Role of Bacterial Flora in Oral Cancer- An Insight

Abstract

The human body contains about 1014 bacteria which usually colonise different parts of the body. The bacterial flora is important for a person’s health as well as normal functioning of tissue and organ systems. Bacteria are single celled organisms and are found on almost all surfaces of human body. They act in synergy with host immune mechanism and provide protection against various undesirable foreign invasions, especially in the oral cavity, where they exist in a diversified form which survive in a symbiotic relationship with the host. When there is a disturbance in this equilibrium due to various factors like trauma or tobacco smoking, betel nut chewing and alcohol intake, which makes the mucous membrane more permeable to invading microorganisms, these commensal bacterial species can become virulent and give rise to oral diseases ranging from dental caries to oral carcinoma. The effects of these bacteria can be either direct or indirect initiation of chronic inflammation, formation of procarcinogens that contribute to the development of oral carcinoma. This article focuses on the role of oral bacterial flora in initiation and progression of oral carcinogenesis. Various bacterial and fungal species associated with oral carcinoma and predominant bacterial species in oral cavity and oropharyngeal region along with measures to prevent their adverse effects are described.