Nearly one in four infants lacks enough healthy gut bacteria essential for training their immune systems, putting them at greater risk of developing non-communicable diseases (NCDs) such as allergies, asthma, and eczema by age 2.
Bifidobacteria are among the first group of good bacteria to colonize the human gut, and their presence has been linked to positive health outcomes for the host, including protection against metabolic diseases, gastrointestinal tract infections, and inflammation.
A recent study published in Communications Biology analyzed the gut microbiomes of 412 infants, selected to represent the diverse demographics of the U.S, and found a widespread deficit of Bifidobacteria in infants. Long-term health data from the infants suggested that a lack of detectable Bifidobacteria in infants may contribute to the development of atopy, a genetic predisposition to developing allergic diseases.
Global estimates suggest that up to 40% of the population has some form of allergy to substances present in the environment—pollen, dust, mites, or animal dander. The last few decades have also witnessed a growing prevalence of allergic conditions among children, ranging from seasonal allergies with mild symptoms, such as a runny nose, sneezing, and itchy eyes, to severe eczema and life-threatening food allergies that can send someone into an anaphylactic shock.
A baby’s mode of delivery (C-section or vaginal birth), whether they were breastfed or formula-fed, and exposure to antibiotics can shape the diversity of their gut microbiome, a factor that has been linked to health issues later in life, including allergies, autoimmune diseases, obesity. Previous studies in the U.S. looking at gut bacteria in babies were mostly small and didn’t include data representative of the diverse infant demographic.
To fill in the gap, the researchers designed the My Baby Biome study, a seven-year longitudinal investigation that involved nationally representative data of both the infant gut microbiome and the compounds produced by the metabolic activities of the microbes.
They also found that microbiomes rich in Bifidobacterium had fewer antimicrobial-resistant and disease-causing genes, along with more beneficial metabolic profiles.
The researchers highlight that while the term dysbiosis or imbalance in the microbiome is still up for debate, the strong correlation between microbiome composition and infant health suggests that the absence of these key Bifidobacterium strains represents a true dysbiosis in early life.
Written for you by our author Sanjukta Mondal,
edited by Stephanie Baum, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive.
If this reporting matters to you,
please consider a donation (especially monthly).
You’ll get an ad-free account as a thank-you.
More information:
John B. Jarman et al, Bifidobacterium deficit in United States infants drives prevalent gut dysbiosis, Communications Biology (2025). DOI: 10.1038/s42003-025-08274-7
© 2025 Science X Network
Citation:
Missing beneficial bacteria in infant guts linked to rising asthma and allergy cases (2025, July 4)
retrieved 4 July 2025
from https://medicalxpress.com/news/2025-07-beneficial-bacteria-infant-guts-linked.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
