Oregano oil has been shown to have antimicrobial properties in preliminary research. In one study, oregano oil showed significant  antibacterial activity7  against 11 microbes that were resistant to multiple antibiotics. Both carvacrol and thymol have also been studied  to work with antibiotics8  to overcome resistant bacteria.  For its antibacterial effects, functional nutrition expert English Goldsborough, FNTP, often recommends oregano oil to clients who are battling mold exposure, a sinus infection, or a cough or sore throat.