Good Dental Health Essential in Sickle Cell Anemia, New Study Finds
Harmful bacteria more common in patients with poor oral care
Good oral health is essential in people with sickle cell anemia (SCA), according to a new study from Saudi Arabia that found that several disease-causing bacteria species — including Enterobacteriaceae — were significantly more abundant in a group of patients with poorer dental health than in those with better oral care.
“A healthy mouth has a balance of bacteria, but inadequate oral health narrows the range of bacteria, resulting in oral dysbiosis, a state in which beneficial bacteria decrease and potentially pathogenic [disease-causing] bacteria increase,” the researchers wrote.
The findings also indicated that patients with low levels of hemoglobin F — a type of hemoglobin normally produced during fetal development — had a significantly higher prevalence of harmful bacteria species than those who had higher levels of the protein.
“Our data further emphasise the importance of routine oral hygiene visits for patients with SCA,” the team wrote, adding, “This is especially important for patients with SCA and low [hemoglobin F], who have a higher probability of hospitalisation and clinical complications compared to patients with SCA and high [hemoglobin F].”
The research’s findings were reported in “Oral microbiota analyses of Saudi sickle cell anemics with dental caries,” a study published in the International Dental Journal.
Examining good versus poor dental health in SCA
Sickle cell disease (SCD) is caused by mutations in the HBB gene that lead to the production of a faulty version of hemoglobin, the protein in red blood cells that is responsible for carrying oxygen through the body. This faulty version is called hemoglobin S.
People with sickle cell anemia or SCA, the most common and often the most severe form of SCD, have two faulty gene copies encoding hemoglobin S.
Complications of dental caries or tooth decay, including acute pain, are often observed in patients with SCA — and have been associated with poor quality of life.
In a healthy mouth, different bacteria species co-exist in a balanced ratio. However, in cases of inadequate oral health, the number of beneficial bacteria decreases, while that of potentially harmful ones increases. This can lead to dental caries, which often result in cavities and other oral health problems.
“Although ample evidence indicates a causative correlation between the disruption of the oral [bacteria] and dental caries, the effect in SCA has not been investigated,” the researchers wrote.
Now, a team from the Netherlands and Saudi Arabia conducted a study to examine oral bacteria composition in people with SCA. Their aim was to compare bacteria species in patients with a high decayed, missing, and filled permanent teeth (DMTF) index — a measure of dental health — compared with others who had a low index.
In addition, they evaluated the effect of hemoglobin F levels on bacterial composition by comparing the profiles of patients with low and high levels of the protein. Fetal hemoglobin or hemoglobin F is considered a major modulator of disease severity in SCA.
This type of hemoglobin normally is found in fetuses and newborn babies, but is typically replaced by another hemoglobin variant after birth. However, hemoglobin F is more effective at transporting oxygen than its adult counterpart, and may, therefore, help to counteract the harmful effects of hemoglobin S on blood flow and oxygen transport.
In some individuals, the levels of hemoglobin F remain relatively high during childhood, and only start to decline later on in life, rather than immediately after birth.
High levels of Enterobacteriaceae bacteria found
This new study was conducted in the Eastern Province of Saudi Arabia, where the disease is highly prevalent. It included 100 patients, ages 5–12, from whom saliva was collected.
Among the patients, 27 had high dental caries — reflected by a high DMTF index of five points or more — and 73 had low dental caries, indicated by a low DMTF index of four points or fewer.
The research team identified 416 bacteria species in the patients’ samples. When analyzing their prevalence, seven were found to be significantly more abundant in patients with a high DMTF index than in those with a low index.
In addition, eight bacteria species were found to be significantly more prevalent in patients with low hemoglobin F levels compared with those with high levels of the protein.
In particular, the Enterobacteriaceae bacteria species, which have been associated with severe infections and high rates of antibiotic resistance, were found in great abundance in both patient groups, being the most significantly abundant bacteria species among those with low levels of hemoglobin F.
“It has been suggested that the presence of the Enterobacteriaceae species in the oral cavity is favoured when an individual’s immunity is compromised,” the researchers wrote, adding that “patients with SCA are immunocompromised.”
Overall, these findings indicate that Saudi SCA patients with poorer dental health and low levels of hemoglobin F have a higher predominance of harmful bacteria in their mouth.
Our data further emphasise the importance of routine oral hygiene visits for patients with SCA.
“Our results provide a valuable addition to the global microbiome reference data set in an underexamined community,” the researchers wrote, adding, “These efforts are essential and warranted given the scarcity of [bacteria composition] data in Middle Eastern populations.”
Nevertheless, a study with a large sample size evaluating how oral bacterial species can relate to dental caries in SCA patients is required, the team noted.
The researchers said their findings indicate the important of good dental health in people with sickle cell anemia, given that the bacteria species otherwise found “are thought to drive the development and progression of dental caries.”
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