Effects of Enterococcus faecalis administration on the community structure of airborne bacteria in weanling piglet and layer hen houses

Probiotics have been shown to improve microbial compositions in animal intestine and feces, but the effects of probiotic administration on airborne microbial composition in animal houses remain unclear. In this study, we investigated the effects of dietary Enterococcus faecalis on the bacterial community structure in the air of piglet and layer hen houses. Indoor air and feces from piglet and layer hen houses were sampled after supplementing E. faecalis in feed for 60 days, and bacterial community structures were analyzed using Illumina high throughput sequencing technology. Results showed that Chao1, ACE, Shannon, and Simpson indices of bacterial diversity did not significantly change in feces or indoor air of piglet or layer hen after supplementation with E. faecalis (P 0.05). However, E. faecalis administration resulted in a decrease in the relative abundance of Proteobacteria (P < 0.05). In addition, E. faecalis significantly reduced the relative abundance of opportunistic pathogens such as Acinetobacter, Escherichia, and Shigella (P < 0.05), and beneficial bacterial genus such as Lactobacillus was significantly enriched in both feces and indoor air (P < 0.05). These changes should be of benefit to livestock, farm workers, and the surrounding environment.