I have a website that have same idea of Twitter's follow feature

one table has the relationship between users named user_followers as follows:

user_id follower_id
1---------2
1---------3
1---------4
2---------1
2---------4
2---------5
2---------6
3---------4
3---------5
3---------6


Now can I retrieve a list of users to suggest for a specific user like "Who to follow" in Twitter