More than moods: Why your teen’s gut health is changing (and what it means)

Written by: Alba Health team

Last updated: 2025-11-06

Summary

The teenage years aren’t just an emotional rollercoaster – they’re also a time of change for the gut. Research shows the teen microbiome goes through a “second window of opportunity,” actively shaped by puberty, hormones, diet, and lifestyle. These changes may affect skin, mood, and overall wellbeing. Supporting gut balance during this time could help teens build resilience that lasts.

In this article

Why the teen years may be a “second window” for gut health

The gut’s links to hormones, skin, and mood

How parents can support their teen’s gut and overall wellbeing

Summary

The teenage years can be a time of immense pressure: navigating school, social media, and rapid physical and emotional changes.

We often think of the gut microbiome – the community of bacteria in the gut – as something that is "set" in early childhood. But research suggests this isn't the whole story. The teen years appear to be another dynamic period of change for the gut: a "second window of opportunity" where the gut is actively being shaped.

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A second window of change

We are learning that puberty appears to be an event that influences the gut. As teens mature, studies suggest their gut microbiome diversity increases, and the types of bacteria present begin to shift.

This change has been noted in girls, whose gut microbiomes may become more "adult-like" as they progress through puberty. The key takeaway is that the teen microbiome is likely not static. It is a dynamic system, which means diet and lifestyle choices during this time may have a meaningful impact.

How the teen gut connect to the body

This adolescent gut remodeling doesn't happen in isolation. Research is exploring its links to many of the hallmark challenges of the teen years.

  • The Gut-Hormone Connection:

    There appears to be a complex, two-way relationship between gut microbes and hormones. Hormones help shape which microbes thrive. In return, some gut bacteria may play a role in influencing hormone metabolism.

  • The Gut-Skin Axis:

    For many teens, skin issues like acne are a major concern. Emerging research points to a "gut-skin axis". One theory is that diet and stress can affect the gut, leading to low-grade inflammation which may then show up on the skin.

  • The Gut-Brain Axis:

    The gut and brain are in constant dialogue. In adolescents, growing evidence associates gut health with mood. For example, some studies show that lower microbial diversity is associated with higher anxiety symptoms.

What you can do

Seeing these connections helps frame the teen years in a new light. This "second window" may be a chance to build resilience. As a parent, you can't control everything, but the goal is to offer support, not start battles.

  • Focus on fiber and diversity:

    Without being restrictive, try to "add in" foods like fruits, vegetables, and whole grains. These provide fiber that helps feed beneficial gut bacteria.

  • Support stress and sleep:

    The gut-brain axis is a two-way street. Supporting healthy sleep schedules and finding ways to manage stress can also benefit their gut.

  • Understand, don't guess:

    Instead of guessing which probiotic to buy or which foods to cut out our eat more of, you can get a clearer picture of your teen's unique profile.

Summary

  • The teen years appear to be a "second window" of change for the gut microbiome, not a static period.

  • Research suggests a two-way connection between the gut and hormones during puberty

  • The "gut-skin axis" concept links internal gut inflammation and microbial balance to skin health

  • A balanced microbiome is associated with better mood regulation, highlighting the "gut-brain axis" in teens

  • Diet and lifestyle choices during these years likely play a role in shaping the microbiome's trajectory.

  • Korpela et al. (2021)

    Gut microbiota develop towards an adult profile in a sex-specific manner during puberty.

  • Adolescent microbiome prediction paper

    (Genome Medicine, 2025)

  • Acne & gut-skin axis paper

    (PMID: 35711021, Frontiers in Microbiology, 2022)

  • Kallio et al. (2024). Early-life gut microbiota associates with allergic rhinitis during 13-year follow-up.