Dietary soya protein during pregnancy and lactation in rats with hereditary kidney disease attenuates disease progression in offspring.

Dietary soya protein substitution for casein initiated at weaning slows disease progression in animal models of chronic renal disease. As there is increasing evidence that fetal programming can have a significant impact on kidney physiology and function in offspring, the objective of the current study was to determine whether exposure to soya protein in the diet earlier than weaning would have further benefits. Han:SPRD-cy (cy/+) breeder rats were fed a casein-based or soya protein-based diet 2 weeks prior to mating, throughout pregnancy and during lactation. Following this maternal period, 3-week-old pups were given either the same or the alternate diet for a 7-week weaning period. Dietary soya protein compared with casein in the maternal or weaning period both independently resulted in less renal inflammation (macrophage infiltration lower by 24% (P=0.0003) and 32% (P<0.001), respectively). When soya protein was given in both feeding periods, the effect was additive. Soya protein substitution for casein resulted in less oxidative damages as indicated by 28% lower oxidized-LDL staining (P=0.013) when present in the maternal period, or in the weaning period (by 56%, P<0.0001). Renal cell proliferation was reduced by 29-33% (P<0.05) in rats given soya protein whether the exposure was during the maternal or weaning period. Soya protein compared with casein in the maternal period also resulted in 33% (P=0.0013) less proteinuria, indicating superior renal function. Dietary soya protein during pregnancy and lactation represents a potential preventative approach in treating for those with congenital kidney diseases.