Gum disease bacteria linked to esophageal cancer.
Published: Monday 29 February 2016 ________________________________________
In a new study, researchers propose for the first time that Porphyromonas gingivalis – the bacterium behind gum disease – could be a risk factor for esophageal cancer.
The researchers found levels of P. gingivalis were significantly higher in the cancerous tissue of ESCC patients than in surrounding tissue or tissue of normal controls.
The researchers, from the University of Louisville (UofL), KY, and Henan University of Science and Technology in Luoyang, China, report their findings in the journal Infectious Agents and Cancer.
According to the Centers for Disease Control and Prevention (CDC), every year, around 15,000 people in the US are diagnosed with esophageal cancer – a cancer that starts in the esophagus or gullet, the muscular tube that moves food from the throat into the stomach.
The lining of the esophagus is made of two kinds of cell, which is why there are two main types of esophageal cancer: esophageal adenocarcinoma and esophageal squamous cell carcinoma (ESCC). ESCC is more common in developing countries.
For their study, the team tested tissue from 100 patients with ESCC and 30 patients who did not have the disease (the controls).
They tested samples taken from three types of esophageal tissue: cancerous tissue, non-cancerous tissue adjacent to cancerous tissue and normal tissue from the controls.
Bacterium present in 61% of cancerous tissue samples
The team found P. gingivalis was present in 61% of cancerous tissue samples and only 12% of adjacent tissue samples. They found none in the normal tissue samples.
Co-senior author Huizhi Wang, assistant professor of oral immunology and infectious diseases at the UofL School of Dentistry, says:
“These findings provide the first direct evidence that infection could be a novel risk factor for ESCC, and may also serve as a prognostic biomarker for this type of cancer.”
He notes that if these findings are confirmed, then it could mean that eradication of a common oral bacterium could help reduce the significant number of people who develop ESCC.
Prof. Wang says should further studies actually prove that P. gingivalis causes ESCC, then the implication would be enormous, and:
“It would suggest that improving oral hygiene may reduce ESCC risk; screening for P. gingivalis in dental plaque may identify susceptible subjects; and using antibiotics or other antibacterial strategies may prevent ESCC progression.”
Trouble sleeping? The size of your tongue, tonsils could be why
Date: March 8, 2016
Source: University at Buffalo
Oversized tonsils and tongues place people at high risk for obstructive sleep apnea, a disorder in which breathing repeatedly stops and starts during sleep due to blocked upper airways, suggests a new report.
The best time to identify signs of obstructive sleep apnea may not be at night while snoozing in bed but, instead, while sitting in the dentist’s chair.
According to a new study led by University at Buffalo orthodontic researcher Thikriat Al-Jewair, dentists are in the unique position as health care professionals to pinpoint signs of obstructive sleep apnea (OSA), a disorder in which breathing repeatedly stops and starts during sleep due to blocked upper airways.
The research found that oversized tonsils and tongue indentations, which are teeth imprints along the tongue that indicate it is too large for the mouth, placed people at high risk for OSA. Obese patients were almost 10 times more likely to report OSA symptoms than non-obese patients.
Although dentists cannot diagnose the disorder, they can spot an enlarged tongue or tonsils and recommend a patient to a sleep medicine specialist.
“Dentists see into their patient’s mouths more than physicians do and the signs are easy to identify,” says Al-Jewair, clinical assistant professor in the UB School of Dental Medicine.
Analyzing 200 patients at the dental clinics at the University of Dammam’s College of Dentistry in the Kingdom of Saudi Arabia, the researchers tested participants for OSA using the Berlin Questionnaire, a validated assessment used to screen people for OSA.
Participants were then screened for potential risk factors of OSA, such as weight, neck circumference, blood pressure, and size of the tongue, tonsils and uvula- the tissue that hangs in the back of the throat.
The results found that 23 percent of participants were at risk for OSA, of which nearly 80 percent were male.
The factors most common among people who were identified as high risk for OSA on the Berlin Questionnaire — along with obesity — were large tonsils, tongue indentations.
Could a probiotic pill prevent dental cavities?
Published: Friday 11 March 2016
Dealing with cavities could one day be as simple as taking a supplement to keep unwanted bacteria in check, according to findings published in Applied and Environmental Microbiology.
Incorporating A12 into probiotic treatment could reduce the risk of cavities.
In 2011-2012, dental cavities, or caries, affected 91% of adults aged 20-64 years, exacerbated by consumption of sugary foods and drink, lack of oral hygiene and not paying regular visits to the dentist.
For the mouth to stay healthy, pH levels must be neutral. Too much acid can cause dental cavities or other disorders.
Acid in the mouth causes bacteria on the teeth to create more acid, and acid dissolves the teeth.
Researchers at the University of Florida (UF) College of Dentistry, led by Robert Burne, PhD, and Marcelle Nascimento, PhD, wanted to know what causes high pH.
Their search revealed a new strain of bacteria that could keep bad bacteria under control, and pave the way to using probiotics to prevent cavities.
Keeping a balanced pH in the mouth
Previous research by the same authors has found that two main compounds are broken down into ammonia, and this helps to neutralize acid in the mouth.
The two compounds are urea, which everyone secretes in the mouth, and arginine, an amino acid. The researchers already knew that people who had few or no cavities were better at breaking down arginine than those with cavities.
They knew that bacteria were responsible for breaking down these compounds, but did not know which bacteria do this best, or how this activity prevents cavities.
Part of the answer is a previously unidentified strain of Streptococcus, currently called A12.
They hope to use the findings to develop a screening tool for people with a higher risk of developing cavities, alongside other factors, such as diet and oral hygiene habits.
Nascimento says that if they can confirm that people with a higher level of A12 develop fewer cavities, A12 could be used to measure for cavity risk.
‘Good’ bacteria to fight the bad
Burne explains that, just as we might use a probiotic approach to the gut to promote health, a similar strategy could be effective for the mouth.
“You would implant this probiotic in a healthy child or adult who might be at risk for developing cavities. However many times you have to do that, once in a lifetime or once a week, the idea is that you could prevent a decline in oral health by populating the patient with natural beneficial organisms.”
The fact that A12 helps to neutralize acid by metabolizing arginine was not the only discovery. The authors also found that A12 often kills Streptococcus mutans, an especially harmful kind ofl bacteria.
Even when A12 did not kill S. mutans, it hindered it from causing disease by disrupting the processes.
Burne points out that growing A12 and S. mutans together reduced the ability of the bacterium to develop properly or to make biofilms, also known as dental plaque.
S. mutans metabolizes sugar into lactic acid, and this contributes to the acidic conditions that form cavities.
While the development of an effective oral probiotic is still a long way off, A12 looks a promising candidate.