How Stress Impacts Gut Health + Why Your Gut Affects Your Mood

If you've ever felt your stomach drop before a big decision, lost your appetite during a stressful season, or dealt with bloating during emotional overwhelm, you've felt the gut–nervous system connection in real time.

And as science is catching up with what many of us have known intuitively for years:
👉 Your gut and brain are in constant conversation.
👉 Stress directly affects digestion and microbiome health.
👉 Gut imbalances can affect your mood, sleep, and ability to heal.

In other words: this isn’t just in your head. It’s in your gut, too.

Let’s explore how stress and gut health affect each other — and what you can do about it.

How Stress Impacts Gut Health (The Science)

When you're under stress — whether it's obvious (work deadlines, parenting, relationship tension) or subtle (over-exercising, skipping meals, emotional suppression) — your nervous system shifts into sympathetic mode, also known as fight-or-flight.

This state is designed for survival, not digestion. Here’s what happens:

  • Blood flow is shunted away from the digestive tract

  • Stomach acid and digestive enzymes decrease

  • Gut motility (how food moves through your GI tract) slows or becomes erratic

  • The tight junctions in your gut lining become more permeable (hello, leaky gut)

  • Stress hormones like cortisol alter your gut microbiome, increasing inflammatory bacteria and decreasing beneficial species

In short, stress weakens digestion, increases inflammation, and disrupts your microbial balance, all of which affect your physical and mental health over time.

How Gut Health Impacts Mood and Nervous System Function

The connection goes both ways. I know, as if it wasn’t already confusing!

Your gut is home to trillions of microbes and is commonly referred to as your "second brain".. and for good reason. Over 80% of your serotonin and about 50% of your dopamine are made in the gut. (Not to mention 70% of the immune system is in the gut, but that’s a topic for another day!)

When the gut is imbalanced, whether due to poor diet, chronic stress, antibiotics, or infections like Candida or parasites, your neurotransmitter production and signaling can become dysregulated.

You might experience:

  • Anxiety or panic

  • Low mood or depression

  • Brain fog or trouble concentrating

  • Sleep issues (especially falling or staying asleep)

  • Feeling "wired but tired" or emotionally fragile

Gut inflammation also sends distress signals to the brain via the vagus nerve, further dysregulating the nervous system and keeping your body stuck in a stress loop.

Why You Can’t Heal One Without the Other

If you’ve been focusing on gut health alone with food, supplements or testing, but still feel anxious, exhausted, or emotionally dysregulated…
Or if you’ve been working on mindset and nervous system support, but still deal with bloating, cravings, or inconsistent bowel movements…

It’s probably time to address both.

You are a whole person — not a collection of parts.
Your gut and nervous system are intertwined in both biology and lived experience.
To heal one, you must support the other.

Where to Begin: Gut + Nervous System Healing Tips

Here are a few practical ways to start:

1) Eat in a calm state

Take 3 deep belly breaths before meals. Light a non-toxic candle. Sit down. Chew slowly. This shifts your body into parasympathetic (rest-and-digest) mode.

2) Feed your gut microbes

Add prebiotic and fermented foods: cooked leeks, garlic, onions, asparagus, sauerkraut, and kefir (if tolerated). Focus on fiber, which help promote short chain fatty acids + fuel gut bacteria.

3) Regulate your rhythm

Waking, eating, and sleeping around the same time daily helps restore internal safety. Your body craves predictable patterns.

4) Support vagus nerve tone

Gargling, humming, cold exposure, and intentional breathwork can help rewire your gut-brain connection.

Want to Go Deeper?

If you’re feeling stuck, like your symptoms don’t make sense or you're tired of patchwork solutions, I’d love to help you uncover the why behind what you're feeling.

You can work with me in a few ways:

Regulate & Reclaim

For women ready to understand the gut–hormone–nervous system connection and take practical, daily steps toward healing.

👉 Click here to get started today

Deep Dive Testing Package

For those ready to get insight into their gut, hormones, or inflammation levels through advanced at-home testing and a customized protocol.

👉 Click here to get started today

Final Thoughts

Healing your gut is powerful.
Supporting your nervous system is essential.


But doing both - with curiosity, compassion, and expert guidance, is where the real & lasting transformation happens.

Kelsey Stang