Can gut problems cause fatigue, anxiety, or brain fog?
Yes. Your gut and brain are closely connected through the gut-brain axis, a two-way communication system linking nerves, hormones, and immune signals. When gut health is off, it can disrupt nutrient absorption, trigger inflammation, and alter neurotransmitters, all of which can lead to fatigue, anxiety, and brain fog.
4 Ways that Gut Problems Can Affect Mental Health & Energy:
- Disrupt nutrient absorption, leaving you low in B vitamins, iron, and amino acids needed to make hormones and neurotransmitters for energy and mental clarity.
- Trigger chronic inflammation, which increases inflammatory markers (cytokines) linked to fatigue and mood shifts.
- Alter neurotransmitter production, over 90% of serotonin is made in the gut, and an unhealthy microbiome can reduce GABA (a calming brain chemical) and increase stress hormones like cortisol.
- Activate immune responses, through a loss of immune resilience in the gut. This is sometimes referred to as “leaky gut,” but better defined as intestinal hyperpermeability.
Common gut-related culprits include SIBO, candida overgrowth, food sensitivities, or low stomach acid. Even if you eat a clean diet, these imbalances can leave you feeling tired, anxious, and mentally “foggy.”
A functional stool test or organic acids testing can help pinpoint what’s driving your symptoms, so you’re not just chasing supplements or guessing at diets.
Learn more by watching my collaboration on the Gut-Brain Axis with Topher Scott, LPC-A (supervised by Lesly Smith, LPC-S), a holistic, trauma-informed counselor and mindfulness coach. We explore important points around the gut-brain axis and what you can do to help support it!
Research continues to show how gut imbalances impact mental health. A 2024 PubMed review on the gut-brain axis highlights how dysbiosis and stress influence neurotransmitters like serotonin and GABA, directly affecting mental health.
Ready to find out if your gut is behind your fatigue, anxiety, or brain fog?
Answered by Dr. Kenny Mittelstadt, DACM, DC, IFMCP
Certified functional medicine practitioner specializing in advanced lab testing and personalized healing protocols to uncover root causes of health roadblocks.