Department of Food Science and Engineering, Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, Zhejiang Provincial Key Laboratory of Animal Protein Food Intensive Processing Technology, Ningbo University, Ningbo, China.
Foodborne Pathog Dis. 2023 Nov;20(11):521-530. doi: 10.1089/fpd.2023.0039. Epub 2023 Sep 19.
The human gut flora is highly diverse. Most lactic acid bacteria (LAB) are widely used as probiotics in human and animal husbandry and have a variety of physiological benefits. This article mainly studied the bacteriostatic ability of LAB against four pathogenic bacteria, gastrointestinal environment tolerance, and adhesion ability to Caco-2 cells. The genome of L461 was sequenced and analyzed. The results showed that strains F512, L461, and D469 had the most significant inhibitory effects on , , , and . In addition, strains L461, C502, and P231 showed good tolerance after exposure to simulated gastric fluid for 0-4 h. Strains C502, H781, and L461 showed good tolerance in simulated intestinal fluid. Strains L461 and H781 showed good adhesion to Caco-2 cells. The number of viable bacteria was more than 60. Therefore, we screened L461 from 12 LAB strains through three aspects of evaluation, and conducted whole genome sequencing and analysis. Sequencing results showed that L461 had more defense mechanisms and phage annotation genes than WCFS1. Virulence factor studies showed that L461 has iron absorption system and adhesion-related gene annotation, indicating that L461 has survival advantage in intestinal tract. The predicted results showed that there were eight phages with phage resistance in L461. L461 is sensitive to several antibiotics, notably penicillin and oxacillin. In summary, the results of this study prove that L461 has good prebiotic function and is safe. Therefore, L461 can be safely used as a potential functional probiotic.
人体肠道菌群高度多样化。大多数乳酸菌（LAB）广泛应用于人和动物的养殖业中，具有多种生理益处。本文主要研究了 LAB 对四种致病菌的抑菌能力、胃肠道环境耐受能力和对 Caco-2 细胞的黏附能力。对 L461 进行了基因组测序和分析。结果表明，菌株 F512、L461 和 D469 对 、 、 、 的抑制效果最为显著。此外，菌株 L461、C502 和 P231 在模拟胃液中暴露 0-4 h 后表现出良好的耐受能力。菌株 C502、H781 和 L461 在模拟肠液中表现出良好的耐受能力。菌株 L461 和 H781 对 Caco-2 细胞具有良好的黏附能力。活菌数超过 60。因此，我们通过三个方面的评估，从 12 株 LAB 菌株中筛选出 L461，并进行了全基因组测序和分析。测序结果表明，L461 比 WCFS1 具有更多的防御机制和噬菌体注释基因。毒力因子研究表明，L461 具有铁吸收系统和黏附相关基因注释，表明 L461 在肠道中具有生存优势。预测结果表明，L461 中有 8 个噬菌体具有噬菌体抗性。L461 对几种抗生素敏感，特别是青霉素和苯唑西林。综上所述，本研究结果证明 L461 具有良好的益生元功能和安全性。因此，L461 可以安全地用作潜在的功能性益生菌。
