source all files in a directory from .bash_profile

Oneliner (only for bash/zsh):

source <(cat *)

I agree with Dennis above; your solution should work (although the semicolon after "done" shouldn't be necessary). However, you can also use a for loop

for f in /path/to/dir*; do
   . $f
done

The command substitution of ls is not necessary, as in Dirk's answer. This is the mechanism used, for example, in /etc/bash_completion to source other bash completion scripts in /etc/bash_completion.d

Wouldn't

 for f in ~/.bash_profile_*; do source $f; done

be sufficient?

Edit: Extra layer of ls ~/.bash_* simplified to direct bash globbing.