Using D-Bus for private IPC

Hello,

I'm designing a service that exists as multiple separate processes. 
These processes communicate over IPC. I'm considering using D-Bus as 
that IPC, but I have a couple questions. I would like to isolate the 
processes onto a private bus. Is that a good idea, or does that go 
against the design principles of using a message bus for IPC? Is there 
some other recommended way of isolating services so that they are not 
easily interacted with except by authorized processes? Is there a 
better way to create a private bus session from within a systemd unit, 
or is 'ExecStart=dbus-run-session /usr/bin/myprog' the recommended way 
to start up a private bus?

Thanks in advance!

~link