Scientists believe that they have discovered a way to determine the risks of having a premature baby by studying the bacterial community inside the reproductive tact of the mother — and the results weren’t what they were expecting.

The microbiome of our bodies includes trillions of microbes that are essential to our health, and if they get out of balance, significant health problems can result — and researchers at Stanford University believe they’ve found the pattern of vaginal bacteria that separates mothers who are likely to give birth prematurely from those who have a low risk, according to an Associated Press report.

The researchers followed the pregnancies of 49 healthy women, closely tracking their microbial makeup. They found that at-risk mothers tended to have low levels of the lactobacillus bacteria, which has long been believed to be necessary to both vaginal and intestinal health. It’s a new lead in scientists’ effort to pinpoint risk factors for such a phenomenon, and seems to suggest that the microbiome is indeed a very important factor when it comes to premature birth.

More studies will be needed to confirm that there is indeed a link, as well as to determine if the problem is not enough protective bugs or if there is a harmful bacteria taking its place. But it certainly gives scientists a new lead.

It may result in treatments that could help at-risk mothers reduce their likelihood of giving birth prematurely. A probiotic regimen could be prescribed, or other methods to boost the microbial neighborhood in these women, according to the report.

Scientists were surprised after finding that all of the participants in the study seemed to have a different and more diverse collection of microbes in the vagina following the birth, no matter if their birth was premature or not.

The findings were published in the Proceedings of the National Academy of Sciences.