When you become a parent, you become obsessed with baby poop (#realtalk). But we mamas aren’t the only ones examining baby stool. Scientists are looking into diapers too, and they don’t like what they see.

According to a new study published in the journal mSphere, baby poop isn’t the same as it was generations ago—and researchers think there may be a link between rising pH levels in dirty diapers and the rising rates of allergies and asthma.

The study was funded by Evolve BioSystems, a company that spun out from the Foods for Health Institute at the University of California to develop commercial probiotics, and it is part of a growing body of research on the connection between our gut microbiomes and our overall health.

The Center for Disease Control (CDC) is among those currently investing in and investigating applied research into protecting the health of our microbiomes, the communities made up of “bacteria, fungi, viruses, and other microbes (germs) [that] live naturally on our skin and in our gut and other places within our body.”

The CDC is worried about how antibiotics can disrupt our microbiomes, a concern shared by the scientists who studied decades worth of baby poop.

The study’s authors reviewed 14 clinical studies published between 1926 and 2017 that analyzed the pH levels in poop from 312 healthy, breastfed newborns (pH measures if something is more acidic or more alkaline; the higher the levels, the more alkaline, and the lower the pH, the more acidity). They found the average pH levels in a baby’s stool have risen from 5.0 to 6.5 over the last 100 years, indicating a significant change in infant gut microbiome.

The uptick in pH correlates with a loss of Bifidobacterium, a group of beneficial gut bacteria vital during infancy, and a rise in potentially dangerous bacteria such as E. coli and Clostridia. The researchers say this change has led to a possibly harmful gut microbiome imbalance that can impact an infant’s short- and long-term health.

“These alarming changes to the infant gut microbiome and thus, gut environment, may be due to modern medical practices like antibiotics, C-sections, and formula feeding,” says study co-author Dr. Jennifer Smilowitz, associate director of the Human Studies Research Program for the Food for Health Institute at UC Davis. “These are all potentially life-saving medical practices, but have unintended consequences on the infant gut microbiome.”

As a result, Smilowitz continues, babies are put at higher risk for health problems such as asthma, allergies, colic, eczema, diabetes and obesity because “bad” bacteria is allowed to “thrive.” In fact, a 2015 study published in the journal Allergy, Asthma & Clinical Immunologyfound that certain gut bacteria can affect a child’s likelihood of developing asthma and allergies. Research has also shown that gut bacteria may play a part in immune function and autoimmune disorders.

“The need for clinicians to have a quick and reliable method to determine Bifidobacteriumlevels in baby’s gut, and an effective way to replace the right Bifidobacterium to correct dysbiosis when detected, are the critical next steps for infant health,” she says.

One possible solution to get the good bacteria back into the next generation’s diapers is through probiotics. Evolve BioSystems discovered in a clinical trial that infants given Evivo, a probiotic containing the good bacteria B. infantis, saw an 80% reduction in E. coli and other potentially harmful bacteria. Those trial results were published last year.

Modern medical practices have changed the contents of our babies’ diapers, but science might help get that good bacteria back into them, too.