Maternal oral health. (Image: AI Generated)
A new study suggests that microbial transmission from mother to fetus through the mouth as well as alterations in oral organisms in the mother during gestation may contribute to mother's immune system. A team of scientist determined that the oral microbiome differs significantly during pregnancy and that certain of these shifts in the bacteria were correlated with specific immune cells that play a role in the defense of the mother and baby. These findings offer new clues for understanding how pregnancy affects women's oral health and the role it might play in oral health.
During pregnancy there are major hormonal and immune changes that help support the growth of the fetus. These changes may also impact other microbiotas in the body such as the oral microbiome which is a vast and intricate community of bacteria, fungi and microbes in the mouth. An earlier study indicated that there may be an increased risk for gum inflammation, bleeding gums and oral health problems which could happen during this time. But the biological reasons for these changes are not well understood.
To explore this correlation, researchers examined the oral microbiota, metabolites in saliva, gut microbiota and immune profiles of 25 women at term pregnancy and those of 25 women who are not pregnant. Interestingly, the result published in the journal Nature's npj Biofilms and Microbiomesrevealed important links between the presence of 'oral' bacterial species in pregnancy and specific immune cell types.
The researchers identified several bacteria species that increased in abundance during pregnancy were strongly associated with a type of immune cell known as 'natural killer' (NK) which has a critical role in immune defence and helps maintain pregnancy.
Among the findings, Streptococcus anginosus and Prevotella denticola were positively associated with overall natural killer cell ratio. Additionally Prevotella histicola and Prevotella micans were positively correlated with CD56brightCD16 a natural killer cells which are a specialised type of cells that regulate immune response.
The study indicates that changes in the oral bacteria population in the mother during pregnancy could be linked to wider immune changes in her body. There is no obvious link between salivary metabolites and the salivary function. They also investigated whether oral microbiota changes and immune system alterations could be bridged by fatty acids found in saliva.
But there was little evidence for this theory in the mediation analysis. The outcome showed that there was little evidence that changes in oral microbes were directly linked to changes in systemic immune responses in pregnancy via salivary fatty acids.
One of the interesting data points was the discovery of some microbes that seemed to be able to be transmitted from the mouth to the gut. The potential microbes transmitted orally-gut transmitted microbes were correlated with increased levels of CD56brightCD16 a natural killer cells and with increased overall NK cell ratios. Simultenously they were inversely correlated with T helper Type 1 cells and the T helper Type 1 (Th1): T helper Type 2 (Th2) ratio, suggesting a possible relationship between microbial mobility and immune regulation during pregnancy.
Why tending your oral microbiome is the secret to a long, healthy life https://t.co/yL3fYjDKFW
New Scientist (@newscientist) January 2, 2024
Good oral hygiene practices during pregnancy include regular brushing, flossing and routine dental visits. Gums may become more sensitive and prone to inflammation during this time so it's essential to take care of your mouth.
The study doesn't directly indicate that oral bacteria trigger immune changes but rather that there's a complex relationship between the oral microbiome and gut microbes and maternal immunity. The researchers said that larger and more diverse studies are needed to validate their findings and to determine how the changes in microbes during pregnancy could affect the health of the mother and child.
Disclaimer: This content is for informational purposes only and does not replace professional medical advice. Always consult a qualified healthcare provider for pregnancy-related oral health concerns.
