August 04, 2019

Interpretive Summary: Gastrointestinal morphology and nutrient digestibility in weaned pigs

Interpretive Summary: Rapid Communication: The relationship of enterocyte proliferation with intestinal morphology and nutrient digestibility in weaning piglets.

By: Dr. Caitlin Vonderohe 

In young pigs, weaning stress can negatively affect the architecture and function of the gastrointestinal tract. These alterations, such as reduced villous length, reduced absorptive capacity, and changes in enzyme activity can result in enteric diseases, which can, in turn, result in increased morbidity and mortality. Small intestine function and integrity is dependent on a balance between enterocyte proliferation, differentiation, and death. Enterocyte proliferation changes with the morphology of the small intestine and responds to nutrients present in feed.  A recent rapid communication, “The relationship of enterocyte proliferation with intestinal morphology and nutrient digestibility in weaning piglets” by Wang et al., published in the Journal of Animal Science analyzed the correlation between enterocyte proliferation with villus height, crypt depth, nutrient digestibility, digestive enzyme activity and nutrient transporter expression in weanling piglets.

Sixty-four, 21-day-old weanling piglets were used in this study to measure enterocyte proliferation and villus height/crypt depth. Of these 64 piglets, 42 were used to evaluate intestinal enzyme activity, and 18 used for nutrient digestibility and transporter analysis. Immunohistochemistry was performed for Ki-67, and the number of positive cells per field was counted. Ki-67 is a well-established marker of cell proliferation. On hematoxylin and eosin slides, 20 well-oriented villi and corresponding crypts were measured. Apparent total-tract digestibility was also measured. Lactase and sucrase activity was also measured in jejunal mucosa. SGLT-1 (sodium-glucose transporter 1) and peptide transporter-1 (PEPT-1) protein abundance were measured using a Western Blot.

There was a positive relationship between the number of Ki-67 positive cells (cells undergoing active proliferation) and villus height and crypt depth. This indicates that the micro-architecture of the porcine small intestine is significantly influenced by cellular proliferation. There was also a positive relationship between proliferating (Ki-67+) cells and protein digestibility, but a weak positive relationship with gross energy digestibility. The number of proliferating cells was also positively related to lactase activity, but weakly correlated to sucrase activity. There was also a correlation between nutrient transporter abundance (SGLT-1 and PEPT-1) and proliferating cells. Overall, these results correlated digestive and absorptive capacity to enterocyte proliferation, indicating that cellular proliferation is closely tied to gastrointestinal function and capacity.

Overall, these investigators found that intestinal cell proliferation, measured by the presence of marker Ki-67, is positively correlated with villus height, crypt depth, digestive enzyme function, and intestinal absorptive function. Future studies have an opportunity to study enterocyte proliferation and their ability to improve gastrointestinal morphology and function in young pigs.

To view the full article, visit the Journal of Animal Science