Niki Bezzant: Use your gut feeling

Homemade kombucha tea. Photo / 123RF

COMMENT: I am sent quite a few supplement samples in my line of work. Supplements, like anything else, seem to follow trends. Right now there's a trend towards turmeric, which may or may not be beneficial.

But by far the most popular "new release" category of supplements coming across my desk are things relating to gut health: mostly prebiotics and probiotics.

Probiotics have been a focus of attention from scientists for a few years now, along with all things gut. Food industry sites are full of reports on new findings in this area; it's getting food manufacturers excited as well.

Why? It's acknowledged now that the health of our gut affects almost every aspect of our health, from mental health to our likelihood of developing diseases, and it may even influence our propensity to gain or lose weight.

Probiotics are so-called good bugs that could help populate our gut with friendly bacteria; crowding out the bad bugs and creating positive health effects.

Probiotics can be found in foods: all things fermented such as yoghurt, kombucha, kefir and sourdough. And of course they're available as supplements.

Probiotics are categorised by genus (eg lactobacillus), species (eg reuteri) and strain (eg 6475). There are thousands of strains of probiotics and not all are equal — the holy grail for researchers is matching the right strain with the right condition. This is clearly not easy.

Looking at recent findings, though, you can see reason for the excitement. For example, Lactobacillus reuteri 6475 was found to improve bone density in one trial.

Lactobacillus rhamnosus HN001 improved symptoms of post-natal depression. Probiotics are being studied in relation to diseases as diverse as obesity and Alzheimer's, and they may even hold the key to curing the common cold — one trial found that supplementing with a particular strain lowered the risk of developing an upper respiratory tract infection.

There's also fascinating potential for probiotics to reduce risk of chronic diseases. Researchers at Otago University are currently trialling probiotics as a possible prevention for type 2 diabetes in patients with prediabetes — raising the possibility of a very simple intervention on one of our most pressing health problems.

So it's exciting, but what does this all mean right now for us as consumers? Should we be searching for probiotics in our yoghurt? Chugging kombucha? Taking supplements?

The answer seems to be that what's not known about our gut bacteria is still a lot more than what is known. The effect of probiotic-containing food or drinks could be beneficial, and it's unlikely to do any harm. Including them in the diet for general health is probably good, since at the very least the foods they're in have other benefits.

Trying to address specific problems with probiotic supplements seems a bit trickier: you need evidence of specific effect, and an effective dose. Manufacturers are somewhat limited in what they're allowed to say on labels, but if a product doesn't at least allude to its benefit, spending your money on food might do more good.

• Niki Bezzant is editor-at-large for Healthy Food Guide www.healthyfood.co.nz