Jet Lag, Gut Health and Immunity: Why Travel Can Make You Sick and How to Bounce Back
Travel can be soul-filling and still be hard on your biology. Time-zone shifts, meal changes and sleep disruption can lower immune resilience by throwing off your circadian rhythm, melatonin signaling and gut microbiome. A few simple habits before, during and after your trip help you stay well.
A quick personal note
I just traveled two time zones ahead for a quick weekend to visit family. It was wonderful. My heart felt full, the hotel was comfy, food was nourishing and we walked everywhere. Even with a smooth trip, travel still asks more of the body. Over the last year I have also taken two big international trips, and I am reminded each time: honoring recovery is part of traveling well.
I explain why we sometimes feel rundown or get sick after trips, plus exactly how I help clients prevent that “post-travel crash.”
Why travel can weaken your immune system
1) Your immune system runs on a clock
Your body follows a 24-hour rhythm. That rhythm coordinates sleep, hormones, metabolism and immune activity. Crossing time zones desynchronizes these systems. When your internal clock is off, immune defenses slow and inflammation can rise. Frequent or rapid shifts make it harder to bounce back.
Reference: circadian rhythm and immune function. PMID: 20944004
2) Melatonin is not only for sleep
Melatonin supports night-time repair, calms inflammation and helps immune cells work efficiently. Jet lag, late-night light, odd meal timing and travel stress can suppress or delay melatonin. Lower melatonin often equals lighter sleep and slower overnight recovery.
3) Your gut microbiome feels the time change
About 70 percent of your immune system is in the gut. Irregular schedules, different foods, less sleep, alcohol and stress can shift gut bacteria and weaken gut-immune crosstalk. This is a common reason for post-flight bloating and why some people get sick after travel.
Reference: circadian disruption, microbiome, and immunity. PMID: 36164341
What to do before, during and after travel
1) Anchor your rhythm
Morning light on landing and each morning. Go outside within 30 minutes of waking for 5 minutes.
Bedtime target at your destination on night one. Hold the same sleep window for 2–3 nights.
Meals on local time as soon as you arrive. Aim for protein at the first local breakfast.
2) Protect sleep and melatonin
Screens down 60 minutes before bed. Room dark and cool.
Consider low-dose melatonin (0.5–3 mg) at destination bedtime for a few nights. If you are sensitive, start at the low end.
Evening calm: warm shower, light stretch or legs-up-the-wall for five minutes.
3) Support your gut
Fiber + fermented foods most days: sauerkraut, kimchi, kefir or plain yogurt if tolerated.
Hydrate wisely. If safe locally, add electrolytes or a pinch of mineral-rich salt to one or two waters daily.
Pack gentle staples: mixed nuts, clean protein bars, or salmon packets to avoid ultra-processed airport meals.
4) Move your lymph and lower inflammation
Walk after flights and after dinner. Even 10–15 minutes helps.
Simple breathwork: inhale 4 seconds, exhale 6–8 seconds for 2 minutes to calm the nervous system.
Alcohol and sugar: keep lighter the first two nights while your clock resets.
5) Smart immune supports
Nutrients: vitamin C, vitamin D (if appropriate), zinc and magnesium are common choices.
Probiotic: begin 3–5 days before travel and continue through your trip if you tolerate probiotics well.
If you are supplement-sensitive, focus on food, sleep, hydration and rhythm first.
My simple “Travel Day” checklist
Protein-forward meals on local time
1–2 bottles of water with minerals
10–15 minute outdoor walk on landing
Screens down an hour before bed
Dark, cool room and morning light the next day
Who needs extra care
History of frequent colds after travel
Perimenopause or menopause with sleep disruption
Known gut issues, bloating or food sensitivities
High stress load or poor baseline sleep
If this is you, we build a personalized plan and often add testing when needed.
Thriving Through Travel
I created Thriving Through Travel to help you take trips near or far without sacrificing your health. It is a Guided Wellness Journey, loaded with sleep tools, gut support, circadian strategies, timezone tapping protocols, recovery plans and more you can reuse all year.
Click here to access your Thriving Through Travel Guided Wellness Journey.
Work with me
I help clients across the U.S. travel well, balance their immune system and recover faster after time-zone shifts. If you want a tailored plan for your next trip, let’s connect.
Click here to book a Complimentary Connection Call to see if I can support you on your Functional Wellness journey for a lifetime.
References
Circadian rhythm and immune function: PMID: 20944004
Travel, circadian disruption, microbiome, and immunity: PMID: 36164341