DB Rows, performed unilaterally, of course, engage the core in an anti-rotational manner.
This is good and helps lay the foundation for a stronger core, thereby serving as prehab for spine issues, especially lower back ones.
Additionally, the lats have a stabilizing effect on the spine, too.
Performed correctly, this exercise is pure win.
As to the 'trunk widening' effect: as already has been stated in this thread, your lats grow wider (and thicker), too.
Besides, I daresay most people asking about such stuff aren't really at risk of having their whole packages ruined by widened trunks
If your spine, especially your lower back, isn't stable enough, your body will not allow maximum force output of muscles anchored (directly and indirectly) by the spine.