Gut flora, microbiome, beneficial bacteria- it seems everywhere you turn, someone is offering you a kefir-and-sauerkraut smoothie to make your intestines more welcoming for teeming hordes of bacteria.

It’s true we’re only beginning to discover the importance of having a healthy gut. What happens in the gut impacts every other part of your body, from your immune system to your reproductive functions to your emotional well-being. So if we have to quaff kombucha to keep the bacteria happy, we say, “Cheers!”

But what’s actually happening in there, how important is it, really, and what do we need to do about it?

What Does Having a Healthy Gut Mean?

Your body is home to trillions of bacteria, good and bad. Some cause disease; others prevent it. Having a healthy gut means providing a good, nutrient-rich home for the good bacteria to thrive.

So useful is this 2-5 pound wad of bacteria, that they’re often considered an additional organ, just like your brain or kidneys.

Where Does it Come From?

Gut flora starts populating the moment you pass through the birth canal; they’re your very first birthday present! So important is the bacteria you pick up from mom that some doctors now give C-section babies a swab of bacteria from mom’s vagina so they don’t miss out.

Shortly after birth, mom’s breast milk is an important source of beneficial bacteria, including the very useful Bifidobacteria that helps us break down fiber and complex carbohydrates in our food. These bacteria are often used in consumer probiotics because they perform so many important functions for us.

While our gut microbiome can be pretty consistent throughout our lives, the things we do can have an impact: the food we eat, the medicines we take, even exercise, and the people we live with can affect the diversity of our gut bacteria.

Because we can alter our gut bacteria in the choices we make, it’s important to make good, gut-friendly choices.

Benefits of a Healthy Microbiome

While many people take probiotics to improve digestion, the truth is a healthy gut does so much more.

The good bacteria that hang out in your large intestine are crucial to healthy digestion: they metabolize your food, making the nutrients available. They boost your immune system and keep disease carriers from thriving. They affect your central nervous system and contribute to brain health. And they help prevent “leaky gut” by maintaining your gastrointestinal tract.

Having a healthy gut can mean healthy aging. When your beneficial bacteria are doing their jobs properly, they move oxygen around more efficiently and reduce inflammation. They keep your brain sharp and motor skills smooth. They also keep pathogens out of your system, reducing the risk of disease. Want to live longer? Feed your gut well.

Gut bacteria may even play a role in the development of autoimmune disorders such as rheumatoid arthritis and neurological issues like obsessive-compulsive disorder and chronic fatigue syndrome.

Gut Flora and Estrogen

There’s an interesting symbiosis in women’s bodies when it comes to our microbiome: estrogen helps protect our intestinal flora, encouraging bacterial diversity, which is good for our health. In turn, a special kind of gut flora help maintains optimal estrogen levels.

The “estrobolome,” as the collection of microbes that metabolize estrogens is called, makes estrogen available for your body to use. This keeps estrogen levels balanced, so the right amount of estrogen is circulating through your body. That helps regulate weight, reduces belly fat, and helps control blood sugar levels, among other things.

Then along comes menopause.

Reductions in estrogen mean our gut flora loses an important protective advantage. Some bacteria die off, resulting in dysbiosis, or an imbalance of gut microbiota. Dysbiosis can mean reduced circulating estrogen being available for the body, which further reduces the protections women get from estrogen.

Fewer gut bacteria in the estrobolome can mean a higher risk of obesity, heart disease, and osteoporosis as well as certain kinds of cancers.

Nourish Your Healthy Gut

Clearly, you want to bolster that healthy bacteria. So how do you do it?

1. Adopt a largely plant-based diet. Plants have complex carbohydrates that gut flora love, and they’re good for us, too.
2. Avoid fat, sugar, and animal products. These promote unhealthy bacteria, so keep indulgences to a minimum.
3. Take probiotics. The live bacteria in probiotics can “reseed” your gut after dysbiosis.
4. Boost bacteria-nourishing polyphenols. Good news! These are present in red wine, dark chocolate, green tea, and olive oil.
5. Take antibiotics only when you have to. These medicines are good for killing bacteria, but sadly they aren’t very discerning, taking the good with the bad.
6. Eat fermented foods. Sauerkraut, kefir, yogurt, miso, kimchi—all of these naturally contain healthy bacteria. Prebiotics are also good for your gut: bananas, asparagus, apples, and oats all have prebiotic fiber beneficial bacteria love.
7. Cardio actually helps us create butyrate, a short-chain fatty acid that’s good for our gut.
8. Get dirty and get a dog. There are healthy bacteria both in healthy soil and in a healthy pup, so dig in and dog up.
9. Don’t overclean. Maybe your cleaner really does kill 99% of bacteria, but like antibiotics, it probably doesn’t discriminate.
10. Skip the sugar-free stuff. Artificial sweeteners can be hard on your gut because the carbs they contain are non-digestible. That can cause gas and bloat but also does nothing to nourish your beneficial bacteria.

You may not entirely love the fact that your intestines are hosting a bacterial party, but the guests are good for you. Provide healthy food and a welcoming environment, and they can reward you with a lifetime of good physical, mental, and emotional health.