Are Fermented Foods the Secret to Gut Health and Longevity?

September 03, 2025 3 min read

Are Fermented Foods the Secret to Gut Health and Longevity?

Being healthy is about much more than training and recovery. Nutrition has always been a big part of the equation, and fermented foods are an ancient food hack. Once used to preserve foods long before fridges existed, fermented foods are popular as a simple way to support gut health. Let’s look at what they are, why they matter, and even how to make them at home.

What Are Fermented Foods?

Fermentation is a natural process where microorganisms like yeast or bacteria break down sugars and starches in food. The result is food rich in probiotics (beneficial bacteria) and nutrients, with a tangy flavour many people love.

Fermented foods are having a moment, but this isn’t a new trend. They’ve been eaten in different cultures for centuries because they kept food fresh and supported wellbeing.

Five Examples of Fermented Foods

Kefir – a drinkable yoghurt full of diverse bacteria
Sauerkraut – cabbage or other vegetables fermented in brine
Kimchi – spicy fermented vegetables from Korea
Miso – a fermented soybean paste from Japan
Kombucha – fizzy fermented tea

Why Are Fermented Foods Healthy?

Fermentation makes food easier to digest and absorb. For example, in yoghurt, bacteria break down lactose, which is why some people who struggle with dairy can still tolerate yoghurt or kefir.

Fermentation also boosts vitamin levels (like B vitamins and vitamin K2) and creates beneficial plant compounds.

The biggest benefit, though, comes from probiotics that support the microbes living in our gut.

What Is Gut Health and Why Is It Important?

Your gut microbiome is made up of trillions of bacteria, fungi, and other microbes. When balanced, it supports digestion, energy levels, immune health, and even mood.

Gut health has been linked to:

Better digestion and nutrient absorption
A stronger immune system
Reduced risk of diseases like diabetes and heart disease
Improved mental health and reduced stress
Potential links to longevity

On the other hand, an unhealthy gut microbiome can contribute to bloating, fatigue, skin issues, and higher risk of illness.

How Do Fermented Foods Support Gut Health?

Fermented foods introduce probiotics and compounds that help your own microbes thrive.

Probiotics top up your gut with good bacteria, reduce inflammation in the gut lining, and help break down foods.
Some fermented foods also contain prebiotic fibre, which feeds healthy gut microbes.

Can You Make Fermented Foods at Home?

Fermented foods can be expensive to buy, but you can easily make some at home. Sauerkraut and kefir are two simple starting points.

Homemade Sauerkraut

1 medium cabbage
1 tablespoon salt
Optional add-ins: peppercorns, fennel seeds

Shred the cabbage and massage with salt until it releases liquid. Wait a few minutes and repeat. Mix in any add-ins, then pack tightly into a jar so the cabbage is submerged in brine. Cover with a loose lid and leave at room temperature for 1–4 weeks, tasting as you go.

Homemade Kefir

2 tablespoons kefir grains
500 ml milk

Place the kefir grains in the milk, cover loosely, and leave at room temperature for 24 hours. Strain through a sieve (keep the grains to reuse indefinitely). Store the kefir in the fridge for 7–10 days. No need to wash the grains, just keep them for next time.

How Often Should You Eat Fermented Foods?

There’s no set rule, but research suggests regular, consistent intake of a variety of fermented foods is best. Start with a few servings a week to let your gut adjust.

Examples include:

Yoghurt or kefir in the morning
Kimchi or sauerkraut with dinner
Kombucha as an afternoon drink swap

Fermented foods aren’t the only factor in a healthy diet, but they’re a powerful and natural way to support gut health, energy, and long-term wellbeing.