Data from: Olive oil bioactives protect pigs against experimentally-induced chronic inflammation independently of alterations in gut microbiota

Subclinical chronic inflammation (SCI) is associated with impaired animal growth. Previous work has demonstrated that olive-derived plant bioactives exhibit anti-inflammatory properties that could possibly counteract the growth-depressing effects of SCI. To test this hypothesis and define the underlying mechanism, we conducted a 30-day study in which piglets fed an olive-oil bioactive extract (OBE) and their control counterparts (C+) were injected repeatedly during the last 10 days of the study with increasing doses of Escherichia coli lipopolysaccharides (LPS) to induce SCI. A third group of piglets remained untreated throughout the study and served as a negative control (C-). In C+ pigs, SCI increased the circulating concentration of interleukin 1 beta (p < 0.001) and decreased feed ingestion (p < 0.05) and weight gain (p < 0.05). These responses were not observed in OBE animals. Although intestinal inflammation and colonic microbial ecology was not altered by treatments, OBE enhanced ileal mRNA abundance of tight and adherens junctional proteins (p < 0.05) and plasma recovery of mannitol (p < 0.05) compared with C+ and C-. In line with these findings, OBE improved transepithelial electrical resistance (p < 0.01) in TNF-α-challenged Caco-2/TC-7 cells, and repressed the production of inflammatory cytokines (p < 0.05) in LPS-stimulated macrophages. In summary, this work demonstrates that OBE attenuates the suppressing effect of SCI on animal growth through a mechanism that appears to involve improvements in intestinal integrity unrelated to alterations in gut microbial ecology and function.

亚临床慢性炎症（subclinical chronic inflammation, SCI）与动物生长受损密切相关。既往研究表明，橄榄来源的植物生物活性物质具有抗炎特性，有望拮抗亚临床慢性炎症所引发的生长抑制效应。为验证该假说并阐明其潜在机制，本研究开展了一项为期30天的动物实验：将受试仔猪分为三组，其中饲喂橄榄油生物活性提取物（olive-oil bioactive extract, OBE）的实验组与阳性对照组（C+）在实验最后10天，反复注射梯度剂量的大肠杆菌脂多糖（Escherichia coli lipopolysaccharides, LPS）以构建亚临床慢性炎症模型；第三组仔猪全程不予任何处理，作为阴性对照组（C-）。在阳性对照组仔猪中，亚临床慢性炎症可使循环中白细胞介素1β（interleukin 1 beta）的浓度显著升高（p < 0.001），同时降低仔猪的采食量（p < 0.05）与体重增重（p < 0.05），而在橄榄油生物活性提取物组仔猪中，未观察到上述异常变化。尽管各处理组均未改变肠道炎症状态与结肠微生物生态，但与阳性对照组及阴性对照组相比，橄榄油生物活性提取物组可显著提升回肠紧密连接与黏附连接蛋白的mRNA表达丰度（p < 0.05），同时升高血浆甘露醇回收率（p < 0.05）。与上述结果一致，橄榄油生物活性提取物可显著提升肿瘤坏死因子α（TNF-α）刺激后的Caco-2/TC-7细胞的跨上皮电阻（p < 0.01），并抑制脂多糖刺激的巨噬细胞中炎性细胞因子的产生（p < 0.05）。综上，本研究表明，橄榄油生物活性提取物可通过改善肠道屏障完整性（而非改变肠道微生物生态及其功能）的途径，拮抗亚临床慢性炎症对动物生长的抑制效应。