Antimicrobial Food Additives Influence the Diversity of the Human Gut Microbiota: In Vitro Studies

The role of gut microbiota in health and disease is becoming increasingly more obvious, but environmental factors, such as food components, specifically antimicrobial food additives (AMFAs) which may influence its diversity and function are not well understood. To address this issue we have isolated culturable bacterial strains from human gut microbiota, identified them using 16S rDNA sequence analysis and determined the minimum inhibitory and fractional inhibitory concentrations in broth microdilution assay with the most widely used AMFAs. Our results from these in vitro studies indicate that some intestinal bacteria are highly susceptible to selected AMFAs while others are resistant. We have also observed a synergistic effect of some AMFA combinations which may further increase the impact of AMFAs on the gut microbiota diversity. We conclude that AMFAs have the capacity to modify the diversity of human gut microbiota even at very low concentrations especially when used in combinations.