Dietary β-hydroxy-β-methylbutyrate improves intestinal function in weaned piglets after lipopolysaccharide challenge.

Objectives: The aim of this study was to explore the effects of β-hydroxy-β-methylbutyrate (HMB) on intestinal function of lipopolysaccharide (LPS)-challenged piglets.

Methods: Forty weaned piglets were used in a 2 × 2 factorial design. The major factors were challenge (saline or LPS) and diet (basal diet or 0.6% HMB-Ca diet). After 15 d of treatment with LPS or HMB, blood and intestine samples were obtained.

Results: The results showed that in LPS-injected pigs, HMB supplementation significantly increased jejunal villus height and ileal villus height-to-crypt depth ratio and decreased ileal crypt depth (P < 0.05). HMB also improved intestinal function indicated by elevated activities of intestinal mucosal disaccharidase and tricarboxylic acid cycle key enzymes. Furthermore, HMB significantly downregulated mRNA expression of Sirt1 in jejunum and mRNA expression of AMPKα1 and Sirt1 in ileum (P < 0.05), with a concurrent decrease of AMPKα phosphorylation in jejunum and ileum. Microbiota analysis indicated that HMB supplementation significantly increased α-diversity and affected relative abundances of Romboutsia and Sarcina at the genus level, accompanied by increased concentrations of all short-chain fatty acids except propionate in the terminate ileum of LPS-injected piglets.

Conclusion: Dietary HMB supplementation could improve intestinal integrity, function, microbiota communities, and short-chain fatty acid concentrations in LPS-challenged piglets, suggesting its potential usage as a feed additive in weaned piglets to alleviate intestinal dysfunction triggered by immune stress.