Microbiota & Mood: What if your gut influenced your emotional balance?

Mental fatigue, anxiety, loss of motivation... What if these conditions weren't just psychological, but linked to a digestive imbalance?
More and more studies confirm that our gut, often called the “second brain,” directly influences our mood, mental clarity, and even behavior ¹ .

The Depressive Microbiota: What the Science Says

The intestinal microbiota influences:

• the production of neurotransmitters (such as serotonin and GABA),

• the permeability of the intestinal barrier ,

• and modulation of the immune system .

People with depression commonly experience:

• a reduction in anti-inflammatory bacteria, such as Faecalibacterium prausnitzii ,

• an overrepresentation of pro-inflammatory bacteria,

• increased levels of cytokines (inflammatory markers) ^{2 3} .

A major 2022 study identified 13 bacterial species associated with the production of glutamate, butyrate, serotonin, and GABA, all of which were altered in patients with depression ⁴ .

Why Probiotics Aren't Enough

Probiotics can modulate certain functions of the microbiota, but are not sufficient on their own to correct leaky gut or chronic inflammation.
What the literature shows:

• Probiotics are more effective when accompanied by prebiotics and an anti-inflammatory dietary background ⁵ .

• Overconsumption without strategy can even promote opportunistic strains , if the intestinal barrier is damaged ⁶ .

What worked for me

For me, the Autoimmune Paleo Protocol (AIP) was the most effective.
In 4 months of strict application (gluten-free, dairy-free, refined sugar-free), I observed:

• significantly improved digestion,

• a stabilized mood,

• and a clear reduction in chronic fatigue.

Time is a key factor: intestinal regeneration takes several weeks or even months ⁷ .

Dr. Gundry's approach: field first

Dr. Steven Gundry points out in his publications that certain plant molecules such as lectins (present in cereals, legumes and nightshades) can irritate the intestinal wall and promote an inflammatory response ⁸ .
He also recommends supporting the microbiota with:

• postbiotics (such as butyrate),

• polyphenols (green tea, cocoa, olive oil, pomegranate): they promote protective strains such as Akkermansia muciniphila and Bifidobacterium spp. ⁹ .

What you can do today

1. Cut down on ultra-processed foods, simple sugars, and refined grains.

2. Introduce foods rich in prebiotic fiber : green banana, Jerusalem artichoke, garlic, onion, leek.

3. Promote targeted probiotic strains :

   • Bifidobacterium longum (anxiolytic effect) ¹⁰ ,

   • Lactobacillus rhamnosus GG (GABA regulation) ¹¹ ,

   • Akkermansia muciniphila (strengthening the intestinal barrier) ¹² .

     Butyrate-producing bacteria

     • These bacteria produce butyrate , an essential short-chain fatty acid (SCFA).

     • Butyrate nourishes intestinal mucosal cells , strengthens the epithelial barrier, and reduces intestinal inflammation .

     • A higher relative abundance of these bacteria is linked to reduced intestinal permeability (less leaky gut) .

     Akkermansia muciniphila

     • Specializes in breaking down intestinal mucus — it stimulates the production of healthy mucus and maintains the intestinal barrier.

     • Associated with healthier body weight , better blood sugar regulation, and less metabolic inflammation .

     Bifidobacterium

     • One of the first bacteria to colonize the microbiota at birth.

     • Protects against pathogens , modulates immunity, and reduces intestinal permeability .

      

4. Support intestinal regeneration with L-glutamine ^, zinc , and vitamin D13 .

Correlation with vitamin D

• Vitamin D would positively modulate these beneficial bacteria .

• By promoting their presence, it reduces inflammation and prevents neurological disorders such as dementia , via the gut-brain axis.

Conclusion

Mental health is about more than just the brain.
Your emotional balance also depends on the quality of your microbiota , your digestion and your level of low-grade inflammation.

🌱 Repairing the gut is repairing the foundations of your well-being.

References

1. Mayer EA et al. (2014). Gut/brain axis and the microbiota. J Clin Invest , 124(10):4204-4211. ↩

2. Kelly JR et al. (2016). Transferring the blues: Depression-associated gut microbiota induces neurobehavioral changes in the rat. J Psychiatr Res , 82:109-118. ↩

3. Jiang H et al. (2015). Altered gut microbiota profile in patients with generalized anxiety disorder. J Psychiatr Res , 63:1-7. ↩

4. Valles-Colomer M et al. (2022). The neuroactive potential of the human gut microbiota in quality of life and depression. Nat Microbiol , 7:530–543. ↩

5. Sarkar A et al. (2016). The Microbiome in Psychology and Cognitive Neuroscience. Trends Cogn Sci , 20(9):611-623. ↩

6. El Hage R et al. (2017). Probiotics and prebiotics in intestinal health and disease: from biology to the clinic. World J Gastroenterol , 23(38):6504–6519. ↩

7. Ballantyne S. (2013). The Paleo Approach: Reverse Autoimmune Disease and Heal Your Body. Victory Belt Publishing. ↩

8. Gundry S. (2017). The Plant Paradox. Harper Wave. ↩

9. Brahe LK et al. (2016). Specific dietary components and gut microbiota composition: a review. Microb Ecol Health Dis , 27:10.3402. ↩

10. Allen AP et al. (2016). Bifidobacterium longum 1714 as a psychobiotic: modulation of stress, cognition and brain activity. Transl Psychiatry , 6(11):e939. ↩

11. Well done JA et al. (2011). Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. PNAS , 108(38):16050–16055. ↩

12. Everard A et al. (2013). Cross-talk between Akkermansia muciniphila and intestinal epithelium controls diet-induced obesity. PNAS , 110(22):9066–9071. ↩

13. Garg M et al. (2018). The role of micronutrients in the gut microbiome and inflammatory bowel disease. Curr Opin Gastroenterol , 34(4):259-265.