Paul Pitchford's recently revised book "Healing With Whole Foods: Asian
Traditions and Modern Nutrition" has an interesting discussion on the
health impact of using yeast vs. natural leaveners. You have to wade
through quite a bit of Chinese and Ayurvedic philosophy and diagnostics but
that's not the worst experience one can have. Pitchford has good
information, backed by science, on yeast, sugar, and calcium metabolism.
Your library probably has a copy.
Before you give up the good life and revert to quick bread, you might wish
to try "lean" sour dough or naturally leavened bread. Because the starter
is different from yeast, and there is no sugar, oil or dairy, it may not
generate the fermentation byproduct that is troubling you. Peter Reinhart
via "The Baker's Apprentice" has the most current and comprehensive
discussion on it.
I gave up yeast breads for levains years ago. There is a difference.