Scholarlink

Background <p>Tibetan sheep grazing on the Qinghai-Tibet Plateau require dietary protein supplementation; however, they face economic constraints due to the high cost of feed transportation in this region. Given that the leucine metabolite β-hydroxy-β-methyl butyrate (HMB) enhances both protein synthesis and intestinal nutrient absorption, this study employed metagenomics and untargeted metabolomics to systematically evaluate HMB's effects on antioxidant capacity, immune response, microbiota, metabolites, and the health of the small intestine in Tibetan sheep. A total of&#xa0;120&#xa0;healthy&#xa0;weaned 60-day-old male Tibetan lambs were assigned to diets containing 0&#xa0;mg/kg (control group, CON), 430&#xa0;mg/kg (low HMB, L-HMB), 715&#xa0;mg/kg (medium HMB, M-HMB), or 1,000&#xa0;mg/kg (high HMB, H-HMB) for 90&#xa0;d. At the end of the experiment, 6 lambs from each group were slaughtered for intestinal tissue and content sampling.</p> Results <p>The M-HMB treatment significantly increased average daily gain of the lambs without affecting feed intake, thereby improving feed utilization efficiency. M-HMB promoted the development of small intestinal morphological and elevated villus height, while also enhancing the activities of digestive enzyme and disaccharidase activities. Furthermore, M-HMB enhanced the antioxidant capacity, immune response, and barrier function of the small intestine. Metagenomic analysis revealed that M-HMB supplementation improved the composition of the small intestinal microbiota in Tibetan sheep, specifically increasing the relative abundance of <i>Ruminococcus bacterium P7</i> and <i>R. bromii</i>, and enhanced microbial carbohydrate degradation capacity. Metabolomic analysis demonstrated that M-HMB supplementation significantly altered the small intestinal metabolite profile, enhancing carbohydrate metabolic pathways and increased the production of short-chain fatty acids (SCFAs). M-HMB upregulated PLCβ1 and ERK1/2 protein expression levels in small intestinal tissue and elevated the proportion of Ki67-positive cells at the basal crypt region of small intestinal crypts, suggesting enhanced proliferative activity of intestinal epithelial cells.</p> Conclusions <p>In summary, dietary supplementation with M-HMB (715&#xa0;mg/kg) promoted small intestinal growth and development, enhanced digestive and absorptive functions, optimized the microbial composition, improved carbohydrate degradation, and increased the production of SCFAs, ultimately improving the growth performance of Tibetan sheep lambs.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Dietary β-hydroxy-β-methyl butyrate supplementation improves intestinal health and growth performance in Tibetan sheep lambs via modulating small intestinal microbiota

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年2月9日

查看全文
  • Jieqiong Cai,
  • Weibin Wu,
  • Lamei Wang,
  • Dandan Meng,
  • Hao Yang,
  • Shimin Liu,
  • Shengzhen Hou,
  • Yangchun Cao

摘要

Background

Tibetan sheep grazing on the Qinghai-Tibet Plateau require dietary protein supplementation; however, they face economic constraints due to the high cost of feed transportation in this region. Given that the leucine metabolite β-hydroxy-β-methyl butyrate (HMB) enhances both protein synthesis and intestinal nutrient absorption, this study employed metagenomics and untargeted metabolomics to systematically evaluate HMB's effects on antioxidant capacity, immune response, microbiota, metabolites, and the health of the small intestine in Tibetan sheep. A total of 120 healthy weaned 60-day-old male Tibetan lambs were assigned to diets containing 0 mg/kg (control group, CON), 430 mg/kg (low HMB, L-HMB), 715 mg/kg (medium HMB, M-HMB), or 1,000 mg/kg (high HMB, H-HMB) for 90 d. At the end of the experiment, 6 lambs from each group were slaughtered for intestinal tissue and content sampling.

Results

The M-HMB treatment significantly increased average daily gain of the lambs without affecting feed intake, thereby improving feed utilization efficiency. M-HMB promoted the development of small intestinal morphological and elevated villus height, while also enhancing the activities of digestive enzyme and disaccharidase activities. Furthermore, M-HMB enhanced the antioxidant capacity, immune response, and barrier function of the small intestine. Metagenomic analysis revealed that M-HMB supplementation improved the composition of the small intestinal microbiota in Tibetan sheep, specifically increasing the relative abundance of Ruminococcus bacterium P7 and R. bromii, and enhanced microbial carbohydrate degradation capacity. Metabolomic analysis demonstrated that M-HMB supplementation significantly altered the small intestinal metabolite profile, enhancing carbohydrate metabolic pathways and increased the production of short-chain fatty acids (SCFAs). M-HMB upregulated PLCβ1 and ERK1/2 protein expression levels in small intestinal tissue and elevated the proportion of Ki67-positive cells at the basal crypt region of small intestinal crypts, suggesting enhanced proliferative activity of intestinal epithelial cells.

Conclusions

In summary, dietary supplementation with M-HMB (715 mg/kg) promoted small intestinal growth and development, enhanced digestive and absorptive functions, optimized the microbial composition, improved carbohydrate degradation, and increased the production of SCFAs, ultimately improving the growth performance of Tibetan sheep lambs.

Graphical Abstract