Improving oral health with lactic acid bacteria
by Delphine Saulnier
By developing an effective way to determine persistence of bacteria in the mouth, NIZO scientists have found that probiotic strains differ greatly in their persistence in the oral cavity. Persistent probiotic bacteria can be effective in fighting bad breath and tooth decay.
Microorganisms in the mouth can produce compounds that cause bad breath or tooth decay. Beneficial microorganisms such as lactic acid bacteria might offer opportunities as oral probiotics by outcompeting the unwanted bacteria or by reducing their activity. Only with those bacteria that are persistent in the mouth a positive effect can be achieved.
In a new study, led by Hans Snel at NIZO food research, persistence of beneficial microbes (probiotics) in the oral cavity was found to differ greatly between bacterial strains.
Using a new selection method, the scientists evaluated the competitive persistence of a range of LAB in the human mouth (journal of Applied and Environmental Microbiology). A total of 69 food-grade lactic acid bacteria strains from the Lactobacillus, Lactococcus, and Streptococcus genera were evaluated for their persistence in vivo in the human oral cavity.
Colonization, or at least temporal persistence of probiotic, is a phenotypic trait, which is highly likely to be required for strategies to decrease the activity or abundance of the detrimental bacteria. Some strains were found to be present in the mouth more than two weeks after consumption.
The ability of a bacterial strain to persist in the oral cavity is likely to support oral probiotic efficacy. According to Delphine Saulnier, probiotic expert at NIZO, the approach presented here can serve as an initial step in the selection of candidate probiotic strains aiming to promote oral health.