Besides religion, what other changes came to sub-saharan africa as a result of increased contact with the outside world?

The sub Saharan Africans got guns during the slave trade, this greatly expanded sub Saharan African nations and made some of them strong enough to expel or defend against colonial empires, at least for a little bit. A lot of them also got a lot more wealth with trading. A lot of diseases where introduced though and Africans where incouraged to capture other Africans to sell in the slave trade which was bad.