Environmental exposure to swine farms reshapes human gut microbiota.

The gut microbiota can change to varying degrees because of changes in the environment. In the present study, we performed microbial amplicon sequencing on the feces of people who had long-term exposure to swine farms (F) and that of people living in normal environments (S) to investigate the impact of the environment on the human gut microbiota. A total of 1,283,503 high-quality ordered sequences were obtained, which provided different levels of microbial classification and statistics. We found that different environments did not alter the richness and diversity of the microbial communities in participants, but caused significant changes in the proportion of some bacteria. The main bacterial phyla found in group F participants were Firmicutes (69.44-89.03%), Actinobacteria (1.7-18.95%), and Bacteroidetes (1.17-22.35%); those found in group S participants were Firmicutes (49.93-95.04%), Bacteroidetes (0.62-39.59%), and Proteobacteria (0.98-11.95%). Additionally, because of changes in phylum proportions, the Bugbase phenotypic classification predicted an increase in the proportion of Gram-positive bacteria in group F and an increase in the proportion of Gram-negative bacteria in group S. In conclusion, our findings suggest that human exposure to swine farms can reshape the gut microbiota, resulting in changes in the microbial abundances. This change can potentially reduce the odds of developing bowel disease and contribute to the prevention of intestinal diseases, providing a theoretical basis for improving human health.