Now There’s Fungi In Our Guts Too?

The 2010s were arguably the year of the gut bug. Before then, in mainstream culture at least, bacteria were seen as the baddies, something to eradicate with nose hair-singing anti-bacterial sprays and frequent hand-washing.

Then we started hearing more and more about these so-called “good bacteria” that were living in and on us. We weren’t supposed to want to kill these microbes. In fact, we were supposed to take more of them in the attempts to boosting the diversity and amount of what was already living in our guts and on our skin.

Now that we’ve finally got a handle on that reality, experts are adding another player to the mix: fungus. Yep, it turns out that in addition to the good bacteria in our guts, there’s also fungi. I’m sorry.

“Everybody has been so focused on the bacteria in the gut that they’ve completely missed that there is a whole eco-system of fungi that not only lives in the gut but works intimately with bacteria to control health in positive and negative ways,” says Mahmoud Ghannoum, PhD, the director of the Center for Medical Mycology at Case Western Reserve University in Cleveland. “If you look at bacteria alone, without taking into account fungi, you’re missing an important layer,” he says.

In his new book Total Gut Balance, Ghannoum describes a plan for balancing both the bacterial and fungal communities in your body in order to eliminate GI issues like bloating and constipation, to reduce body-wide inflammation, and to boost energy.

Just like bacteria, there are both beneficial and harmful fungi. You may have heard of Candida yeast, for instance. That’s the stuff that causes vaginal yeast infections and oral thrush — not good. Then there’s Saccharomyces, a type of yeast. We use it to make bread and beer, but it’s also found in high levels in people who are healthy.

Your gut bacteria can influence your fungi levels, says Ghannoum. “If you take an antibiotic, it will kill both good and bad gut bacteria. That can let candida overgrow,” he says. (Ever get a yeast infection shortly after being on an antibiotic? Yeah.)

But there are other little tweaks you can make to your diet and your lifestyle that can help suppress levels of harmful fungi while nurturing your good fungi. And, Ghannoun says, while it may take a few days to feel the effects, your gut mycobiome will start to shift within 24 hours after making these changes.

“Many studies have demonstrated that protein from animal sources is more likely to encourage more pathogenic bacteria,” which can in term damage the healthy fungi in your gut, Ghannoum writes in his book. “Plant-based proteins in particular appear to encourage beneficial bacteria,” he says. Solid sources of plant protein include legumes (including black beans, chickpeas, and peas), quinoa, nuts, and tofu. Two exceptions to the animal protein rule: whey, which is beneficial for good bacterial growth, and casein, which reduces intestinal inflammation. They’re both dairy-based.

Or really, anything stress busting. The brain directly affects the gut, and vice versa. The communication that occurs between the two systems is called the gut-brain axis. Since the two are linked, the health of one influences the health of the other. “The brain talks to the gut, and the gut talks to the brain,” Ghannoun explains. That means stress can wreak havoc on your mycobiome, and reducing it can improve the balance of healthy bacteria and fungus in your gut, he says. He suggests yoga because it has the added benefit of improving sleep quality, which has also been tied to gut fungi and bacteria balance. But anything that makes you feel less stressed will help.

We know. It might feel borderline irresponsible. But so much of the news we tune into these days is just the same fact being repeated and rehashed. And it’s stressful, and as we explained above, stress can seriously disrupt your gut mycobiome, Ghannoun says. He suggests setting a time limit on your news consumption. Read or watch enough to stay informed, but not so much that you feel frazzled.

Too many simple carbs (the ones that come from refined white flour, white rice, and white sugar) can feed your Candida, the type of yeast that can cause infections. Fine to eat in moderation, Ghannoum says. But balance your intake with so-called indigestible carbs: foods with high fiber (vegetables, whole grains, legumes, fruit); resistant starch (potatoes, squashes, barley); and whole grains (brown rice, whole wheat), he says. The microbes that live in your gut eats this type of carb. The result, says Ghannoum, is “greater microbiome diversity, a lower abundance of pathogenic bacteria like certain species of Clostridium and Enterococcus, and a greater abundance of beneficial bacteria like Bifidobacterium and Lactobacillus.” And those bacteria can positively impact your fungal community.

The research Ghannoum cites in his book are mostly to do with smoking old-school cigarettes. “One report surveyed all the literature on this subject between 2000 and 2016, and the studies revealed that in smokers, many pathogenic bacterial species were increased, while beneficial species were decreased. Smoking also decreased microbiome diversity,” Ghannoum writes. The exact cause for the negative effects aren’t known, but they think smoking may thin the mucus lining the protects the intestinal lining or create microbiome-damaging oxidative stress. And while we don’t know whether vaping causing all the same effects as smoking, we do know it’s likely pretty dangerous in its own right.

“Exercise is critical,” says Ghannoum. Regular activity reduces inflammation, which is known to kill off healthy bacteria and fungi in the gut. But when it comes to working out, more isn’t necessarily better, he points out. When you work out strenuously, blood is sent to your heart, lungs, and muscles instead of the gut, Ghannoum says. If you keep it up for too long, you can disrupt the balance of your gut microbes. You can exercise a ton if you love it, but for the purpose of improving the mycobiome, Ghannoum says that 40 minutes three or four times a week is more than enough.