You can find the articles here:

and here:

The analysis was done using isotopes; unfortunately no dna analysis has yet been done.

From 105 skeletons found in two cemeteries, and dating from the 1st through the 3rd centuries AD, 8 seem to have spent their formative years in places as distant as the "Alps, the Apennines, and North Africa".

I don't know if hot, dry climate necessarily means North Africa, as we've seen from the Near Eastern Roman J2b sample found in Britain, who may very well have come from Arabia or the southern Levant.

That there might be people from the Apennines in ancient Rome seems to me unremarkable. Rome was sucking in people from all the poorer areas of the Italian peninsula, in a pattern replicated in most societies then and now.

"The individuals were mostly children and men, and the authors suggest their burial in a necropolis indicates that they may have been poor or even slaves. They also found that their diet probably changed significantly when they moved to Rome, possibly adapting to the local cuisine, comprising mostly wheat and some legumes, meat and fish."

Read more at:

In this regard, the authors claim that they factored in the fact that the water supply for Rome came from long distances, and that the grain predominantly came from Egypt. I certainly hope they did and that it was done properly, because that could confound all the results.

I just found the actual paper. I'll see if there's more clarity there.