Lactobacillus salivarius is a type of beneficial bacteria that naturally resides within the human body. As a lactic acid bacterium (LAB), it contributes to maintaining a balanced microbial environment by fermenting carbohydrates into acids. This bacterium supports overall health through its presence in various bodily systems.
Natural Presence in the Body
Lactobacillus salivarius is found across several mucosal sites within the human body. It is detected in the oral cavity, colonizing saliva, the tongue, and dental plaque.
It also inhabits the gastrointestinal tract, including the small intestine and colon. In the vaginal tract, this bacterium is present alongside other lactobacilli. Its natural occurrence in these areas is considered normal.
Key Roles in Human Health
Lactobacillus salivarius plays a role in supporting human health, primarily through its antimicrobial activities, immune system modulation, and contributions to digestive, oral, and vaginal well-being. This bacterium produces organic acids, such as lactic and acetic acids, which lower the local pH, creating an environment less hospitable for certain opportunistic microbes. It also generates hydrogen peroxide, an antimicrobial compound that helps keep undesirable microbes in check.
Lactobacillus salivarius secretes small antimicrobial peptides called bacteriocins. These bacteriocins can selectively inhibit the growth of competing bacteria, including harmful pathogens like Listeria monocytogenes and Staphylococcus aureus. This activity helps prevent infections and maintain a healthier microbial environment. The bacterium also competes with undesirable microbes for space and nutrients on mucosal surfaces, further preventing pathogen colonization.
Immune System Modulation
For immune system modulation, Lactobacillus salivarius interacts with mucosal immune cells and epithelial cells, influencing specific functions of the immune system. It can activate antigen-presenting cells and modulate their function by influencing the expression of surface receptors and cytokines. Studies suggest it can help restore levels of certain immune biomarkers, indicating an activation of immune responses towards homeostasis. This includes promoting a healthy inflammatory response and enhancing both innate and adaptive immune functions.
Digestive Health
Within the digestive system, Lactobacillus salivarius contributes significantly to gut health. It strengthens the intestinal barrier function by potentially increasing mucus production and improving the integrity of tight junctions between intestinal cells. This helps restrict the influx of potentially harmful antigens and microbes, while allowing for nutrient absorption. The bacterium’s fermentation byproducts also help maintain a favorable environment for other beneficial gut microbes, supporting comfortable digestion. Its presence may also alleviate symptoms in certain gastrointestinal disorders by balancing the gut microbiota and reducing inflammation.
Oral Health
For oral health, Lactobacillus salivarius is abundant in saliva and influences daily oral comfort and hygiene. It can help reduce plaque accumulation and support gum health, contributing to better resistance against factors linked to dental issues. The bacterium’s ability to produce bacteriocins and organic acids helps inhibit the growth of bacteria responsible for bad breath by decreasing volatile sulfur compounds. Additionally, it can inhibit the growth of cavity-causing bacteria like Streptococcus mutans.
Vaginal Health
In the vaginal tract, Lactobacillus salivarius contributes to maintaining a healthy microbial balance. Along with other Lactobacillus species, it helps to create and sustain an acidic environment. This acidity is important for discouraging the proliferation of undesirable microorganisms, thereby supporting overall vaginal health.
Probiotic Applications and General Safety
Due to its diverse beneficial roles, Lactobacillus salivarius is often included in probiotic formulations designed to support specific health areas. These applications commonly target oral health, gastrointestinal comfort, and women’s health. Probiotic supplements containing Lactobacillus salivarius are available in various forms, including tablets and capsules.
Generally, Lactobacillus salivarius is considered safe for consumption, particularly for healthy individuals. It is recognized as part of the “Generally Recognized As Safe” (GRAS) category for food ingredients. Clinical trials and animal studies involving Lactobacillus salivarius have not reported significant adverse effects.
However, like all probiotics, individual responses can vary. While generally well-tolerated, individuals with weakened immune systems should consult a healthcare professional before taking probiotics. It is also advisable to discuss probiotic use with a healthcare provider, especially when managing specific health conditions or concurrently taking other medications, such as antibiotics, as antibiotics can reduce the effects of probiotics.