Travelling to Benin from Finland
Background Visitors to low- and middle-income countries (LMICs) encounter numerous new intestinal microbes, including diarrhoeal pathogens and multidrug-resistant (MDR) bacteria, such as extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-PE). Consequencently, many develop travellers' diarrhoea (TD) and/or become colonised by ESBL-PE. We explored the impact of LMIC travel, TD, and ESBL-PE/diarrheal pathogen colonisation on gut microbiota.   Methods Participants of a clinical vaccine trial, OEV123, spent 12 days in Benin, West Africa and provided exploratory pre- and post-travel stool samples, undergoing qPCR for diarrhoeal pathogens and 16S rRNA gene amplicon sequencing for microbiota analyses.   Results Travel significantly altered gut microbiota, showing reduced richness, decreased a-diversity, and a 40-fold increase in Escherichia/Shigella. qPCR detected diarrhoeagenic Escherichia coli (DEC) in post-travel stools of 89% of participants. No specific microbiota profiles linked to TD or ESBL-PE acquisition. Participants acquiring multiple DEC pathotypes had higher pre-travel levels of Ruminococcaceae and Coprococcus spp., while their post-travel microbiota showed increased oxygen-tolerant and oral-associated taxa.  Conclusion Travel to LMIC significantly impacted intestinal microbiota. Individuals with high pre-travel proportions of Ruminococcaceae and Coprococcus  spp. acquired a greater DEC pathotype diversity. However, no specific pre-travel microbiota profile was identified as protective against or predisposing to TD or acquisition MDR bacteria.