Comparative Gut Physiology Symposium
The 2021 ASAS Comparative Gut Physiology Symposium focused on the integration of parents and offspring in the promotion, evaluation, and improvement of gut health. Overall, the speakers agreed that there are very defined times in young animal lives, before and after birth, when an intervention can improve, or in some cases, decrease their potential for health and productivity.
Dr. Adam Moeser first presented work his lab has performed linking early exposure to stress to development of gastrointestinal and immune diseases. If a pig, particularly a female pig, is exposed to early life stress, that animal is more likely to experience long term inflammation, leaky gut, and shifts in mucosal nutrient transport. Additionally, mast cells from stressed animals tend to be more reactive, causing greater levels of bystander damage when stimulated, resulting in greater inflammation, reductions in growth performance, and increased susceptibility to pathogens.
Dr. Kjiersti Aagaard next presented the human biomendical perspective on the early establishment of the microbiome, and how it is affected by how and how early a baby is born, antimicrobial use, and maternal diet. The placenta contains low abundance, poor richness levels of microbiota, making it a potential site of infant gut modulation. Additionally, changes in the infant microbiota and metabolome, brought about by a high fat maternal diet, can persist long after birth. Overall, Dr. Aagaard hypothesized that the placenta is not a sterile connection between mom and baby; it may be using microbiota to “train” the fetal gut and immune system to tolerate commensal bacteria.
Dr. Michael Steele presented the dairy perspective on early and maternal nutrition; gut health is a massive issue in dairy calves, as are growth and colostrum management. Overall, there are multiple opportunities to improve calf health and eventual productivity by increasing milk and colostrum feeding, slowing the transition between colostrum and mature milk and appropriate use of prebiotics to improve gut health and commensal microbiota colonization.
Dr. Stafford Vigors presented work on the development of the piglet microbiome, focusing on potential times and means to improve piglet performance by using a supplement to alter the microbiome of the sow. The experiment he described showed limited correlation between the fecal microbiome of the sow and the cecal and colonic microbiota of the piglet, however there were improvements in growth performance and lower incidence of post-weaning diarrhea in the piglets from supplemented sows.
Dr. Nadia Everaert specifically focused on nutritional strategies to improve piglet microbiota colonization by manipulating the sow diet. Changes observed in piglets after the microbiota of the sow has been nutritionally manipulated are likely due to a combination of limited in-utero colonization, short-term colonization in the birth canal by the vaginal microbiome, post-natal piglet interaction with the sows skin, nipples and feces, consumption of milk oligosaccharides that select for specific bacterial families, and other environmental factors.
Finally, Dr.Rajesh Jha closed the symposium by discussing his work in poultry. He presented interesting work that successfully used in-ovo exposure to prebiotics to improve bird growth and performance, demonstrating that early, even prenatal interventions can improve outcomes in both birds and mammals.