There’s a lot of focus on healthy gut bacteria these days, and how we can achieve and maintain a healthy balance. And that, of course, creates an opportunity for the supplement makers. But how useful are the products they sell?
First of all, probiotics are foods or supplements containing bacteria that are beneficial to gut health, help us to digest our food, or keep potentially harmful micro-organisms in check.
Foods that are good sources of probiotics are fermented foods like yogurt, sauerkraut, kefir or kimchi. Most of the bacteria are destroyed in your stomach before they ever reach your gut, but these foods are easy to digest and certainly do no harm. The same applies to probiotic supplements, although there is evidence that if you take them while taking antibiotics, they can prevent diarrhoea and other digestive upsets.
Then there are prebiotics: foods that nourish gut bacteria and encourage them to grow. Basically, it’s the fibre in foods like bananas, onions and many other vegetables and fruits that makes them a good source of prebiotics. Again, you can take supplements to boost your intake, but if you’re eating a healthy diet rich in fibre, you should be getting enough.
Some manufacturers are now making what they call ‘synbiotics’, or supplements which contain both probiotics and prebiotics. It’s a convenient way to get both at once, and if, for example, you have had to take a lot of antibiotics, or gone through chemotherapy, or had gastro-enteritis, a course of these may help you to get back on track. But there’s very rarely a strong argument for taking any of these supplements on a long-term basis, and you can spend a lot of money to no good effect.