You may have noticed that after 45, things you used to brush off, mood swings, brain fog, digestion hiccups, or that “wired-but-tired” feeling, seem to hang around longer. What’s happening isn’t just in your head; it’s also in your gut.
Your gut and brain are in constant conversation through what scientists call the “gut-brain axis”. Essentially a communication highway connecting your digestive tract, immune system, hormones, and nervous system. As hormones shift and the body ages, this dialogue changes. Understanding that change can help you take simple, informed steps to feel like yourself again.
1. What Exactly Is the Gut-Brain Axis?
Think of your gut as a second brain. One that constantly sends messages to your real one. Those signals travel along the vagus nerve, through immune pathways, and even via chemical messengers made by gut bacteria. These bacteria produce short-chain fatty acids, B vitamins, and neurotransmitters like serotonin and GABA which are all crucial for mood, focus, and calm.
Around midlife, this two-way system becomes less efficient. Estrogen and progesterone, which once supported healthy gut function, begin to fluctuate. Research shows these hormonal shifts can alter the gut microbiome’s composition and weaken the gut barrier. When that barrier thins, small amounts of endotoxins can leak into the bloodstream creating low-grade inflammation that interferes with brain clarity and emotional steadiness.
2. How the Gut-Brain Axis Changes After 45
a. Hormones and Microbes
Estrogen supports microbial diversity and the integrity of the gut lining. As it declines, diversity often drops, and beneficial bacteria like Lactobacillus and Bifidobacterium may decrease.
This change can influence how efficiently estrogen is metabolized and is part of why some women notice new digestive patterns, bloating, or mood changes during perimenopause.
b. Inflammation and Brain Fog
An aging gut barrier can allow inflammatory molecules to travel through the bloodstream to the brain, where they activate microglia, the brain’s immune cells. Over time, this can dull mental clarity and energy.
c. Slower Stress Recovery
Stress hormones such as cortisol directly affect the gut lining and microbiome balance. When you combine midlife stressors with lower resilience in the gut-brain system, it can feel like you’re “on edge” more often.
3. What You Can Do Today to Support a Healthy Gut-Brain Axis
Step 1: Feed Your Microbiome
Start with food before supplements.
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Add diversity: Aim for at least 20 - 30 different plant foods a week: fruits, vegetables, beans, nuts, herbs, and seeds. Variety feeds different beneficial microbes.
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Incorporate fermented foods: Yogurt, kefir, sauerkraut, kimchi, or kombucha can add friendly bacteria naturally.
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Focus on polyphenols: Berries, green tea, and colorful vegetables contain plant compounds that beneficial bacteria convert into anti-inflammatory metabolites.
Step 2: Consider a Clean - Label Synbiotic
Probiotics and prebiotics together, a synbiotic, can help restore microbial balance. Pure Essentials’ Ultra Synbiotic blends clinically studied probiotic strains with organic cranberry and reishi extract.
Both ingredients provide natural polyphenols that feed the right microbes and support gut-brain communication.
It’s shelf-stable, vegan, and free from excipients like magnesium stearate, corn maltodextrin, and silicon dioxide, meeting the highest Made Wise™ standards.
Step 3: Support the Barrier
Nutrients shown to strengthen the gut lining include:
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Omega-3 fatty acids support gut barrier integrity and reduce inflammation. Try a verified-pure supplement such as Ultra Omega, encapsulated in marine gelatin and tested for PFAS and heavy metals.
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Magnesium (glycinate or malate forms) helps smooth gut motility and relax the nervous system.
Ultra Magnesium will make a comeback! And it combines four bioavailable types to support both muscle and mood without upsetting digestion. -
Vitamin D3 influences gut barrier proteins and immune regulation. Low levels are common after 45; look for organic, additive-free formulas such as Ultra Vitamin D3.
Step 4: Manage Stress and Sleep
The vagus nerve, your gut-brain information superhighway, responds to calm. Daily breathing exercises, gentle yoga, time in nature, and consistent sleep patterns all help regulate the nervous system and improve digestion. It doesn’t have to be perfect; small, consistent habits matter most.
Step 5: Test and Tailor
If symptoms persist, functional testing can help:
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Stool microbiome analysis (for diversity and inflammation markers)
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Vitamin D and Omega-3 Index testing
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Blood sugar and cortisol rhythm testing
Pure Essentials offers home tests for both vitamin D and omega-3 levels practical starting points for personalized nutrition.
4. The Bottom Line
The gut-brain axis is one of the most powerful and overlooked systems influencing how you feel every day. After 45, that system naturally shifts, but with the right nutrients, foods, and stress-support habits, you can help it thrive again.
At Pure Essentials, we created our formulas with this exact transition in mind. Clean, clinically validated ingredients, third-party tested, and free from anything that doesn’t serve your body. Because you deserve supplements that are made for you.
References
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López-Muro, X., Rodríguez-Gallego, E., Roura, E., & Camps-Bossacoma, M. (2025). Hormonal changes and the gut-brain axis in midlife women. Frontiers in Endocrinology, 13, 1562332. https://doi.org/10.3389/fendo.2025.1562332
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Yang, P. L., Lee, O. Y., & Yoon, S. M. (2021). Irritable bowel syndrome in midlife women: A narrative review.Women’s Midlife Health, 7(1), 8. https://doi.org/10.1186/s40695-021-00064-5
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Loh, J. S., Mak, W. Q., Tan, L. K. S., Ng, C. X., Yeow, S. H., & Khaw, K. Y. (2024). Microbiota–gut–brain axis and its therapeutic applications in neurodegenerative diseases. Signal Transduction and Targeted Therapy, 9, 37. https://doi.org/10.1038/s41392-024-01743-1
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Tangestani, H., Jafari, A., & Shab-Bidar, S. (2024). Omega-3 fatty acids and bone mineral density in women aged 40 and older: A systematic review. Frontiers in Nutrition, 11, 1467559. https://doi.org/10.3389/fnut.2024.1467559
