Gastrointestinal tracts in pigs’ neonates

Only a few centers specialize in the study of the development of the structure and function of the gastrointestinal tract in newborn animals. Studies in newborn pigs have an impact not only on progress in these animals breeding, but to a large extent can be transferred to the man. Especially the early-born piglets may be regarded as the only model for premature babies.

The development of the mammalian gastrointestinal tract is a complex process that starts prenatally and ends in the early postnatal period. It involves tissue growth combined with cells differentiation and the development of digestive functions, which leads to irreversible gut maturation. Any disruption in this process may generate serious consequences for the neonate such as diarrhea, which often causes high mortality in suckling piglets. This results in great losses in pig breeding, an important branch of the international agricultural and food industry.

Studies on the maturation and functioning of the gastrointestinal tract in newborn piglets are a specialty of Professor Jarosław Woliński and his team at the Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, in Jablonna, Poland. Their research focuses on bioactive colostrum and milk compounds, i.e. hormones, growth factors and cytokines, which may affect gut maturation as well as motor functions of the small intestines on both in vitro and in vivo models. The researchers established the unique animal model that enables nursing and rearing of neonatal piglets in controlled laboratory conditions. Many of their collaborators are from Lund University, Sweden. The scientific results of this group have been presented in numerous scientific conferences and published in reputable journals.

Professor Woliński’s team have shown that leptin, ghrelin and obestatin – gastrointestinal peptides involved in energy expenditure – are also present in colostrum and milk, and, when given orally to suckling animals, they significantly influence intestinal maturation. Interestingly, enteral administration of leptin and ghrelin regulates the process of autophagy in the small intestine epithelium. Autophagy is a cellular process that breaks down cellular components to promote cellular survival during starvation by maintaining energy levels. It was down-regulated after enteral administration of leptin and up-regulated after ghrelin treatment. The team believes that leptin/ghrelin control of autophagy is the effect of physiological control of energy balance at the epithelial cell level.

The last decade brought much evidence that a neonate pig is the best model for studying the physiology and pathophysiology of the gastrointestinal tract in the human neonate. Various aspects of intestinal motor function appear to be the most critical problems, resulting in feeding intolerance in low-birthweight infants. The motility of the small intestine is considerably less organised in premature infants than in term infants. This is caused by an intrinsic immaturity of the enteric nervous system that delays transit, causing subsequent bacterial overgrowth and distension from gases that are the byproducts of fermentation.

Woliński’s research group has recently been interested in nutritional programming, a phenomenon based on epidemiological and animal model studies which have shown that development and growth during the early life period is markedly influenced by maternal health and diet composition. Maternal diet influences the metabolic status and plays a crucial role in the development of metabolic functions in offspring and their risk of metabolic diseases in adulthood. Dr Monika Słupecka, from this team, investigates the role of maternal high-fat diet on the development of the gastrointestinal tract in offspring and the ability of obestatin to influence gut maturation and reverse maternal programming. The project includes studies on human and animal models. The preliminary results show that obestatin expression differs according to the mother’s diet, and enteral administration of this peptide significantly influences the intestinal contractility. As the project researchers are also members of the Polish Foundation of the Bank of Milk, they hope that studies on obestatin’s role in neonates and also observations on its fluctuations in mother’s milk and its availability for neonates will aid in choosing the proper milk, derived from the right donor mother, for feeding pre-term babies.

Professor Woliński’s group also participates in the scientific consortium established to investigate the role of bacterial-origin pancreatic enzymes in the development of the exocrine pancreas function in neonatal and growing animals. They are open to co-operation with individuals from a similar specialisation.

Participation of the Kielanowski Institute of Animal Physiology and Nutrition as a partner in the projects of Horizon 2020 would have significant effects on its scientific activities and raise the prestige of the institute in the country and across the EU.

Professor Tomasz Misztal
Director
The Kielanowski Institute of Animal Physiology and Nutrition
Polish Academy of Sciences
tel: +48 22 76 53 301
[email protected]
www.ifzz.pl