Besides promoting nutritional digestion, intestinal microflora is also involved in host immunity and pathology. Bacterial infections or enteritis, antibiotic treatment, and immunosuppression may alter the population, quantity, or habitat of gut microflora and may lead to the excessive growth of opportunistic pathogens as well as microbial dysbiosis (Bouhnik et al., 2004; Taur and Pamer, 2013). Numerous studies showed that probiotics can regulate and maintain the balance of intestinal flora by enhancing indigenous bacterial colonization and/or competitive exclusion to battle pathogens (Gareau et al., 2010). The present results revealed that administering L. plantarum G83 not only increased the abundance of Lactobacillus and Bifidobacterium, but also decreased the number of Bacteroidetes and Enterobacteriaceae in the colon. Our results were also similar to those of the reports where LGG and Lactobacillus Bar13 greatly reduced the colonization of pathogenic E. coli and Salmonella (Collado et al., 2007; Candela et al., 2008). Probiotics secrete some bacteriocin that can kill or inhibit pathogens (Nakamura et al., 2013; Pandey et al., 2013). Furthermore, Lactobacillus and Bifidobacterium can also create a biomembrane on intestinal mucosa to serve as a barrier against colonizing pathogen and improve gut immunity (Collado et al., 2008; Jones and Versalovic, 2009; Chen et al., 2014). Probiotics can also compete with harmful bacteria for nutrition (Elli et al., 2000; Hooper, 2009). Overall, our results demonstrated that L. plantarum G83 is beneficial to host health.