Quick answer: Your gut and brain are in constant two-way communication through the vagus nerve, immune signals, hormones and compounds made by gut bacteria. When the microbiome is imbalanced or the gut is inflamed, those signals can contribute to anxiety, low mood, brain fog and poor memory. Supporting gut health with fiber variety, fermented foods, omega-3s, stress practices and targeted supplements can be part of supporting mental wellness.
Key takeaways
The gut and brain talk constantly through the vagus nerve, immune signals, hormones and compounds made by gut bacteria.
When the microbiome is out of balance or the gut is inflamed, those signals can be part of anxiety, low mood or brain fog.
Slow breathing, time outdoors, regular walks and fiber-rich meals are everyday ways to calm the gut-brain connection.
How the gut and brain talk
The vagus nerve is a direct line carrying signals between the gut and brain, and the enteric nervous system is a network of hundreds of millions of neurons in the gut wall. Through immune signals, gut inflammation can raise inflammatory messengers that reach the brain, and through microbial compounds, gut bacteria make short-chain fatty acids and neurotransmitter precursors.
Related: short-chain fatty acids and root causes of brain fog.
Signs the gut-brain axis may be involved
The gut-brain axis may be involved if you have anxiety or low mood alongside gut symptoms, or brain fog after meals. It may also play a role when symptoms started after antibiotics, a gut infection or a stressful period, or when stress immediately shows up in your digestion.
Natural ways to support the gut-brain axis
Probiotics studied for mood (“psychobiotics”) are one option, since certain strains are being researched for stress and mood. Prebiotic fibers and a wide variety of plants feed bacteria that make butyrate, and fermented foods such as yogurt, kefir, sauerkraut and kimchi can help if tolerated. Omega-3s (EPA and DHA) support brain cell membranes (see who should consider omega-3s).
Curcumin and saffron have been studied for mood and inflammation, and L-theanine and magnesium are often used for calm and focus. Lion’s mane is a mushroom being studied for cognitive support.
Amounts should be individualized. If you take antidepressants or other psychiatric medications, talk with your prescriber before adding supplements, and never stop medication on your own. If you work with me, products I commonly use are in my Fullscript dispensary.
Daily habits that calm the gut-brain axis
Slow, diaphragmatic breathing, time outdoors and regular walks all help calm the gut-brain axis. So do consistent sleep with an overnight gap between meals, and brief cold exposure, if appropriate for you.
The gut-brain axis and healthy aging
A less diverse microbiome, chronic inflammation and declining mitochondrial energy in brain cells are processes that shape how the brain ages. The brain also relies on clearing out misfolded proteins, which gets harder with age. Supporting the gut is one practical way to lower inflammatory load on the brain over time. Related: building a diverse, resilient gut.
When to see a naturopathic doctor
It may be time to see a naturopathic doctor if you have mood, focus or memory problems together with gut symptoms, or if your symptoms started after antibiotics, illness or a stressful period. The same is true if you want natural support alongside your current mental health care, or if you have brain fog that has not improved with sleep and diet changes.
See a medical provider promptly If you have thoughts of harming yourself, call or text 988 (Suicide & Crisis Lifeline) or call 911. Also seek prompt care for sudden confusion or memory loss.
Gut and mood symptoms at the same time? Let us talk about the connection.
A free 15-minute consultation with Dr. Kneessi. No cost, no obligation. In-office in Odenton, MD or by telehealth.
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
Could my mood or focus changes be connected with my gut health?
Could any of my current medications or supplements interact with the options discussed here?
Would any lab testing add useful information in my situation, or is it reasonable to start with daily habits?
Which one or two changes would be most worthwhile for me to focus on first?
Practitioner-grade options in my Fullscript catalog: if you and your clinician decide a supplement makes sense, my supplement guide by health goal links to the practitioner-grade products I trust.
Frequently asked questions
Can gut problems cause anxiety?
Research shows the gut and brain influence each other. Gut inflammation and microbiome changes may contribute to anxiety in some people, alongside many other factors.
What are psychobiotics?
They are probiotics (and sometimes prebiotics) studied for effects on mood and stress. Research is promising but still developing.
Can I take probiotics with antidepressants?
Probiotics are usually considered low-risk, but always review supplements with your prescriber.
How long does it take to improve the gut-brain axis?
It varies. Diet and lifestyle changes usually take several weeks to months to show effects.
Sources
- Cryan JF, et al. The Microbiota-Gut-Brain Axis. Physiol Rev 2019. PMID: 31460832. https://pubmed.ncbi.nlm.nih.gov/31460832/
- Liu RT, Walsh RFL, Sheehan AE. Prebiotics and probiotics for depression and anxiety: A systematic review and meta-analysis of controlled clinical trials. Neurosci Biobehav Rev 2019. PMID: 31004628. https://pmc.ncbi.nlm.nih.gov/articles/PMC6584030/
- Fusar-Poli L, et al. Curcumin for depression: a meta-analysis. Crit Rev Food Sci Nutr 2020. PMID: 31423805. https://pubmed.ncbi.nlm.nih.gov/31423805/
- Hausenblas HA, et al. Saffron (Crocus sativus L.) and major depressive disorder: a meta-analysis of randomized clinical trials. J Integr Med 2013. PMID: 24299602. https://pmc.ncbi.nlm.nih.gov/articles/PMC4643654/
- Mori K, et al. Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytother Res 2009. PMID: 18844328. https://pubmed.ncbi.nlm.nih.gov/18844328/
- NIH Common Fund: Human Microbiome Project
- NCCIH: Probiotics: Usefulness and Safety
This article is for educational purposes only and is not medical advice. It does not replace an individual evaluation. Talk with your healthcare provider before starting supplements or changing medications, especially if you are pregnant, nursing, or managing a health condition.
