When we feel stressed, we often blame external factors such as work, family life, traffic, or the World Cup. But recent research on the microbiome and studies on gut-brain connections show that what we eat and when we eat can alter our moods.

Our gut health can determine how anxious, happy, positive, and energetic we feel. Many scientists believe that small bugs in our colon have the say in some of our decisions. Yes, it sounds like science fiction but evidence of the gut’s influence on our moods is coming to light.

What is the Microbiome?

In the last few decades, a buzz about gut bacteria has everybody asking questions about this little understood, but essential part of our bodies.

The microbiome or microbiota is the community of good and bad bacteria, fungi, viruses, and other tiny organisms that colonise our bodies. Those familiar with the term usually refer to gut bacteria but these microorganisms live in almost all parts of our bodies. Without them, we’d die. They are as essential to our survival as the blood that flows in our veins.

Our immune systems are just one system of the body that depend on the microbiota.

If you’ve never heard of this term before you might be wondering why it’s not front-page news. Well, one reason is that the big pharmaceutical companies fear the day when microbiome-friendly nutritional regimes solve many of our health issues. They can’t sell us drugs when we don’t need them. Natural health remedies are often the least profitable for big industry.

As a result, funding for this type of medical research is harder to get because there are fewer avenues for monetisation. However, some organisations like the Kavli Microbiome and the Human Microbiome Foundation grant research funds to scientists, universities and private organisations that show promise in this area.

Companies like 23 and Me in the US, and Atlas Biomed in the UK provide home testing kits that you send off to their labs for testing. The results can help you understand the “health” of your gut and what you can do to improve it.

Note: before signing up to these services, ask yourself if you want information about your DNA on a database in Silicon Valley.

Ireland is home to some important research into the “new” science of the gut. The APC Microbiome Institute in UCC, Ireland is a world-leading researcher into the bacteria of the gastrointestinal tract. According to the APC Microbiome Ireland, microbiota (the microscopic organisms of a particular environment) is the quickest growing areas of research in biology.

It’s very possible that the master key to unlocking chronic disease will be the health and composition of the microbiota in your gut. —Michael Pollan and Ruth Reichl

So now we know what the microbiome is, let’s take a look at how our gut health affects our stress levels.

Stress and Gut Health

We live in a stressful world, far removed from the world of our ancestors. Back in the day, we had the stresses of working the land, running away from predators, and fighting off enemies, but we also had a food supply sourced from non-polluted, nutritionally dense soils. Modern stresses such as traffic, office work, and the toxic environment of cities affect your body in the same way as your ancestors’ stressors affected their bodies.

Stress is linked directly to the microbiome via the gut-brain axis.

It’s important to realise that the mind-body connection is strong. We can’t separate our gut health from our mental health. They are interlinked. There is research to suggest that the bacteria in our gut can influence how we think. “Bad bacteria” can send signals to the brain which influence your decisions and desires. That craving for junk food you have every day might have nothing to do with you. It could be the millions of bad bacteria in your gut that want to get fed.

Millions of minds working together (our bacteria) are stronger than a single human mind that is bombarded with advertising for junk food and treats. If you live in a city, it’s hard to get away from fast food and snacks. Biological processes that nag at you to eat junk foods are hard to resist.

This is how our bodies trick us into eating things we shouldn’t.

Mood and Gut Bacteria

Eating sugar creates feelings of contentment. Consuming sweet food sends signals to the brain that boost ‘feel-good’ hormones. But the effect is short-lived and like any drug (sugar is more addictive than cocaine), the crash can be severe. Depression and stress are two of the negative effects of the sugar crash we often experience after binging.

By tempting us to eat sugar our gut flora can indirectly increase our stress levels. What’s the solution?

Eat foods that increase gut bacteria and decrease bad bacteria.

The microbiome is a key regulator of stress and inflammation. Increasing or introducing healthy bacteria such as Lactobacillus Rhamnosus has been shown to reduce depression and anxiety in animals under stress. Scientists noticed behavioural changes in these animals after the introduction of the healthy gut bacteria. In animal tests, at least, gut bacteria gut influences behaviour by affecting stress levels.

What’s even more interesting is that scientists were able to show that they could reverse the effects by severing the vagus nerve, a very important nerve connecting the brain to the stomach, intestines, and gastrointestinal tract.

Another study showed that two probiotics, Lactobacillus helveticus and Bifidobacterium longum, orally administered for one month to healthy adults showed significant improvements in anxiety, depression and lowered levels of cortisol, the stress hormone.

The biggest takeaway from this article should be that if you want to improve your gut health, stay away from junk food.

Kombucha and the Microbiome

The Kombucha-Gut health connection is touted in hippie circles, new age foodies, and Bali expats.

On the face of it, kombucha seems like the perfect supplemental food for health. The fermented tea drink, that teems with healthy bacteria, seems to offer an instant solution to a gut depleted of nutrients thanks to a western diet of junk food.

Research has not yet proven the efficacy of Kombucha as a supplement for improving our gut health. Although Kombucha is a source of potentially healthy microorganisms, the drink’s long-term benefits on gut flora diversity have yet to be examined.

Other foods that may feed and increase the good bacteria in your gut include kimchi and sauerkraut, both fermented products that humans have consumed for centuries.

The human gut microbiome is complex. We’re only just beginning to understand it. Research in the last few years has uncovered some amazing facts.

5 Things You Probably Didn’t Know About the Microbiome

1. Fecal microbiota is sometimes transplanted between humans to alter the gut flora of the recipient.

Sounds gross, but the effects can be life-changing. This procedure could one day be an integral part of gut health treatments. Promising results have already shown improvements in IBS, GI disorders and obesity.

2. Our microbiome can influence our mental state but the reverse is also true. Stress can alter the balance of good to bad bacteria in the gut. From this point a circular pattern of bad bacteria that causes stress which in turn, increases the bad bacteria, and so on.

3. The gut bacteria of Western populations is less diverse than that of the populations of developing nations. The people of less developed nations that live in rural areas have the most diverse microbiomes of all. Industrialised nations are less connected to the environment. There’s evidence to show that connecting with animals (owning a pet, for example) improves the microbiome’s resistance to allergies and infections.

4. Our microbiome cells outnumber our own native cells by a factor of ten. Human bodies are essentially a framework optimised to carry around a large collection of bacteria, which have their own agenda.

5. There is evidence to suggest that cesarean births prevent babies from benefiting from their mother’s healthy and protective bacteria. The birth canal is teeming with bacteria and newborns receive a healthy covering of bacteria which helps them populate their gut flora. It takes caesarean babies longer to build up healthy gut bacteria.

microbiome and stress