Most replayed moment: Why fermented foods are the future of gut health | Professor Tim Spector

Fermented foods have evolved from a niche health trend into a supermarket staple. Kefir, kimchi, kombucha. Our shelves are now filled with products rich in beneficial bacteria. But with so many options to choose from, it can be difficult to know where to begin. Today, Professor Tim Spector shares simple, practical ways to incorporate fermented foods into your daily meals. He’ll also show why fermenting at home is much easier than most people think, taking us inside his fridge to demonstrate how to make four of his favourite homemade ferments. 🌱 Try our science-backed and tasty wholefood supplement Daily30 🌿Let your gut microbes snack on the ZOE Gut Health Bar Get our brand-new app and Gut Health Test designed by world-leading gut health and nutrition scientists to build healthy eating habits 👉 Join ZOE Follow ZOE on Instagram. 📚Books by our ZOE Scientists The Food For Life Cookbook Every Body Should Know This by Dr Federica Amati The Appetite Reset by Dr Federica Amati Food For Life by Prof. Tim Spector Ferment by Prof. Tim Spector Good Mood Food (preorder) by Prof. Tim Spector Free resources from ZOE The Smart Snacking Guide: How to feed your gut, fuel your day, and snack without guilt The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra Eating for Better Brain Health: Your brain-gut blueprint How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health Live Healthier: Top 10 Tips From ZOE Science & Nutrition Gut Guide - For a Healthier Microbiome in Weeks Better Breakfast Guide Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.

• 0:01Speaker 00

  Hello and welcome to Zoe Recap, where each week we find the best bits from one of our podcast episodes to help you improve your health.

• 0:10Speaker 00

  Fermented foods have evolved from a niche health trend into a supermarket staple. Kefir, kimchi, kombucha, our shelves are now filled with products rich in beneficial bacteria. But with so many options to choose from, it can be difficult to know where to begin. Today, Professor Tim Spector shares simple, practical ways to incorporate fermented foods into your daily meals. He'll also show why fermenting at home is much easier than most people think, taking us inside his fridge to demonstrate how to make four of his favourite homemade ferments.

• 0:45Speaker 00

  So let's start for people who are new to this. And then as far as they're aware, they're not eating any fermented foods a day. Where would you start?

• 0:55Speaker 01

  I'd start with breakfast, always a good place to start because you're at home, you're near your fridge. Start with my classic breakfast, get some full fat yoghurt. When you're starting off, mix it with some milk kefir, because some people find when you start milk kefir, it's a bit too sour. But if you mix it with yoghurt, that should be fine. You can sweeten it by adding fruits to it, berries, et cetera. That way you've got two ferments, easily done.

• 1:23Speaker 00

  And that's because the yoghurt's one and the kefir's the second?

• 1:25Speaker 01

  Yeah, and they're separate. They have different microbes in them.

• 1:27Speaker 00

  They both count, do they?

• 1:28Speaker 01

  They both count.

• 1:29Speaker 00

  So it's a win. You can get two before you leave the house.

• 1:32Speaker 01

  Before you left the house, you've got two, exactly. Then it's very easy in your lunch. You can either have some cheese, which as long as you get anything that isn't completely plastic, avoid things like children's cheeses or pizza cheeses. But even Philadelphia cream cheese, I did a study, we looked at that, that's got three microbes in it. So you can, cream cheeses are actually quite good. Any other cheddar or basic one, or raw milk cheese, even better. That would be your third one. But add to it some pickle, some basic beetroot kraut or some sauerkraut on it. If you're having an evening meal, any form

• 2:13Speaker 01

  of soup, instead of adding cream to it at the end, you just pour in some more kefir or yoghurt, that's an easy win. Into your salads, you can put, again, these krauts and pickles. I would ask everyone to swap their stock cube for some miso paste. You can buy miso paste, it lasts a long time, which is this fermented soybean paste that gives a marmy flavour that's fantastic. I never use stock cubes anymore. And I've just replaced that with a teaspoon of this miso paste, which if you're using in cooking,

• 2:55Speaker 01

  it would be dead, but it's still, it gives you, let's give it half a point for that one, Jonathan. And then you just think that when you're having a salad, can you put in some fermented vegetables into there? And start experimenting. You know, I don't expect you to eat kimchi straight away because it's quite spicy, but start experimenting with small amounts. And if you want to start thinking about kimchi, get some toast, put some cream cheese on it, and then mix in the kimchi with the cream cheese. So actually you're giving a mellower flavour to it and you're getting used to it. I managed to convince

• 3:36Speaker 01

  Davina McCall to start eating kimchi this way, and now she's an absolute addict. So usually people won't like it the first time. It's a bit like toddlers with some new food. You've got to keep going at it, introducing it, doing it a mild way. And then start thinking about other drinks you can have. So kombucha, the first ones might be a bit sour, but there's some nice fruit ones to start on. And you can wean yourself off the sweetness or the artificial sweeteners, just get used to those flavours. Water kefir is another one. Tibikos, you don't, it's not as common as kombucha, but it has just as many microbes in it, and is an easier fruter flavour for the novice starting off. They're just some

• 4:21Speaker 01

  of the things that you can do. Zoe Cookbook has got plenty of ways you can incorporate into recipes as well.

• 4:28Speaker 00

  Tim, you've been pitching this to me for a while. And I think I'm like everything you pitched me, like I slowly start to try and introduce it. And I definitely didn't grow up with eating any of these sorts of fermented foods apart from yoghurt and cheese. It's now really easy to buy them. And these things, honestly, I just don't think they were available at all 10 years ago.

• 4:48Speaker 01

  And even people who don't like dairy. So I'm often asked this in my talks, I don't have dairy, so I can't have these. No, there's plenty of vegan kefirs and yoghurts. The coconut ones are really good. It's a slow journey. And I think people will pick the foods and tastes that they like. And people have a different spice threshold, certainly, and a different sourness threshold. Some people immediately love it. Some people, it can take more time. But I can tell you, you go to Japan or Korea, you don't find people who don't have either miso or kimchi. So in a way, everyone can train their palate.

• 5:24Speaker 00

  Now, I'd love to wrap up with the idea of fermenting yourself at home, because I know that you've really got into this, haven't you, Tim?

• 5:31Speaker 01

  I have, yeah. Well, I had to, I'd write a book on it. So I've got to be an expert.

• 5:35Speaker 00

  And I think you have brought some examples of what is literally in your fridge today that you've cycled over with, is that right?

• 5:44Speaker 01

  A small sample of what's in my fridge, yeah.

• 5:45Speaker 00

  Oh, how many have you got in your fridge?

• 5:46Speaker 01

  Oh, far too many, at least 20 pots, I'd imagine.

• 5:51Speaker 00

  So now we understand why your wife is very upset about your fridge. So could you maybe take the first one out, explain what it is, and maybe start with what you think would be a good place to start?

• 6:01Speaker 01

  Well, let's go with the simplest ferment everybody can do. Because, oh, I can't do this. Well, even you could do this one, Jonathan. This is raw, unpasteurised honey, a clear jar, and you put about 10 or 12 cloves of garlic in it, exactly like this. And amazingly, after a few days, the microbes in the garlic transform the honey, they start eating the honey, and that produces the perfect environment for these microbes. They soften the garlic, they take away the hard taste of it, and it's a delicious either hors d'oeuvre, or you can blend it up, and it's perfect for a salad dressing.

• 6:45Speaker 00

  Can I have a smell?

• 6:46Speaker 01

  Well, you've got to try one.

• 6:47Speaker 00

  Oh.

• 6:48Speaker 01

  Just try one, Jonathan. Don't be scared.

• 6:49Speaker 00

  I am a little scared. It looks like something that has been, oh, they're quite hard, aren't they?

• 6:55Speaker 01

  The whole garlic cloves, just go for it.

• 6:57Speaker 00

  I'm going to go for it. All right. I'm not sure that I'm going to be invited back in the house later tonight.

• 7:03Speaker 00

  That's pretty good. Nothing like as strong as the garlic is if I'd eaten that raw.

• 7:10Speaker 01

  Well, that's how microbes transform foods into something completely different.

• 7:15Speaker 00

  And the honey tastes different as well?

• 7:16Speaker 01

  Yes, they're both different. I didn't add anything to that.

• 7:20Speaker 00

  You literally just threw garlic and honey?

• 7:22Speaker 01

  That's it.

• 7:23Speaker 00

  That's, that's the recipe even I could do.

• 7:25Speaker 01

  Exactly. So everyone can ferment if they really want to at home.

• 7:29Speaker 00

  That's really surprising. So this is where you're saying, these microbes do these amazingly complicated things. You just put it in the jar and you left it?

• 7:37Speaker 01

  It's mix, you know, the microbes and the garlic, sitting there bored, doing nothing. But you wake them up with, surround them with honey, and they go crazy. And they come out and they transform the honey. And that in turn transforms the garlic into something, a completely different dish. And I tell you, you blend that up and you have that in your salad dressing. It's, it's an amazing flavour.

• 8:01Speaker 00

  What's next?

• 8:02Speaker 01

  What's next? We've got some sauerkraut. This basically is nothing more than cabbage chopped up and weighed, and you add 2% salt. And then you put it in a jar and you leave it for a week. That 2% salt changes the environment so much that you then get exactly the right microbes leaking out of the cabbage. They eat the sugar that's been leaking out because the salt has released it from the cabbage. And the flavours are amazing, and you get all the acidity. And it's perfectly safe because they've made, it's so acid, nothing, no bugs that you don't want in there will live.

• 8:45Speaker 00

  All right, I'm going to try Tim's sauerkraut.

• 8:50Speaker 00

  Smells like sauerkraut.

• 8:53Speaker 01

  And there are two types of sauerkraut, obviously the one with vinegar, which is the common, cheap one, which doesn't have anything like the flavour and complexity.

• 9:00Speaker 00

  Oh, it's delicious.

• 9:02Speaker 01

  Yeah, there you go.

• 9:03Speaker 00

  So I've now had two ferments.

• 9:05Speaker 01

  But anyone can make, I mean, that's the key. So they're the two ones that are so easy, chop a cabbage and you've got to be able to weigh it. That's about the two skills you need. This one is slightly more advanced. This is my blob.

• 9:22Speaker 00

  And if you're not watching this on YouTube, it looks disgusting. And Tim is now reaching into what looks a bit like

• 9:30Speaker 01

  I won't get you to eat this, Jonathan.

• 9:31Speaker 00

  Tea water and pulling out which, something that looks a bit like a bit of a squid or an octopus or something. What is that?

• 9:39Speaker 01

  It is called a, um, a jellyfish, um, in some countries, Russian jellyfish or Japanese jellyfish. This is a scoby, um, which is a kombucha mother. Okay, so this is made by the microbes. It's like a shell they produce themselves. So there's about 50 different microbes in here.

• 10:03Speaker 00

  Living inside that sort of jellyfish thing?

• 10:05Speaker 01

  Yeah, they live inside there and they, they produce it for themselves. It's like a little protective shell that they live in. So this allows them to live for years. I've had this for about 10 years. This one, it has babies and I give it to special friends.

• 10:19Speaker 00

  I'd note that I've never been a special enough friend to get given your baby scoby. But on the other hand, it looks disgusting.

• 10:28Speaker 01

  It looks disgusting, but when you add it to sugary tea, so you make a big pot of sugary tea, you just add that to it, leave it for a week, you will get kombucha and a completely different flavour. And again, once you've got this sorted out, it is actually much easier than it looks.

• 10:47Speaker 00

  And that goes from sugary tea, and we know anything that's just like full of sugar is not healthy for you, to kombucha.

• 10:53Speaker 01

  Which is a sour, complex, uh, some say it's, you know, the closest you can get to beer.

• 11:00Speaker 00

  And it's good for me.

• 11:01Speaker 01

  And it's very good for you. Yes, it's, uh, lots of studies show it reduces blood pressure, helps your blood sugar level, all kinds of benefits. So again, you know, having this in the house, uh, the drinks of kombucha, but buy it in the stores first to see if, you know, what it, what it should taste like. But you, you can, this is incredibly cheap and easy to make.

• 11:22Speaker 00

  And so that, I guess, is a brilliant example of like the magic of these bacteria, moving something really terrible like water and sugar on one hand into something that suddenly is actually healthy for me.

• 11:33Speaker 01

  And it actually produces a bit of alcohol as well, um, usually below 1%, so you can't feel it. But it's just giving you an idea of what, what these microbes are doing. The yeast, there's yeast in there and they make CO2 and alcohol.

• 11:46Speaker 00

  So it's very complicated.

• 11:47Speaker 01

  And finally, your advanced lesson, Jonathan. So this is, uh, miso.

• 11:55Speaker 00

  I'd say something that looks even more disgusting than a kombucha. All right. So I'm looking at it and it's a sort of brown paste. If anyone has had a small child who maybe ate their food and then regurgitated it, I'd say it looks a bit like that, Tim. It's not the most appetizing thing. What, what have I got in front of me?

• 12:16Speaker 01

  What you've got is fermented soybeans mixed with koji fungus. Okay, and salt.

• 12:23Speaker 00

  So I've got fungus, fermented soybeans and salt.

• 12:26Speaker 01

  So basically I boiled up a whole bag of soybeans for four hours and then I got some koji fungus, which is coated on white rice from the internet, mixed them together, added a whole load of salt and put it in a jar, pressed down, left it for three months. So this is more professional than

• 12:51Speaker 00

  All right.

• 12:51Speaker 01

  It's definitely different to the garlic and the honey. Uh, it took me a while to pluck up the courage to do this, but I was so into my miso, I was spending a fair bit at the store on, on miso. I thought, I can do this myself. And actually it's really easy to do if you just know the essentials and you've done a bit of fermenting first. So the incredible taste of that compared to just a boiled soybean is amazing. So I want you to just dip your little finger in there.

• 13:19Speaker 00

  All right. And this is a jar full of fungus, but Professor and Doctor Tim Spector says it's safe and I can try it.

• 13:25Speaker 01

  Yes, you can. And this is what you should be using instead of your stock cube.

• 13:29Speaker 00

  Smells good, actually.

• 13:33Speaker 00

  Tastes pretty great.

• 13:35Speaker 01

  It does. And it just shows you, and if you just had boiled soybeans, they are virtually inedible. And so this, it just shows you how the microbes and the salt and the fungus in the right conditions just were, given time, will convert this into an absolutely delicious dish.

• 13:52Speaker 00

  And there's definitely like a layer that tastes a bit like soy sauce within this.

• 13:55Speaker 01

  Yeah. It's, well, it's the same basic principle. So there you have it. That's from the easiest to perhaps, you know, one of the more complex ones that you need three or six months to, to make. But, uh, you've now got all the tools you need, Jonathan.

• 14:10Speaker 00

  That's all for this week's recap. At Zoe, we believe that when it comes to your health, small changes can actually add up to a big improvement over time. And that's why we developed Daily 30, the gut supplement that's specifically formulated to become your new daily healthy habit. You simply add a scoop to any meal once a day to support your health and increase the plant diversity in your diet. By the way, whenever we talk about Daily 30 as a good source of fibre, we're required to say that it contains four grams of total fat per serving. Obviously, that's all amazing healthy fats from plants. To make Daily 30 part of your gut health routine, simply visit zoe.com/daily30. See you next time.