AUTHOR=Zhang Wei , Zhu Yao-Hong , Yang Gui-Yan , Liu Xiao , Xia Bing , Hu Xiong , Su Jin-Hui , Wang Jiu-Feng 

TITLE=Lactobacillus rhamnosus GG Affects Microbiota and Suppresses Autophagy in the Intestines of Pigs Challenged with Salmonella Infantis

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.02705

DOI=10.3389/fmicb.2017.02705

ISSN=1664-302X

ABSTRACT=<p><italic>Salmonella enterica</italic> serovar Infantis (<italic>S</italic>. Infantis) is a common source of foodborne gastroenteritis worldwide. Here, <italic>Lactobacillus rhamnosus</italic> GG (LGG) was administrated to weaned piglets for 1 week before <italic>S</italic>. Infantis challenge. <italic>S</italic>. Infantis caused decreased ileal mucosal microbiota diversity, a dramatic <italic>Lactobacillus amylovorus</italic> bloom, and decreased abundance of <italic>Arsenicicoccus, Janibacter, Kocuria, Nocardioides, Devosia, Paracoccus, Psychrobacter</italic>, and <italic>Weissella</italic>. The beneficial effect of LGG correlated with the moderate expansion of <italic>L. amylovorus, L. agilis</italic>, and several members of the phyla <italic>Proteobacteria, Firmicutes</italic>, and <italic>Bacteroidetes</italic>. <italic>S</italic>. Infantis translocation to the liver was decreased in the LGG-pretreated piglets. An <italic>in vitro</italic> model of LGG and <italic>S</italic>. Infantis co-incubation (involving the porcine intestinal epithelial cell line IPEC-J2) was established, and nalidixic acid was used to kill the extracellular <italic>S</italic>. Infantis. LGG suppressed the initial <italic>S</italic>. Infantis invasion in the IPEC-J2 cells and deceased the rate of cell death. LGG inhibited <italic>S</italic>. Infantis-induced autophagy and promoted epidermal growth factor receptor (EGFR) and Akt phosphorylation in both the ileum and IPEC-J2 cells. Our findings suggest that LGG inhibited <italic>S</italic>. Infantis-induced autophagy by promoting EGFR-mediated activation of the negative mediator Akt, which, in turn, suppressed intestinal epithelial cell death and thus restricted systemic <italic>S</italic>. Infantis infection. LGG can restore the gut microbiota balance and preserve the autophagy-related intestinal epithelial barrier, thereby controlling infections.</p>