Getting Your Gut Ready for Flu Season

My nutrition students (and family members) always laugh when I use the term “gut” because it sounds so non-scientific. I get it, I do. However, it is a term that doctors, researchers and nutrition professionals do use, and are using more and more—especially when talking with the public.

What’s so special about the gut? In a word, lots. Where we used to concentrate mostly on food digestion and nutrient absorption when talking about the gut, we are now learning so much more about what goes on in the gut (and how it impacts the rest of the body) that gut-centered conversations are now frequently about the role of the microbiome in immunity, obesity and metabolism, allergies and more. What’s the microbiome? It’s the collective term for the trillions of microbes we all carry around with us in and on our bodies—primarily in our digestive tracts (sometimes referred to as the gut microbiome).

Couscous, Lentil & Arugula Salad with Garlic-Dijon Vinaigrette
Fiber-rich foods are important for keeping your good gut bacteria well-fed and healthy.

The Flu and You

Influenza, usually just called “the flu,” is a contagious respiratory illness that can strike anyone, causing a cluster of symptoms that can include fever and chills, cough, body aches, headaches, fatigue, sore throat and runny or stuff nose. Some people have digestive symptoms as well (especially children). Anyone can get the flu, and although most people recover in a week or so, it can be serious and cause hospitalizations and even death. The flu is especially serious for the very young, people over age 65, pregnant women, nursing home residents and people with certain chronic medical conditions (such as asthma). The Centers for Disease Control and Prevention advise everyone age 2 and older to get an annual flu vaccine early in the flu season (aim for October or November). This year they are suggesting skipping the nasally-administered vaccine and get the shot as it appears to be more effective. Also, aside from getting the flu vaccine, the CDC recommends some preventative measures against the flu including washing hands often, covering your mouth and nose with a tissue when coughing or sneezing and staying away from people who are sick (as well as staying home when you are sick).

Can a healthy gut help battle the flu?

Animal research indicates that the bacteria in our guts impacts how our bodies respond to the influenza vaccine. Researchers at Emory University found that mice who had most of their gut microbiota destroyed by antibiotic treatment (or were raised in a sterile environment and therefore don’t have lots of bacterial colonies in their guts) were unable to create the normal antibodies in response to a flu vaccine like regular mice do. Having those antibodies is what prevents you from getting the flu when you come in contact with the actual flu virus after being vaccinated. For the mice, a healthy gut microbiome helped the flu vaccine be more effective. Further investigation with humans has helped narrow down the genetic component that impacts whether the body mounts an antibody defense following a flu vaccination. The research continues, but it does suggest that characteristics of an individual’s gut microbiome can impact whether the flu vaccine works for that individual. It also suggests that avoiding antibiotics around the time that you’ll be having your flu vaccine may make a difference in its efficacy.

Diet Tweaks for a Healthy Gut

It’s estimated that about 70% of our immune system is located in the digestive tract. There’s no doubt that the food you eat can impact the health of your gut microbiome and ultimately, your immune status. Here are some diet “dos” to consider putting into place now to enhance your gut health:

  • Eat lots of fruits and vegetables: not only do they contain healthy nutrients and beneficial plant compounds, they also provide the fiber that gut bacteria need to thrive
  • Consume probiotic foods (such as fermented foods like kimchi, kefir, miso and yogurt) with live cultures to help add helpful bacteria to your gut
  • Eat more seafood and fish to get more omega-3 fatty acids into your body—they have anti-inflammatory action that may help boost immunity
  • Focus your feasts on whole foods instead of processed foods for more fiber, fewer fats and sugar, and nutrient combinations made by Mother Nature