Levels of vaginal bacteria could be a potential indicator of preterm labor, finds a new study, helping doctors to assess if a woman is at high risk for early delivery. The bacteria in question was a strain called Lactobacillus, which when found in low numbers was linked to an increased likelihood of premature birth. A similar result was observed in women who were missing two other strains of bacteria known as Gardnerella and Ureaplasma, which seemed to increase the risk even more. This new evidence has left researchers wondering if the absence of this bacteria is causing the preterm labor, or if it is indicative of greater issues. The study has been published in the journal Proceedings of the National Academy of Sciences.

For their study, researchers from Stanford University analyzed the bacteria levels in 49 women, over the age of 18, both while they were pregnant and after they gave birth. To see if bacteria from any other parts of the body impacted full-term labor, researchers examined levels from the vagina, gums, stool, and saliva. Out of their total pool of participants, 15 gave birth to children preterm.

Just as they thought, levels of Lactobacillus seemed to drop within the vagina right after delivery, and instead were replaced by a diverse community of many other forms of bacteria that lasted in the environment for up to a year later. Interestingly enough, researchers found that vaginal bacteria became more like gut bacteria around the time of delivery, but they are not sure why.

As of now, the team is still not sure if the lack of bacteria is causing preterm labor, or if other issues associated with bacteria levels are causing the issue. They believe there is a chance that missing bacteria could affect the delivery of another pregnancy that happens right after the issue is observed, but researchers believe they must delve into the topic more to find out.

But aside from possibly determining premature labor, Lactobacillus happens to be essential to pioneering other human health alternatives. In a 2014 study, a team of researchers from the University of California, San Francisco, endeavored to take this common vaginal bacteria and put it to use as an antibiotic. Known to protect the organ from outside invaders that could inhibit reproduction, researchers felt the specific strain Lactobacillus gasseri could do the same for the rest of the body. Their subsequent antibiotic, which they called Lactocilin shows promise in destroying dangerous pathogens, while leaving vital microbes unharmed.

In another study, a different breed of Lactobacillus was used to help cure severe peanut allergies in children. After giving 60 children with the allergy a dose of a probiotic containing Lactobacillus rhamnosus mixed with a peanut protein over 18 months, researchers observed that 80 percent of children no longer had severe reactions.

Even though they could not determine causality, the team is hopeful that Lactobacillus levels might aid in the 11 percent of preterm pregnancies that happen each year worldwide. According to Dr. David Relman, professor at Stanford and author of the study, this could be the start of a new test to determine whether a woman is at a higher risk for early labor. “The first possible application is to use high-risk features in the vaginal microbiome as a marker, as a diagnostic tool to identify women early in pregnancy who are destined to have a higher risk of preterm labor,” Relman told Live Science.

The team hopes to conduct future research to find out what the exact relationship is between this bacteria, and delivery.

Source: Relman D, DiGiulio D, Callahan B, et al. Temporal and spatial variation of the human microbiota during pregnancy. PNAS. 2015.

Tang M, Ponsonby A, Orsini F, Tey D, Robinson M, Su E. Administration of a probiotic with peanut oral immunotherapy: A randomized trial. The Journal of Allergy and Clinical Immunology. 2015.

Fischbach MA, Donia MS, Cimermancic P, et al. A Systematic Analysis of Biosynthetic Gene Clusters in the Human Microbiome Reveals a Common Family of Antibiotics. Cell. 2014.