Oral Gut Axis

Help us better understand the connection between oral and gut health

Take part in a first-of-its-kind study by Bristle Health and Tiny Health. Receive both an oral and gut microbiome test at exclusive research pricing. By joining, you'll gain insights into your oral and gut health, and help our scientists better understand the connection.

Recruitment starts Oct 2025
For Adults 18+ (see criteria) ( see criteria)
Location: United States
By Kimberley Sukhum, PhD and Dr. David Lin, PhD

People with gum disease are 2–3× more likely to develop gut conditions like IBD - and that's just the beginning

The connection between oral and gut health runs deeper than most people realize.

Research shows that gum disease significantly increases the risk of conditions like IBS and IBD — but the oral-gut axis also influences immunity, metabolism, blood pressure, and systemic inflammation.*

Oral bacteria doesn't just stay in your mouth; they travel to your gut daily, where they can affect how your body digests food, regulates blood sugar, and responds to inflammation. Yet, despite these wide-ranging effects, oral health is rarely assessed in conjunction with gut health.

This pioneering study from Tiny Health and Bristle examines both microbiomes together to uncover patterns that could help detect imbalances earlier and improve health outcomes across multiple systems.

* Source

Get a complete picture of your digestive and oral health

By joining, you’ll gain comprehensive insights into both your oral and gut microbiomes — giving you a more complete view of your digestive health than either test alone. You’ll collect simple at-home samples and receive clear, personalized reports to help you improve your oral & gut health. Plus, your de-identified results will contribute to research exploring how oral bacteria may influence gut conditions, helping shape future care.

Am I eligible to participate?

Inclusion criteria

You may be eligible to participate if you are 18 years or older.

Inclusion Criteria

• You are eligible to participate if you are over 18 years old. You must be a resident of the US with US postal service (Excluding NY)

Exclusion criteria

Exclusion Criteria:

• Participants cannot have taken IV or oral antibiotics in the past 8 weeks. Participants cannot have had dental procedures (ex. cleaning or other in-office work) in the past 2 weeks.
• Participants do not need to have a gut or oral condition. Healthy participants are encouraged to participate.

How to join the study

If you are interested, you can participate immediately by purchasing the research edition bundle below. If you've recently taken a Tiny Health Test or Bristle Health Test in the last 6 months, you may be eligible for a discounted single test below. Apply below.

1x Mess-free Tiny Health Gut Microbiome stool test to further understand how gut health relates to oral microbiome

• Track essential bacteria that support oral health, metabolic health and fight inflammation
• Gut Health Report with personalized recommendations (delivered in 2-3 weeks)

1X Bristle Oral Health Saliva Test to get to the root cause of oral health issues

• Identify the root cause of chronic bad breath, inflamed gums, tooth decay, gum recession and more.
• Personalized results (delivered in 2-3 weeks)

About Tiny Health

Tiny Health helps you to optimize your health from within

Tiny Health offers microbiome testing for every stage of life, from womb through adulthood. Tiny Health gives individuals personalized insights and evidence-based recommendations to improve lifelong health from the inside out.

Tiny Health’s mission is to improve health outcomes of future generations through evidence-based insights.