Chen Yingying, You Yingting, Ren Lizhen, Fu Guilin, Zhou Naiji, Xiao Yuncai, Shi Deshi
State Key Laboratory of Agriculture Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
Microorganisms. 2025 Jun 28;13(7):1518. doi: 10.3390/microorganisms13071518.
This study aimed to identify the heat-resistant bioactive components of HDRsEf1 (HDRsEf1) and investigate their beneficial mechanism. Heat-treated culture supernatants of HDRsEf1 significantly suppressed expression in LPS-stimulated MODE-K cells ( < 0.001), indicating the presence of heat-resistant anti-inflammatory components. Crude protein (P-Ef1) and crude expolysaccharide (EPS-Ef1) were isolated from an HDRsEf1 culture supernatant using ammonium sulfate and ethanal precipitation. Critically, only crude EPS-Ef1 retained an anti-inflammatory effect after heat treatment, while crude P-Ef1 lost this activity. Further investigation revealed that crude EPS-Ef1 (25 μg/mL) promoted MODE-K cell proliferation via EdU assays ( < 0.001), potentially through an upregulation of mRNA expression ( < 0.001). Animal studies demonstrated that an oral administration of crude EPS-Ef1 (4 mg/kg bw, 14 days) significantly increased body weight gain and jejunal crypt depth ( < 0.05) while reducing intestinal mRNA levels ( < 0.001). These in vivo findings are consistent with in vitro observations. A structural analysis using HPAEC and SEC-MALLS-RI characterized crude EPS-Ef1 as a heteropolysaccharide (Mw 80.3 kDa) with a near-spherical conformation (slope 0.13) composed of mannose, glucose, glucuronic acid, and galactose (5.4:4.4:1.2:1). In summary, this study identifies crude EPS-Ef1 as the heat-resistant postbiotic component. Crude EPS-Ef1 possesses the dual effects of suppressing intestinal inflammation and promoting intestinal epithelial cell proliferation, which provides a theoretical foundation for a crude EPS-Ef1-based postbiotic.
本研究旨在鉴定热抗性双歧杆菌发酵乳杆菌 Ef1（HDRsEf1）的生物活性成分，并研究其有益机制。HDRsEf1 的热处理培养上清液显著抑制 LPS 刺激的 MODE-K 细胞中的表达（<0.001），表明存在耐热抗炎成分。使用硫酸铵和乙醛沉淀从 HDRsEf1 培养上清液中分离出粗蛋白（P-Ef1）和粗胞外多糖（EPS-Ef1）。至关重要的是，只有粗 EPS-Ef1 在热处理后仍保留抗炎作用，而粗 P-Ef1 失去了这种活性。进一步研究表明，粗 EPS-Ef1（25μg/mL）通过 EdU 试验促进 MODE-K 细胞增殖（<0.001），可能是通过上调 mRNA 表达（<0.001）。动物研究表明，口服粗 EPS-Ef1（4mg/kg bw，14 天）显著增加体重增加和空肠隐窝深度（<0.05），同时降低肠道 mRNA 水平（<0.001）。这些体内研究结果与体外观察结果一致。使用 HPAEC 和 SEC-MALLS-RI 进行的结构分析将粗 EPS-Ef1 表征为一种杂多糖（Mw 80.3 kDa），具有由甘露糖、葡萄糖、葡萄糖醛酸和半乳糖（5.4:4.4:1.2:1）组成的近球形构象（斜率 0.13）。总之，本研究将粗 EPS-Ef1 鉴定为耐热后生元成分。粗 EPS-Ef1 具有抑制肠道炎症和促进肠道上皮细胞增殖的双重作用，为基于粗 EPS-Ef1 的后生元提供了理论基础。
