Display all the feed from all the SharePoint community and Feed from his joined community in SharePoint 2013 Online (Office 365 E3 version)

Hi,

We have created many SharePoint out of box community in SharePoint 2013 Online (Office 365 E3 version).

Now, Need help to display all the data/feed from all the SharePoint community in home page.  

Also, user can view all the feed of all the SharePoint community to whom he has joined.

Any approach, information, code about this would be greatly appreciated. Thanks!