AUTHOR=Zhong Yifan , Fu Dongyan , Deng Zhaoxi , Tang Wenjie , Mao Jiangdi , Zhu Tao , Zhang Yu , Liu Jianxin , Wang Haifeng 

TITLE=Lactic Acid Bacteria Mixture Isolated From Wild Pig Alleviated the Gut Inflammation of Mice Challenged by Escherichia coli

JOURNAL=Frontiers in Immunology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.822754

DOI=10.3389/fimmu.2022.822754

ISSN=1664-3224

ABSTRACT=<p>Wild pigs usually showed high tolerance and resistance to several diseases in the wild environment, suggesting that the gut bacteria of wild pigs could be a good source for discovering potential probiotic strains. In our study, wild pig feces were sequenced and showed a higher relative abundance of the genus <italic>Lactobacillus</italic> (43.61% vs. 2.01%) than that in the domestic pig. A total of 11 lactic acid bacteria (LAB) strains including two <italic>L. rhamnosus</italic>, six <italic>L. mucosae</italic>, one <italic>L. fermentum</italic>, one <italic>L. delbrueckii</italic>, and one <italic>Enterococcus faecalis</italic> species were isolated. To investigate the synergistic effects of mixed probiotics strains, the mixture of 11 LAB strains from an intestinal ecology system was orally administrated in mice for 3 weeks, then the mice were challenged with Escherichia coli ATCC 25922 (2 × 10<sup>9</sup> CFU) and euthanized after challenge. Mice administrated with LAB strains showed higher (<italic>p</italic> &lt; 0.05) LAB counts in feces and ileum. Moreover, alterations of specific bacterial genera occurred, including the higher (<italic>p</italic> &lt; 0.05) relative abundance of <italic>Butyricicoccus</italic> and <italic>Clostridium</italic> IV and the lower (<italic>p</italic> &lt; 0.05) abundance of <italic>Enterorhabdus</italic> in mice fed with mixed LAB strains. Mice challenged with <italic>Escherichia coli</italic> showed vacuolization of the liver, lower GSH in serum, and lower villus to the crypt proportion and Claudin-3 level in the gut. In contrast, administration of mixed LAB strains attenuated inflammation of the liver and gut, especially the lowered IL-6 and IL-1β levels (<italic>p</italic> &lt; 0.05) in the gut. Our study highlighted the importance of gut bacterial diversity and the immunomodulation effects of LAB strains mixture from wild pig in gut health.</p>