The Gut-Brain Axis (Explained Without the Jargon)

The Gut-Brain Axis (Explained Without the Jargon)

Why your stomach and your brain are in constant conversation—and how to make that conversation a bit friendlier.

Let me tell you about my stomach.

For most of my adult life, my stomach and I have had what you might call a "complicated relationship." When I'm anxious, my stomach is anxious. When I'm panicking, my stomach is... well, let's just say it registers its objections loudly and often at the most inconvenient moments. Job interview? Stomach cramps. First date? Urgent need for a loo. Quiet Tuesday evening with no obvious stressors? Stomach: "I think I'll just feel a bit off today, if that's alright with you."

For years, I thought this was just "nerves." A bit of a dodgy tummy. One of those things. And then I learned about the gut-brain axis, and suddenly a lot of things made sense.

So let's talk about it. No jargon. No complicated diagrams. Just a simple explanation of why your stomach and your brain are basically in a group chat together—and what you can do to make that chat a bit less chaotic.

Your Gut and Your Brain Are Having a Constant Conversation

Here's the thing that blew my mind when I first learned it: you have a "second brain" in your gut. It's called the enteric nervous system, and it's a network of over 100 million nerve cells lining your digestive tract. That's more neurons than in your spinal cord.

Your gut brain and your head brain are connected by the vagus nerve—a long, wandering nerve that runs from your brainstem down through your chest and into your abdomen. Think of it as a dedicated phone line. A very busy, very chatty phone line.

And here's the kicker: most of the traffic goes upward. About 80-90% of the signals on that phone line are travelling from your gut to your brain, not the other way around.

So when your gut is unhappy—inflamed, imbalanced, struggling to digest something—it sends distress signals up the vagus nerve. Your brain receives those signals and goes, "Oh. Something's wrong down there. Must be danger. Sound the alarm!"

And suddenly you're anxious. Not because anything in your life is actually threatening, but because your gut microbiome is having a bad day.

Meet Your Microbiome (Your Internal Roommates)

Your gut is home to trillions of bacteria, fungi, and other microorganisms. Collectively, they're called your gut microbiome. Think of them as tiny roommates. Some are lovely. They pay rent on time, keep things tidy, and make you feel good. Others are... less lovely. They're noisy, they leave messes, and they stress everyone out.

When the balance tips towards the less lovely roommates—a state called dysbiosis—your gut lining can become inflamed. The vagus nerve picks up on this inflammation and sends "something's wrong" signals to your brain. Your brain responds with anxiety, low mood, brain fog, and that general sense of being perpetually on edge.

This is why gut health and mental health are so deeply connected. They're not separate issues. They're the same conversation, happening on the same phone line.

What Makes the Gut Unhappy? (The Usual Suspects)

If your gut-brain group chat is full of alarm signals, it's worth asking: what's upsetting the roommates?

Chronic stress. Stress itself changes the composition of your microbiome. It reduces the diversity of good bacteria and makes the gut lining more permeable. (This is sometimes called "leaky gut," though the science is still evolving on that term.)

Highly processed food. The lovely roommates thrive on fibre, plants, and variety. The less lovely roommates thrive on sugar, refined carbs, and ultra-processed ingredients.

Antibiotics. Sometimes necessary. But they nuke the microbiome along with the infection. It takes time to rebuild.

Lack of sleep. Your microbiome has a circadian rhythm too. Disrupted sleep disrupts your gut bacteria.

Alcohol. In excess, it's not great for the gut lining or the microbial balance. (I know. I'm sorry.)

Caffeine. We'll get to this in the next post, but caffeine can irritate the gut lining and stimulate the "urgent" signals. More on that shortly.

How to Make the Conversation Friendlier (Without Becoming a Wellness Influencer)

I'm not going to tell you to do a juice cleanse or buy expensive probiotics or only eat fermented vegetables while standing on one leg. That's not realistic, and frankly it sounds exhausting.

Here are some small, doable things that might help. Pick one. Try it. See how you feel.

1. Eat More Plants (But Not Like, Loads More)

The lovely roommates in your gut love fibre. Fibre comes from plants. Vegetables, fruits, legumes, whole grains, nuts, seeds. You don't need to go vegan or eat 47 different plants a day. Just... add a bit more. An extra vegetable with dinner. Some berries on your porridge. A handful of nuts as a snack.

The goal is diversity. Different bacteria like different fibres. The more varied your plant intake, the more diverse and resilient your microbiome becomes.

2. Try Some Fermented Foods (If You Like Them)

Fermented foods contain live bacteria that can support your gut microbiome. Things like:

• Yogurt (look for "live cultures" on the label)
• Kefir
• Sauerkraut or kimchi (the refrigerated kind, not the shelf-stable kind)
• Kombucha (if you like it; I personally think it tastes like slightly off fizzy tea, but each to their own)
• Miso

You don't need to eat them every day. Even a few times a week can help. And if you hate them? Don't force it. There are other ways.

3. Move Gently (For Your Gut, Not Just Your Mood)

Gentle movement—walking, stretching, yoga—helps stimulate digestion and supports a healthy gut. You don't need to run a marathon. A 10-minute walk after a meal can make a noticeable difference to how your stomach feels.

4. Drink Water

Simple. Boring. Effective. Your gut needs water to move things along and keep the lining healthy. Dehydration makes everything sluggish and unhappy.

5. Consider a Probiotic (But Don't Stress About It)

Probiotics are live bacteria supplements. The science on them is... mixed. Some people find them helpful. Some don't notice a difference. If you want to try one, look for a reputable brand with multiple strains. But don't feel like you have to. Food-based approaches (plants, fermented foods) are often more effective in the long run.

6. Manage Stress (I Know, I Know)

This is the annoying one. Because "manage stress" is what everyone says, and when you're anxious, "just manage your stress" feels about as helpful as "just calm down."

But here's the thing: stress directly affects your gut. The vagus nerve works both ways. When your brain is stressed, it sends signals down to your gut, changing how it functions. Slowing digestion. Increasing inflammation. Upsetting the roommates.

So the same things that calm your brain—breathing, grounding, gentle movement—also calm your gut. They're not separate projects. They're the same project.

A Simple Gut-Friendly Recipe (Because I Promised One)

Here's something I make when my stomach feels off and I need something warm, soothing, and easy. It's the Turmeric & Ginger Overnight Oats from my recipe collection. Anti-inflammatory. Gentle on the stomach. No thinking required in the morning.

Ingredients (serves 1):

• 50g rolled oats
• 1 tbsp chia seeds
• ½ tsp ground turmeric
• ¼ tsp ground ginger
• Pinch of black pepper (helps absorb the turmeric)
• 1 tsp maple syrup or honey
• 150ml milk of choice (oat milk works beautifully)
• 2 tbsp Greek yogurt or coconut yogurt

Method:

1. Combine everything in a jar or bowl. Stir well
2. Cover and refrigerate overnight.
3. In the morning, stir again. Add a splash more milk if it's too thick.
4. Eat cold, or warm gently in a pan or microwave.

That's it. One less decision in the morning. One less thing for your anxious brain to process. And a breakfast that supports your gut and your nervous system at the same time. 

A Final Thing

Your gut and your brain are on the same team. They're just not always very good at communicating calmly. One gets inflamed, the other gets anxious. One gets stressed, the other gets upset.

You can't fix this overnight. But you can start listening to the conversation. Noticing the patterns. Making small, gentle changes that support both ends of the phone line.

And if your stomach is still being dramatic despite your best efforts? You're not alone. Mine is too. We're in this together.

Anxiously Ever After is written by me, Jennie, a 50-something-year-old woman with a lifelong anxious stomach and a newfound appreciation for overnight oats. I write about mental health, neurodivergence, and the general chaos of being human.