And for the fans of probiotics, this makes for a rather sobering read:

"Probiotics: elixir or empty promise?"

(The Lancet Gastroenterology & Hepatology)

Just a few points, though it isn't a long read:

Evidence for the efficacy of probiotics is weak or, in some cases, non-existent.

Probiotics are classed as food, not medicines, so are not subject to anything like the same regulation, if at all, and are not subject to clinical trials.

Some probiotics in some people may actually interfere with the gut flora recovery process after illness or antibiotic use.

There is limited evidence that probiotics may help to reduce diarrhoea in some people after antibiotic treatment, but consistent evidence is thin.

The suggestion is that a healthy, varied diet may be a better way forward.

A number of medical websites suggest that while probiotics are probably harmless, you shouldn't waste your money!