T test.Results: Supplementation of the maternal diet with SO resulted in an increase of the total CLA at 28 days (Control, n=8, 7.247±0.60; SO, n=7, 13.54±0.54 mg/g fat, p<0.0001). The most abundant isomer, cis-9, trans-11 was also higher in the SO group (Control, n=8, 6.3±0.53; SO, n=7, 11.64±0.51 mg/g fat, p<0.0001). This was accompanied with a greater abundance of perirenal adipose tissue in females (Control 10.23±2.06; SO 18.04±1.03 g/kg bodyweight, n=5 per group, p=0.005). There were also gender differences in the SO group, with males possessing less perirenal adipose tissue (Females, n=5, 18.04±1.03; males, n=4, 7.42±0.74 g/kg body weight, p<0.0001). The greater fat mass in female offspring fed SO was also accompanied by an increased mRNA expression of UCP1 (Control 0.36±0.02; SO 0.47±0.03 arbitrary units, n=5 per group, p=0.01).Conclusions: The addition of SO to the maternal diet increases the cis-9, trans-11 CLA content of the milk and promotes fat deposition in the female offspring. Future analysis will determine whether this is depot specific and the extent to which amount of UCP1 is also raised.

Where applicable, experiments conform with Society ethical requirements