Probiotics

What it is

Probiotics are live bacteria taken to support the gut. The crucial point is that "probiotics" is a huge category of different strains doing different things — a benefit shown for one named strain says little about an unrelated one in another product.

What the evidence shows

Gut and immune outcomes in athletes. Preliminary· human data Some strains have preliminary evidence for gut comfort, reducing the frequency or duration of colds, and supporting the gut during heavy training. Benefits are strain-specific.

Who it suits

People targeting a specific, studied strain for a specific reason — not everyone looking for a general "gut health" boost.

Practical notes

Because effects don't generalise, the label detail matters: a product without a named, studied strain and dose may do nothing. Fermented foods like yoghurt, kefir and sauerkraut supply live cultures alongside a broader diet-quality benefit, and are a sensible first port of call. People who are seriously immunocompromised should only use probiotics under medical guidance.

Sources

PubMed: probiotics supplementation, athletes, gut and immune outcomes (trials and reviews)

Frequently asked questions

Do probiotics help with training or health?

Some strains have preliminary evidence for gut comfort, reducing the frequency or duration of colds, and supporting the gut during heavy training. But benefits are strain-specific — results with one strain don't transfer to another.

Why does the strain matter so much?

'Probiotics' is a huge category of different bacteria doing different things. A benefit shown for one named strain at a given dose says nothing about an unrelated strain in another product, which is why the label detail matters.

Food or supplement?

Fermented foods like yoghurt, kefir and sauerkraut supply live cultures and a broader diet-quality benefit. A supplement makes sense mainly when targeting a specific, studied strain for a specific reason.