Mind-Gut Connection: How Our Diet Affects Our Mental Health

I've always had an... interesting... relationship with food. That's the simplified version of my story. I'm trying to spare you the deets, but basically I've:

  • Gone on several crash diets

  • Obsessively tracked my food down to the very last gram

  • Had a phase where I stress-ate entire Domino's pizzas multiple days a week

  • Became paranoid of all refined sugars and caffeine

  • Stopped eating meat because I was worried about "absorbing the animal's fear when they were slaughtered"

  • Had HORRIBLE chronic bloating and indigestion thanks to anxiety

And with each experience, I realized over time that my eating habits (and consequently my gut health) has a massive effect on my mental health, and vice versa.

However, what compelled me to finally write this post is this new thing going on in my life: I haven't really been eating.

Now as someone with a history of eating disorders, I know this is going to raise some alarms. But rest assured (ish) that me not eating has nothing to do with my body image or my toxic fixation on control. I've literally just been forgetting to eat.

In the past 5 days, I've been glued to my computer screen, only pausing for pee breaks and to fill up my water bottle. I'll eat an orange here or there, maybe some hastily-spread butter on bread, and before I know it, surprise! It's 11pm and I need to get ready for bed.

I'm sure many of you can relate. You become so preoccupied with work or school that you don't even feel the pangs of hunger that inevitably come up throughout the day. Or you do, but you put them off until it's too late.

Three nights ago, I started getting severe panic attacks before bed, something I haven't experienced consistently since 2019 (you can read about that here). In hindsight, I feel like MAYBE it has something to do with the fact that I was barely eating 500 calories a day, for several days.

It's scary, isn't it, when something is very very wrong but you're not sure why? I'll never know for sure where these random attacks are coming from, but the pieces of the puzzle are starting to fit together. For example, I only realized today that the worst of my anxiety back in 2019 coincided with the peak of my orthorexia, when I had an extremely restrictive keto diet, over-exercised, and always went to bed feeling ravenous.

The more I forget to eat, the more anxious I feel at the end of the day, and the more dizzy and nauseous I get... which in turn absolutely destroys my appetite.

Have you ever experienced something "gut-wrenching?" Or felt totally nauseous before a big presentation?

The gut is extremely sensitive to our emotions, and our language has evolved widely to acknowledge this relationship between the mind and body. We get "gut feelings," "butterflies" in our stomachs, etc.

I won't get into the basics of how our brain communicates with our digestive system. That stuff? We've known about it for ages.

But what really piqued my interest in this subject (beyond my mysterious panic attacks) is newer research and discussions around the idea that the trillions of bacteria that inhabit our gut might actually be... controlling us?

(Because this concept is so recent, it's hard to find anything super conclusive online so do take everything said here with a grain of salt!)

Gut is King

However, there are some things we know for certain. For example, the gut is the largest immune organ in our body. In fact, did you know that the surface area of the intestine could cover half a badminton court? I know, I was shook too. It goes to show you that there is SO much going on underneath the surface that our naked eye can't see. As you're reading this right now, trillions of microbes in your body are working hard to boost your immune system, help you make nutrients, digest the food you eat, protect you against infection, and a whole lot more. Long story short, our microbes are the GOAT.

Of course, that's the "good bacteria" that's making sure everything is working properly. Its evil cousins are, unfortunately, the ones we hear about more often. We've all heard of (and feared) names like E.coli, salmonella, and candida (an overgrowth of candida can lead to yeast infections and oral thrush).

If you've ever had strep throat or pneumonia or food poisoning, you can blame the "bad bacteria" for that. But for the most part, the microbes that live in us serve important functions for our health and wellbeing.

Where do our microbes come from?

It all starts in our mother's womb. Most scientists believe that we are sterile in utero, meaning every cell in our tiny body is our own, up until the point that we either get pushed out of our mom's vagina or leave the womb through C-section.

As you exit through the birth canal and/or get exposed to the "outside" for the first time, your body starts picking up on a bunch of microbes—from breast milk, skin, your birth environment, the various things that you'll put in your mouth as a curious toddler, and the foods you eat. By the time you're an adult, your gut microbiome has fully developed and stabilized, although it can still change depending on factors like antibiotics, disease, diet, age and such.

Okay let's go back even further...

I listened to a super interesting podcast episode of Psyched! that delves deeper into the evolutionary relationship of humans and microbes. In it, gastroenterologist Emeran Mayer, MD, PhD explains: "If you go back in evolution you'll find that microbes were obviously the dominant life form on planet Earth for billions of years... and then at some point there was a decision made by some algae in the ocean to settle inside the digestive system of a primitive marine animal, the Hydra... The microbes started living inside that system, and used their own communication signals that they had developed over four and a half billion years in the oceans to start communicating with the nerve cells of these floating digestive tubes."

It seems that the ongoing communication between the bacteria in our GI tract and the rest of our bodies (namely, the mind) is something that's developed and strengthened over the last BILLIONS of years, and it's only recently that we're starting to explore the implications of this.

Cool story bro, but what does this all mean? In "speaking the same language" as our brain and other body parts, our gut microbiome can actually enact change depending on the signal it gives/receives.

For example, when we're stressed, the main stress molecule that we excrete, norepinephrine, reaches the microbes through connecting nerves and actually changes their gene patterns, leading to change in behaviors that, in turn, affect how we feel (e.g. craving certain foods, losing our appetite, feeling sick to the stomach).

Even more interesting is the fact that a lot of our neurotransmitters are actually produced in the gut, such as GABA, which helps control feelings of fear and anxiety. Studies with lab mice have shown that certain probiotics (that boost gut health) can actually increase production of GABA, thus reducing anxiety-like behavior.

Gut and mental health

All this science-y stuff to say that our gut health can have a huge impact on our mental health.

Many researchers are starting to wonder whether beneficial gut bacteria could ease the anxiety and depression that often accompany GI disorders such as Crohn's disease, ulcerative colitis and irritable bowel syndrome (IBS).

In one study, Peng Xie, MD, at Chongqing Medical University in China, and colleagues found that the gut microbes of patients with major depressive disorder differed significantly from those of healthy controls.

Psychobiotics are becoming a popular topic, as more researchers look into how bacterial interventions could alleviate symptoms of certain psychiatric disorders such as depression or bipolar disorder. Of course, it's still very much a chicken-or-egg situation: are abnormal gut biomes a cause or consequence of certain diseases and disorders? Regardless, this emerging field of research is really exciting for me personally because I've always been a firm believer in holistic health, and looking at our minds, bodies and souls as a collective, dynamic unit. How cool would it be if we could take probiotics that's proven to not only help our digestion but ALSO improve our mental wellbeing?

A girl can dream.

Until then, here are some ways you can boost your gut health:

  1. Stop stressing. Chronic stress is SO bad for our bodies in general. Look into mindfulness-based stress reduction techniques, such as meditation, learning how to eat mindfully, breathing exercises, dialectical behavioral therapy and more.

  2. Load up on your fermented foods. This includes kimchi, sauerkraut, yogurt (ideally the kind that's not full of artificial sugar). Start out with naturally fermented products instead of jumping straight into probiotic/prebiotic pills.

  3. Try to stick to a high-fiber, low-sugar, mostly plant-based diet, which is what doctors across the board recommend for overall health and longevity. This means pairing your fermented foods with a variety of veggies and fruits, including but not limited to:

  • Raspberries

  • Artichokes

  • Green peas

  • Broccoli

  • Chickpeas

  • Lentils

  • Beans (kidney, pinto and white)

  • Whole grains

This is all advice I plan on taking myself. It's no wonder that I'm having such bad anxiety and depression when my diet has been crap lately. I hope this leaves you with some food for thought (ha ha) and that you learned something new from this post.