Gut Microbiota: Your Second Brain

The gut microbiota refers to all microorganisms living in our digestive tract. It weighs about 1.5 kg and contains as many bacterial cells as our body has human cells.

Roles of the Microbiota

• Digestion: fermentation of dietary fiber, production of short-chain fatty acids (butyrate, propionate, acetate)
• Immunity: 70% of the immune system is in the gut. The microbiota educates and regulates defenses.
• Synthesis: production of vitamins (K, B12, B9), neurotransmitters (95% of serotonin is produced in the gut)
• Barrier: protection against pathogens through competition and production of antimicrobial substances

What Disrupts the Microbiota?

• Antibiotics (major but often reversible impact)
• Diet poor in fiber and rich in ultra-processed foods
• Chronic stress
• Sedentary lifestyle
• Certain medications (PPIs, NSAIDs)

How to Take Care of It

• Varied fiber: 25-30 g/day from diverse sources (vegetables, fruits, whole grains, legumes)
• Fermented foods: yogurt, kefir, sauerkraut, kimchi, miso
• Prebiotics: garlic, onion, leek, asparagus, banana (nourish good bacteria)
• Physical exercise: increases microbial diversity

Diversity is the key to a healthy microbiota. The more varied your diet, the richer and more resilient your microbiota.