College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China.
College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China; Affiliated Cixi Hospital, Wenzhou Medical University, Cixi, 315300, Zhejiang, PR China.
Carbohydr Polym. 2022 Nov 15;296:119971. doi: 10.1016/j.carbpol.2022.119971. Epub 2022 Aug 12.
Exopolysaccharide (EPS) isolated from Lactobacillus helveticus SNA12 were purified, and one fraction (SNA12-EPS) was obtained. The structure of SNA12-EPS was proposed using Fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry, and nuclear magnetic resonance. Results showed that SNA12-EPS was rich in galactose and glucose with the molar ratios of 2.1:1.0, and SNA12-EPS possessed the repeat units of →3)-β-D-Glcp-(1→3)-β-D-Glcp-(1→4)-β-D-Galp-(1→ with an average molecular weight of 3.81 × 10 Da. The scanning electron microscope results showed that SNA12-EPS had a tight structure with a smooth and uneven surface. Furthermore, the prebiotic potential of SNA12-EPS was performed using in vitro simulated digestion with human faecal fermentation. SNA12-EPS was not digested by digestive juice, and it could markedly regulate the gut microbiota composition by increasing the relative abundances of Parabacteroides and Blautia and decreasing the abundance of pathogenic bacteria of Fusobacterium. Additionally, SNA12-EPS improved the ability of gut microbiota to produce short-chain fatty acids.
从瑞士乳杆菌 SNA12 中分离出的胞外多糖（EPS）进行了纯化，并得到了一个部分（SNA12-EPS）。使用傅里叶变换红外光谱、气相色谱-质谱和核磁共振对 SNA12-EPS 的结构进行了推测。结果表明，SNA12-EPS 富含半乳糖和葡萄糖，摩尔比为 2.1:1.0，SNA12-EPS 具有重复单元→3)-β-D-Glcp-(1→3)-β-D-Glcp-(1→4)-β-D-Galp-(1→，平均分子量为 3.81×10 Da。扫描电子显微镜结果表明，SNA12-EPS 具有紧密的结构，表面光滑且不均匀。此外，通过人体粪便发酵的体外模拟消化来评估 SNA12-EPS 的益生元潜力。SNA12-EPS 不能被消化液消化，但可以通过增加 Parabacteroides 和 Blautia 的相对丰度和降低梭菌属等致病菌的丰度来显著调节肠道微生物群落组成。此外，SNA12-EPS 提高了肠道微生物群落产生短链脂肪酸的能力。
