A guide to probiotics

Over recent years we’ve learned more about how much our digestive health and the bacteria and yeast that grow in our digestive system can affect our physical and mental health. This has led to a huge increase in probiotic supplements designed to help us manage a range of conditions. Dietitian Katrina Pace investigates.

What are probiotics?

A probiotic is a living microorganism (like a bacteria or yeast) that may give us health benefits if we take it in the right amount. Probiotics can benefit our health through changing the amount and types of bacteria and yeasts that grow in our digestive system.

When would I think about taking probiotics?

We are used to reaching for the probiotics when we have a gastro bug or have been prescribed an antibiotic. Good quality research does support that using a probiotic can help manage or prevent travellers’ diarrhoea and prevent antibioticrelated diarrhoea.

But now research suggests that probiotic supplements may be beneficial for other conditions as well. There are suggestions that taking a probiotic may be useful alongside other medical treatments if you have anxiety, depression, problems with blood sugar control or need to lose weight. But these effects are not conclusive and can’t be attributed to all probiotics.

Where do we get probiotics?

Probiotics are naturally present in many fermented foods. Kefir, kombucha and sauerkraut are particularly high in probiotics, although the amount of bacteria they contain will be variable.

Probiotic supplements often contain higher amounts of probiotics and specific strains can be identified.

What’s on the market?

Gazing along the pharmacy shelves you’ll find probiotic supplements with different doses, such as 10 billion or 100 billion colony forming units (CFU) of probiotics per dose. You’ll also see probiotics labelled as helping certain conditions, such as “Metabolise”, “Gut restore”, “Mood and immune”, “IBS” and “Derma Protect”.

There’s a growing body of evidence suggesting that specific probiotic strains benefit specific health conditions.

We can expect that probiotic supplements labelled with a specific condition will contain the probiotics identified as potentially helping that condition. But, as this is cutting-edge research, the effectiveness of taking a probiotic for many conditions isn’t conclusive.

There are now strains that can be kept on the shelf as well as in the fridge. In the supermarket you’ll also find low-dose probiotic products such as Yakult drinks and Symbio yoghurt.

Are there any side effects?

Taking even very high doses of probiotics (over 1 trillion CFU) doesn’t seem to cause harm. The higher doses are expensive and may not be any more beneficial than lower doses. But you may feel worse before you feel better.

Some people complain of bloating, diarrhoea and flu-like symptoms when they start taking probiotics.

What to look for

• If you want to take a probiotic to help a specific condition, look for one that says it’s specific to that condition
• Check whether the supplement needs to be kept in the fridge or is shelf stable
• See also ‘How to make the most of probiotics’ for more information on probiotic strains