Dental cavities or caries cause holes in teeth in about 80% of people. Caries are caused by the action of mouth bacteria such as Streptococcus mutans.
A number of studies have reported that diets high in total sugar and/or sweetened colas are associated with more dental cavities. High amounts of sugar in the diet can promote growth of Streptococcus mutans and also promote the growth of the yeast (fungus) Candida in the mouth.
Other studies have reported that diets low in protein, calcium, fluoride, zinc and b-vitamins can also increase risk of cavities and poor overall dental health. A well balanced diet with little or no refined sugar (such as Doug Kaufmann’s phase diet’s) are helpful in maintaining tooth health.
Several human studies have reported that eating yogurt containing live (viable) probiotic bacteria such as Lactobacillus, Bifidobacterium and Streptococcus thermophilus can significantly reduce risk of tooth cavities and significantly reduce levels of Streptococcus mutans in the mouth. Note: Streptoccous thermophilus is a relative of Streptococcus mutans but does not cause cavities.
Other studies have reported that eating yogurt with live probiotics can significantly reduce the incidence of the gum disease gingivitis and halitosis (bad mouth odor).
More research is needed to determine the best strains of probiotic bacteria to promote oral health. A good review of the effects of probiotics and mouth health is found in the October 2009 Journal of the Canadian Dental Association.