The transgenerational effects of maternal low-protein diet during lactation on offspring.

Environmental factors such as diet and lifestyle can influence the health of both mothers and offspring. However, its transgenerational transmission and underlying mechanisms remain largely unknown. Here, using a maternal lactation-period low-protein diet (LPD) mouse model, we show that maternal LPD during lactation causes decreased survival and stunted growth, significantly reduces ovulation and litter size, and alters the gut microbiome in the female LPD-F1 offspring. The transcriptome of LPD-F1 metaphase II (MII) oocytes shows that differentially expressed genes are enriched in female pregnancy and multiple metabolic processes. Moreover, maternal LPD causes early stunted growth and impairs metabolic health, which is transmitted over two generations. The methylome alteration of LPD-F1 oocytes can be partly transmitted to the F2 oocytes. Together, our results reveal that LPD during lactation transgenerationally affects offspring health, probably via oocyte epigenetic changes.