When Does a Child's Gut Microbiome Become Stable and Mature?

Have you ever wondered whether your child's gut microbiota is healthy? When does a child's gut microbiome development become relatively stable?

The latest research tells us that the human gut microbiome is not fixed at birth. It is like a growing organ that needs time to develop and mature, only forming a stable, adult-like ecosystem around the age of 7. 

The Long Road of Gut Microbiota Development: Why Seven Years Old?

It is because the establishment of our gut microbiota is a dynamic journey spanning several years:

Infancy (0-1 year): Breast milk is one of the most important influencing factors during this period. Breast milk is a significant source for the development of the infant's gut microbiota. It not only provides probiotics but also contains prebiotics that nourish beneficial bacteria, laying the foundation for the nascent gut ecosystem.

Toddler Years (1-3 years): As children begin to encounter various solid foods, their gut microbiota undergoes a "great revolution." The explosive increase in dietary variety drives a rapid increase in microbial diversity, but the overall structure remains very unstable and is easily disrupted by illness or antibiotics.

Preschool Age (3-7 years): Although a core microbiota is initially formed around age 3, the subsequent years remain a critical stage of continuous fine-tuning and maturation. It is not until around 5 to 7 years old that this complex ecosystem becomes stable and resilient enough to be considered an "adult-like" gut microbiota.

Why do we need to wait until the gut microbiome is mature and stable?

• Establishing Reliable Test Results
  Before the age of 7, a child's gut microbiota is unstable. Test results at this stage cannot represent their future "stable state." Only after the microbiota is stable can the data obtained then serve as a meaningful "personal health baseline." Once a child's gut microbiome development has gradually matured and stabilized, they can undergo gut testing to understand the state of their gut microbiota and, based on the test results, be supplemented with customised probiotics for their gut.
  
  
• Test Results Become "Actionable"
  Once the gut microbiota matures, it truly reflects your long-term dietary habits, lifestyle, and health status. If an imbalance is detected through testing at this stage, we can then confidently link it to specific health risks (such as obesity, metabolic issues, and chronic inflammation). Therefore, a test report reflecting this stable state can provide truly valuable directions for improvement.
  

So, How Can We Lay a Solid Foundation for Our Child's Gut Health?

1. Encourage a Diverse Diet: Provide plenty of vegetables, fruits, and whole grains to supply beneficial bacteria with ample "prebiotic" dietary fiber.
   
   
2. Take Probiotics: Probiotics can help balance the ratio of good and bad bacteria in the gut, it's best to ensure the gut  microbiota has stabilized and matured first.
   
   
3. Use Antibiotics Judiciously: Antibiotics indiscriminately destroy gut bacteria. They must be used strictly under a doctor's guidance.
   

In summary, a child's gut microbiota matures and stabilizes around the age of 7, making the results of gut testing more accurate from that point onward. Building a strong foundation for your child's gut health can give them a healthier life.

Want to know more about your gut or your child's gut? Check how can our Microbiome Test Pro help you!

Reference:
1. Developmental trajectory of the healthy human gut microbiota during the first 5 years of life. (2021). Cell Host & Microbe, [online] 29(5), pp.765-776.e3. doi:https://doi.org/10.1016/j.chom.2021.02.021.

2. Biocodex Microbiota Institute. (2021). Gut microbiota not yet considered ‘adult’ at 5 years old? [online] Available at: https://www.biocodexmicrobiotainstitute.com/en/pro/gut-microbiota-not-yet-considered-adult-5-years-old [Accessed 22 Oct. 2025].

3. Derrien, M., Alvarez, A.-S. and de Vos, W.M. (2019). The Gut Microbiota in the First Decade of Life. Trends in Microbiology, 27(12). doi:https://doi.org/10.1016/j.tim.2019.08.001.

4.  Prados, A. (2021). Does gut microbiome development end by age 3? [online] Gut Microbiota for Health. Available at: https://www.gutmicrobiotaforhealth.com/does-gut-microbiome-development-end-by-age-3/ [Accessed 22 Oct. 2025].

5. Ke, S., Weiss, S. T., & Liu, Y. Y. (2022). Rejuvenating the human gut microbiome. Trends in molecular medicine, 28(8), 619–630. https://doi.org/10.1016/j.molmed.2022.05.005