Fermented foods have been with humanity for over 8,000 years: originally as a way to preserve food, and today as one of the cornerstones of modern healthy eating.^¹ . From yogurts and kefir to kombucha, sauerkraut, tempeh, or miso, fermentation adds flavor, durability, and a range of benefits that extend from the gut to the immune system and the prevention of chronic diseases. Current scientific evidence is confirming that these products are much more than just foods—they are living systems capable of influencing the human microbiota and modulating metabolic and inflammatory responses . ^{^2-4}

Fermentation: an ancient and sustainable technology

Fermented foods result from the controlled growth of microorganisms that transform ingredients through enzymatic reactions – a process that gives rise to products as diverse as sourdough bread, miso, or kombucha.

In addition to increasing food safety and preservation, fermentation is a sustainable and environmentally friendly method. It allows the transformation of plant-based raw materials (and even agricultural waste) into foods rich in protein, essential amino acids, and bioactive compounds – contributing to the United Nations Sustainable Development Goals and therefore potentially being an important ally in eradicating hunger and promoting global health ¹ .

How does fermentation improve the nutritional value of such simple foods?

Essentially in two ways:

• It increases the availability of minerals, such as calcium, iron, and zinc, by breaking down compounds that hinder their absorption;
• It stimulates the production of B complex vitamins (especially B2 and B12), folic acid and vitamin K, nutrients often lacking in diets based on processed foods ^2,4 .

Main types of fermented foods and their properties.

Today we know that virtually every culture in the world has developed its own versions of fermented foods, using local ingredients and the microorganisms naturally present in them ^3-5 . Among the best known are:

• Fermented dairy products (yogurt, kefir, certain cheeses): rich in lactic acid bacteria that improve lactose digestion, promote the intestinal barrier, strengthen the immune system, and help reduce markers of systemic inflammation 3,4 . Fermentation decreases lactose content and reduces allergenic proteins, making these products more tolerable for lactose-intolerant people ^3,4 ;
• Fermented vegetables (sauerkraut, kimchi, natural pickles): contain probiotics and antioxidants, in addition to increasing the bioavailability of vitamins and minerals 5 ;
• Fermented legumes and grains (tempeh, miso, natto, sourdough bread): have an improved protein profile, with fewer antinutrients and more bioactive compounds such as GABA — a natural substance that helps relax the nervous system ^4,5 ;
• Fermented beverages (kombucha, kvass, fermented milk drinks): rich in organic acids, enzymes and polyphenols that promote the balance of the intestinal microbiota and support liver detoxification ⁴ ;
• Fermented animal products (some cured meats, fermented fish): preserve proteins and fats in a safe and natural way, developing unique antioxidant compounds (and flavors) ^1,4 .

These foods provide not only live microorganisms, but also enzymes and metabolites - known as postbiotics - that contribute to immune balance, energy and digestive well-being ^1-5 .

Fermentation and its health benefits

1. Mental health and the gut-brain axis

Today we know that several important neurotransmitters are produced in the gut ⁵ , and fermentation can help in this process by stimulating the natural production of GABA, a neurotransmitter associated with relaxation, stress reduction and brain health ¹ .

The consumption of probiotics, including those from fermented foods, has also been associated with improvements in mental health, reducing symptoms of depression, anxiety and stress, and contributing to improvements in mood and emotional regulation ^1,5 .

Some specific strains, such as Lactobacillus rhamnosus and Bifidobacterium longum, are even considered “psychobiotics” due to their anxiolytic and antidepressant effects, which result from their ability to communicate with the nervous system through the gut-brain axis ²⁻⁴.

2. Weight management and blood glucose balance

Diets rich in yogurt have been associated with less long-term weight gain, better body composition, and improved metabolic health ³ . Traditional fermented yogurt has even been shown to be more effective than milk in reducing insulin resistance in women with obesity and metabolic syndrome ^1. Kimchi consumption has also been associated with reduced body weight and improvements in metabolic parameters in overweight and obese individuals⁶.

3. Cardiovascular health and blood pressure

Higher consumption of fermented milk and cheese is associated with a reduced risk of cardiovascular disease, specifically in the female population ^2. Fermented foods can also help lower blood pressure, thanks to the formation of small protein fragments during fermentation (peptides) that act similarly to antihypertensive drugs, helping blood vessels to relax ^4,6 .

Current scientific evidence confirms that regular consumption of fermented foods contributes to maintaining the balance of the gut microbiota, strengthening the immune system, and preventing various metabolic, cardiovascular, and neurological diseases. These benefits result not only from the live microorganisms present in the food, but also from the metabolites and enzymes produced throughout the fermentation process.

In a world searching for sustainable food solutions, fermented foods bring together a unique triad — flavor, health, and sustainability — that places them at the heart of the nutrition of the future.

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