Changes of gut microbiota by the Lactobacillus casei anchoring the K88 fimbrial protein prevented new born piglets

As most pathogens invade the bodies through the mucosa, it is crucial to develop vaccines that induce mucosal immunity. Lactobacillus casei (L.casei) is a normal flora of the gastrointestinal tract in mammals, and as a great mucosal delivery vehicle have widely used in bioengineering. However, an alteration of commensal intestinal microbiota via the recombinant L.casei interfering to new born piglets is not well-understood. In our study, new born piglets were orally fed with the recombinant L.casei surface-displayed the fimbrial protein K88 of enterotoxigenic Escherichia coli (ETEC) and their feces were collected for a period of time after feeding. The next generation sequencing of these fecal samples showed that the relative abundance of L.casei was significantly increased. The oral administration of the recombinant L.casei altered the intestinal microbial community as evidenced by altered microbial diversity, microbial taxonomic composition. Remarkably, the functional enhancing of the intestinal bacterial community by the recombinant L.casei administration was positively correlated with nucleotide metabolism, replication and repair and translation (p<0.05).