How Your Gut Talks to Your Brain—and Why It Might Be Making You Anxious

I’ll be honest with you—I didn’t used to give much thought to my gut beyond whether my jeans fit after dinner. I thought digestion was just about food going in, nutrients getting absorbed, and waste coming out. End of story.

But then I started noticing something. On the weeks when my stomach felt “off”—bloating, cramping, or just that sluggish heavy feeling—my mood tanked. I’d get more irritable, more on edge, and sometimes flat-out anxious. And when I started paying closer attention, it wasn’t just me. Patients, friends, even women in my coaching calls were describing the same thing: “When my stomach’s a mess, my brain feels scrambled.”

That, my friends, is the gut-brain axis in action.

The Gut-Brain Axis, Explained Without the Jargon

Picture this: your gut and your brain are like best friends who never stop texting each other. They’ve got this direct line of communication through the vagus nerve (like the world’s longest phone cord), plus they’re constantly sending chemical “DMs” through hormones and neurotransmitters.

About 90% of your body’s serotonin—that’s the “feel-good” chemical most people associate with mood—comes from your gut, not your brain. Let that sink in. No wonder when the gut is inflamed or imbalanced, the brain often gets dragged down with it.

Here’s a real-life example:
I remember one week where I was grabbing more processed snacks than usual (packing boxes, no time to cook, lots of “just one more granola bar”). Within a few days, my stomach was in rebellion—gassy, uncomfortable, just blah. But what hit me harder was the mental fog. My patience was paper thin. I felt jittery for no reason. I kept snapping at my kids over little things, then spiraling into guilt. That was the week I really understood how gut health could show up as anxiety.

Food, Mood, and the Rollercoaster

Different foods can either calm or stir up that gut-brain chatter. For example:

• Refined sugar and ultra-processed foods can cause blood sugar spikes and drops, which trigger cortisol (your stress hormone). That jittery, heart-racing feeling after a sugary latte? Not just in your head—it’s your gut-brain axis yelling.

• Fiber-rich foods like beans, oats, and veggies feed the good bacteria in your gut microbiome. Those little guys produce short-chain fatty acids that help lower inflammation, which in turn steadies your mood.

• Fermented foods (think yogurt, sauerkraut, kimchi) bring in probiotics that can literally change how your brain responds to stress.

I had one client who swapped her daily soda for sparkling water with lemon. Just that one change steadied her blood sugar enough that she reported fewer afternoon “anxiety crashes.” Small tweaks like that can feel deceptively simple, but they’re powerful.

Stress Makes It a Two-Way Street

Here’s the kicker: it’s not just food that shapes this connection. Stress runs the show, too.

Have you ever had to give a big presentation or sit through a nerve-wracking interview? Chances are your stomach chimed in with butterflies, cramping, or maybe a sudden sprint to the bathroom. That’s the gut-brain axis on full display.

Stress signals from the brain change how fast food moves through your gut, how much acid gets secreted, and even which bacteria thrive. Over time, chronic stress can thin the gut lining (hello, “leaky gut”) and worsen anxiety symptoms. It’s a vicious cycle: stress hurts the gut, the gut worsens stress.

One of the most surprising things I learned was how much my own nervous system calms when I slow down at meals. Instead of scarfing food while scrolling my phone, I’ve made it a habit to take a deep breath before eating. Sometimes I even say a quick prayer of gratitude. That simple pause nudges my body into “rest-and-digest” mode. Tiny, but it works.

Everyday Signs Your Gut Might Be Driving Your Anxiety

This isn’t about diagnosing yourself, but here are some red flags that your gut-brain axis might be fueling anxious feelings:

• Frequent bloating, gas, or abdominal pain

• Unexplained mood swings or irritability

• Brain fog or difficulty concentrating

• Food cravings tied closely to mood (stress = sugar, sadness = salty)

• Anxiety that flares right after meals

Here’s where food sensitivities come in. Sometimes, certain foods quietly stir up inflammation in the gut without you realizing it. For some people it’s gluten, for others it might be dairy, soy, or even eggs.

If you’ve tried the “usual” fixes but still feel moody, anxious, or foggy after eating, at-home food sensitivity testing can help you uncover hidden triggers. I recommend Everlywell’s Food Sensitivity Test as a scientifically credible option that uses IgG blood testing. It helps identify potential triggers while staying aligned with healthcare best practices.

If you want a broader—but slightly less clinically validated—approach, Check My Body Health also offers at-home kits that test hundreds of foods and environmental factors. Either way, results should be used as a guide, and it’s wise to review them with a healthcare professional to make the safest, most personalized choices.

When you start connecting the dots, patterns emerge. For me, dairy lattes were a sneaky trigger. I’d get bloated, then restless and cranky within hours. Once I cut them back, my mood leveled out in ways I didn’t expect.

*This post contains affiliate links. If you choose to purchase through these links, I may earn a small commission at no extra cost to you. I only recommend products I trust and believe could genuinely support your health journey.

Practical Ways to Calm the Gut—and the Mind

If you’re nodding along thinking, “Yep, that’s me,” here are some nurse-tested, real-life strategies you can try:

1. Eat more prebiotics and probiotics. Prebiotics are the “fertilizer” for good gut bacteria (garlic, onions, bananas). Probiotics are the live cultures in foods like kefir and kimchi. Together, they balance the gut microbiome and reduce inflammation.

2. Steady your blood sugar. Pair carbs with protein and healthy fats. Instead of a plain bagel, try half with peanut butter. Protein slows digestion and keeps your mood steady.

3. Hydrate—seriously. Even mild dehydration can trigger headaches and anxiety-like symptoms. Aim for steady sips through the day, not chugging all at once.

4. Cut caffeine (if it’s messing with you). I know, I know. But if your anxiety spikes after that third cup, your gut-brain axis might be waving a red flag. Swap one coffee for herbal tea and see if it makes a difference.

5. Practice nervous system resets. Breathwork, gentle stretching, or even a five-minute walk after meals helps both digestion and stress regulation.

What Surprised Me Most

The biggest “aha” for me was realizing I wasn’t weak or broken for feeling anxious after certain foods. It wasn’t all “in my head.” It was literally in my gut.

Understanding this shifted my perspective. Instead of shaming myself for being moody or anxious, I got curious. I started tracking meals and moods in a little notebook (now I encourage clients to do the same). Patterns popped up I’d never noticed before.

And once I could see the connections clearly, it felt empowering—not defeating.

Final Thoughts: Your Gut Isn’t Just About Digestion

The gut-brain axis proves that your mental health isn’t separate from your physical health. They’re dancing partners, constantly influencing each other.

If you’ve been on the yo-yo dieting train for years, you’ve probably been taught to focus on calories, willpower, or cutting “bad” foods. But what if your gut health is the missing piece? Supporting your microbiome, reducing inflammation, testing for food sensitivities, and learning how to steady your nervous system could help you feel calmer, clearer, and more at home in your body.

Ready to Take the Next Step?

If this resonated with you, you don’t have to figure it out alone. I help women untangle the mess of dieting rules and rebuild health from the inside out—gut, brain, and everything in between.

Here’s how you can get started today:

• Take my free quiz: What’s Sabotaging Your Healthy Habits? and uncover what’s really getting in your way.

• Download the Inner Critic Playbook if you’re tired of the negative self-talk that makes you feel stuck.

• Grab the What Spikes Me Workbook to start identifying which foods may be fueling your blood sugar rollercoaster.

• Book a free 60-minute consultation with me to map out a plan tailored to your body and your life.

• And if you suspect certain foods are secretly stirring up gut issues, mood swings, or anxiety, I recommend Everlywell’s Food Sensitivity Test as a scientifically credible at-home option. If you want a more exploratory test covering more foods and environmental triggers, Check My BodyHealth is another possibility. Use results as a guide and review them with a healthcare professional to make the safest, most personalized choices.

Your gut is talking. Maybe it’s time to start listening.

Disclosure: Some of the links in this post are affiliate links, including Everlywell and Check My Body Health. This means if you purchase through them, I may receive a small commission—at no additional cost to you. I only share products and services I personally trust, believe in, and would recommend to a friend. Affiliate income helps support the free content I provide here, but please remember these tests are for informational purposes only. Always consult with a qualified healthcare provider before making changes to your diet, supplements, or lifestyle.