AUSTIN, Texas, Sept. 03, 2025 (GLOBE NEWSWIRE) — A new study found that babies born by C-section had 83% lower odds of developing eczema when their families participated in a 6-month gut health support program, compared to those who didn’t receive the intervention.
The research, published today in the medical journal Pediatric Allergy and Immunology, showed that just 6% of babies in the intervention group developed eczema, compared to 29% in the control group. The study highlights how targeted gut health interventions during a baby’s first months may help reduce risks of immune-related conditions.
Study Details
The randomized controlled trial followed 54 full-term babies born by C-section over six months. Families were randomly divided into two groups: 25 babies received personalized gut health support from Tiny Health, while 29 served as controls without the program.
Parents in both groups collected stool samples from their baby’s diaper at the beginning of the study and again after three months. The intervention program included a detailed microbiome analysis, personalized nutrition and probiotics guidance, and coaching from microbiome specialists. Researchers tracked changes in gut bacteria and surveyed parents about their babies’ health outcomes.
Why C-Section Babies Face Higher Risks
About one in three U.S. babies are born by C-section annually. Unlike vaginal birth, C-section birth means babies may miss out on beneficial bacteria normally transferred from mother to child during birth. Instead, their guts are often colonized by hospital-associated bacteria that can be antibiotic-resistant and related to gut inflammation later in life.
Research shows these early differences in the gut microbiome — the community of bacteria and other microbes living in the digestive system — can persist for years and are associated with higher microbiome risks of eczema, allergies, asthma, and even conditions like obesity and type 1 diabetes.
“Our data show that early microbiome support can shift gut bacterial patterns away from those associated with eczema and allergies,” said Dr. Kimberley Sukhum, Head of Science at Tiny Health. “The first 1,000 days are a critical window of opportunity, when the gut microbiome can be most effectively shaped for lifelong immune health.”
Key Findings Beyond Eczema
By the study’s end, babies who received the intervention showed several positive changes:
- Higher levels of beneficial bacteria: Bifidobacterium reached a median relative abundance of 82% (a 51% increase from the first sample) compared with 55% in the control group
- Better nutrient processing: More genes in their microbiome for digesting HMOs, which are beneficial complex sugars in breastmilk
- Gut bacteria more similar to vaginal birth: Lower “C-section index” scores, meaning their gut bacteria composition trended toward those of vaginally-born babies
What This Means for Parents
For the estimated 1.2 million C-section babies born in the U.S. each year, these findings suggest early gut health interventions may significantly reduce chronic disease risk.
More than 20 million children in the U.S. now live with a diagnosed allergic condition. Eczema alone affects up to 1 in 5 infants and is the first step in the atopic march — the progression of allergic diseases from eczema to food allergies, hay fever, and eventually asthma. By addressing gut imbalances early, parents can potentially disrupt or reverse this progression.
“As a mom of a C-section baby who struggled with eczema and food sensitivities, I wanted to turn what I’d read about course-correcting the infant gut into a reality for myself and other parents,” said Cheryl Sew Hoy, CEO and Founder of Tiny Health. “Research now shows that the first 1,000 days can profoundly shape a child’s lifelong health, and growing awareness among both parents and medical professionals means families can benefit from these insights much earlier.”
Broader Health Impact
According to the CDC, over 100 million Americans have eczema, food allergies, or hay fever, and 28 million have asthma. Annual costs related to asthma alone surpass $81 Billion. This study reinforces the microbiome’s role in immune health – and offers a proactive, evidence-based path to prevention to reduce national health and economic burdens.
Research Methodology, Limitations, and Next Steps
This randomized controlled trial ran from August 2023 to May 2024, and included healthy, full-term infants born by C-section and under 3 months old at enrollment. Parents sent in their baby’s stool samples at the beginning and after three months and completed health surveys at multiple time points to track outcomes. Researchers used advanced shotgun metagenomic sequencing to analyze gut bacteria composition and function.
The research was conducted as an open-label trial, meaning participants knew whether they were receiving the intervention. No adverse effects were reported in either group during the study period.
Despite limitations including a focused sample size and short-term follow-up, this preliminary study’s statistically significant results are highly encouraging, with Tiny Health already advancing larger-scale studies to build upon these promising outcomes.
About Tiny Health
Tiny Health is the first and only precision microbiome wellness platform designed for lifelong health — from the first 1,000 days to the last. Founded in 2020 and built by microbiome scientists and physicians, Tiny Health uses shotgun metagenomics to deliver strain-level and functional microbiome insights. Its clinical-grade gut and vaginal tests help families and practitioners address the root causes of many chronic conditions with evidence-based interventions. Trusted by over 80,000 people, Tiny Health is redefining the microbiome as a cornerstone of personalized wellness. Learn more at tinyhealth.com.
Media Contact:
Hannah Goering
press@tinyhealth.com
Study Citation: Nieto PA, Nakama C, Trachsel J, et al. Improving immune-related health outcomes post-cesarean birth with a gut microbiome-based program: A randomized controlled trial. Pediatr Allergy Immunol. 2025; 36:e70182. doi:10.1111/pai.70182
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