Due to the overuse of antibiotics scientists are starting to re-examine essential oils and their potential to fight diseases; click here, here and here.

The next step would be to examine the effects of combining different essential oils into a single treatment.

Researchers are finding that a combination of essential oils proves to be more effective then a single essential oil.
It is these combined essential oils that can defeat some of the highly resistant bacteria.

 

It seems synergystic effects are achieved through the following mechanisms:

  1. sequential inhibition of a common biochemical pathway
  2. inhibition of protective enzymes
  3. use of cell wall active agents to enhance the uptake of other antimicrobials

I can roughly translate this in: make the targets of the bacteria stronger, inhibit how the enzymes (how the bacteria works) and weaken the bacteria.
Through these mechanisms it seems likely that some essential oils can help reduce the dosage of antibiotics.

More research needs to be done which essential oils work well together against which bacteria.