Probiotic Supplementation May Reduce Levels of Bacteria Associated with Dental Cavities

What's new

A systematic review analyzed seven randomized controlled trials to investigate the impact of the probiotic Bifidobacterium lactis BB12 on levels of Streptococcus mutans in the mouth [1]. S. mutans is a bacterium widely recognized for its role in initiating dental cavities. The review found that daily intake of B. lactis BB12, typically mixed with yogurt or ice cream, led to a general reduction in salivary S. mutans levels across the studies [1]. Reductions observed ranged from 15% to 90% [1].

The science behind it

Dental cavities, also known as tooth decay, are primarily caused by bacteria in the mouth that produce acids when they metabolize sugars from food and drinks. Streptococcus mutans is a particularly aggressive bacterium in this process, adhering to tooth surfaces and forming biofilms (plaque) where acid production can demineralize tooth enamel [1].

Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. In the context of oral health, the hypothesis is that introducing beneficial bacteria like Bifidobacterium lactis BB12 could alter the oral microbiome, potentially by competing with harmful bacteria like S. mutans for resources or attachment sites, or by producing substances that inhibit their growth [1].

This systematic review compiled data from studies involving children and adults aged 3 to 30, who consumed B. lactis BB12 daily for periods ranging from 2 to 8 weeks [1]. The consistent finding was a decrease in S. mutans concentrations in saliva during the intervention period. This suggests that B. lactis BB12 can indeed influence the oral bacterial environment by reducing the numbers of a key cariogenic (cavity-causing) bacterium [1].

What it means in practice

For individuals concerned about dental cavities, incorporating a probiotic containing Bifidobacterium lactis BB12 might offer a complementary strategy to traditional oral hygiene practices. The studies reviewed used the probiotic daily, often mixed into a food vehicle like yogurt or ice cream, making it a potentially palatable option, especially for children [1].

However, it's crucial to understand that while the probiotic reduced S. mutans levels, none of the included studies directly assessed whether this reduction translated into a lower incidence of dental cavities [1]. Therefore, while the mechanism of action seems plausible, the direct clinical benefit in terms of cavity prevention has not yet been demonstrated. The effects on S. mutans levels also appeared to be transient, meaning the reduction did not persist once probiotic consumption ceased [1]. This implies that continuous or regular intake might be necessary to maintain any potential benefits.

Caveats

The primary limitation of this systematic review is the absence of studies directly measuring cavity formation as an outcome [1]. While a reduction in S. mutans is a promising indicator, it does not definitively prove that cavities will be prevented or reduced. Future research needs to focus on long-term randomized controlled trials that assess clinical endpoints like cavity incidence and progression [1].

Another point of consideration is the temporary nature of the observed effects. The review noted that the shift in the oral microbiota, specifically the reduction in S. mutans, did not persist after the probiotic intervention stopped [1]. This suggests that B. lactis BB12 may not permanently colonize the oral cavity or that its beneficial effects require ongoing consumption. The studies included also varied in duration (2 to 8 weeks), and longer-term studies are needed to understand sustained impacts and optimal dosing regimens [1].

Source: [1] https://examine.com/research-feed/study/1raNVd/?srsltid=AfmBOooeVEXPmSVVl6B8uhjbiUcopS7-jjUi2BbGwo7FHxMVwVA0hM9L