Antimicrobial Food Additives Influence the Diversity of the Human Gut Microbiota: Studies in Germ-free Mice

The incidence of allergies and autoimmune diseases is increasing worldwide. Recent data suggest that gut microbiota have the capacity to modulate not only local, but also systemic immune responses and to the extent previously unthinkable. In this study, we focus on environmental factors, specifically food additives, which may modify the composition of gut microbiota and thus influence host’s immune responses. To address this issue, we administered germ-free C57BL/6 mice colonized with human microbiota either sterile water or water supplemented with antimicrobial food additives. The daily intake of additives was calculated to match the maximum daily intake reached in human populations in Europe. The effect of additives on microbial diversity was analyzed by amplification and high-throughput sequencing of the hypervariable regions of the 16S rDNA genes. The resulting sequences were compared with RDP database and OTU assigned. Our preliminary data indicate a significant effect of antimicrobial food additives on the diversity of the human gut microbiota.