We often think about gut health when our children experience constipation, bloating or tummy discomfort. But what if the bacteria living in their gut are also playing a role in how their immune system develops?
Emerging research suggests that the gut microbiome, the community of microorganisms living in our digestive system, may have a much bigger influence on children’s health than we previously realised.
In particular, scientists are increasingly interested in how the development of a baby’s gut microbiome during the early years of life may be linked to the risk of developing allergies, eczema and asthma.
So, could your child’s gut health be connected to their allergy risk? Here’s what the research tells us.
1. Your child’s gut is home to trillions of microorganisms
The gut is not simply where food gets digested. It is home to trillions of microorganisms, including bacteria, viruses and fungi, collectively known as the gut microbiome.
These microorganisms help break down food, produce useful substances and interact with the body’s immune system.
One of their most important roles is helping the immune system learn how to respond to different things it encounters.
As children grow, their immune systems need to learn to recognise harmful threats, such as certain disease-causing organisms, while learning not to overreact to harmless substances, including everyday foods and environmental materials.
This ability to tolerate harmless substances is known as immune tolerance.
Researchers believe that gut bacteria help support this learning process, which may have implications for the development of allergic conditions.
2. The first few years of life may be an important window for immune development
A baby’s gut microbiome begins developing early in life and changes significantly throughout infancy and childhood.
During this period, the types and balance of microorganisms in the gut are influenced by various factors, including birth, feeding, diet, antibiotic exposure and the surrounding environment.
This is also a time when the immune system is developing rapidly.
A 2025 review published in Mucosal Immunology, titled How the Early Life Microbiome Shapes Immune Programming in Childhood Asthma and Allergies, explored the relationship between early gut microbiome development and childhood allergic diseases.
The researchers highlighted that the proper development and composition of the gut microbiome may play an important role in immune system maturation.
In other words, the bacteria living in a baby’s gut may help shape how their immune system responds to the world around them as they grow.
This is one reason scientists are paying closer attention to the early years, rather than looking at gut health only when digestive problems appear.
3. What does gut bacteria have to do with allergies?
Allergies happen when the immune system reacts to substances that are usually harmless, such as certain foods, pollen or dust mites.
Scientists believe that the gut microbiome may influence this process by helping regulate immune responses and supporting immune tolerance.
When the gut microbiome develops differently or becomes less balanced, this may affect how the immune system responds to certain substances.
A systematic review published in the Journal of Asthma in 2024 examined 5,319 participants across 27 studies investigating maternal and infant gut microbiomes and childhood allergic diseases.
The review found associations between differences in gut bacteria and allergic conditions, including asthma, eczema and dermatitis.
Some interesting findings included:
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Bifidobacterium: Lower levels of this bacterial group were associated with a higher risk of allergic conditions.
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Lachnospira: Lower levels were also associated with greater allergy risk.
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Roseburia and Flavonifractor: Higher levels of these bacteria were associated with a lower risk of allergies.
These findings suggest that the composition of a child’s gut microbiome may be connected to how their immune system develops.
However, it is important to understand that these are associations. They do not prove that having lower levels of a particular bacterium directly causes a child to develop allergies.
4. What can influence your baby’s gut microbiome?
A baby’s gut microbiome does not develop in isolation. Several factors during pregnancy, birth and early childhood can influence the types of microorganisms that establish themselves in the gut.
Some of the factors researchers are studying include:
Birth and delivery
The mode of delivery can influence a baby’s early microbial exposures. Babies born via caesarean section may develop different early gut microbiome patterns compared with babies born vaginally. However, this does not mean that babies born via C-section will inevitably develop allergies.
Breastfeeding and infant feeding
Breast milk contains components that support the development of beneficial gut bacteria. In particular, human milk oligosaccharides (HMOs) help nourish certain bacteria, including Bifidobacterium.
This is one of the reasons breastfeeding and infant gut microbiome development are frequently studied together.
Antibiotic exposure
Antibiotics are important medicines for treating bacterial infections, but they can also affect the balance of bacteria in the gut. Research is exploring how antibiotic exposure during early childhood may influence microbiome development and allergy risk.
Antibiotics should still be used when medically necessary, according to a healthcare professional’s advice.
Diet and food diversity
As babies transition to solid foods, their gut microbiome continues to change. Dietary variety, particularly the introduction of different plant-based foods and sources of fibre when age-appropriate, can provide nourishment for different gut bacteria.
The surrounding environment
Everyday environmental exposures, including contact with other people, siblings, pets and the natural environment, may also influence the development of a child’s microbial community.
Together, these factors help shape the complex ecosystem living inside your child’s gut.
5. How can parents support their child’s gut health?
While scientists are still investigating exactly how gut bacteria influence allergy development, supporting a healthy gut microbiome is a worthwhile part of overall child health.
Here are some everyday habits parents can consider:
Offer a varied diet
Once your child is developmentally ready for solids, introduce a variety of age-appropriate foods. Vegetables, fruits, legumes and wholegrains provide dietary fibre that gut bacteria can use.
Include fibre-rich foods
Foods such as oats, bananas, beans, lentils, broccoli and other vegetables can help support a diverse gut microbiome.
Follow appropriate infant feeding guidance
Breastfeeding can support the development of infant gut bacteria, but parents who use formula should not feel guilty. Infant formula is designed to meet babies’ nutritional needs. Speak to your healthcare professional if you have questions about feeding.
Avoid unnecessary antibiotics
Antibiotics should be used when needed, but they do not treat viral infections such as the common cold. Always follow your doctor’s advice rather than stopping or avoiding prescribed treatment.
Do not rush into probiotic supplements
Probiotics are often marketed as a way to improve gut health. However, different probiotic strains can have different effects, and current research does not establish that taking probiotics can prevent or cure childhood allergies.
If you are considering supplements for your child, speak to a healthcare professional first.
6. Does a healthy gut mean your child will have fewer allergies?
Not necessarily.
Although research increasingly suggests that gut microbiome development is linked to immune health, allergies are complex conditions influenced by many factors, including genetics, environmental exposures and immune system development.
Having a particular combination of gut bacteria does not guarantee that a child will or will not develop allergies.
Likewise, a child with allergies does not necessarily have an unhealthy gut.
There is still much researchers need to understand, particularly whether changes in gut bacteria directly contribute to allergic diseases or are partly a result of other factors.
For now, probiotics should not be viewed as a proven way to prevent or treat allergies.
The takeaway for parents
We often associate gut health with digestion, but its influence may extend much further.
The bacteria living in your child’s gut are part of a much bigger relationship between the digestive system and the immune system. And the early years may be an especially important period for this relationship to develop.
We cannot control every factor that influences our children’s health, and we certainly cannot prevent every allergy. But offering a varied diet, following appropriate feeding guidance and avoiding unnecessary medication are practical ways to support their overall wellbeing.
Perhaps it’s time we started thinking about gut health as more than just a solution for tummy troubles. It may also be an important part of understanding how our children’s immune systems grow.
At KidYouNot, we believe parenting is easier when we navigate together. Follow @kidyounot.sg for more research-backed parenting discoveries, health insights and conversations that matter to Singapore parents. 💜
References
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Hoskinson C, Petersen C, Turvey SE. (2025). How the early life microbiome shapes immune programming in childhood asthma and allergies. Mucosal Immunology, 18(1), 26–35.
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Mousavian AH et al. (2024). The association of infant and mother gut microbiomes with development of allergic diseases in children: a systematic review. Journal of Asthma, 61(10), 1121–1135.
Hello! I am Mummy Kim!
A beauty-loving mum who believes that looking good and feeling good go hand in hand. My parenting mantra is raising happy, confident kids with strong self-esteem! Between facial masks and storybooks, I’m all about nurturing both inner and outer beauty, for myself and my little ones.
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