I confirm that MBB are open to people with all backgrounds and they actually encourage diversity in their talent pool. Also ATK, Oliver Wyman and Roland Berger to quote others.
I had few colleagues with background in research/ science subjects and they were able not only to succesfully land a consulting job, but to grow succefully within Consulting.
Another opportunity related to Top Consulting companies, in particular MBB is the possibility to do MBA / Externships as part of the career curriculum.
Best of luck with your job applications!