ACID PRODUCTION FROM LACTULOSE BY DENTAL PLAQUE BACTERIA

Representative strains of oral streptococci, lactobacilli and bifidoba cteria were incubated overnight with lactulose or other carbohydrates and the final pH recorded. Most bacteria tested were able to metaboliz e lactulose with the exception of strains of Streptococcus salivarius Lactobacillus acidophilus and Lact, fermentum. Streptococcus mutans pr oduced most acid overnight but the initial rate of acid production fro m lactulose by uninduced cultures was very low. Plaque pH was monitore d in 12 volunteers following rinsing the mouth with lactulose, sucrose or sorbitol or Lactulose BP. These studies in vivo showed both lactul ose and Lactulose BP to exhibit low acidogenic potential. Thus, althou gh plaque bacteria are capable of fermenting lactulose, the results su ggest that lactulose is likely to pose a small acidogenic challenge to teeth under normal conditions of use.