Hello and welcome to Zoey Shorts, the bite-sized podcast where we discuss one topic around science and nutrition.

I'm Jonathan Wolfe and today I'm joined by Dr. Will Bullswitch and today we're talking about Lactose.

Lactose is a very vilified substance. In fact, you've probably only heard that word lactose said next to intolerance.

It's actually very true will and this is a topic actually you know lactose intolerance that I'm personally very interested in as it turns out for 20 years everything that I understood about lactose was wrong.

So will let's start at the beginning. What is lactose intolerance and is it as dangerous as we've been led to belief?

Jonathan, like most of the topics we cover on the show, the truth is a lot more complicated.

Well, let's hear the truth about lactose then. So will can we start with the basics of what lactose is? It's a special sort of sugar found in milk and milk products, right?

Yes, so lactose is actually two types of sugars, galactose and glucose and they've been linked together and what we would call this and to be a nerdy biochemistry guy but we would call this a disaccharide.

So in order for this disaccharide to be absorbed our body needs to actually break this bond that's holding the two sugars together and without that their male absorbed.

So how do our bodies break this lactose apart then will to get at these these two sugars that we you know we can digest?

So Jonathan, our body produces an enzyme called lactase that basically is able to break this bond between the two sugars and in breaking that bond it breaks down the lactose and frees these sugars.

So help me and all the listeners to sort of imagine this.

What happens you know help me to understand the path of lactose as it goes through this digestive process?

Okay, so after you after you trigger a swallow this milk is going to pass through your esophagus into your stomach and then ultimately it's going to descend down into your small intestine and when it enters into the small intestine.

This is where we expect the milk to come into contact with this enzyme.

Lactase is in the cells that are lining the intestine but let's imagine for a moment that you don't have enough lactase there.

In that case the lactose from the milk will continue to pass through the intestine and as it moves through it's drawing water in it's drawing electrolytes in and then eventually if it moves far enough along it's going to come into contact with your gut microbes and they will do what they're known to do which is ferment the lactose and that produces gas.

There's almost always a bacteria that has the ability that has the enzymes to break down the chemicals in the food that we eat.

So even when your own body can't digest something many times your gut microbes can do that for us and we see this with fiber and we're seeing it here with lactose.

Sometimes though our body will struggle with what these bacteria or these microbes are producing.

So now this explains lactose intolerance because basically what we've created here is we've created more water in the intestines we've created more gas, gas, diarrhea, loading.

This is the picture of lactose intolerance.

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