The most common yeast population among Americans (relevant because of diet) is called Candida albicans, commonly referred to as Candida. Candida in associated with vaginal yeast infections and thrush. It may be a surprise but yeast infections originate in the intestine. When Candida levels fall out of balance, the yeast emits toxins that travel through the body via the body (via the blood stream) and result in a variety of physiological imbalances. If left unchecked, toxic yeast may rise up and disturb hormone production, impair immune function, and generally wreak havoc on many organs with the skin being the common victim.
The use of antibiotics to treat acne (used to counteract the bacteria that feed of the sebum in the skin) can cause an additional suppression of the immune system plus negatively affect digestive health which will inevitability exacerbate the development of acne. In my opinion, the colon and its related toxin build up is the primary source of acne. Suffice it to say that acne could be greatly reduce to changes in one's diet, colonics and detoxes (do your research and consult your physician as appropriate).