Our My Baby Biome Study: Explained

Science should be accessible. As parents, you care deeply about your baby’s health, but you shouldn’t need a PhD and a few hours to understand what the latest research means for your family. That’s why we’re breaking down Persephone’s latest study, published in Nature’s Communications Biology, into clear, simple insights so you can see what we discovered and why it matters for your baby’s gut health.

With noncommunicable diseases on the rise, there is increasing evidence that the microbiome may play a role.¹  Persephone’s My Baby Biome study was designed to evaluate what the early infant gut looks like in the United States and what that means for infant health today. The research looked at the gut microbiomes of 412 U.S. infants (aged about 1 to 3 months) with a diverse range of birth modes, feeding types, and backgrounds. This is being collected with ongoing health outcomes collected each year to understand how the foundational microbiome impacts lifelong health.

Key Findings 

• Roughly one-in-four babies had no detectable Bifidobacterium, a type of bacteria that plays a critical role in infant gut development. ³ Although the issue of missing Bifidobacterium has been characterized in other studies ³, the proportions observed here in the United States were unexpectedly high.

• Babies who did have Bifidobacterium tended to have healthier guts. This means things like having less antibiotic resistance and an increased metabolism of what is consumed by infants (such as human-milk oligosaccharides, or HMOs).

• Babies born by C-section, or who had other early-life disruptions such as antibiotics, were far more likely to fall into a “low Bifidobacterium” group. In these cases, less desirable microbes happily replaced Bifidobacterium, even going so far as to feed on their preferred food source, HMOs.

• Bifidobacterium were associated with a reduction in atopic disease risk by two years of age, with Bifidobacterium breve offering a nearly five-fold reduction in risk. 

• These findings suggest that the microbiome helps train immunity and gut health early in life and may impact the development of noncommunicable diseases, such as allergies, asthma, and eczema.

What It Means for You and Your Baby

If you’re a parent or caregiver, here’s the takeaway:

• The early months of life are a foundational window for gut and immune health. The presence (or absence) of key microbes like Bifidobacterium matters.
  

• Things like birth mode, antibiotic exposure, feeding mode and other early factors can impact how these microbes establish. The study shows that many infants today are missing these microbes compared to what we might expect based on historical populations like the Old Order Mennonites.²

Bottom Line

Bifidobacteria are missing in today’s young infants. Persephone is not the only group publishing on these global trends.³ The My Baby Biome study was designed to assess the scope of the issue in the U.S. and understand how changes in the infant microbiome may impact long term health outcomes. If you are interested in reading more, you can find our publication here: https://doi.org/10.1038/s42003-025-08274-7. Feel free to reach out to our team with any questions you may have!

*Medical Disclaimer

The information provided on this blog is for educational purposes only and is not intended as medical advice, diagnosis, or treatment. Every baby is unique, and health decisions should always be made in partnership with a qualified healthcare professional. If you have questions or concerns about your child’s health, diet, or development, please consult your pediatrician or another trusted healthcare provider before making changes.

References:

1. West, C. E., Renz, H., Jenmalm, M. C., Kozyrskyj, A. L., Allen, K. J., Vuillermin, P., et al. (2015). The gut microbiota and inflammatory noncommunicable diseases: associations and potentials for gut microbiota therapies. The Journal of Allergy and Clinical Immunology, 135(1), 3–13. https://doi.org/10.1016/j.jaci.2014.11.012.

2. Seppo, A. E., Bu, K., Jumabaeva, M., Thakar, J., Choudhury, R. A., Yonemitsu, C., et al. (2021). Infant gut microbiome is enriched with Bifidobacterium longum ssp. infantis in Old Order Mennonites with traditional farming lifestyle. Allergy, 76(11), 3489–3503. https://doi.org/10.1111/all.14877. 

3. Insel, Richard A. et al. Restoring a gut Bifidobacterium community in early infancy. Cell Host & Microbe, Volume 33, Issue 12, 2012 - 2016. https://pubmed.ncbi.nlm.nih.gov/41380667/.