Intrauterine growth retardation (IUGR) is defined as the impaired growth and development of a mammalian embryo/fetus or fetal organs during pregnancy and is a major concern in pig farming. IUGR animals exhibit impaired growth and development, lower meat quality, and higher morbidity and mortality after birth. About 25% of newborn piglets suffered from IUGR, and even died in swine production. Therefore, IUGR is a major problem for the pig industry due to the lack of comprehensive understanding of the IUGR piglets' growth regulation mechanism.

Recently, Xiangfeng Kong's research team from the Institute of Subtropical Agriculture, Chinese Academy of Sciences, systematically investigated the growth and development, body metabolism, and intestinal microecological profiles of normal birth weight pigs and IUGR pigs during different growth stages. Further combined with Fecal Microbial Transplantation and Germ-free mice verified that the IUGR altered the diversity of intestinal microbiota and their metabolic pathways, resulting in abnormal intestinal energy, amino acids, and bile acid metabolism, which hindered the later growth and development of IUGR pigs. The application of dietary bile acid showed that bile acid supplementation could improve liver function, enhance the relative abundances of potentially beneficial bacteria in the intestine, and alleviate intestinal mucosal oxidative damage of IUGR piglets. In addition, dietary bile acid supplementation can also improve the colonic barrier function and redox status of IUGR piglets, which is beneficial to intestinal health. These findings suggest that the intestinal microbiota can be used as targets for regulating IUGR, and bile acids play an important role in improving IUGR metabolism and maintaining intestinal health in piglets.

These research results have been successively published in J Anim Sci Biotechnol, Front Microbiol, Front Nutr, J Appl Microbiol, and Chinese Journal of Animal Nutrition. This research was jointly funded by the Key Project of Regional Innovation and Development Joint Fund of National Natural Science Foundation of China (U20A2056), National Natural Science Foundation of China (31772613), National Key Research and Development Project (2017YFD0500503), and the Special Funds for Construction of Innovative Provinces in Hunan Province (2019RS3022).

More details could be found at https://doi.org/10.1186/s40104-020-00490-x, https://doi.org/10.1111/jam.14304, https://doi.org/10.1186/s40104-022-00772-6, https://doi.org/10.3389/fmicb.2022.989060, https://doi.org/10.3389/fmicb.2022.1053128, https://doi.org/10.3389/fnut.2022.991812.

Contact: Xiangfeng Kong

E-mail: nnkxf@isa.ac.cn

Institute of Subtropical Agriculture, Chinese Academy of Sciences

Figure Schematic diagram of bile acid metabolism in normal birth weight (NBW) piglets and IUGR piglets.(Image by Yang Liu)