How to build muscle & stay strong at any age: The surprising links between your gut health, strength training and healthy ageing | Prof Claire Steves & Prof Tim Spector

Jonathan Wolf (0:02)

Welcome to ZOE Science & Nutrition, where world-leading scientists explain how their research can improve your health.

Right now, in every muscle in your body, a demolition is underway. Old proteins are being torn down brick by brick, and right alongside it, a rebuild. New proteins being laid down just as fast. This constant, invisible tug of war between breaking down and building up muscle fibers continues from the cradle to the grave. But this delicate balancing act doesn't keep working as it should forever. Once you pass the age of 30, the demolition crew starts to work faster than the builders, and most of us lose muscle mass. We all know that exercise can help build muscle, but today's guest has discovered something completely new in her research. It turns out that this demolition tug of war is influenced by something other than your decision to go to the gym. And that something is hiding in the dark, coiled 30-foot tube that is your gut. Or more accurately, it's one trillion things, your gut microbes. But how can they possibly influence the muscle fibers in your calf? The answer is that the microbes that inhabit your gut manufacture molecular messages that travel through your bloodstream and then directly in your muscle tissue, tipping that tug of war one way or the other. And when it tips the wrong way, the consequences are real. Our bones weaken, our risk of foals rises, and for some it can even prove fatal.

This is called the gut-muscle axis, and scientists are only now unraveling its complexities to understand how harnessing it might keep us strong now and into the future. To guide us through this amazing new research, I'm joined by Claire Steves, a Professor of Aging and Health at King's College London, who's at the forefront of research connecting the gut microbiome to muscle health and aging. And alongside her is Professor Tim Spector, one of the world's leading microbiome scientists and my scientific co-founder at ZOE. Today, we're going to listen to the constant conversation between your gut and your muscles, and uncover what advice it has for us, what to eat, how to train and how to stay strong for the rest of your life.

Claire, do we only start to lose muscle mass when we're old?

Claire Steves (2:29)

No.

Jonathan Wolf (2:31)

If we lose muscle mass as we age, does it increase our risk of bone fractures?

Claire Steves (2:36)

Yes.

Jonathan Wolf (2:38)

Is it true that a healthy gut microbiome helps to build healthy muscles?

Claire Steves (2:43)

Possibly.

Jonathan Wolf (2:45)

Tim, can our gut bacteria communicate with our muscles?

Claire Steves (2:49)

Yes.

Jonathan Wolf (2:50)

Claire, as we age, should we increase our protein intake?

Claire Steves (2:55)

Yes, with some caveats.

Jonathan Wolf (2:58)

Can exercise on its own change the makeup of our gut microbiome?

Claire Steves (3:03)

Probably not on its own, but we do know that people who exercise, when they exercise their gut microbiome changes.

Jonathan Wolf (3:12)

Finally, Claire, what's the most common myth that you hear about muscle health and strength?

Claire Steves (3:18)

I think it is maximum protein equals maximum muscle health.

Jonathan Wolf (3:22)

That is not true?

Claire Steves (3:23)

It's not true.

Jonathan Wolf (3:25)

One of my favorite things about doing this podcast is learning brand new science direct from the researchers who are actually doing the studying, and research that just totally changes the way that I think about the world. I think that this episode is going to be one of those times. Listening to those answers, I find it a bit crazy to think that my muscles and my gut microbiome are linked, and even crazier to think that my gut microbes might actually be helping me to grow my muscles.

If you thought that building muscles as you age comes down to lifting weights and eating more protein, you're about to find out that's only half the story. When I think about muscle building, I think of my son who's 18 going to the gym and proudly showing me his biceps. So if you're listening to this and you're not an athlete, you're not 18 years old, you're not hoping to look great without your top on, why should you even care about your muscles?

Claire Steves (4:17)

Well, you really should care about your muscles because actually muscles are what's important for everything we do. Because even to get up out of the chair right now, I need to use my quads and that gets difficult as we get older actually. And so we can do a lot earlier in life to make sure we maintain our muscle function. But also our muscles can do good things for the rest of our body as well. It kind of influences how our brain works, influences all manner of different other organs in the body as well.