Understanding gut microbiome and what it means for your health - The Little Things

Dr Will Bulsiewicz is a gastroenterologist and expert in digestive health. Photo / Supplied

Trillions of gut microbiomes are inside us right now – and until a few years ago, people knew little about them.

In just a few years, gut health has become one of the hottest topics in medical research, as doctors seek to understand the relationship our gut has with our mental health, longevity, and disease resistance, to name just a few areas.

Dr Will Bulsiewicz is a gastroenterologist and researcher, focusing on the gut and digestive diseases.

Speaking to Francesca Rudkin and Louise Ayrey on their NZ Herald podcast, The Little Things, he said it is amazing to consider how familiar people are with the gut microbiome now, given it wasn’t long ago that there was “zero awareness” even among the medical community.

“We’ve come a long way to where now this is bordering on a mainstream conversation that you may be having with other people. I love that.

“It’s important for everyone to understand that there has been this huge discovery that’s taken place during the last 20 years in science, and it’s transforming the way that we think about our own body as humans – and that is the microbiome.

“So it turns out that we are completely covered from the top of our head to the tip of our toes with invisible micro-organisms, bacteria, yeasts, these things called archaea.

“They’re there in all of those places. Our skin, our nose, our mouth, but they’re most concentrated inside of the large intestine, which is the colon.

“And in that place, just that place alone, your large intestine, you will find approximately 38 trillion micro-organisms now.”

To put that into context, Bulsiewicz said if you took every star in our galaxy and put them into a ball and put it into your large intestine, you would have to do this 380 times.

“So you have 380 galaxies full of stars. And perhaps even more shocking to me is that we only have about 30 trillion human cells.

“So with total clarity, I can say you are less than 50% human.”

He said that among the 380tn micro-organisms, the viruses, bacteria and parasites in there aren’t necessarily always working in harmony, but we have evolved to give these micro-organisms a lot of control over our bodies, including our relationship to nutrition, inflammation, metabolism, and the immune system.

“Seventy percent of your immune system resides within the wall of your gut.

“And in fact, so close to these microbes that just let me pretend for a moment that we pick up our microscope and we take a look and we’re zooming in on this very, very minute part of what’s happening inside of you.

“And what you would see is you would see these microbes and then there’s a single layer of cells, we call it the epithelial layer, and it’s thinner than a fraction of a hair off the top of your head. And the epithelial layer separates those microbes from the immune system on the other side, 70% of the immune system is on the other side.”

Listen to the full episode of The Little Things for more detail from Dr Will Bulsiewicz about the importance of the gut in maintaining your health.

The Little Things is available on iHeartRadio, Apple Podcasts, Spotify or wherever you get your podcasts. The series is hosted by broadcaster Francesca Rudkin and health researcher Louise Ayrey. New episodes are available every Saturday.