An article was recently published in “Science Translational Medicine” entitled “The Placenta Harbors a Unique Microbiome”. The researchers collected placentas from 320 subjects and analyzed DNA to accurately identify which strains of microbial life were present.
In the past, placentas and the intrauterine birth environment were thought to be sterile sites. This study shows that is simply not true. The researchers found microbiota from the Firmicutes, Tenericutes, Proteobacteria, Bacteroidetes and Fusobacteria phyla. But the most interesting piece of information is where did the placenta bacteria come from?
Bacteria found in the placenta have to come from somewhere and you would think, geographically speaking, that they would most likely come from the vaginal tract. Not true. Not true at all! Bacteria found in the placenta are most similar to bacteria found in the mouth. Read that sentence again. Lots of research demonstrates the link between pre-term (<37 weeks) birth and periodontal disease (i.e. gingivitis), but this paper provides insight into a possible mechanism. It is possible that bacteria in the placenta are “seeded” from bacteria in the mouth. Additionally, factors that were NOT associated with clustering of the placental microbiome included:
- GBS infection
- Infant gender
- Maternal BMI and,
- Route of delivery (c-section vs. vaginal)
That information alone is highly valuable. It would seem that the critical time period to ensure a “microbially” healthy placenta is prior to conception and placental formation/implantation. This places attention on the importance of patient education regarding healthy dental hygiene practices and the importance of these practices during the child bearing years, especially prior to pregnancy. If something as simple as brushing and flossing twice a day can help prevent preterm labour, every health care practitioner needs to have this discussion with their patients. Who would have guessed that your oral microbial population would be so closely linked with a developing placenta.