While much attention has been focused on the gut microbiome in recent years, current research is increasingly showing the important role of the oral microbiome in our health. A balanced microbiome in the mouth is essential for our well-being. The oral cavity is inhabited by a variety of microorganisms, including bacteria, fungi, viruses and single-celled organisms. In addition to regular oral care, a balanced diet and the intake of probiotics are crucial to promoting a healthy oral microbiome.
The microbiome of the oral cavity
The microbiome in the mouth is an important part of the human body and is considered the second most important microbiome after the intestine. The oral cavity is home to a wide variety of microorganisms, an estimated 700 different species, many of which are only found there. Numerous studies in recent years have shown that the oral microbiome plays a crucial role in the development of various diseases.
Composition of the Oral Microbiome
The oral microbiome is composed of a variety of anaerobic bacterial strains, including gram-positive and gram-negative bacteria such as cocci, bacilli and spirilla. The most common include Bifidobacterium , Fusobacterium , Lactobacillus , Leptotrichia , Peptococcus , Selenomonas and Veillonella . These microorganisms live in a balanced ratio to each other in a healthy oral cavity. In addition to bacteria, fungi, viruses and unicellular organisms are also found in the oral flora.
Effects of a disturbed oral flora
A disruption of this balance, also known as dysbiosis, can lead to the uncontrolled proliferation of pathogenic bacteria that colonize both hard and soft tissues and can cause diseases such as periodontitis and caries, as well as tonsillitis, pharyngitis and middle ear infections. The pathogenic bacteria that play a role in these diseases include Streptococcus mutans , Streptococcus pyogenes , Staphylococcus aureus and Porphyromonas gingivalis .
Development of the Oral Microbiome over the Life Course
The composition of the oral microbiome changes throughout life. Newborns come into contact with the mother's microbiome at birth and through breastfeeding. The mode of birth significantly influences the child's early microbiome. In a natural birth, the child comes into contact with the maternal microbiome as it passes through the birth canal, whereas in a cesarean section, the first contact with bacteria occurs through the skin of the parents and medical staff, which reduces colonization with protective bacteria.
Factors influencing the microbiome
Over the course of a lifetime, many factors influence the composition of the oral microbiome, including genetics, diet, lifestyle habits (such as smoking and alcohol consumption), oral hygiene, and medication use. In particular, the use of antibiotics can have far-reaching effects on the oral flora.
The Oral Microbiome and Disease
caries and periodontitis
Tooth decay is one of the most common diseases in the mouth. An imbalance in the microbiome can lead to dysbiosis, which is promoted by factors such as poor diet, chronic diseases, hormonal changes and poor oral hygiene. The pathogenic bacterium Streptococcus mutans plays a central role in the development of tooth decay. Periodontitis begins with inflammation of the gums (gingivitis), which is triggered by poor oral hygiene, smoking and other factors.
diabetes
Diabetes can be both the cause and the consequence of a disturbed oral flora. Excessive blood sugar can lead to a lack of saliva, which increases the risk of tooth decay and inflammation. Oral diseases can in turn worsen the course of diabetes. Treating mouth inflammation can help improve glycemic status.
cardiovascular diseases
Alterations in the oral microbiome are associated with cardiovascular disease. Inflammation in the mouth can release proinflammatory molecules and bacteria into the bloodstream that damage the endothelium and lead to atherosclerosis. Pathogens such as Porphyromonas gingivalis and Streptococcus mutans are associated with an increased risk of these diseases.
digestive diseases
Saliva transports numerous microorganisms into the digestive tract every day. Dysbiosis in the mouth can lead to inflammatory bowel disease, as pathogenic bacteria such as Porphyromonas gingivalis can alter the intestinal flora and impair the barrier function.
cancer
Altered compositions of the oral microbiome are associated with various types of cancer, such as pancreatic, esophageal and colon cancer. Microorganisms can influence tumor formation directly or indirectly by influencing the immune reaction between tumor and body.
Alzheimer
There is evidence that the oral microbiome is linked to the development of Alzheimer's disease. Severe periodontitis can impair cognitive abilities by releasing inflammatory cytokines into the brain via the bloodstream. Poor oral hygiene in Alzheimer's patients promotes inflammation and tooth loss, which further worsens eating behavior and nutrition.
Rheumatoid arthritis
Rheumatoid arthritis (RA) and periodontitis share similar risk factors and symptoms. Effective treatment of periodontitis may have beneficial effects on RA. Both diseases have similar immune-inflammatory causes, and it is thought that RA may be caused by oral bacteria.
The importance of Streptococcus salivarius for the oral microbiome
Streptococcus salivarius plays a central role in the healthy oral microbiome. It is one of the first colonizers in the mouth of newborns and provides protection against childhood infections. Its dominance in the first years of life indicates an important protective function. Streptococcus salivarius forms biofilms, produces antibacterial substances and neutralizes the pH value in the mouth. It displaces pathogenic bacteria and protects against oral diseases.
Importance of a Balanced Oral Microbiome
A healthy oral microbiome is essential for overall well-being. An imbalance can lead to periodontal disease, which in turn is linked to systemic disease. Good oral care, healthy diet and avoiding harmful habits are crucial to maintaining a healthy oral microbiome and thus promoting overall health.
