Signs of an Unhealthy Gut (And How to Fix It)

Written by SecondKind Team

Reviewed by Dr. Zachary Schwartz, MD
signs of an unhealthy gut

You might not see your gut every day, but you definitely feel it in your energy, your mood, your focus, even your immune strength. When something’s off in your gut, everything else can feel off too.

That’s because your gut isn’t just for digestion. It’s your second brain, producing about 91% of your serotonin and housing 74% of your immune system. When it’s inflamed, imbalanced, or leaking toxins into your bloodstream, the effects can show up everywhere from your skin to your sleep to your state of mind through the Gut brain axis.

Let’s look at the most common signs of an unhealthy gut, and more importantly, how to start repairing it fast as part of your Gut Health Journey. 

1. You’re Bloated (Even When You Eat “Clean”)

If your belly feels tight or swollen after meals, even healthy ones, it’s a sign your gut microbes are out of balance. This imbalance, called dysbiosis, can cause excess fermentation, gas, and inflammation.

Gut repair tip:
Simplify your meals with fewer ingredients to reduce reactivity. Then, support your gut microbiome and lining balance with postbiotics. Unlike probiotics, postbiotics are bioactive compounds your body can use immediately to calm inflammation and restore microbiome balance.

2. You Feel Foggy or Fatigued for No Clear Reason

That can’t focus feeling often starts in your gut. A disrupted microbiome can leak inflammatory molecules into your bloodstream, crossing the blood-brain barrier and clouding cognition. Some gut microbes directly affect neurotransmitter production, including serotonin and dopamine, which influence energy, mood, and mental clarity.

Gut repair tip:

Support the gut-brain axis with nutrients and postbiotics that influence mood and focus. Bereum™, a postbiotic from Bifidobacterium breve, has been shown to improve mood and stress resilience by modulating GABA pathways and increasing short-chain fatty acids (SCFAs) that nourish brain function.

3. You Catch Every Cold (or Feel Run-Down Constantly)

Your gut is home to much of your immune system. When it’s compromised, your defenses weaken.

EpiCor®, a postbiotic from Saccharomyces cerevisiae, has been shown to reduce cold and flu incidence by 21% and improve stool regularity, clear signs of a stronger gut-immune connection.

Gut repair tip:
Look for postbiotics clinically studied to train and regulate immune responses. They help your body respond more effectively, not just more aggressively.

4. Your Mood Swings (And Stress Hits Harder)

Ever notice how anxiety seems to hit your stomach first? That’s your gut-brain axis at work. Gut inflammation can interfere with serotonin signaling, leading to stress sensitivity and mood instability.

Gut repair tip:

Feed your second brain with gut-friendly foods such as fiber, polyphenols, and fermented vegetables, alongside proven gut-brain postbiotics. Studies show these compounds enhance stress resilience and neurotransmitter balance, helping you stay calm and focused.

5. Irregular Digestion or Uncomfortable Bowel Movements

Constipation, diarrhea, or unpredictable digestion are more than annoyances. They often signal inflammation in your intestinal lining or a “leaky gut,” where microscopic gaps allow toxins to enter the bloodstream.

Gut repair tip:

Add ingredients that strengthen the gut barrier and promote smoother digestion. Totipro™ (a heat-treated Lactobacillus plantarum postbiotic) has been clinically shown to reduce bloating, abdominal pain, and GI symptoms while supporting mucosal immunity.

6. Skin Flare-Ups or Breakouts

Your skin often mirrors your gut health. Dysbiosis and leaky gut can trigger systemic inflammation that appears as acne, eczema, or rosacea.

Gut repair tip:

Balance gut bacteria through anti-inflammatory foods and postbiotic compounds that calm the gut barrier and reduce inflammation. Addressing the gut often brings visible relief to the skin.

7. Cravings, Weight Fluctuations, and Blood Sugar Swings

If your cravings feel uncontrollable or your weight shifts easily, your gut microbes might be influencing your hunger hormones. Certain imbalances can disrupt ghrelin and leptin, which regulate appetite and satiety.

Gut repair tip:

Eat to feed balance, not bacteria. Focus on fiber-rich, plant-based meals and postbiotics that increase beneficial microbes like Bifidobacterium and Prevotella, both linked to healthy weight regulation and metabolic balance.

Rebuilding Your Gut: Fast-Acting Fixes That Actually Work

If you’ve tried probiotics, prebiotics, or endless gut cleanses and still feel off, it’s not your fault. Probiotics are live bacteria, fragile and often destroyed before they can make a difference.

Postbiotics, on the other hand, are what your body actually uses: the bioactive metabolites produced by probiotics. They’re stable, fast-acting, and clinically studied to support gut comfort, mood, immunity, and clarity within days.

SecondKind’s proprietary BiomeBalance™ formula harnesses:

  • EpiCor® for immune balance and digestive comfort

  • Totipro™ for reducing bloating and strengthening gut lining

  • Bereum™ for lifting mood and improving focus

Together, these postbiotics address gut inflammation, leaky gut repair, and microbiome balance the foundations of a healthy second brain.

You’ll feel it fast: lighter, clearer, and calmer.

The Takeaway: Listen to Your Gut (Literally)

Your gut speaks through bloating, fatigue, brain fog, or mood shifts. These aren’t random issues, they're signals.

Repairing your gut isn’t about masking symptoms. It’s about restoring balance where it begins.

Signs of an unhealthy gut can look like stress, skin, sleep, or energy problems. But the fix starts with targeted gut repair: nurturing your microbiome, strengthening your barrier, and feeding your second brain what it truly needs.

Welcome to the Postbiotic Era, where gut health supplements become felt health.

References

  1. Moyad, M. A. et al. (2008). Effects of a modified yeast supplement on cold/flu symptoms. Urologic Nursing, 28(1), 50–55. https://asu.elsevierpure.com/en/publications/effects-of-a-modified-yeast-supplement-on-coldflu-symptoms

    Chen, L. et al. (2020). Effects of heat-killed Lactobacillus plantarum on IBS symptoms: a randomized controlled trial. Journal of Functional Foods, 68, 103860. https://www.sciencedirect.com/science/article/pii/S2095809920303714

  2. Li, J. et al. (2024). Postbiotic B. breve 207-1 improves mood and stress response in healthy adults. European Journal of Nutrition, 63, 2567–2585. https://link.springer.com/article/10.1007/s00394-024-03447-2

  3. Qian, Y. et al. (2024). Gut microbiota-derived indole-3-lactic acid alleviates depression via AhR signaling. Cell Reports Medicine, 5(7), 100545. https://www.cell.com/cell-reports-medicine/fulltext/S2666-3791%2824%2900545-7

  4. Wang, Y. et al. (2020). SCFA-producing microbes and their role in gut-brain axis modulation. Trends in Microbiology, 28(10), 874–886. https://www.sciencedirect.com/science/article/pii/S2352289520300060

About Dr. Zachary Schwartz, MD

Dr. Zachary Aaron Britstone-Schwartz, MD, is a board-certified family medicine physician at Baptist Health Medical Group, where he brings personalized, whole-family care to patients in Corydon and the surrounding communities. With a medical degree from the Sackler School of Medicine and residency training at Indiana University School of Medicine, Dr. Schwartz blends evidence-based practice with a compassionate, patient-centered approach to preventive health and chronic condition management. His broad experience spans care for all ages and stages of life, grounded in a philosophy of treating every patient the way he’d want his own family treated - with clarity, respect, and clinical excellence.