Your brain and your gut are playing a complex game of telephone with each other all day, all the time. With around 70-80 percent of your immune system living in your gut, your brain relies on the information the gut sends out for clues on how to react to its surroundings.

When the gut microbiome is healthy, illness, chronic inflammation and disease are typically kept under control. But when things go south in the case of antibiotic and non-antibiotic drug use, exercise, stress, diet and environmental factors like smoking and heavy metal toxicity, it can spell disaster for your body’s many other systems.   

Unfortunately, without solid footing, the telephone wires between belly and brain get crossed, signalling the body’s immune system to overreact to “invaders” that in healthier guts would be innocuous.

Researchers have now linked the health of the gut microbiome to conditions ranging from Alzheimer’s to arthritis to cancer, but what about something most of us fear contracting every year: the flu.

In a recent study published in Science, a team of Washington University School of Medicine researchers found that in mice, a particular gut microbe thwarted the damage to lung tissue caused by the influenza virus. This is important because it’s often the infections and complications of the flu, like pneumonia, that cause problems in weakened populations such as the elderly.

While it’s still slightly unclear why the microbe works, the scientists think it’s likely because of the bacteria’s ability to break down flavonoids, or the phytonutrients (plant chemicals), found in nearly all fruits and vegetables.

The study brings to light an interesting question: if someone is eating a diet rich in flavonoids but doesn’t have the right gut bacteria to break them down, does it even matter?

For now, that question remains unanswered, but it opens the door for more research about how to boost specific microbiota in people who don’t have adequate levels of helpful bacteria. Perhaps in the future, we’ll all start taking an illness-specific probiotic based on the conditions we’re up against.

In terms of keeping yourself healthy this upcoming flu season? The scientists recommend eating a diet rich in flavonoids, such as those commonly found in black tea, apples, leafy greens, red wine and blueberries.

Science has also shown that diversity in the gut microbiome is a critical piece of the immune puzzle, so it’s in your best interest to work on diversification of your bug buddies. This is best achieved by eating a wide ranging diet that includes a variety of plants, animals and fermented foods.

In the past, humans ate over 200 various species of food, while today, that number has dwindled to a measly fifteen. By incorporating as many different foods as possible into your weekly rotation, you’ll take a big step forward in boosting your immunity and staying healthy all year long.