The interaction of the gut microbiota with key metabolic and physiological processes may be associated with poor growth outcomes in animals born with intrauterine growth restriction (IUGR). Growth performance, plasma hormone concentrations, and intestinal microbiota composition were analyzed in IUGR pigs and in normal birth weight (NBW) pigs when the NBW pigs reached 25, 50, and 100 kg of body weight (BW). Compared to NBW pigs, IUGR pigs had lower initial, weaned, and final BW, and lower average daily gain and average daily feed intake in all the considered time points. In the 25 kg BW group, IUGR pigs had higher concentrations of plasma ghrelin and pancreatic polypeptide (PP), but lower insulin concentration than NBW pigs, while the situation was reversed in the 50 kg BW group. As compared to NBW pigs, IUGR pigs had higher microbial alpha diversity in the jejunum and ileum; in the 50 and 100 kg BW groups, IUGR pigs had higher Firmicutes abundance but lower Proteobacteria abundance in the jejunum, and lower Lactobacillus abundance in the jejunum and ileum; in the 25 kg BW group, IUGR pigs showed higher unclassified Ruminococcaceae abundance in the ileum; and in 25 and 50 kg BW groups, IUGR pigs showed lower Ochrobactrum abundance in the jejunum. Spearman’s correlation revealed that Lactobacillus was negatively correlated with growth performance, while unclassified Ruminococcaceae was positively correlated. Predictive metagenomic analysis detected significantly different expression of genes in the intestinal microbiota between IUGR and NBW pigs, suggesting different metabolic capabilities between the two groups. Growing-finishing IUGR pigs showed lower growth performance, higher microbial alpha diversity, and differences in plasma hormone concentrations compared to NBW pigs. Alterations in the abundance of Firmicutes, Proteobacteria, Ruminococcaceae, Lactobacillus, and Ochrobactrum in the small intestine may be associated with IUGR, and may therefore serve as a future target for gut microbiota intervention in growing-finishing IUGR pigs.

中文翻译：

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宫内生长受限会改变生长肥育猪的生长性能、血浆激素和小肠微生物群落。

肠道微生物群与关键代谢和生理过程的相互作用可能与出生时患有宫内生长受限 (IUGR) 的动物的不良生长结果有关。当 NBW 猪达到 25、50 和 100 kg 体重 (BW) 时，分析了 IUGR 猪和正常出生体重 (NBW) 猪的生长性能、血浆激素浓度和肠道微生物群组成。与 NBW 猪相比，IUGR 猪在所有考虑的时间点具有较低的初始、断奶和最终 BW，以及较低的平均日增重和平均日采食量。在 25 kg BW 组中，IUGR 猪的血浆 ghrelin 和胰多肽 (PP) 浓度较高，但胰岛素浓度低于 NBW 猪，而 50 kg BW 组的情况则相反。与 NBW 猪相比，IUGR 猪在空肠和回肠中具有较高的微生物 α 多样性；在 50 和 100 kg BW 组中，IUGR 猪在空肠中厚壁菌门丰度较高，但变形杆菌丰度较低，而空肠和回肠中乳酸杆菌丰度较低；在 25 kg BW 组中，IUGR 猪的回肠未分类瘤胃球菌科丰度较高；在 25 和 50 kg BW 组中，IUGR 猪在空肠中的 Ochrobactrum 丰度较低。Spearman 的相关性表明，乳酸菌与生长性能呈负相关，而未分类的瘤胃球菌科呈正相关。预测性宏基因组分析检测到 IUGR 和 NBW 猪肠道微生物群中基因的表达存在显着差异，表明两组之间的代谢能力不同。与 NBW 猪相比，生长育肥 IUGR 猪表现出较低的生长性能、较高的微生物 α 多样性以及血浆激素浓度的差异。小肠中厚壁菌门、变形菌门、瘤胃球菌科、乳杆菌和黄杆菌的丰度变化可能与 IUGR 相关，因此可能作为未来生长育肥 IUGR 猪肠道微生物群干预的目标。