Moment 145: The Alarming Link Between Your GUT & Depression: Tim Spector

Steven Bartlett (0:03)

What is the microbiome?

Tim Spector (0:05)

It's the word we use for the community of gut microbes. These are microscopic bugs in our intestines. And it's a biome because it's like this jungle community. It's lots of different species altogether, thousands of them that coexist in our lower intestine, our colon.

And it's like we've discovered in the last 10 years a new organ in our bodies. If you put them all together, they weigh about the same as our brain. OK, so that's mind-boggling really to think about all these bugs, which individually are tiny, putting them together, they actually weigh several pounds. So you can either think of them as a microbial garden, but increasingly I'm shifting that towards thinking of them as an incredible pharmacy. So all of them are able to pump out chemicals all the time that are vital for our body. So thousands of different chemicals are pumped out every minute by these gut microbes when they're fed the right foods. And these chemicals are key for our immune system. Most of our immune system is actually in our gut. Most people don't know that. We think it's under our armpits or somewhere. But actually all the immune cells are actually talking all the time to our gut microbes through these chemicals. And our immune system obviously is crucial for our whole body and fighting aging and cancer, COVID infections, allergies, all these kinds of things. So then you've also got the microbes can produce chemicals that affect the brain and will make the difference between you being happy or sad, or we know that they're vital in depression. Important for regulating how much you eat, your appetite, when you feel full, they also provide key vitamins for you, all the B vitamins and many other components, neurochemicals like serotonin that's key for the happiness and how antidepressants work are all produced by your gut microbes. So we're slowly learning that these guys are absolutely crucial to how our body responds to anything coming into it, whether it's painkillers, whether it's antidepressants, whether it's chemicals in the form of food. And this is why I want people to think about food very differently than we have done in the past. The idea, the old idea that food is just calories, macros with its fats and carbs and proteins. Those four things, that's 100 years old mentality. But key to it is this core of our gut health, which we've ignored totally. And this was this big aha moment for me after research for 10 years. Why would identical twins be different? What could it be? And it turns out their gut microbes are different. That's the only thing I've ever found in 30 years that's really different about identical twins. And that explains why one gets cancer, the other one doesn't. Why one gets an autoimmune disease or one's depressed and one's happy. So for me that the twins were a perfect obvious way to show that how important these these microbes are for all of us.

Steven Bartlett (3:42)

What are some of the biggest myths you encountered as you started researching the microbiome that most people currently believe that I probably sat here now believe about how to keep my my gut healthy? What are some of those key myths? Because I know you like myth busting.

Tim Spector (3:58)

Well, I think most people believe that probiotics in yogurt get killed by your stomach acid. So they don't work because everything gets killed off. That's a common one I hear.

Steven Bartlett (4:10)

But they don't?

Tim Spector (4:11)

No. Some get killed, but you're ingesting billions. So always enough get through to have an effect. And we know that probiotics do work. Although the best probiotics are in food rather than in capsules. And there's plenty of fermented foods, which is the same. I think most people know very little about microbes. They think that most of them are harmful. So, oh, they cultured this microbe or they found a parasite. 50,000 people have now looked at their gut microbes in the US and the UK. In the UK, 24% have a parasite.

And that parasite is actually beneficial. It's called Blastocystis, and it's associated with good health, being thinner, having less internal fat, lower blood pressure. And, you know, in the past, we were trying to kill it off. And actually, the reason we're in this state is we've killed off all of our good bugs. So I think people need to realize that most of the bugs in our system are trying to help us. And we've actually lost half of the good ones compared to if you go to hunter-gatherers or, you know, I spent some time with the Hadza tribe in Africa. And, you know, they have twice the number of species that we have because they don't pop antibiotics, they don't have sterile foods, they have a very wide range of diverse plants, et cetera. So I think people think that their gut microbes are really only there to hurt them when they have a bad kebab or something. They don't think of all the positive benefits. They don't think that you need to build them up and that actually, you know, the more you've got, the better it is.