Human gut microbiome is altered by occupational exposure to conventional, confined swine operations--more antibiotic resistant genes discovered

Organic certification prohibits continuous confinement and the use of antibiotics in livestock production, which increases the health and wellbeing of the animals, as well as those who handle them on the farm. A recent study published in Nature Communications found that occupational exposure of veterinary students to confined swine operations resulted in a change in the students’ gut microbiome to increase their risk of exposure to antibiotic resistance bacteria. After just three months of on-site exposure, the number of pathogen bacterial strains and antibiotic-resistant genes in the students’ gut microbiomes were increased. Researchers analyzed the composition of the students’ gut microbiomes before and after occupational exposure. A significant increase in new genes was found after exposure. The students’ microbiomes after exposure were then compared to samples taken from around the farm including samples from ventilation system dust, swine feces, sewage, and compost soil. Roughly two-thirds of the new genes found in the students’ microbiomes overlapped with those found from environmental samples, indicating significant exchange of bacteria and antibiotic resistance genes between swine and humans. This study illuminates an occupational hazard that is often overlooked and highlights the importance of raising animals in a spacious, healthful environment free of antibiotics.