A love letter to our gut

The Vitl Nutrition Team / 17 May 2022

Dearest gut,


You are not alone if you think of your gut as a one simple, long, twisting garden hose that extends from your mouth to your rear end. But news flash: it is far more complex than the description suggests. The research about this weird and wonderful organ has exploded in the last decade. Let’s take a look at the findings. 

Why are you so special? 

You are so vital in the body for many different reasons, actually without you...I wouldn’t be me! 

You are also known as the gastrointestinal system, comprising our intestines (both small and large) and stomach. However, more colloquially, the word ‘gut’ refers to trillions of microorganisms that live in our large intestine, also known as the ‘microbiome’ or, as I like to call it, “the intestinal garden”. 

Did you know? You weigh approximately 3 pounds (1-2kg) which is about the same weight as my brain…

Let’s look at all the amazing things you do for me.

Ok so maybe the most obvious, you help break down my food and help me absorb all the nutrients (such as vitamins and minerals) that I need. Actually the microorganisms found within you stop growing as soon as they run out of food, so there will only ever be enough of what you need. You are also fundamental in removing (solid) waste from our body. Yes, I’m talking about bowel movements!

Did you know? ‘Normal’ bowel movement is anywhere from 4 times a day to 3 times a week!

You support my immune system (yes the gut actually trains our immune cells!). 70% of our immune system resides in you; when pathogens enter my body, you are on hand to fight them off. 1 

The microbiome and our innate immune system (non-specific immunity, or the immune system with which we were born) engage in a bi-directional communication pathway. 

The good guys keep the bad guys in check. It’s all about balance (like with so many other things); if you are populated with more bad bacteria than good ones then complications start to occur. The risk of developing certain chronic diseases such as obesity, type 2 diabetes and inflammatory bowel disease (IBD) therefore increases. 2 

The connection between you and my brain is very strong. This is called the gut-brain axis (or connection). There is an extremely long (and rather) important nerve that runs from our brain all the way down to our abdomen called the “vagus nerve”. We originally thought that the chief operating officer of the body (our brain) runs the show but actually our gut sends many more signals from our intestines to our brain. 3 

This connection is why:

  • We get butterflies in our stomach before a big speech or going onstage
  • We get nervous or get cramps before a hard workout or race

This fight-or-flight state or psychological response can translate to digestive symptoms. (More on that below!) Another way you impact my mood is through the production of many brain chemicals such as serotonin. 4 

Did you know? Our gut provides about 95% of total body serotonin, which exists in plasma. 

How can I keep you healthy and happy?

I know that if I keep you happy you will keep me healthy. What a lovely synergistic relationship we have! There are several things that I can do that will keep you and the friendly gut bugs happy. 

What I eat
Probably one of the most important factors, and unsurprisingly as you eat the same food I do. To keep you functioning at your best, nutritious foods should be the priority. Your favourite foods are those which are high in fibre. Specifically, a certain type of fibre called prebiotics which I have difficulty digesting but it’s your bread and butter (or in other words, your food). These foods are; garlic, onions, asparagus, chicory, oats, artichokes, berries, the list goes on…

Another thing I can do that you will love is eat foods that have been fermented, such as kefir, kimchi, sauerkraut, miso or tempeh. These contain bacteria (the friendly kind) which will help diversify the population of bacteria within you. 

Did you know? Eating at least 30 different kinds of fruit and vegetables a week is considered an ideal amount! 

New research suggests that aerobic exercise specifically can help improve the diversity of our intestinal garden of gut bugs. 5 Low intensity exercise can reduce stool transit time, which means the contact between pathogens and the gastrointestinal mucosal layer. 6

Growing evidence suggests that you can influence my sleep quality. What?! Yes, there are a few studies analysing the effects of an unbalanced microbiome on sleep, but the key takeaway is that by improving our health (ie. looking out for our gut health) will result in us sleeping better too. 7, 8 

What do you not like?

Ok, so we’ve talked about what you like, but what about things in my diet and lifestyle that you are not a fan of? 

I know, I’ve heard it before that stress in small amounts can be good. But chronic stress or prolonged periods of stress can be quite detrimental. In scientific research, our autonomic stress response is known as the fight or flight response, and this was particularly helpful a long time ago when our ancestors needed to flee from real dangers such as being eaten by a lion. Whilst this is no longer a reality (thankfully!), the biological response remains the same. When we perceive something as being stressful, our sympathetic nervous system is activated and initiates a stress response. Cortisol is released into our bloodstream which can cause changes in our gut, such as negatively impacting the acidity of our stomach, which leaves us prone to digestive issues. 

Did you know? Chronic stress is associated with reduced diversity in the microbiome and increased intestinal permeability.

Processed food
Junk food and sugary foods such as fizzy drinks stimulate the production of bad bacteria within you. That means that by eating these foods often I am feeding the bad guys, this in turn can cause an overgrowth of them leading to an unbalance or ‘dysbiosis’. Many studies done on animals reveal that eating diets high in sugar, fat and processed food can cause inflammation, which in turn can have some pretty serious consequences. But that isn’t to say we should never eat these foods, moderation is key! 

3 fun facts we didn’t know about you

  • 70% of our immune system is located in our gut. And the entire immune system is protected from the rest of the body by a thin, fragile lining only one cell thick. 
  • When stressed, it's harder for us to digest our food as energy is diverted elsewhere, for example to our limbs in anticipation of movement.
  • Even thinking about food can trigger the gut to secrete digestive enzymes in preparation for a meal.

“The gut is not like Vegas; what happens in the gut doesn't stay in the gut” Dr Alessio Fasano

You might also be interested in:

Our ‘second’ brain: an investigation into the gut-brain axis

Daily Biotic formula: what's inside?

Food for your mood: nutrition’s role in mental health