What Microorganisms Naturally Live in the Mouth?

Over 700 bacterial species co-inhabit healthy human mouth. These species exist at diverse locations in the mouth including hard palate, soft palate, teeth, tongue, and even tonsillar area.
Bacteria in Mouth
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What are Commensals of the Oral Cavity?

Most of the microorganisms that inhabit the oral cavity live in a symbiotic relationship. symbiosis means where both the host and guest coexist mutually for the benefit of each other. Commensals of the oral cavity keep a close watch on the growth of species which may pose damage to homo health. They prevent the attachment of microorganisms which can stick to the mucous membrane or tooth surfaces.

broadly these microorganisms belong to Streptococcus, Eubacteria, Fusobacterium, Capnocytophaga, Eubacteria, Staphylococcus, Eikenella, Porphyromona, Leptotrichia, Prevotella, Peptostreptococcus, Treponema, Actinomyces genus .
Some bacteria like Streptococcus, Granulicatella, Gemella, and Veillonella are amongst the prevailing microorganism of the oral cavity ; however, the majority of bacteria are denotative to sealed sites. Around 20 to 30 divers species were found at a specific site and the proportion varies from 34 to 72 at different oral locations .
Understanding these oral floras can help in assessing assorted dental diseases like gingivitis and periodontal disease which account for the most frequent bacterial infections in the human torso .
More importantly, these microorganisms can even result in serious systemic infections like bacterial endocarditis, preterm british labour party, pneumonia, and cardiovascular diseases .

What is a dental biofilm and its adverse effect on dental health?

Dental biofilm is the first gear sign of bode dental problems. Microorganisms salute in the oral pit human body a layer on the oral surfaces. once a single layer is formed, these microorganisms start pilling up and form multiple layers which result in the formation of a multicellular matrix. Microscopic evaluation of these biofilms indicated that streptococcus accounts for approximately 80 percentage of this colonization .
soon after establishing multilayered biofilms streptococcus establish adhesions on their surfaces. These adhesions are made of proteins and antigens. Besides streptococcus, respective early microorganisms can besides form biofilms at varied sites .
The oral microbiome is susceptible to frequent disruptions caused by the host. routine oral hygiene practices can disturb these biofilms. however, over some time these microorganisms do survive in the presence of assorted inhibitory actions like brush, floss, chew of food, and swishing with oral disinfectants .

Which diseases are associated with oral microbiota?

Biofilms present in the oral cavity are essential for the sustenance of good oral health but an increase in the volume and complexities of these biofilms can result in diseases like gingivitis and Periodontitis.

Biofilms are chiefly composed of Gram-positive anaerobic bacteria like Streptococcus anginosus and A.naeslundii ; however, unhygienic conditions can dwell gram-negative bacteria like Porphyromonas spp., Treponema denticola, Campylobacter spp, and A. actinomycetemcomitans .
Studies have highlighted that if dental hygiene is not maintained these gram-negative bacteria can infect other organs. For case, bacterial endocarditis is one such condition that can affect the human center. Besides this, bad breath, infection of the dental roots, and actinomycosis are besides listed as some of the other concerns by these biofilms .
Maintaining adept oral hygiene is the spinal column of prevention of many diseases. Though not always but complex dental treatments can even transport these bacteria to the bloodstream, vital organs like lungs, kidneys, and brain .
research has shown a close up association between periodontic diseases and diseases of the respiratory arrangement. oral microbiota can act as a storehouse of respective respiratory pathogens specially in patients admitted to intensive manage units. regular swishing with oral disinfectants like chlorhexidine and antiseptic solutions can ward off these bacteria .
Fungal infections in the oral cavity can be a resultant role of the growth of fungal biofilms. C. Albicans are naturally occurring fungi in the oral cavity but in the presence of unhygienic conditions, it cursorily multiplies and grows particularly on the unvoiced surfaces like dentures .
One late research conducted at Harvard University has even indicated that one oral bacteria named P.gingivalis can cause dangerous health concerns like Alzheimer ’ sulfur disease .
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Can probiotics help in reducing the overproduction of oral microorganisms?

Over the past few years, probiotics have shown capital benefits in aiding good health, but less is known about the impingement of inhalation of probiotics on oral health. Due to the egress of antibiotic-resistant bacteria, probiotic-based dental products are becoming popular .
One such sketch was conducted to assess the effect of probiotics on oral health. The results revealed that probiotics can help in neutralizing the highly acidic environment of the oral pit and thereby, prevents the activity of cariogenic bacteria .
Results besides reflected that patients suffering from alveolar consonant concerns like gingivitis and periodontal disease showed tag improvement in their chewing gum health post chewing probiotic-based chew gums. Swishing the mouthpiece with probiotic-based mouthwashes prevented the growth of sulfur-based bacteria resulting in an odor-free breath .


  • Harvard University. (2019). Oral bacteria may be responsible for Alzheimer’s disease sitn.hms.harvard.edu/…/
  • Avila Maria et al. (2009) The Oral Microbiota: Living with a Permanent Guest https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2768665/
  • PD Marsh et al (2006) The oral microflora–friend or foe? Can we decide? https://www.ncbi.nlm.nih.gov/pubmed/16972398
  • Mysak. Jaroslav, et al. (2014) Porphyromonas gingivalis: Major Periodontopathic Pathogen Overview. Journal of immunology research. https://doi.org/10.1155/2014/476068www.hindawi.com/…/
  • Kumar anil et al (2017) Role of Microbes in Human Health www.longdom.org/…/…-microbes-in-human-health-2471-9315-1000131.pdf
  • Hulick Kathryn (2018). Science News for Studentswww.sciencenewsforstudents.org/…/newly-discovered-microbe-keeps-teeth-healthy
  • Aas. A. Jørn et al (2005). Defining the Normal Bacterial Flora of the Oral Cavity. Journal of Clinical Microbiology doi: 10.1128/JCM.43.11.5721-5732.2005

Further Reading

informant : https://nutritionline.net
Category : Healthy