Can Acids Produced From Probiotics Demineralize the Tooth and Cause Progression of Caries: A Critical Review

Abstract

Background: Probiotics are known to provide various health benefits to the host in adequate concentrations. Lactobacilli, Propionibacterium, and Bifidobacterium are common “Lactic Acid-producing bacteria (LAB)” present in various probiotic formulations. These probiotic bacteria release large amount of organic acids, mainly acetic acid, lactic acid, and propionic acid, into their surrounding environment. Increased concentration of these inorganic and organic acids can reduce the saliva's critical pH to below 5.5, and can initiate demineralization of the tooth surface. Thus, the present review aims to critically appraise the existing evidence on this emerging clinical perspective and double edged nature of the probiotic bacteria, and explain as to how probiotic supplements can increase the risk of enamel demineralization and tooth decay. Results: Lactobacilli and Bifidobacterium are associated with rampant caries in preschool children and progression of caries. All probiotics were found to be acidogenic in nature as they reduced the pH of the saliva, and eroded the enamel. Probiotics release extracellular polysaccharides that help in plaque formation and can cause leaching of essential elements like calcium and phosphorous from the enamel surface. The lactic acidproducing efficiency of probiotics is increased when combined with supragingival plaque. Conclusions: Acids released from probiotic bacteria can reduce the critical pH of the oral environment and play an important role in initiating enamel demineralization and progression of caries.