TV presenter Sophie Morgan and Professor Simon Gaisford sat on a sofa together in Sophie's home

Sofa Science with Sophie Morgan and Professor Simon Gaisford

Like us, TV presenter Sophie Morgan is curious about the gut and keen to get answers on some common questions. So we sent Professor Simon Gaisford round to her house to dig into the science from the comfort of her sofa.

Watch the full episode of Sofa Science here:

4 things you need to know about the gut from Professor Simon Gaisford...

Why is gut health so important?

If I go back to basics, your gut is a big tube and everything that you eat, and drink goes through that tube. Your body absorbs nutrients from your gut, it’s going to absorb water, it's going to break food down, and it's going to absorb that. And there's some stuff that you can't break down, complex carbohydrates and fibre. If you didn't have anything else going on in your gut, that fibre would come out of your bum, and you'd basically waste that as a foodstuff.

You've got trillions and trillions of bacteria that live in your gut. They're doing a good job for you and you need to look after them. They've chosen to live inside you as their home, and you as the host, you've got to make it a welcoming environment. When you eat, you're not really eating for you, actually, you're eating for your gut bacteria. The way that works is the gut bacteria being alive, like all living things, they eat and they produce waste, turning it into millions of different types of compounds that might be useful for you.

You gain something out of having your gut bacteria inside you because they're producing all these compounds. Bacteria that produce compounds that are useful to you in some way, I would call good bacteria. And those that are producing compounds which are harmful or toxic, I would call bad bacteria. Gut health really comes down to this balance of good to bad.

How does stress impact your gut?

Well, stress impacts your gut because a lot of your immune system is wrapped around your gut. It's easy to think about our senses as sort of touch and sight and hearing, but a lot of our immune response is wrapped around our gut.

Your gut is constantly checking everything you've eaten to make sure it's not going to harm you in some way. And Western diets and the stress of modern living means your immune system is constantly on edge. And so that irritation is going to feed into your daily life. It's going to make you feel irritated because you are never allowing your immune system to be properly at rest.

The other interesting thing is that there is a big nerve that runs from the gut to the brain called the vagus nerve or the gut-brain axis. This allows your gut and your brain to communicate with each other. Imagine that we were sat here, and a big hungry lion walked into the room. We would start to panic because our brain would say, this is a very bad thing. The first thing it does is say to your guts, you need to expel all your content so we can run away. People don't have a problem with your brain communicating with your gut, but it's a two-way street. And so your gut can also communicate with your brain.

How does good gut health impact your sleep quality?

The thing about the gut is it's digesting all the food, and you are absorbing it. That requires a lot of energy. To go to sleep, your body wants to shut down. If you eat something right before bed, for instance, you are diverting all that blood to your gut in order to digest that. I normally say to people stop eating a bit earlier, several hours before going to bed anyway, simply because you don't want that.

What are key things that people can do to look after their gut health?

I would say diet and exercise, reduce stress if you can, try and get good sleep, that's tied in with reducing stress, obviously. And then I would say take a supplement. Try and incorporate that into your daily routine. It really does make a difference in rebalancing your gut health.

Want to watch more from Sophie and Simon? Find out everything there is to know about antibiotics.