The distribution of the cariogenic bacterium Streptococcus mutans in the gastrointestinal tract of monkeys (Macaca fascicularis).

The success of oral vaccines based on Strep. mutans might be influenced by its presence in the gastrointestinal (GI) tract. Enumeration of Strep. mutans at various sites of the GI tract of sucrose-fed monkeys revealed a localized distribution. High numbers of Strep. mutans were recovered from only the dental plaque, caecum and the large intestine. Where Strep. mutans was not detectable in the dental plaque it could not be isolated from regions of the GI tract sampled. The absence of Strep. mutans from the small intestine suggests that the disparate results obtained from experiments in which this organism was used to immunize monkeys orally, are not attributable to the prior colonization of such an immunologically important region.