What’s the difference between prebiotics and probiotics?
It’s easy to get these two mixed up, so we spoke to an expert to settle the matter.
As well as talking to Scott Anderson—author of The Psychobiotic Revolution: Mood, Food, and the New Science of the Gut-Brain Connection—about psychobiotics, we also got him to answer a few of our burning questions about the confusingly named prebiotics and probiotics.
You can listen to the entire podcast here.
Q&A with Scott Anderson
Right, let’s start at the beginning. What is a probiotic?
Probiotics are bacteria that are good for your health. For a long time, we thought that we were at war with bacteria. And when we first discovered bacteria, we decided that we would just kill them all. So we set out to do that. We've been working on killing bacteria for a long time, and some of that is a good thing, and some of that is a bad thing. Antibiotics have saved billions of lives, but we’ve also recruited our own set of beneficial bacteria. These help us fight pathogens, and prevent conditions like leaky gut.
And what is a prebiotic?
They sound way too similar—we should probably have thought of a different name. But prebiotics are foods that we can’t digest, but our gut bacteria can. Food for the microbiome. Beneficial bacteria can convert fibre to butyric acid, and other short-chain fatty acids, which are full of energy. It’s a good trick, as you've got a gut bacteria that is trying to get every last little ounce of energy out of the food that you eat.
That was perfect back in the days when we were foraging. But today, when the food is so plentiful, there are some issues. How do we get the right bacteria? And how do we get the right food for that bacteria?
But those are the two: probiotics are the bacteria themselves, and prebiotics are the food for that bacteria.
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How can we get more of them into our diet?
There are two things to consider: ingredients and preparation. Potatoes, for instance, are full of fibre when raw, but that’s converted to starch when they’re cooked. Even just letting a cooked potato cool down means that you’ll get more resistant starch—a type of prebiotic.
Some other foods that are high in fibre include:
Jerusalem artichokes (not the same thing)
Remember, you won't find any fibre at all in meat, so don't look there. All the fiber that you want is in vegetables.
What are existing probiotic and prebiotic supplements like?
I’d encourage that you try to alter your diet first, and try to bring yourself up that way, but there are definitely times when supplements can be helpful,
If you’re buying probiotics, chances are it was easy to make—a leftover from brewing, or from making yogurt. These can be useful and do some good going through your system, but they're not going to colonize your gut because they're not meant for the gut. That's not where they came from, that's not where they're going. But in the meantime, probiotics can have some good effects on you, and your mileage may vary. Everybody needs to try them first to see if there's something that's going to work and some people swear by them.
But it just wasn't really working for me. So I moved on to prebiotics—these complex sugars that feed the bacteria. I went through several but didn't get any comfort, until I finally hit upon galacto-oligosaccharides. This chain of indigestible sugars changed my life overnight. And so, you need to try lots of different things because everybody's different, and take notes, it's gonna take a while for some of these things to work.
What can we look forward to in the future?
The hope is that we’ll soon have better symbiotics—that is, a combination of probiotics and prebiotics. And that's when we start to see some real action. I think that in terms of real mood elevators, these are the things that are going to start to have a really big impact on your brain.
And is there anything we should watch out for?
When you’re eating prebiotics, the bacteria love it and they’re producing these beneficial fatty acids, but they’re also producing gas. If you start eating some of those foods that are fibrous, you might end up with some more gas than you're used to. So start slow, but over time you can build up and that gassiness actually goes away.
Besides, we like to say that farts are funny. Diabetes is not.
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Any final tips?
Try new vegetables. People get stuck in their ways really easily and especially with vegetables. There are a lot of people who just don't eat vegetables, and they're missing out because they don’t know how to prepare them properly. If well-prepared, they're delicious and they're very good for you.
So you may have to get over some of your early childhood problems. We're going to grow up and we're going to do the right thing now, as adults.