Did you now that there are many more messages going from the gut to the brain than the other way around? Why is that? Could it be that our guts are sometimes in the driver’s seat of our wellbeing? Curious? Read on.

It’s not hard to make the case that our physical health impacts our wellbeing. We all know this. When we don’t take care of ourselves, we can get out of shape, lack energy and can get a case of the blahs. Worst even: we can become sick…sometimes very sick.

The standard health advice centers on eating right, moving our bodies, and getting sleep. I think we have all seen enough research around these elements to agree that these are critical to our wellbeing. But let’s look a level deeper by unpacking some of a recent body of research that highlights how our guts can have a big impact on our health and wellbeing.

Welcome to your Microbiome

What is the Microbiome?

Your microbiome is a population of microscopic critters (microbes) that live in your gut*** and make up your microbiome. These critters include multitudes of bacteria, viruses, funguses, and even parasites.

Your Microbiome is its own little ecosystem. And, while small, it’s an incredibly complex system, filled with species that cooperate and others that compete. Your microbes number in the trillions. They are not only high in number but also high in variety – our guts are meant to be diverse. In fact, increased diversity is associated with decreased illness and leaner body types.

I am not an expert on the microbiome, by any means. But I have spent some time digging into the research because our microbiome impacts our wellbeing and wellbeing is what we care about at Positive Voices. To that end, I am going to share some of the big takeaways I have garnered. I will focus on three major ways your microbiome impacts you: controlling your immune system, regulating your body weight, and even impacting your mental health.

Your Microbiome Is your Biggest Immune System Organ

Our guts are made up of one hundred million neurons that line your enteric system from your throat to your rectum. Imagine that! Brain neurons that exist outside our brains and, if they were clumped together, weigh about 3 pounds! I guess it’s no surprise many call our microbiome our second brain.

These neurons aren’t just sitting around or taking commands from the brain. There seems to be clear two-way communication that is ongoing via our vagus nerve (which is like a busy telephone line with messages flying back and forth). What has stunned many is that there are many more messages going from the gut to the brain than the other way around.

Our microbes are sending information to our overall immune system on how to behave – providing information on what are friend and what are foe to our bodies.  When our gut is not balanced, it can under inform or misinform our immune system. If our immune system identifies a foe as innocuous, we can become sick with flu, cold, infection or even cancer. If our immune systems identify a friend (or a neutral party) as foe, this might lead to an overactive immune system, manifesting in potential ailments such as asthma, allergies or an autoimmune disease.

Contributing to this: our western guts are becoming less diverse overall. Due in no small part to lifestyle, we are losing good microbes that have been part of human makeup for centuries. How can we instruct our immune system effectively when we are losing some important data?

Your Microbiome Impacts Your Mental Health

When we don’t take care of our gut (more on that later), communication can be disrupted or even hijacked. There is growing evidence that our microbes can potentially “hack” into the communication (altering the neural signals via your vagus nerve) and talk directly to our brains – impacting mood and behavior.

Consider the case of toxoplasmosis. Previously pregnant women might remember this toxin from our physician’s admonishment to stay away from kitty litter while gestating. Toxoplasmosis is dangerous to fetuses. Infected cats secrete toxoplasmosis in their feces. Fascinating and disturbing is the fact that mice infected with toxoplasmosis exhibit a change their behavior. While normally, mice avoid risk-taking around cats, when infected with toxoplasmosis, mice behavior changes. Their brains, as if hijacked, now are directing them to be much riskier. For example, infected mice will stand around in open spaces where there are cats nearby, almost as if they wanted to be eaten. Researchers believe this is an evolutionary adaptation to help the parasite complete its life cycle to enter the feline. Fancy that: a microbe that is directing behavior!

Another way that our guts can impact our moods and behaviors is through hormones and neurotransmitters. Our guts produce many including

  • Dopamine: This is known as the “feel good” hormone.
  • GABA: Gamma-Aminobutyric Acid is a neurotransmitter that can help calm us and is associated with decreased depression and anxiety.
  • BDNF:  Brain-derived neurotrophic factor supports the function and survival of neurons and impacts our cognition. Low levels of BDNF in the hippocampus have also been associated with anxiety and depression.
  • Serotonin: Serotonin is known for its mood-boosting powers. Interestingly, our guts produce ten times more serotonin than our brains do.

This is a hot area of research and there are studies on everything from the gut’s role in depression, sleep, and even our ability to learn.

Your Microbiome Helps Regulate your Weight

Our microbiome also plays a role in regulating our weight. Our microbes can determine how much energy our bodies extract from the food we eat.  Also, when our gut is out of balance, we can have increased inflammation, which has been linked to being overweight or obese. Inflammation has also been identified as a major factor in many lifestyle diseases such as Type-2 Diabetes, Alzheimer’s and cancer. When scientists have studied the microbiome of obese individuals, they have very low diversity on average.

Consider this experiment by Dr. Jeffrey I. Gordon and his team at the Washington University in St. Louis. They studied identical twins (with identical DNA), where one twin was obese and the other was lean. They took samples from each of the twins and transplanted their microbiome to two separate mice: one received the “obese microbiome” and the other the lean. Fast forward five weeks and the mice who received the sample from the obese twin had between 15 and 17 percent more body fat along with some of the metabolic changes associated with obesity. The other remained lean. Additionally telling, they now put the two mice together. Fast forward again and both mice were now fattened up. Why? Because mice have the distasteful habit of eating each other’s feces.

Now What? Eat Drink and be Merry

So, what now? Are there things you can do to improve your gut health? Yes! There are! First, our diet has a huge impact on our gut. It has been shown that our microbiome starts to shift in as little as four days after a change in diet.

What should I eat?

Eat plants! Eat your veggies and your fruit. Eat a wide variety of them. Eat lots of fiber, not just found in fruits and veggies, but also in foods like beans and legumes. These are considered prebiotics, which helps set the right environment for fermentation in the gut. But, don’t stop there: eat probiotics, too. You can get a healthy dose of probiotics in fermented foods such as sauerkraut, kombucha, yogurt, live cheese, miso, kimchi, and apple cider vinegar. It’s always advisable to get your nutrition in the form of food, but if you want to layer on a probiotic supplement, go for it. Other foods that help increase gut diversity are dark chocolate, red wine, and high-quality fats such as olive oil, coconut oil, avocado, free-range eggs, grass-fed butter, nuts, seeds and fatty fish.

There are also foods you should minimize: sugar and starches. Examples of starches are potatoes, rice, bread, and pasta.

There are some bacteria that cannot be fed. One important one is Akkermansia, for example, which feeds on the mucus lining of your gut. This lining can build, a good thing, when we fast or reduce calories. In fact, diversity has been shown to rise after fasting. A healthy dose of Akkermansia is associated with leaner body types. So, if you haven’t tried fasting, you might want to give it a whirl. I practice modified intermittent fasting myself. You can read about the protocol I follow here (https://thefastdiet.co.uk/how-many-calories-on-a-non-fast-day).

Beyond Diet

Diet is fundamental. That said, there are other things you can do. It comes down to nurturing (or keeping) the microbes you have and increasing your exposure to new microbes in your environment.

One of the most important things you can do to keep your existing population of microbes is to limit antibiotic usage to when it’s truly needed. Now, if you are sick and in need of antibiotics, yes! Please! Take your antibiotics! They can be lifesaving. Since the introduction of antibiotics, millions of lives have been saved. Prior to that, infectious diseases were our worst killer. The problem is that when we take antibiotics, they not only kill off our bad bugs, but also the ones we need. It’s well worth it when we are sick. But when we overprescribe or mis-prescribe antibiotics, we can end up killing off our microbe population for nothing. If you do need a course of antibiotics, it’s important to finish your full course. From there, you can work to rebuild your gut. But that can take weeks, months, and sometimes, especially if we have serially taken antibiotics, our guts won’t bounce back completely. The bottom line: be judicious.

Another way we can build our microbiome is by exposing ourselves to more microbes in our environment. This includes not overusing antibacterial soaps and sanitizers as well as harsh chemicals that can leave our environment too sterile. It can be a bit difficult to find the right balances for our families and so I leave that to you. For my family, I am more diligent in certain environments where the flu and other illness are more likely to lurk (airplanes, hospitals, and malls) and at certain times (during flu season).  Couple your own plan of attack with some proactive exposure to the good stuff. Here are some things to try to up your exposure to good microbes:

  • Get outside
  • Open a window
  • Get your hands dirty (perhaps try gardening or a new outdoor sport)
  • Get a dog or other pet

Finally, our advice is (you knew this advice would emerge because, well, doesn’t it always?): exercise.  There are many studies underway but the evidence is accumulating. Dr. Paul Cotter, at the Microbiome Institute in Cork, Ireland, found microbiome samples were more diverse in exercisers over nonexercisers. He has studied elite athletes and couch potatoes who recently started exercising and the answer was the same: exercisers have more diverse microbiomes. So, yes, exercise is a good tact for gut diversity improvement.

Parting Advice

For our children and future children, there is one more important thing to note. What we now know is that children have their microbiome seeded when they are born. This is a particularly important time. The best way to assure a healthy start to a baby’s microbiome is a natural entry into the world via the birth canal.  When we are born naturally, we are exposed to our mothers’ microbiome in her vagina. This seeds our guts. C-sections can save lives and are often imperative, but now that we are armed with better information, we can reconsider whether we really do want to opt for a C-section, if it’s not needed. Once your baby is here, if you are able, consider breastfeeding. Big surprise: much what of what is in breast milk is perfect food for the baby’s emerging microbiome.

We hope this has been informative and helpful. Remember, you don’t have to do it all in a day. Just start by making some changes and layer from there.  One step in the right direction can be followed by yet another. So, take good care of you and remember: Don’t hate your guts – treat them right!

***Microbes also live on your skin, in your breath, and throughout your body.


Dietert, Rodney. The Human Superorganism: How the Microbiome Is Revolutionizing the Pursuit of a Healthy Life. New York: Penguin Publishing Group. 2016. Kindle Edition.

Emeran, Mayer MD. The Mind-Gut Connection: How the Hidden Conversation Within Our Bodies Impacts Our Mood, Our Choices, and Our Overall Health. New York: HarperCollins Publishers. 2016. Print.

Knight, Rob. Follow Your Gut: The Enormous Impact of Tiny Microbes. New York: Simon & Schuster/TED Books. 2015. Kindle Edition.

Mosley, Michael. The Clever Gut Diet: How to Revolutionize Your Body from the Inside Out. New York: Simon & Schuster. 2017. Kindle Edition.

Perlmutter, David. Brain Maker: The Power of Gut Microbes to Heal and Protect Your Brain–for Life. New York: Little, Brown and Company. 2015. Kindle Edition.

Sonnenburg, Justin. The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-term Health. New York: Penguin Publishing Group. 2016. Kindle Edition.

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