College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Microb Pathog. 2021 May;154:104856. doi: 10.1016/j.micpath.2021.104856. Epub 2021 Mar 22.
Enterohaemorrhagic Escherichia coli (EHEC) is a prominent foodborne pathogen that causes infectious intestinal diarrhoea. Lactobacillus is a recognized probiotic that inhibits intestinal pathogens and maintains the balance of the intestinal flora. The purpose of this study was to investigate the regulatory effects of three Lactobacillus strains, L. johnsonii, L. plantarum, and L. rhamnosus, on the intestinal flora of EHEC-infected mice. The initial weight and diarrhoea index of the mice were recorded. After 21 days, the faeces of the mice were subjected to 16S rDNA high-throughput sequencing. The diarrhoea index of mice treated with Lactobacillus improved, their body weight continued to rise, and their liver index gradually decreased. The α diversity analysis showed that the intestinal flora diversity and abundance were lower in mice infected with EHEC than in healthy mice. L. plantarum, L. johnsonii, and L. rhamnosus significantly improved the diversity of the flora species. In terms of flora composition, the three main phyla present were Bacteroidetes, Firmicutes, and Proteobacteria. The abundance of these three phyla was reduced to 93.81% after infection and restored to over 96.30% after treatment. At the genus level, Lactobacillus reduced the abundance of Bacteroides, Helicobacter pylori, and Shigella, while increasing the abundance of butyric acid-producing bacteria and Lactobacillus. Finally, a heat map and non-metric multidimensional scaling analysis showed that the intestinal flora structures in the L. johnsonii, L. plantarum, and L. rhamnosus treatment groups were closest to those of healthy mice. In conclusion, L. johnsonii, L. plantarum, and L. rhamnosus regulated and improved the structure of intestinal flora and relieved diarrhoea caused by EHEC infection.
产肠出血性大肠杆菌（EHEC）是一种重要的食源性病原体，可引起感染性肠道腹泻。乳杆菌是一种公认的益生菌，可抑制肠道病原体并维持肠道菌群的平衡。本研究旨在探讨三株乳杆菌（L. johnsonii、L. plantarum 和 L. rhamnosus）对 EHEC 感染小鼠肠道菌群的调节作用。记录小鼠的初始体重和腹泻指数。21 天后，对小鼠粪便进行 16S rDNA 高通量测序。用乳杆菌处理的小鼠腹泻指数改善，体重持续增加，肝指数逐渐降低。α多样性分析表明，与健康小鼠相比，EHEC 感染小鼠的肠道菌群多样性和丰度较低。L. plantarum、L. johnsonii 和 L. rhamnosus 显著提高了菌群种类的多样性。就菌群组成而言，存在的三个主要门是拟杆菌门、厚壁菌门和变形菌门。感染后，这三个门的丰度降低至 93.81%，经治疗后恢复至超过 96.30%。在属水平上，乳杆菌降低了拟杆菌属、幽门螺杆菌属和志贺氏菌属的丰度，同时增加了产丁酸菌属和乳杆菌属的丰度。最后，热图和非度量多维尺度分析显示，L. johnsonii、L. plantarum 和 L. rhamnosus 治疗组的肠道菌群结构与健康小鼠最接近。综上所述，L. johnsonii、L. plantarum 和 L. rhamnosus 调节并改善了肠道菌群结构，缓解了 EHEC 感染引起的腹泻。
