Well, I'm not a statistician, but... as I understand it, the issue is that breastfeeding isn't independent of gut microbiome, because it *affects* gut microbiome. This isn't a random factor which is different from the variable you're studying (microbiome); it's one of the things that *causes* differences in the variable you're studying. So adjusting for that would screw up the statistics and make it look as though the effect of the microbiome was less than it actually is. Let me know if that makes sense.
***********************************************
Archives: http://community.lsoft.com/archives/LACTNET.html
To reach list owners: [log in to unmask]
Mail all list management commands to: [log in to unmask]
COMMANDS:
1. To temporarily stop your subscription write in the body of an email: set lactnet nomail
2. To start it again: set lactnet mail
3. To unsubscribe: unsubscribe lactnet
4. To get a comprehensive list of rules and directions: get lactnet welcome