Impact of international travel and diarrhea on gut microbiome and resistome dynamics

International travel contributes to the global spread of antimicrobial resistance. Travelers' diarrhea exacerbates the risk of acquiring multidrug-resistant organisms and can lead to persistent gastrointestinal disturbance post-travel. However, little is known about the impact of diarrhea on travelers' gut microbiomes, and the dynamics of these changes throughout travel. Here, we assembled a cohort of 159 international students visiting the Andean city of Cusco, Peru and applied next-generation sequencing techniques to 718 longitudinally-collected stool samples. We find that gut microbiome composition changed significantly throughout travel, but taxonomic diversity remained stable. However, diarrhea disrupted this stability and resulted in an increased abundance of antimicrobial resistance genes that can remain high for weeks. We also identified taxa differentially abundant between diarrheal and non-diarrheal samples, which were used to develop a classification model that distinguishes between these disease states. Additionally, we sequenced the genomes of 212 diarrheagenic Escherichia coli isolates and found those from travelers who experienced diarrhea encoded more antimicrobial resistance genes than those who did not. In this work, we find the gut microbiomes of international travelers' are resilient to dysbiosis; however, they are also susceptible to colonization by multidrug-resistant bacteria, a risk that is more pronounced in travelers with diarrhea. Here, the authors characterize the microbiome and resistome in a longitudinal cohort of 159 international students visiting the Andean city of Cusco, Peru. They find that international travel associates with spread of antimicrobial resistance, and that travelers' diarrhea increases a persons' risk for acquiring antimicrobial-resistant pathogens, while a diverse, healthy microbiome can be protective against diarrhea.

Automated summary

International travel contributes to the global spread of antimicrobial resistance, and travelers' diarrhea increases the risk of acquiring multidrug-resistant organisms. This study found that diarrhea disrupts the stability of gut microbiome and leads to an increased abundance of antimicrobial resistance genes. The study also identified bacterial taxa that differ between diarrhea and non-diarrhea samples.