Your Gut and Your Brain Are Talking — And IPA Is Part of the Conversation

Have you ever had one of those days when your stomach just doesn't feel right, and somehow your whole body seems to know about it?

Maybe you're tired, your concentration isn't quite there, or you're simply not feeling like yourself.

It turns out that your gut and your brain are much more closely connected than we once thought.

And one of the fascinating pieces of this gut–brain puzzle is a little compound called indole-3-propionic acid — or IPA for short.

Let's take a simple look at what IPA is, where it comes from, and why your gut bacteria are so important.

First, let's talk about tryptophan

IPA starts with something we get from food called tryptophan.

Tryptophan is an essential amino acid, which simply means that our bodies can't make it themselves. We need to obtain it through our diet.

You'll find tryptophan in everyday foods including:

• Eggs
• Dairy products
• Fish
• Poultry
• Nuts
• Seeds
• Legumes

Once tryptophan enters your body, it can be used in several different ways.

And this is where things get really interesting.

Your gut bacteria get involved

Some of the bacteria living in your large intestine can use tryptophan and transform it into compounds called indoles.

One of these compounds is IPA.

So, in a very simplified way, you can think of it like this:

Food → tryptophan → gut bacteria → IPA

This is a beautiful example of the relationship between what we eat and the trillions of microorganisms living inside our digestive system.

Your gut bacteria aren't simply sitting there doing nothing. They are interacting with the food we eat and producing a whole range of substances that can affect our bodies.

But what does IPA have to do with your brain?

Your gut and your brain are in constant communication through what we call the gut–brain axis.

Think of it as a two-way communication network connecting your digestive system and your nervous system.

Once produced in the intestine, IPA can enter the bloodstream and interact with different systems throughout the body, including pathways involved in the nervous system.

The communication between your gut and brain involves several routes — including the bloodstream, immune system, intestinal barrier and nervous system.

So where does the "gut health" part come in?

This is where we need to move away from thinking about our gut as simply a digestive tube.

Your gut is home to an enormous community of microorganisms, and what those microorganisms are doing can be just as interesting as which bacteria are present.

That's an important distinction.

A gut microbiome test that simply gives you a long list of bacterial names doesn't necessarily tell you the whole story.

A more useful question can be:

"What are these microbes actually doing?"

The Gut Brain Science material, for example, looks at functional markers such as IPA, short-chain fatty acids (SCFAs), LPS, ammonia, histamine and TMA to provide a broader picture of microbial activity and its relationship with gut and whole-body health.

IPA — one piece of a much bigger picture

IPA isn't the whole story.

Just as we wouldn't judge a person's overall health from one number on a blood test, we shouldn't judge the health of a microbiome from a single marker.

Your gut is an ecosystem.

There are lots of different players, and they all interact.

So, what can you do?

The good news is that you don't need to become a microbiologist to start looking after your gut!

One of the simplest things you can do is give your gut bacteria a varied diet to work with.

Think:

🥕 A variety of vegetables
🍎 Different fruits
🌾 Fibre-rich whole foods
🌰 Nuts and seeds
🫘 Legumes
🥚 Protein sources containing tryptophan

Variety matters because you're not simply feeding yourself — you're also providing different types of food for your microbial community.

And don't forget the basics:

Eat a variety of whole foods.
Stay hydrated.
Keep moving.
Look after your digestion.
And avoid making every meal about highly processed foods.

Small, consistent habits can be much more valuable than searching for one magical "gut health" food.

Your gut is unique to you

Perhaps the most important thing to remember is that everyone's microbiome is different.

There isn't one perfect gut microbiome that looks exactly the same in every person.

That's why I believe gut health is much more interesting when we stop looking for a one-size-fits-all answer.

Your gut is your own ecosystem.

So, the next time someone tells you that your gut and brain are connected, remember that there's a fascinating world happening behind the scenes.

The food you eat provides the raw materials.

Your gut bacteria help transform those materials.

And the compounds they produce can become part of a complex communication network involving your gut, immune system, bloodstream and nervous system.

IPA is just one small piece of that much bigger story.

And perhaps that's the most exciting thing about gut health.

We're beginning to understand that it's not simply about which bacteria you have.

It's about what your microbial community is doing — and how that activity interacts with the rest of you.

Your gut has a story to tell.  Sometimes, we just need to learn how to listen.