Jet lag shown to wreak havoc on the gut microbiome in new review ‘cause…, for every action there’s always an effect, whether we realize or not!
Many experienced travelers grab a bottle of probiotics as they head out the door for a trip. It’s a great way to reinforce the body’s first line of defense against new bacteria they may be exposed to on their travels.
But there’s another reason it may be a good idea to take probiotics when traveling: it turns out the simple act of traveling through different time zones wreaks havoc on the gut microbiome.
This means the gut microbiome will already be weakened even before exposure to new strains of bacteria at the travel destination.
Study background
According to a new narrative review in the journal Nutrients, long-distance travel disrupts the body’s clock–and that disruption “scrambles the gut’s microbial community.”
For their review, which was published in May 2026, the researchers were especially focused on athletes. The researchers noted that athletes are “highly susceptible to circadian cycle and gut microbiome disturbances.”
This “athlete risk” occurs because athletes are frequently traveling across time zones. This contributes to regular jet lag, which, in turn, impairs cognitive performance, sleep quality… and gut health.
Scientists even have a name for this problem: Gut jet lag.
The “gut jet lag” recipe
Trillions of gut microorganisms follow their own daily rhythms tied to when a person eats and sleeps. When travel scrambles those patterns, the microbial community gets scrambled too–manifesting into “gut jet lag.”
Evidence suggests that, in this situation, the gut lining becomes more permeable–meaning bacteria and their byproducts could leak into the bloodstream and trigger low-grade inflammation. Much previous research–not related to travel–has already shown a link between poor gut health and chronic inflammation.
Study highlights
To conduct the current study, the researchers conducted targeted, non-systematic literature search using databases including PubMed, Scopus, and Web of Science to identify relevant studies. The search primarily focused on publications from 2016 to 2026, while earlier seminal studies were included to provide essential physiological context.
While the ultimate goal of the study was to determine how traveling affected athletic performance, many of the studies reviewed did not include athletes.
One study of 267 non-athlete travelers found gut microbial diversity dropped in 61% of participants after their trip, particularly those who used antibiotics.
A separate study on airline pilots found lower levels of beneficial bacteria than in fitness instructors–though the researchers noted this was a small observational study, not definitive proof.
How travel destroys the microbiome
Travelers with even a rudimentary knowledge of sleep patterns understand that a master biological clock in the brain coordinates sleep and wake cycles, hormone release, immune activity, and energy metabolism.
Additionally, organs like the liver and gut follow cues from light and meal timing. When a traveler lands eight or nine time zones away, that clock does not instantly reset, clinging to the old schedule while the body tries to function on a new one. Scientists call this disruption “circadian misalignment.”
Besides the time shift itself affecting the gut, travel causes a number of other “gut stressors”: dehydration, travel stress, bouts of exertion, increased junk food intake, and disrupted meal schedule.
All of these varied factors can reduce blood flow to the gut, which strains the intestinal barrier. According to the researchers, this can “push gut bacteria toward less beneficial states.”
Moreover, this is just the time for sleep health to recover–gut health recovery is even longer.
The good news
The researchers noted that wise travelers can take steps to reduce the severity of how travel affects the gut. Among the suggestions: rehydration, timed bright-light exposure to reset the body clock, probiotic and prebiotic supplementation, catch-up sleep, and fiber intake. Take these actions and your gut will love you for it and it will go a long way in helping you experience, “the best performance of your life!”
God bless,
DrB
Primary source: Nutrients.
