BizTalk / SharePoint integration
BizTalk includes SharePoint adapter which can be used for sending and receiving data from/to SharePoint
You could see that that sending adapter even is limited with 16 fields.
But what to do if you want to send more then 16 fields, attach a file to Item, do manipulations with a List/Library etc.
I would like to recommend to use native web services from SharePoint
which can be found at http://localhost/_vti_bin/lists.asmx
Use UpdateList to insert and update List Items
you can use GetListItems method to serach for Items in a List
for more methods and description check
for other SharePoint Services check
which you can use by calling from orchestrations