Oral x Gut Axis Study
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.
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 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)
- 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.
Track your baby's microbiome development over time
You can learn the most about your baby’s health and protect against chronic conditions by tracking changes on their gut health over their first 1000 days.
We recommend testing at 7 days old, and every 3 months until your baby is 18 months old.
A Tiny Health subscription gets you:
- Exclusive $30 discount off each test kit
- Your kits delivered when you need them
- Enter your payment details only once
- Pay only when the tests are shipped
- Free shipping
- Skip or cancel anytime
How to join the study
If you are interested, apply for the study via the survey and purchase the special edition bundle or single tests 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)
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)
Track your baby's microbiome development over time
You can learn the most about your baby’s health and protect against chronic conditions by tracking changes on their gut health over their first 1000 days.
We recommend testing at 7 days old, and every 3 months until your baby is 18 months old.
A Tiny Health subscription gets you:
- Exclusive $30 discount off each test kit
- Your kits delivered when you need them
- Enter your payment details only once
- Pay only when the tests are shipped
- Free shipping
- Skip or cancel anytime
How to join the study
If you are interested, apply for the study via the survey and purchase the special edition bundle or single tests 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)
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)
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)
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)
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)
How to join the study
If you are interested, please complete the survey. If you qualify for the study, you will be directed toward a special purchase link to order your gut or vaginal test at the discounted rate.
Gut health for every age and every stage
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 worldwide, Tiny Health is redefining the microbiome as a cornerstone of personalized wellness
Bristle Health helps you find & fix the root cause of oral health problems
Bristle Health provides at‑home oral microbiome testing and guidance to help people understand their oral health and how to resolve symptoms like bad breath, gum inflammation, tooth decay, and more with evidence-backed recommendations.
How does the Research Edition work?
How does the research edition work?
- Apply for the study and purchase your kits
- Complete the qualification survey via the button on this page to see if you qualify, then purchase the Oral and Gut microbiome tests.
- Both tests will be mailed to you, where you can collect your two samples at-home and mail them back to our respective labs with pre-paid shipping envelopes.
- You will fill out health history and sample surveys upon sampling.
Send in your sample
- Your samples will be processed in a CLIA-certified lab and using proprietary technology, You will receive strain-level insights and a complete list of all microbes in the oral and gut microbiome including bacteria and fungi; as well as virus, parasites, and archaea in the gut microbiome test. Results will take 3-4 weeks to arrive.
Receive oral and gut test results
- Receive actionable, and evidence-based recommendations to help understand your health and course-correct oral and gut imbalances
- The microbiome result report and action plan are a part of the regular Bristle Health and Tiny Health Gut Test product and not associated with the research study.
How do we look at the microbiome?
High resolution analysis
We use shotgun metagenomics, a technology used in microbiome research. Make informed decisions with a comprehensive list of microbes found in your sample.
Functional insights
Through functional profiling, we tell you what microbes are present, how much of them are there, and what they’re actually doing.
Targeted suggestions
Get actionable advice tailored to your age and unique test results. Our at-home tests empower you with strain-level detail and precision science.
Your privacy comes first
We are dedicated to safeguarding your personal information at every turn and we will never sell your personal information. Your data is encrypted with high security standards to ensure complete confidentiality.
CLIA & CAP certified lab
Your samples are processed at a U.S. clinical-grade lab to ensure the accuracy, reliability, and timeliness of test results.
Meet our supporters:
Medical Advisors
Integrative Pediatrician and Pediatric Functional Medicine Expert
Founder, Healthy Kids Happy Kids
Executive director, G. Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA; Author of The Mind-Gut Connection
Demarest Lloyd Jr Endowed Chair in Food Allergies; Senior Pediatrician, Pediatric Gastroenterology and Nutrition, Co-Director of Food Allergy Center, Massachusetts General Hospital; Associate Professor in Pediatrics, Harvard Medical School
Ruben Mars is an Assistant Professor of Medicine at Mayo Clinic in Rochester, Minnesota.
Associate Professor of Epidemiology, Johns Hopkins University
Associate Professor of Pediatrics and Child Health at the University of Manitoba; Co-Director, Manitoba Interdisciplinary Lactation Center (MILC); Deputy Director, CHILD Cohort Study
Board-Certified Pediatrician, Creator of Raising Amazing Podcast
Medical Advisor; Practicing OB/GYN Hospitalist Physician, Creator and Host of The All About Pregnancy & Birth Podcast
Associate Clinical Professor, UCSF; Pediatrician and former Chief Innovation Officer, Kaiser Permanente
Interested? Join this study
If you are interested, please complete the survey. Qualified individuals will be contacted by the study coordinator to provide consent and enroll in the study.
Help us better understand the connection between oral and gut health
Frequently Asked Questions
What is the cost and time commitment?
There is no cost to participation. You must be able to collect and complete a microbiome stool sample, an oral sample, and two online surveys. Collecting a microbiome sample and oral sample can be done on your own time, at home, and should take a few minutes. Each of the surveys can take anywhere between 5-15 minutes to complete, depending on the complexity of your answers.
What do I get for participating?
You will receive a Bristle Oral Microbiome and Tiny Health Gut Health Tests (estimated value $481) and your personalized reports from each test.