If an upset microbiome causes illness, settling it down might effect a cure.

ECONOMIST: Modern medicine

The "cure" took effect within only a few months of taking the drug.

BBC: Fish food poisoning breakthrough

In considering the effectiveness of any medicine, conventional or herbal, it's important to remember that the placebo effect, or the patient's desire to believe in a cure, can have a powerful influence.

CNN: ASIANOW - TIME Asia