Your Baby's Gut Bacteria Could Be the Secret to Preventing Allergies and Asthma

Researchers have discovered that certain gut bacteria in babies produce a natural compound that can reduce the risk of developing food allergies, seasonal allergies, and asthma later in childhood. The breakthrough study followed 147 children from birth to age five and found that infants with specific bifidobacteria in their intestines were significantly less likely to develop these common conditions.

How Do Gut Bacteria Prevent Allergic Reactions?

The key lies in a substance called 4-hydroxyphenyl lactate (4-OH-PLA), which certain bifidobacteria naturally produce in the infant gut. When researchers tested this compound on human immune cells in the laboratory, they discovered it reduces the body's production of immunoglobulin E (IgE) antibodies by 60% without affecting other important antibodies.

IgE antibodies act as the body's "alarm molecule" for allergic reactions. When you encounter an allergen like peanuts, pollen, or dust mites, your immune system produces IgE antibodies that bind to these substances and trigger symptoms like itching, eczema, hay fever, or even anaphylaxis. Higher IgE levels mean greater allergy risk.

What Increases Your Baby's Chances of Getting These Protective Bacteria?

The research team found several natural factors that help infants acquire these beneficial bifidobacteria:

• Vaginal Birth: Children born vaginally were 14 times more likely to acquire the protective bifidobacteria from their mothers compared to those born via cesarean section
• Exclusive Breastfeeding: Babies who were exclusively breastfed had higher levels of these beneficial bacteria in their gut microbiome
• Early Social Contact: Exposure to other young children during the first months of life also contributed to increased abundance of protective bifidobacteria

"The key breakthrough is that we have now identified a specific mechanism that can suppress the development of allergic reactions in the immune system already during infancy," said Susanne Brix Pedersen, professor at DTU Bioengineering and the study's project leader.

Could This Lead to New Allergy Prevention Treatments?

The findings could revolutionize how we prevent allergies and asthma, which are among the most common chronic diseases affecting children worldwide. The research team analyzed data from three large birth cohorts across Sweden, Germany, and Australia, using genetic analyses and molecular testing to map both bacterial composition and metabolite levels in infant stool samples.

DTU has already patented the use of 4-OH-PLA for preventing and treating allergies and asthma. The researchers envision developing probiotic supplements or enriched infant formula containing these beneficial bifidobacteria or their metabolites for babies who don't naturally acquire them.

"It is remarkable that children born vaginally were 14 times more likely to acquire the bifidobacteria from their mothers," explained Rasmus Kaae Dehli, specialist in systems immunology at DTU Bioengineering. "However, our lifestyle has contributed to these bifidobacteria becoming much rarer, and it is therefore also important to look at other preventive measures."

Clinical trials are already underway at Aarhus University Hospital testing one of these beneficial bifidobacteria strains in infants. If successful, Professor Pedersen estimates a preventive strategy for young children could be available within a few years, while treatments for existing allergies and asthma would take up to ten years to reach the market.