Abstract
This paper focuses on 3 main negative effects of Fusobacterium nucleatum on halitosis. Halitosis, which is known as bad breath, is a common disease among people. Fusobacterium nucleatum produces VSCs, such as hydrogen sulfide and methyl mercaptan which cause halitosis. Another effect of Fusobacterium nucleatum is it triggers periodontal disease to induce halitosis. The microbe also collaborates with other bacteria like Porphyromonas gingivalis and Capnocytophaga ochracea to leave a negative influence on bad breath. It is important to recognize this issue in order to further examine and create future treatments.
Introduction
Halitosis, which is also called bad breath, is a condition in which an obnoxious smell is exhaled into the air from our mouth. More than 50% of the general population have this condition (Nachnani, 2011, p. 23). Halitosis could induce embarrassment between people and could impact people socially and mentally by lowering self-esteem, causing anxiety and overall, lowering quality of life (Briceag et al., 2023). Halitosis is caused by odor-causing bacteria. Those bacteria produce volatile sulfur compounds (VSCs), such as hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, and methyl mercaptan (Hampelska et al., 2020). There are many bacteria that affect halitosis. One of the most significant bacteria is Fusobacterium nucleatum. Fusobacterium nucleatum is a Gram-negative anaerobic bacteria that plays a huge role in many periodontal diseases. It is one of the most overflowing bacteria in both healthy and diseased individuals’ mouths (Han 2015). Fusobacterium nucleatum is known for its negative impact on halitosis, which is producing VSCs, triggering periodontal disease, and making synergistic effects with other bacteria to cause halitosis. It is important for the medical field to acknowledge the Fusobacterium nucleatum’s effect on halitosis and investigate more on this topic in order to find more efficient ways to treat diseases.
Review of Literature
In the article, Basic et al. (2017), researchers examined H₂S production of bacterial strains that were correlated with periodontal diseases. They focused on mostly Fusobacterium species. They constructed a study by using cell extracts and using in-gel activity assay in order to determine the enzyme’s activity. The research found out that Fusobacterium species including Fusobacterium nucleatum produces VSC by the gels having brownish bands. H₂S is one of the major VSCs that contributes to halitosis and it is important to know if the Fusobacterium nucleatum is responsible for producing volatile sulfur compounds.
In the paper, Yang et al, (2014) investigators executed an in-depth study about connection between periodontal inflammation and bacteria, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Fusobacterium nucleatum. They collected 77 subgingival plaque sameples from 35 adolescents. Those subgingival plaques were categorized by their conditions and periodontal health. Researchers used Real-time PCR to measure the numbers of each bacteria. They found that the number of bacteria including Fusobacterium nucleatum in the moderate and severe gingivitis group were notably higher compared to the mild gingivitis group. This evidence tells that Fusobacterium nucleatum affects periodontal disease. Periodontal diseases are associated with halitosis because out of 823 participants in the study who suffered from halitosis, 102 of them had gingivitis and 721 had periodontitis (Takeuchi et., al 2010). Therefore, this supports the statement of Fusobacterium affecting periodontal disease to influence halitosis.
In the study of Saito et al, (2008), they investigated the role of Fusobacterium nucleatum on Porphyromonas gingivalis’s ability to invade host cells such as human gingival epithelial and aortic endothelial cells. The study was constructed by adding Ca9-22, which is the cell line of epithelial cells, to a polymicrobial sample (P. gingivalis mixed with F. nucleatum) and monomicrobial sample (only P. gingivalis). The study showed that F. nucleatum enhances the invasion of host cells by P. gingivalis. Invasion of host cells is unpleasant for halitosis because the invasion contributes to periodontal diseases (Lamont et al., 1995) which could induce halitosis (Takeuchi et., al 2010).
Producing Volatile Sulfur Compounds
Firstly, Fusobacterium nucleatum has a negative effect on halitosis by producing volatile sulfur compounds. One of the main VSCs that induce halitosis are hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, and methyl mercaptan (Hampelska et al., 2020). A study result from a recent investigation shows that Fusobacterium nucleatum was detected to have enzymes that produced H₂S (Basic et al., 2017). The bacterium was shown to have enzymes that produce hydrogen sulfide which is one of the main contributors of halitosis. By F. nucleatum directly causing halitosis, this clearly indicates that the bacterium has a bad impact on halitosis. Also, a study shows that Fusobacterium nucleatum contains an enzyme, METase, which produces methyl mercaptan by going through an enzymatic degradation process with L-methionine (Yoshimura et al., 2002). Not only hydrogen sulfide, but the bacterium generates other VSCs like methyl mercaptan with the help of L-methionine to trigger halitosis.
Impacting Periodontal Diseases
Next, Fusobacterium nucleatum directly affects periodontal diseases which influences halitosis. Periodontal disease is a disease that affects the gum. Symptoms for periodontal disease could be swollen, red or bleeding gum, sensitive teeth, bad breath, etc. In a research by Takeuchi et al. (2010) they gathered 823 halitosis patients and found out that 102 of them were diagnosed with gingivitis and the rest of 721 people with periodontitis. This clearly shows that halitosis is linked to periodontal diseases because all of the participants with halitosis have periodontal disease. A study revealed that the quantity of Fusobacterium nucleatum in moderate and severe gingivitis groups was considerably higher than in the mild group (Yang et al., 2014). If there is a bigger amount of F. nucleatum in the more serious gingivitis, this implies that F. nucleatum may be correlated in the development of periodontal disease. Severe periodontal disease will induce bad breath, thus F. nucleatum generates a bad effect on halitosis through impacting periodontal disease.
Making Synergistic Effects
Lastly, Fusobacterium nucleatum makes an amplified effect with other bacteria to trigger halitosis. First of all, Porphyromonas gingivalis is a bacterium that is Gram-negative anaerobic and causes many oral diseases including halitosis and periodontal diseases (How et al., 2016). An investigation found that F. nucleatum elevates Porphyromonas gingivalis’s ability to invade in human gingival epithelial cells (Saito et al., 2008). Invasion of gingival epithelial cells by P. gingivalis is significant in periodontal diseases (Lamont et al., 1995). John Hopkins presented that bad breath is one of the symptoms for periodontal diseases (Halitosis (Bad Breath)). This indicates that P. gingivalis invasion in gingival epithelial cells could be the source of the rise of halitosis. If F. nucleatum enhances the ability for P. gingivalis to invade in the cells, this could aggravate the periodontal diseases which could worsen the bad breath of the patient. Another example of F. nucleatum making synergistic effects is that it impacts the formation of biofilm with Capnocytophaga ochracea. Capnocytophaga ochracea is a gram-negative bacterium that is known for inducing periodontal disease by forming dental plaques (Okuda et al., 2012). Okuda et al. (2012) found that the amount of biofilm formation by the co-culture of F. nucleatum and C. ochracea was significantly higher than the individual effect. Increase in biofilm formation will eventually lead to worse halitosis by having serious periodontal disease. Therefore, F. nucleatum leaves a critical impact on halitosis by enhancing other bacteria.
Conclusion
Overall, the findings implies that the Fusobacterium nucleatum negatively affects halitosis by encouraging the production of volatile sulfur compounds, initiating periodontal disease, and generating a synergistic effect with other bacteria. F. nucleatum produces hydrogen sulfide that is one of the VSCs (Basic et al., 2017). F. nucleatum contributes to the progression of periodontal disease (Yang et al., 2014) that causes halitosis (Halitosis (Bad Breath)). F. nucleatum works with Capnocytophaga ochracea and Porphyromonas gingivalis and lead to more serious halitosis. The purpose of this paper was to acknowledge different effects of Fusobacterium nucleatum on halitosis and how we can apply it to future dental fields. Even though there are many treatments for halitosis, still many people have it. We have to deeply dig into and question the origin of halitosis and develop and investigate new treatments.
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