Intestinal microorganisms have been shown to be important factors affecting the growth performance of pigs. Therefore, to investigate the effect of the intestinal microflora structure on the growth performance of pigs, samples from Duroc (n = 10), Landrace (n = 9) and Yorkshire (n = 21) pigs under the same diet and feeding conditions were collected. The fecal microbial composition was profiled via 16S ribosomal RNA (rRNA) gene sequencing. We also analyzed their growth performance. We found that Duroc and Landrace pigs had significant differences in average daily gain (ADG), feed efficiency ratio (FER), growth index (GI), and number of days taken to reach 100 kg (P < 0.05). Moreover, through analysis of the intestinal flora, we also identified 18 species of intestinal flora with significant differences between Duroc and Landrace pigs (P < 0.05). To eliminate the influence of genetic background, the differential intestinal flora of 21 Yorkshire pigs with differences in growth performance was analyzed. The results showed that there were significant correlations between Barnesiella, Dorea, Clostridium and Lactobacillus and pig growth performance. To explore the effect of the intestinal flora on the growth performance of pigs at the molecular level, Lactobacillus, which is the most abundant in the intestine, was selected for isolation and purification and cocultured with intestinal epithelial cells. qPCR was used to determine the effect of Lactobacillus on MC4R gene expression in intestinal epithelial cells. The results showed that Lactobacillus inhibited MC4R gene expression in these cells. The results provide a useful reference for further study of the relationship between the intestinal flora and pig growth performance.

肠道微生物已被证明是影响猪生长性能的重要因素。因此，为了研究肠道菌群结构对猪生长性能的影响，收集了杜洛克（n = 10），长白猪（n = 9）和约克郡（n = 21）猪在相同饮食和喂养条件下的样本。通过16S核糖体RNA（rRNA）基因测序分析了粪便微生物的组成。我们还分析了它们的增长表现。我们发现杜洛克和长白猪的平均日增重（ADG），饲料效率比（FER），生长指数（GI）和达到100公斤的天数具有显着差异（P  <  0.05）。此外，通过对肠道菌群的分析，我们还确定了18种肠道菌群，杜洛克猪和长白猪之间存在显着差异（P  <  0.05）。为了消除遗传背景的影响，分析了生长性能不同的21只约克夏猪的不同肠道菌群。结果表明，有间显著相关Barnesiella，Dorea，梭状芽孢杆菌和乳酸杆菌和猪的生长性能。探索在分子水平上，对猪的生长性能肠道菌群的效果乳杆菌选择肠中最丰富的，进行分离和纯化，并与肠上皮细胞共培养。qPCR用于确定乳杆菌对肠上皮细胞MC4R基因表达的影响。结果表明，乳杆菌抑制了这些细胞中的MC4R基因表达。研究结果为进一步研究肠道菌群与猪生长性能之间的关系提供了有益的参考。