Myo-inositol is a breakdown product of phytate produced in the gut through the action of phytase. Although the effect of phytase-released phosphorus (P) on growth performance of animals has been well characterized, there is still little understanding of effect of myo-inositol. The first objective of this study was to determine the effects of added myo-inositol to a phytate rich low protein diet on growth performance and apparent total tract digestibility (ATTD) in growing piglets. The second objective was to determine whether myo-inositol could directly affect intestinal epithelial cell proliferation and function for which we used intestinal porcine epithelial cells (IPEC-J2). A total of 128 weanling piglets were allotted to four dietary treatments consisting of eight replicates per treatment and four piglets per replicate in a randomized complete block design for four weeks. The four experimental diets comprised the positive control (PC; 20% crude protein (CP), negative control (NC; 17% CP), negative control plus 2.0g/kg myo-inositol (NC+INO; 17% CP) and negative control plus 3000FTU/kg phytase (NC+PHY; 17% CP). Average daily feed intake (ADFI), average daily gain (ADG), gain-feed ratio (G: F) were recorded. Phytase supplementation in the protein-deficient NC diet increased the G:F ratio (P < 0.05) without myo-inositol effect on growth performance. Phosphorus digestibility in the phytase supplemented group increased compared to the PC, NC, and NC+INO groups whereas plasma myo-inositol concentration was significantly higher (P < 0.05) in the NC+INO group. Due to lack of myo-inositol effect on growth performance, an additional in vitro study was conducted to determine direct effect of myo-inositol on the intestinal epithelium that might not be reflected in growth performance. Myo-inositol increased the mRNA abundance of selected nutrient transporters in a concentration-dependent manner (P < 0.05). Myo-inositol also enhanced barrier integrity in the IPEC-J2 monolayer by increasing the transepithelial electrical resistance (TEER) with reduced paracellular permeability of FITC-dextran (P < 0.05). In conclusion, despite the lack of myo-inositol effect on animal performance, the in vitro data indicates that myo-inositol may directly regulate gut barrier integrity. Addition of myo-inositol to pig diets at levels that enhance intestinal epithelial cell function may result in effects on growth performance and gut health of pigs.

中文翻译：

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添加肌醇对饲喂低蛋白高植酸盐日粮的断奶仔猪生长性能和表观全肠道消化率以及肠上皮细胞增殖和功能的影响

肌醇是通过植酸酶的作用在肠道中产生的植酸盐的分解产物。尽管植酸酶释放的磷 (P) 对动物生长性能的影响已得到很好的表征，但对肌醇的影响仍知之甚少。本研究的第一个目标是确定在富含植酸的低蛋白日粮中添加肌醇对生长仔猪生长性能和表观全消化道消化率 (ATTD) 的影响。第二个目标是确定肌醇是否可以直接影响肠上皮细胞增殖和功能，我们使用猪肠上皮细胞 (IPEC-J2)。总共 128 头断奶仔猪被分配到四种饮食处理，每处理八个重复，每个重复四头仔猪，采用随机完整区组设计，为期四个星期。四种实验日粮包括阳性对照（PC；20% 粗蛋白（CP））、阴性对照（NC；17% CP）、阴性对照加 2.0g/kg 肌醇（NC+INO；17% CP）和阴性对照添加 3000FTU/kg 植酸酶（NC+PHY；17% CP）。记录平均日采食量（ADFI）、平均日增重（ADG）、增重比（G:F）。 NC 日粮增加了 G:F 比值 (P < 0.05) 而肌醇对生长性能没有影响。与 PC、NC、和 NC+INO 组，而血浆肌醇浓度在 NC+INO 组中显着更高 (P < 0.05)。由于缺乏肌醇对生长性能的影响，进行了一项额外的体外研究，以确定肌醇对肠上皮细胞的直接影响，这种影响可能不会反映在生长性能中。肌醇以浓度依赖性方式增加所选营养转运蛋白的 mRNA 丰度 (P < 0.05)。肌醇还通过增加跨上皮电阻 (TEER) 和降低 FITC-葡聚糖的细胞旁通透性 (P < 0.05) 来增强 IPEC-J2 单层中的屏障完整性。总之，尽管肌醇对动物性能没有影响，但体外数据表明肌醇可以直接调节肠道屏障的完整性。