Are fermented foods the missing link in our health, or just the latest wellness trend? 

In this episode, Professor Tim Spector, a world-leading scientist in gut health and co-founder of ZOE, challenges what we think we know about yogurt, cheese, kombucha, and more.

Tim uncovers why milk and cheese aren’t the same in your body - and the surprising science showing cheese might not be the heart villain it was once made out to be. He also shares emerging evidence that fermented foods could influence inflammation, immunity, metabolism, and even mood, often in a matter of weeks.

From a groundbreaking Stanford study to insights from ZOE’s research on 9,000 people, this episode reveals why fermented foods are more powerful, and more misunderstood, than most of us realise.

Tim breaks down the easiest ways to actually eat more fermented foods without overhauling your life. By the end, you’ll be questioning what’s in your fridge - and wondering if one tiny daily habit could do far more than you’d ever expect.

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Timecodes

00:00 Introduction

04:00 The critical difference between healthy fermentation and rotting

09:55 What 'double fermented' food means (and why it's better for you)

11:23 The cheese paradox: why is it so much healthier than milk?

14:12 Why you shouldn't be afraid of 'chemicals' in your food

17:02 Common fermented foods you didn't even know you were eating

18:47 The surprising reason microbes in beer and bread are killed

20:10 Surprising new science: the health benefits of dead microbes

22:07 Why did English-speaking countries stop eating fermented foods?

24:05 What is the real difference between pickling and fermenting?

26:55 The groundbreaking Stanford study that proved the power of fermented foods

30:00 ZOE's 9,000-person study: the results in just two weeks

30:55 The impact of 3 ferments a day on mood, energy, and bloating

34:50 The gut-brain axis: how microbes calm 'neuroinflammation'

37:30 Eating fermented food is like a 'vaccine' for your immune system

39:48 Why sourdough bread is easier to digest than regular bread

40:11 Are fermented foods better than probiotic pills?

44:47 The biggest myth about probiotics: they don't colonize your gut

46:39 Tim's breakfast hack to get two ferments in at once

48:15 The one simple pantry swap for all your stock cubes

49:05 A simple trick to train yourself to like kimchi

51:45 The simplest home ferment: garlic and honey

53:55 How to make your own sauerkraut with just two ingredients

55:08 What is the 'jellyfish' that makes kombucha?

01:00:06 Summary: the top 5 takeaways from this episode

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Mentioned in today's episode

Gut-microbiota-targeted diets modulate human immune status, Cell (2021)

Fermented Food Consumption Is Associated With Improvements in Bloating, Hunger, Energy and Mood in the General Population, CDN (2025)

Have feedback or a topic you'd like us to cover? Let us know here.

Episode transcripts are available here.