Your gut houses billions of bacteria that help your body break down the food you eat and send it either into your bloodstream as nutrients or out of the body as waste. The gut microbiome keeps you alive and healthy, and as you choose foods, it shifts its balance to grow and support "good" bacteria or "bad" bacteria, depending on whether you're eating a healthy plant-based diet or loads of processed junk food and fatty animal products. According to two nutrition experts we interviewed, the bacteria in your gut is not just on the receiving end of this process of metabolizing the food we eat but also signaling the brain that it craves the kind of food that you've been feeding it. So healthy eaters begin to crave healthier food like salads and fruit and vegetables, while regular junk food munchers start to crave more chips, dips and cookies.

To learn more about what happens in the gut, and how to shift the balance to become healthier, we talked to two respected Registered Dieticians, James and Dahlia Marin, creators of Married To Health. who explained how food is medicine, and what you eat can either heal your body's internal cellular-level inflammation and reduce the risk of debilitating disease, or it drives up inflammation, causing greater risk of disease and infection, and diminishing your health, day by day. They shed light on the connection between the gut and the brain, which routinely "speak to each other," so what you eat affects your mental state as well.

Doctors have long known that your microbiome is in constant flux, depending on what you eat. so the bacteria that break down plant-based foods and high-fiber foods like vegetables and fruit are different (and healthier) than the bacteria needed to break down fatty animal products and added sugar, chemicals, and additives in junk food. The difference between which bacteria grows in our gut determines whether you are healthy or unhealthy, according to research. The more plant-based foods you eat, especially if you eat a wide variety of fruits, vegetables, legumes, leafy greens, nuts, and seeds, the healthier your microbiome becomes.

The microbiome is at the core of whether your body is healthy or unhealthy, experts say

The most common lifestyle diseases, such as obesity, age-related weight gain, type 2 diabetes, heart disease, and high blood pressure, are driven up by the existence of "bad" bacteria in your gut, according to experts.  It turns out that if our microbiome is unbalanced, our gut signals the body by creating high cholesterol and blood lipids that lead to heart disease over time. If your gut microbiome is healthy, the fiber-filled foods you eat will help the bacteria carry fat and other byproducts of food out of your body and keep you healthy and lean for years.

To learn how to eat to avoid weight gain, high blood sugar, and high cholesterol–and ultimately heart disease and type 2 diabetes, we interviewed Registered Dieticians James and Dahlia Marin of Married To Health. They explain the importance of keeping your gut microbiome in balance, and how to know if it's out of whack, plus what to do about it. For the full interview, click here.

Elysabeth: You guys help people adjust their diets to a ‘food as medicine’ approach.  The crux of it is that a healthy microbiome is important. What does that mean?

James Marin: So there is a galaxy made up of these small universes within our gut.  We call it the gut microbiome. (We also have the oral microbiome and the lung microbiome.) Specifically, the gut microbiome is made up of bacteria, or protozoa and archaea, and viruses even, which is a big hot topic. All of these little universes are working together to keep us alive and healthy and that is essentially the role of the gut microbiome.

EA: So, it’s a good thing when you say microbes and viruses? Talk to me about how our food choices affect our gut biome and what's good for us and what's be bad for us.

Dahlia Marin: We’ve heard people say, for hundreds of years, that food is medicine. And we know that food can have a huge impact on your microbiome. We now know is [there is] this gut-brain connection, and now we’re starting to understand the impact of our food choices on our mental and physical health.

About 60 to 70 percent of our neurotransmitters are created in the gut so it’s not just our brain that controls our cravings, it’s our microbes that tell us what to eat. When we are eating inflammatory foods or those that generate inflammation, such as processed food, our bodies will then create more microbes that can live off of that type of food. They in turn will tell your brain to create activate those neurotransmitters that crave more of those unhealthy, inflammatory foods. So if you’re eating anti-inflammatory foods, such as vegetables and plant-based foods, it will actually decrease cravings for those junk foods.

So, what are some inflammatory foods? We know animal products can be highly inflammatory…and then we also see that so are highly, highly processed foods, what we call highly palatable foods: things that have refined sugars, refined grains, tons of excess salt, tons of excess oil. Those also tend to create a little bit more of an inflammatory microbiome in addition to alcohol and smoking and other things. And what [foods] are anti-inflammatory? An abundance of a variety of colored plant foods. So that’s really what we highly recommend: Increased amounts of fiber in the diet especially fruits, vegetables, nuts, grains, beans, legumes. Just an abundance of those to feed those anti-inflammatory microbes.

EA: These things are right in our control. You don’t have to go to the doctor or get bloodwork done. Just start with eating a whole food plant-based diet.

DM: A lot of people think they eat healthier than they actually eat.

EA: How do you know if you have a healthy microbiome? How would you know if your gut is out of whack?

JM: So this is where you’re getting in tune with your body. You may be feeling some symptoms, which are your body’s way of talking to you. I wish your brain could tell you “Hey this is your spleen, and I’m talking to you,” or: “This is your lungs. Hey, I have something going on.”  I wish we had that diagnostic tool in our body, but we don’t. We have to go with how we feel. And so typically you may have gas and bloating, but it can also be things you wouldn’t think about in regard to a connection to your gut microbiome or your gut health, such as post-nasal drip, or eczema, or hives. So, a lot of these allergy effects.

DM: Headaches, brain fog, fatigue, absolutely. A change in bowel habits, as well. So, these are all kinds of warning lights that our body shoots out at us for us to then say, “What can I change nutritionally or in my lifestyle that can help make an impact on some of these symptoms?”

EA: Are people understanding this more and more? I think people are so used to going to the doctor and expecting a pill and if the doctor doesn’t give you a pill and instead says, “You really should have more raspberries and blueberries” then the patient leaves thinking, “I didn’t get any advice.”

So, are people starting to make the connection?

JM: Yes, definitely. Again, food is the foundation. We’re seeing a lot more people want to get at the root cause of disease. They want to understand the "why " of eating healthy and how to change the way they do. They want to then understand the "how" of getting healthier and staying healthy.   So it’s important to find the root causes of diseases, and not just cover these big issues with little band-aids or pills or over-the-counter therapies, which don’t work in the long term. It is definitely about choosinng long-term sustainable health and best practices.

DM: I think we’re starting to move past that pill for every ill mindset and people are understanding that yes, there’s a time and a place for them. Honestly, most of the time if you’re just depending on pills over lifestyle, you’re going to end up having your own little pharmacy after a while and necessitate more of the other pills that you’re taking. We really want to integrate both when appropriate and [only] when necessary.

EA: Yes, I definitely understand that, and I want to reiterate to everybody the very basics: eat the colors of the rainbow. So that’s a way to make sure you’re getting everything you need, instead of just saying, “I heard it was berries that are anti-inflammatory.” Just think of a varied diet of whole food plant-based: whole grains and lots of veggies and lots of colors: red peppers, dark leafy greens, yellow squash.

JM: Right! Eat all the colors of the rainbow and you’re off to a good start. The beauty is our gut microbiome is asking for the simplest of things: Fresh, colorful veggies, whole grains, gobs of legumes, and tons of fresh fruit and seeds to keep running well and helping us out.

Elysabeth Alfano is a plant-based business consultant and helps people transition to a plant-based diet. Follow her @ElysabethAlfano on all platforms and at