DuPont Highlights How International Travel Impacts Gut Health
A new study from UTHealth Houston provides important insight into how international travel can disrupt the gut microbiome and increase the risk of gastrointestinal illness. The review, led by Herbert L. DuPont, MD, Professor of Epidemiology and a member of the Center for Infectious Diseases, was recently published in the Journal of Travel Medicine and has brought renewed attention to the health challenges associated with global mobility.
DuPont explains that the gut microbiome is a complex ecosystem that interacts with the brain, the immune system, and the digestive tract. Because this ecosystem is sensitive to environmental change, international travel introduces new microbial exposures, unfamiliar foods, and enteric pathogens that can influence gut health during and well after a trip. These effects can extend beyond the traveler and may also affect family members who come into contact with new bacteria brought home after travel.
The review notes that the first major challenge to the microbiome often begins during long-haul flights, especially when traveling east. Changes in meal timing, disrupted sleep, and shifts in daylight hours can all affect microbial balance. Combined with the stress of travel logistics and reduced physical activity, these disruptions create early conditions that may weaken microbiome stability.
Additional risks emerge upon arrival at the destination, particularly in regions with greater exposure to environmental pathogens. Many parts of Latin America, Africa, and southern and southeastern Asia experience sudden dietary changes, irregular schedules, and increased exposure to unfamiliar microbes. These factors can reduce microbiome diversity and lead to dysbiosis, which is associated with greater susceptibility to illness.
Traveler’s diarrhea remains one of the most significant threats identified in the review. Beyond causing temporary discomfort, it can drastically reduce microbial diversity and promote colonization by pro-inflammatory bacteria such as Escherichia coli and Klebsiella. These changes do not always resolve when symptoms do. Many travelers return home with multidrug-resistant bacteria that may persist and can potentially spread to others. DuPont notes that recent international travel should be considered in the medical history of patients who develop infections such as urinary tract infections or postoperative infections, since travel-related bacteria may influence treatment decisions.
The study highlights the importance of preparation and prevention. Travelers can take several steps to maintain a strong and resilient microbiome. These include selecting safer foods and beverages, aiming for consistent sleep and eating patterns, and minimizing exposure to contaminated environments. DuPont also encourages travelers to have a clear plan for managing diarrhea if it occurs.
This research provides timely guidance for travelers and clinicians alike. As international travel continues to grow, DuPont’s work underscores the importance of understanding how global movement shapes gut health and how preventive strategies can help reduce the spread of antimicrobial-resistant organisms.