Nutraceutical Additives Modulate Microbiota and Gut Health in Post-Weaned Piglets.

Simple Summary: After piglet weaning, with the exposure to the inherent stress of this productive stage, the intestinal microbiota experiences an imbalance, resulting in a loss of beneficial microbial diversity and the development of potentially pathogenic or opportunistic bacteria. This leads to diarrhea and a decrease in the productivity and parameters of intestinal integrity and health. To address this issue, growth-promoting antibiotics have been used. However, in recent years, the search for nutraceutical compounds that can improve intestinal microbial balance and, thus, reduce antibiotic use has become important. In this regard, the effect of four nutraceutical compounds on piglet intestinal microbiota was evaluated for 30 days post-weaning. Following bioinformatic analyses, we report that essential oil from Lippia origanoides and short-chain fructo-oligosaccharides showed promising effects in reducing weaning-induced intestinal dysbiosis, with a decrease in potentially pathogenic taxa and an increase in bacteria associated with improved productivity and morphometric variables of the intestine, as well as the expression of intestinal barrier proteins. These findings elucidate the mechanisms of microbiota modulation by these compounds, aiming to reduce the use of prophylactic antibiotics and promoting the development of new studies focused on exploring metabolic changes in intestinal microbial communities. Due to the challenge of weaning pigs and the need to reduce the use of antimicrobials in animal feed, there is a growing need to look for nutraceutical alternatives to reduce the adverse effects of the post-weaning period. We evaluate the effect of different feed nutraceutical additives on the microbial communities, gut health biomarkers, and productivity of pigs during the post-weaning period. The study involved 240 piglets weaned on the 21st day of age and randomized to six different diets: D1-BD commercial standard feed, D2-AGP: D1 + 150 ppm zinc bacitracin, D3-MD: D1 + 550 ppm maltodextrin, D4-FOS: D1 + 300 ppm fructo-oligosaccharides, D5-EO: D1 + 70 ppm Lippia origanoides essential oil, and D6-SH: D1 + 750 ppm sodium humate. On day 30 post-weaning, zootechnical parameters were evaluated, and jejunal samples were taken to obtain morphometric variables, expression of barrier and enzymatic proteins, and analysis of microbial communities. Animals fed D4-FOS and D5-EO had the lowest feed conversion ratio and higher expression of barrier and enzymatic proteins compared to D1-BD, D2-AGP, and D3-MD. The use of the additives modified the gut microbial communities of the piglets. In conclusion, fructo-oligosaccharides and Lippia origanoides essential oil were the best alternatives to zinc bacitracin as antibiotic growth promoters. [ABSTRACT FROM AUTHOR]