Alterations in the gut microbiota are correlated with ailments such as obesity, inflammatory bowel disease, and diarrhea. Up to 60% of individuals traveling from industrialized to developing countries acquire a form of secretory diarrhea known as travelers’ diarrhea (TD), and enterotoxigenic Escherichia coli (ETEC) and norovirus (NoV) are the leading causative pathogens. Presumably, TD alters the gut microbiome, however the effect of TD on gut communities has not been studied. We report the first analysis of bacterial gut populations associated with TD. We examined and compared the gut microbiomes of individuals who developed TD associated with ETEC, NoV, or mixed pathogens, and TD with no pathogen identified, to healthy travelers. We observed a signature dysbiotic gut microbiome profile of high Firmicutes:Bacteroidetes ratios in the travelers who developed diarrhea, regardless of etiologic agent or presence of a pathogen. There was no significant difference in a-diversity among travelers. The bacterial composition of the microbiota of the healthy travelers was similar to the diarrheal groups, however the b-diversity of the healthy travelers was significantly different than any pathogen-associated TD group. Further comparison of the healthy traveler microbiota to those from healthy subjects who were part of the Human Microbiome Project also revealed a significantly higher Firmicutes:Bacteriodetes ratio in the healthy travelers and significantly different b-diversity. Thus, the composition of the gut microbiome in healthy, diarrhea-free travelers has characteristics of a dysbiotic gut, suggesting that these alterations could be associated with factors such as travel.
Bibliographical noteFunding Information:
SKH was supported by the National Institutes of Health Institute of Diabetes and Digestive and Kidney Diseases by award number R21DK099573. BPY was supported by the National Institutes of Health National Institute of Diabetes and Digestive and Kidney Diseases by award number F31DK094596 and by National Institute of General Medical Sciences by award number R25GM056929. WDW was supported by the National Institutes of Health National Cancer Institute by award 2T32CA096520. Contributions by FC are based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. 0940902. The National Institutes of Health National Human Genome Research Institute award number U54HG003273 also funded parts of the study.
© 2015 Taylor & Francis Group, LLC.
- Enterotoxigenic Escherichia coli
- Gastrointestinal disease
- Travelers’ diarrhea