Epsilon Archive for Student Projects

Abstract

Abstract
Cavities used to be a very common problem but over time humans have learned to take care of their teeth. However, there are still many who have problems. This problem is due to microorganisms and in particular the various streptococci and lactobacilli producing acids which loosens up the enamel on teeth. These bacteria can be found at various places in the mouth and saliva. Besides being a discomfort it can be a major problems and the damaged tooth needs to be removed or make a dental filling.
The aim of the study was to see how intake of probiotic tablets containing Lactobacillus reuteri PTA ATCC 5289 and Lactobacillus reuteri DSM 17938 affects the levels of oral Streptococcus mutans and lactobacilli over a three-week period. Furthermore to see how long probiotics remains in the oral flora one week after the last tablet is taken.
Lactobacillus reuteri (LR), is a "probiotic" good bacterium that normally is used as supplement or added to so-called functional foods. Several companies have products with probiotic bacteria with different characteristics. Depending on the ability of the bacterium, it can be used to possibly reduce or alleviate various disorders in the body.
The effects of probiotics on caries-forming bacteria were good and judging by the results, there was a marked reduction of S. mutans after the first week. This can be compared with the persons who received placebo which had relatively stable levels of S. mutans during the entire study. A significant decrease of S. mutans in the probiotic group was seen between week zero and two, p = 0.02. What is interesting is that some of the participants had both probiotic lactobacilli left when the last study product was taken, while others had only L. reuteri ATCC PTA 5289. One of the participants had even an increased level of L. reuteri ATCC PTA 5289 in week three.
T-RFLP is a good method for studying the distribution of a bacterial community. In this study, only three people were included and to obtain more reliable results more samples should be analysed in the future. The result from analysis of three participants, two probiotics and one placebo, indicated that the microbial composition was surprisingly stable over the two-week period. Approximately 50 percent of TRFs were in common between the participants. Also, L. reuteri does not change the dominant bacterial composition but it cannot be excluded that analysis of more samples over a longer period will change this conclusion.
As conclusion it can be said that the study has worked well and to use the plates in this kind of study to grow S. mutans has not been done before when other products have been used instead. This allowed better quantification of the results than previous studies have received. There was also an entirely new medium for the cultivation of L. reuteri ATCC PTA 5289 which has not existed before, this allow the substrate to be used in future studies. The fact that L. reuteri has been detected a week after the last intake of product is a result that has never been shown before, which would be worth studying further on.