Why would one's body odor change suddenly?

I’m hoping some sciencey types can help me figure this one out..

Okay, so when I’m in the U.S., I work a job that is generally very physical (and hot in the back areas) and I often sweat a lot. Like, a month ago, at the beginning of summer, I would go home with my clothes damp. Gross, I know.. but if you’re still with me, let’s carry on to my question!

I was actually pretty impressed with my deodorant because, despite my perspiring, I did not stink at all, other than smelling of plain sweat and parfum de restaurant. No B.O., yay!

Now, I came to Italy to visit my mom and almost immediately even the smallest amount of perspiration and I find I’m stinky. I realized this trip that it’s pretty much always so, at least in the warmer months, requiring multiple showers a day. I hate being stinky and I’m really confounded as to why it happens. I maintained similar hygiene patterns as back home, the same antiperspirant I was using while working, same clothes, etc.

The only thing I can think is diet (fresh foods, hardly any processed) or the water here being different. Anyone have any theories or perhaps can explain why this is?