Improving intestinal barrier function and intestinal microbiome of weaned piglets fed a low-protein diet through tryptophan and N-Acetylglutamic acid supplementation.

Abstract

The research aimed to evaluate how incorporating NAG and Trp into a low-protein diet affects intestinal functions and alterations in the microbiota, ultimately focusing on enhancing the growth and stress resistance of weaned piglets aged 3-4 weeks.A total of 120 weaned piglets were categorized into five distinct groups: a control group (CON), a low-protein diet group (LP), a low-protein diet group with 0.2% N-acetylglutamic acid (LP + NAG), a low-protein diet group with 0.2% tryptophan (LP + Trp), and a low-protein diet group with 0.2% N-acetylglutamic acid and 0.2% tryptophan (LP + NAG + Trp). The results revealed that the LP + NAG + Trp group exhibited a higher feed-to-gain ratio and improved growth performance, with significantly greater average daily gain and feed intake than the control group. Antioxidant capacity was enhanced, as indicated by elevated levels of catalase and glutathione peroxidase. The expression of tight junction proteins ZO-1 and claudin-1 increased, strengthening the intestinal barrier. Additionally, immunoglobulin levels and the abundance of actinomycetes in the gut microbiota rose, indicating improved immune function and gut health.The increased digestive capacity of the intestine may be linked to the growth in the population of actinomycetes, which is attributed to the combined addition of the NAG + Trp group.