Antibiotic Use in Relation to the Risk of Breast Cancer
While the author does not suggest this as a possible mechanism, I would offer that destruction of normal flora by antibiotics is the key. Normal flora is known to convert isoflavones in soy and flax into compounds like equol and enterolactone that then confer lowered risk of estrogen dependent cancers. These bacteria are also a source of B12. They also have detoxification systems that can break down certain toxins before the toxins get a chance to be absorbed. Maybe one day we will begin to look beyond antibiotic resistance and see that the true negative effect of antibiotic overuse is destruction of normal flora.
JAMA — Abstracts: Velicer et al. 291 (7): 827 –