Streptococcus salivarius K12 is a specific strain of beneficial bacteria that functions as an oral probiotic. Probiotics are often understood as “good” bacteria that support gut health, but they also naturally inhabit other parts of the body, including the oral cavity and upper respiratory tract. K12 was initially isolated from a healthy child and has gained recognition for its potential to support health in these regions. Its presence in the mouth and throat contributes to a balanced microbial environment, offering various health benefits.
How Streptococcus Salivarius K12 Functions
Streptococcus salivarius K12 exerts its beneficial effects through two mechanisms: competitive exclusion and the production of antimicrobial peptides. Competitive exclusion involves K12 colonizing the oral cavity and throat, occupying space and consuming available nutrients. This colonization prevents harmful bacteria from attaching and establishing themselves, reducing their ability to thrive.
K12 also produces specific antimicrobial peptides, known as Bacteriocin-Like Inhibitory Substances (BLIS). These substances, including Salivaricin A2 and Salivaricin B, directly inhibit the growth of certain pathogenic bacteria that are often responsible for common oral and throat infections. This dual action helps K12 maintain a healthier microbial balance in the upper respiratory tract.
Specific Health Benefits
Streptococcus salivarius K12 offers several health benefits, particularly concerning oral, throat, and ear health. One significant application is in combating halitosis, commonly known as bad breath. Bad breath often results from volatile sulfur compounds (VSCs) produced by certain bacteria in the mouth. K12 helps reduce the production of these foul-smelling compounds by outcompeting and inhibiting the growth of the odor-causing bacteria. Clinical trials indicate that K12 can significantly reduce bad breath by neutralizing VSCs and rebalancing the oral microbiome.
K12 also plays a role in promoting throat health, especially in reducing the incidence of pharyngeal infections. It has been shown to counteract beta-hemolytic strains of Streptococcus pyogenes, the bacterium primarily responsible for “strep throat.” Prophylactic administration of K12 has been associated with a considerable reduction in episodes of both streptococcal and viral throat infections in children, with some studies showing reductions of over 90% in streptococcal pharyngeal infections compared to prior years.
The presence of K12 in the nasopharynx may contribute to ear health, particularly in preventing acute otitis media (AOM) or ear infections. AOM is an ascending infection where pathogens from the nasopharynx travel to the middle ear. K12 can inhibit the growth of common otopathogens, such as Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, which are frequently involved in middle ear infections. While some studies have shown promise in reducing the occurrence or severity of secretory otitis media and inhibiting common pathogens in vitro, a large randomized clinical trial did not find a significant reduction in AOM occurrence with daily K12 use in children. Research continues to explore its potential in this area.
Using K12 Probiotics Safely and Effectively
Streptococcus salivarius K12 probiotics are commonly available in forms designed for oral delivery, such as lozenges, chewable tablets, or oral powders. These forms allow the beneficial bacteria to slowly dissolve in the mouth, facilitating their colonization of the oral cavity and throat. This direct application helps to ensure the K12 strain can effectively interact with the local microbiota.
Dosage typically involves one dose daily, often before bed, after brushing teeth, to allow for prolonged contact with oral surfaces. Always follow specific product instructions, as formulations and recommended dosages can vary. A common dosage might be around 1 billion colony-forming units (CFU) per lozenge or sachet.
K12 is generally considered safe for human use, as it is a naturally occurring bacterium in the human oral cavity. Studies evaluating its safety have indicated that daily ingestion does not adversely affect healthy individuals. Reported side effects are typically mild and rare, such as temporary digestive discomfort like bloating or gas as the body adjusts to new bacteria. It is advisable to consult a healthcare professional before starting any new supplement, particularly for individuals with pre-existing medical conditions, those who are pregnant, or for use in young children, to ensure it is an appropriate option.