Gut Feeling: Can you change your brain by changing your gut?

By Posted July 22, 2015

Before we get to today’s article I want to say thank you so much to everyone that took part in our sleep survey. (If you haven’t yet, you can here.)

We’re furiously sorting through all the replies, but one thing is loud and clear: you poor folks are not sleeping well!

Good news: We’re on the case. And because of your valuable feedback, we know prescriptions for sleep are just making you more miserable, and simple melatonin has been an iffy solution at best.

In just a few days, we’re going to give you ways to help you fall asleep naturally, and stay asleep the entire night…without feeling groggy the next day. Keep your eye on your inbox for a sleep message from a brand-new contributor.

But for now, back to today’s article…

Imagine you’re a cricket, just doing your cricket thing.

Then one day, you have a strong urge to move toward light. Anything bright and shiny, you can’t resist. It’s a sunny day, the sunlight is reflecting off a pond. You sit on the edge of the bank, and when a bright flash catches your eye — you jump — straight to a watery death.

Why?

A hairworm took control of your brain.

Hairworms live in land insects like crickets, but can reproduce only in water. So when it becomes time to make little baby hairworms, the parasite alters the cricket’s brain to send it toward bright, shiny things — like sunlight dancing on water.

Mind-controlling parasites are not a rare thing in the animal kingdom.

There’s a type of flatworm that makes its way into the brain of an ant, directing the ant to sit on the tip of a blade of grass, where it can be eaten by ruminating cows. Why? The flatworm can breed only inside of the livers of grazing animals.

There are at least six other types of parasites that have the ability to control the brain of animals to their benefit. Now, parasites are one thing, since by definition they serve no beneficial role to their host. But what about bacteria? Could they too have the ability to change the way the brain works, for better or worse?

Science is shouting a resounding, “Yes!”

You already know that your gut is full of bacteria that help you digest food. But that’s not all they do. Scientists are uncovering the ways that these bacteria produce body-wide effects, including playing a role in immune system response and hormone production.

And stunning research is now showing that gut bacteria directly communicate with the brain and central nervous system, effectively influencing our mood, behavior, and even the types of foods we crave. (1)

Anxiety, and depressive symptoms specifically, seem to be greatly influenced by gut bacteria.

In 2011, researchers demonstrated that the gut bacteria in mice can influence whether they display anxious behavior or not. They took two groups of mice, one that showed anxious behavior and one that did not, and performed fecal transplants so that the bacteria from each mouse group were swapped. Then they watched as the previously anxiety-free mice displayed anxious behavior and the previously anxious mice were calm. (2)

Other research has shown that altering the bacterial balance in the guts of mice has produced or inhibited anxious behavior.

So just how do the bacteria in the gut affect the brain?

One way may be through the byproducts of bacterial fermentation. A certain class of bacteria produce a compound called butyrate, which is believed to have antidepressant properties. In one study, researchers compared the bacterial profile of feces from people that were depressed and people that weren’t. Sure enough, the depressed folks had fewer butyrate-producing bacteria.

Another way may be by directly communicating with the brain via the vagus nerve. The vagus nerve network extends from the brainstem throughout the body to every organ, including the GI tract.

Some bacteria appear to use the vagus nerve to communicate directly to the brain and alter the expression of GABA receptors. (Recall from last week’s article that GABA is an “anti-anxiety” neurotransmitter.)

But what about human studies? Is there any evidence that we can alter our brain function by modulating the gut?

I was actually surprised at the number of studies in humans showing positive results on brain health by addressing gut health. There are many more out there, but here are some I found most interesting.

In one study, folks with chronic fatigue syndrome and anxiety were given 24 billion colony-forming units of Lactobacillus casei or a placebo for two months. Those that were given the probiotic reported a significant decrease in anxiety symptoms.

Interestingly, the researchers also noted that the subjects given the probiotics had not only increased levels of lactobacillus bacteria in their stool but also higher levels of bifidobacteria, indicating a positive change in overall gut health. (3)

So while taking probiotic capsules is not a bad way to go, they can be expensive. Luckily, research is showing that foods rich in probiotics can have the same mood-boosting effect.

A study published in April found that both probiotic yogurt and probiotic capsules improved depression and anxiety scores in petrochemical workers. (4)

In another recent observational study, researchers found that women who ate the most fermented foods had lower rates of social anxiety. (5)

Fermented foods naturally rich in probiotics, such as sauerkraut, kombucha, yogurt, and kefir, are all great options to support the gut-brain axis. If you want to make one change to your diet that can potentially improve your mood, this is it.

Be aware that if you buy sauerkraut or yogurt at the store, pasteurized products do not contain probiotics (unless the manufacturer has added them back in after the pasteurization process). You can make your own sauerkraut at home fairly easily. Check out Brad Lemley’s article from Monday for instructions.

I’ve been drinking GT’s kombucha for about a month now, and not only has my gut health improved, but I also feel as though I’m less stressed on a regular basis. It’s very expensive, though (up to $4 per bottle!), so I’m looking into brewing my own at home.

Even if you don’t experience depression or anxiety, improving your gut health can have profound total-body benefits. And due to our modern lifestyle, just about everyone is probably suffering from some level of GI imbalance. Cesarean birth, antibiotic use, antibiotics in food, chlorinated water, environmental toxins, and a sugar- and processed food-laden diet all contribute to gut dysbiosis.

In addition to foods rich in probiotics, prebiotic foods can help feed your healthy gut bacteria. According to Dr. Perlmutter, a noted expert on the gut-brain connection and author of Brain Maker, some of the best prebiotic foods include Jerusalem artichoke, dandelion greens, garlic, onion, and asparagus.

So simply by making a slight change to your diet, you can profoundly affect your brain function and reduce mood issues like anxiety and depression. If you’re looking for other natural ways to beat anxiety, check out last week’s article.

Until next time,

Jasmine LeMaster
Health Researcher

P.S. Though I won’t make any claims for the safety or effectiveness of the following, your fellow Living Well Daily readers had some suggestions on ways to as reduce anxiety as well…

Give it a time limit and clean the bathroom, Terry wrote in to say:

“A technique I have used when feeling gnawing anxiety is to find and look intently at an analog clock. Then say to myself: ‘Fifteen minutes from now, when the hand has made a quarter turn, I will no longer be feeling this.’ Then take your walk, or furiously clean the bathroom or the kitchen. It really works to relieve the crisis. What’s more, when you see the freshly clean room, you actually feel great!”

Judy wrote:

“I have found vitamin B3 works, either form. I take it in conjunction with a multi B complex. As long as I take it, I don’t suffer from anxiety.”

Sebastien summed up his recommendation with one word:

“Cannabis!!!”