Many processes in our bodies are orchestrated on a ~24-hour schedule called the circadian rhythm. Body temperature, heart rate, blood pressure, the immune system, melatonin, and other hormones, alertness and sleepiness, and much more, rise and fall over the course of a day — timed by our internal clock.
When we travel between time zones faster than our internal clock can adjust, we experience jet lag. Our internal clock is out of sync with local time. We notice this with difficulty being alert during the day and difficulty sleeping at night. We might not notice it, but our physical and mental performance may be impaired as well.
We carry within our gut about 38 or 39 trillion bacteria each with their own internal clocks. The composition and function of this microbiome community changes predictably over the course of the day. Normally, these bacteria, our immune system, and our internal clock all communicate with each other and sync up.
When we travel rapidly between time zones, our bacterial schedule can be in disarray. Just like the rest of us.
Traveler’s Diarrhea: It’s Not Just Contaminated Food or Water
Getting exposed to bacteria like Salmonella is more likely to cause infection at certain times of day. Experts in the circadian rhythm now think that disrupting the circadian rhythm, whether by jet lag, shift work, or blue light in the evening, can make people more susceptible to gut infections.
Several times I’ve gotten traveler’s diarrhea after a long red-eye flight. This is not unusual. Sanitation and hygiene are not the whole story with traveler’s diarrhea.
Mother Nature’s Solution to Traveler’s Diarrhea
In babies, breast milk and colostrum are among the most effective ways to prevent and treat diarrhea. Both colostrum and breast milk contain potent ingredients that protect against infections. Plus specific antibodies to the organisms the mother has encountered.
And they nourish the lining of the gut. But beyond that, there are hundreds of ingredients in colostrum and breast milk that the baby can’t digest. They are prebiotics.
Who do they feed? These prebiotics nourish the bacteria in the gut – and signal the immune system in the gut lining. One way to help your gut bacteria is to eat a diet rich in prebiotics, most notably found in fiber-rich foods such as fruits, vegetables, and whole grains. This can be tough when traveling — especially in countries where it’s not recommended to eat raw vegetables. (Note: Salads have been the traveler’s diarrhea culprit for me on multiple occasions.) My wife travels with both a prebiotic fiber supplement and a great traveler’s diarrhea solution made from colostrum and egg yolks.
Taking care of your gut bacteria helps them take care of you.
References and Resources
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Marcinkevicius EV, Shirasu-Hiza MM. Message in a biota: gut microbes signal to the circadian clock. Cell Host Microbe. 2015 May 13;17(5):541-3. doi: 10.1016/j.chom.2015.04.013. PMID: 25974294.
Thaiss CA, Zeevi D, Levy M, Segal E, Elinav E. A day in the life of the meta-organism: diurnal rhythms of the intestinal microbiome and its host. Gut Microbes. 2015;6(2):137-42. doi: 10.1080/19490976.2015.1016690. PMID: 25901892; PMCID: PMC4615721.
Rosselot AE, Hong CI, Moore SR. Rhythm and bugs: circadian clocks, gut microbiota, and enteric infections. Curr Opin Gastroenterol. 2016 Jan;32(1):7-11. doi: 10.1097/MOG.0000000000000227. PMID: 26628099; PMCID: PMC4721637.
He Y, Liu S, Leone S, Newburg DS. Human colostrum oligosaccharides modulate major immunologic pathways of immature human intestine. Mucosal Immunol. 2014 Nov;7(6):1326-39. doi: 10.1038/mi.2014.20. Epub 2014 Apr 2. PMID: 24691111; PMCID: PMC4183735.
Lane JA, Mariño K, Naughton J, Kavanaugh D, Clyne M, Carrington SD, Hickey RM. Anti-infective bovine colostrum oligosaccharides: Campylobacter jejuni as a case study. Int J Food Microbiol. 2012 Jul 2;157(2):182-8. doi: 10.1016/j.ijfoodmicro.2012.04.027. Epub 2012 May 12. PMID: 22647676.