Antibiotic Treatment Effects on Intratumoral Bacteria Modulation in Surgical Patients With Oral Cancer

Inclusion Criteria: * Pathologically confirmed squamous cell carcinoma of the oral cavity * Must have planned surgery for curative intent * Participants ≥ 18 years of age * Participants must have the ability to understand and the willingness to sign a written informed consent document Exclusion Criteria: * Known allergy to metronidazole and/or chlorhexidine * Severe liver or kidney disease as determined by history of laboratory tests * Participants actively drinking alcohol (unable to abstain for the 10 day antibiotic period) * Recurrent oral cancer after prior radiation or chemoradiation * Participants with unresectable oral cancer * Participants unable to tolerate oral rinse or unable to have metronidazole administered by mouth or by feeding tube * Participants currently or have taken other antibiotics within the prior 30 days * Participant is pregnant