Hunter-gatherers are different
Anthropologist Cecil Lewis, from the University of Oklahoma in exotic Norman, gathered stool samples from both hunter-gatherers and farmers in Peru. Both had a wider range of gut flora than the people in Norman. The hunter-gatherers in addition had species of non-pathogenic Treponemes. An interesting question, not answered by this research, is what happens to the guts of anthropologists who reside with hunter-gatherers for long periods.
Now, go back to your doughnut.