You need to define "spent some time". Was he working? On sabbatical or holiday?
"I travelled somewhere and things improved" has the serious complication that you changed almost everything at once and possibly removed major stress sources. You were even outside of your own home - and buildings have ecosystems themselves anyway as well as just systemic faults.
Yeah ok, but it's just an anecdote so it doesn't count as generalisable evidence in any case.
I would just add that when he got back to Britain and tried baguette style bread there he found that he could tolerate it in Britain too.
Again, I'm just reporting a story as it was told to me because I was reminded of it in response to the previous comment.