Letter: Have we found the very latest quantum food fad?

From Peter Verity, Edinburgh, UK

Penny Sarchet reports that exposure to soil may be key to a healthily diverse microbiome (14 January, p 28). Alongside this you answer the question “Should I wash food?” with “raw fruit and vegetables – yes”.

So do vegetables have to be simultaneously clean and dirty, to nurture an optimum microbiome? Should we, in fact, seek out Schrödinger's carrot?

The editor writes:
• This is indeed a conundrum. Exposure to soil seems to be good for children, but it carries the risk of infection with disease-causing bacteria too.