Science – Tiny Health
There are 38 trillion reasons to care about your microbiome.
Learn More
What is a microbiome?
Your microbiome is a community of 38 trillion tiny microbes that play an essential role in your immune development and overall health.
Why is it important?
of children in the US have at least one chronic health condition, and that number keeps growing
How do we look at the microbiome?
Ruben Mars, Ph.D., Scientific Advisor at Tiny Health, works within an anaerobic chamber at Mayo Clinic's Center – Source: Mayo Clinic
Highest resolution analysis
We use deep-shotgun metagenomics sequencing, the gold standard to get a comprehensive analysis you can rely on to make informed decisions
Breakthrough 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
We use strain-level identification and precision science to detect and confirm microbes' transference, probiotics impact, and more
Developed with experts in early-life microbiome health
Dr. Elisa Song, MD
Chief Medical Officer
Integrative Pediatrician and Pediatric Functional Medicine Expert
Founder, Healthy Kids Happy Kids
Dr. Emeran Mayer, MD
Medical Advisor
Executive director, G. Oppenheimer Center for Neurobiology of Stress and Resilience, UCLA; Author of The Mind-Gut Connection
Dr Qian Yuan, MD, PhD, FAAP
Medical Advisor
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, PhD
Founding Advisor
Ruben Mars is an Assistant Professor of Medicine at Mayo Clinic in Rochester, Minnesota.
Noel Mueller, PhD
Scientific Advisor
Associate Professor of Epidemiology, Johns Hopkins University
Meghan Azad, PhD
Scientific Advisor
Associate Professor of Pediatrics and Child Health at the University of Manitoba; Co-Director, Manitoba Interdisciplinary Lactation Center (MILC); Deputy Director, CHILD Cohort Study
Joel Warsh, MD
Medical Advisor
Board-Certified Pediatrician, Creator of Raising Amazing Podcast
Nicole Calloway Rankins, MD, MPH
Medical Advisor
Medical Advisor; Practicing OB/GYN Hospitalist Physician, Creator and Host of The All About Pregnancy & Birth Podcast
Dr. Kim Green, MD
Medical Advisor
Associate Clinical Professor, UCSF; Pediatrician and former Chief Innovation Officer, Kaiser Permanente
Rodney Dietert, PhD
Scientific Advisor
Professor Emeritus of Microbiology & Immunology, Cornell University
“Imagine a world where you will take your baby to a health care check. They will routinely monitor the gut microbiome development....
If any disruptions are noted, a tailor-made product to restore the gut microbiota will be prescribed. The onset of any chronic diseases will be extremely rare.”
Dr. Henna Maria Uusitupa
Microbiome Researcher, TED Speaker (2.5M views)
The first 1,000 days is when you have the biggest impact on your baby’s gut and lifelong health.
For the best immune health, it's ideal for your baby to have 30-80% bifidobacteria.
“If you upset this process in early life then we may have consequences later and that can lead to production of disease later in life.”
Rodney Dietert, PhD
Professor Emeritus of Microbiology
& Immunology, Cornell University
Low levels of
unfriendly E. coli are actually a good thing! They help train your baby’s immune system. Just don’t let it dominate your baby’s gut.
See the impact of Tiny Health’s insights to these families
Mass General Pediatric GI Doctor Uses Gut Microbiome Testing as First-Line Tool
How Serenity Kids Founder Joe Carr Rebuilt His Gut After an H. pylori Cleanse Backfired
Case Study: How Gut Health Testing Helped Violet End 15 Years of Chronic Diarrhea
Case Study: How Gut Test Data Helped Carolyn Overcome Colitis
More than a microbiome test
Actionable
We support your family's health from before pregnancy through infancy, childhood, and adulthood.
Personalized
We offer medically reviewed guides that are dialed into your unique test results.
Evidence-based
We’re geeky and we embrace it. Our team distills the latest science so that you don’t have to.
We are pioneering microbiome research & gut health testing for families
Our team is engaged in ongoing research to push the boundaries of microbiome understanding and its relationship with chronic conditions. Our research efforts include our own clinical studies & publications.
Look inside!
New study
See how our microbiome test outperforms leading tools at detecting your gut bacteria
Based on our study posted on bioRxiv on July 6, 2026 doi.org/10.64898/2026.07.06.736764
New study
Read our white paper on how we cut infant eczema odds by 83% in C-section babies
Based on our study published in Pediatric Allergy and Immunology on September 2, 2025 doi.org/10.1111/pai.70182
Look inside!
Look inside!\ \ \ \ Open access
Early life gut microbiome and its impact on childhood health and chronic conditions
Read our white paper on key insights and gut microbiome associations
Look inside!
Look inside!
Look inside!
Look inside!
Read our white papers on health conditions & microbiome associations
Contribute to advance research in childhood allergies
We launched our Research Edition test to study the potential link between the infant (and mom) gut microbiome and the development of allergies.
Don't just take our word for it.
Check out these key research papers to learn more about the intricacies of microbiome health.
\ \ Stunted microbiota and opportunistic pathogen colonisation in caesarean section birth.\ \ Researchers analyzed the gut microbiota of 576 healthy, full-term babies and their mothers. They found that the mode of delivery is the driving factor shaping the composition of gut microbiota in the first month of life and up to 1 year of age.\ \ General Studies\ \ \ \ Strain-Level Analysis of Mother-to-Child Bacterial Transmission during the First Few Months of Life.\ \ Researchers tracked down bacterial species - down to the level of strains and genes - transmitted from a mother to her child during birth. These findings confirm transmission of (health) microbes from mother to child and highlight the importance of vertical transmission.\ \ General Studies\ \
\ \ Delivery mode and gut microbial changes correlate with an increased risk of childhood asthma.\ \ Delivery mode and gut microbial changes correlate with an increased risk of childhood asthma.\ \ Allergies & Eczema\ \ \ \ Healthy infants harbor intestinal bacteria that protect against food allergy.\ \ In a study showing that gut bacteria are important to protect against food allergies, researchers transplanted gut bacteria from babies – both healthy and those with cow’s milk allergy – into “germ-free” mice. These are mice without microbes that are kept in a sterile environment, making it easy to clearly see the effects of transplanted bacteria. As it turns out, mice colonized with microbes from healthy babies were protected from an allergic reaction when later exposed to cow’s milk, the most common food allergy in children.\ \ Allergies & Eczema\ \
\ \ Early infancy microbial and metabolic alterations affect risk of childhood asthma.\ \ Researchers found that there are four key bacteria that, if present at 3 months of age, drastically reduce the risk of developing asthma, suggesting a protective effect.\ \ Type 1 & Type 2 Diabetes\ \ Allergies & Eczema\ \ \ \ Neonatal gut microbiota associates with childhood multisensitized atopy and T cell differentiation.\ \ In this study, researchers found that the newborn gut microbiome directly impacts the developing immune system. A dysbiotic newborn gut microbiota, characterized by the depletion of beneficial Bifidobacteria, Lactobacillus, Faecalibacterium, and Akkermansia, led to a dysfunction in T cell populations, influencing the susceptibility to childhood allergic asthma.\ \ General Studies\ \ \ \ Intestinal microbiota in infants and high risk of allergy: Effect of Probiotics and Eczema development.\ \ Hydrolyzed protein formula - with additional prebiotics - has the potential to change the gut microbiome of babies who are at a high risk of developing allergies. The addition of prebiotics to formula supported the development of a baby’s microbiome, helping it to resemble the gut of a breastfed baby and potentially protecting against the development of allergies later in life.\ \ General Studies\ \ \ \ Temporal development of the gut microbiome in early childhood from the TEDDY study.\ \ Using stool samples from the Environmental Determinants of Diabetes in the Young (TEDDY) study, one of the largest datasets on the infant microbiome scientists concluded that during the developmental stage (3-14 months), breastfeeding was the most significant factor associated with microbiome composition, with higher levels of healthy Bifidobacterium bacteria. Microbiome diversity increased after weaning as the infants consumed a greater variety of foods.\ \ \ \ Type 1 & Type 2 Diabetes](https://pubmed.ncbi.nlm.nih.gov/30356187/)
\ \ The human gut microbiome in early-onset type 1 diabetes from the TEDDY study.\ \ In this study, nearly 11,000 stool samples from 783 children were analyzed to try to understand how early gut microbiome can impact Type 1 diabetes. Researchers found that infants without Type 1 diabetes have more microbial genes related to fermentation and production of short-chain fatty acids, which are beneficial to gut health and immune function.\ \ \ \ Type 1 & Type 2 Diabetes](https://pubmed.ncbi.nlm.nih.gov/30356183/) \ \ Roles of Birth Mode & Infant Gut Microbiota in Intergenerational Transmission of Overweight & Obesity From Mother to Offspring.\ \ In this cohort study of 935 mother-infant pairs, infants born to mothers with overweight or obesity were more likely to be overweight at ages 1 and 3 years compared to infants born to mothers with normal weight. In addition, infants delivered by c-section had double the odds for developing childhood overweight or obesity compared to infants delivered vaginally.\ \ \ \ Obesity](https://pubmed.ncbi.nlm.nih.gov/29459942/) \ \ Infants born to mothers with IBD present with altered gut microbiome that transfers abnormalities of the adaptive immune system to germ-free mice.\ \ Babies born to mothers with inflammatory bowel disease (IBD) present an unhealthy bacterial gut composition up to at least 3 months of life, characterized by the absence of healthy Bifidobacteria. This unhealthy microbiome led to important changes in the adaptive immune system of the gut in germ-free mice, highlighting the importance of a microbiome-based intervention during early infancy, thus reducing the risk of developing IBD.\ \ \ \ Obesity](https://pubmed.ncbi.nlm.nih.gov/31036757/)
Evidence-based articles from our science team
Keep up with the latest in microbiome research on the Tiny Health blog.
Adult Gut Health
Gut Health and Chronic Diarrhea: Understanding the Connection
Adult Gut Health
Surgery and the Gut Microbiome: What No One Prepares You For
Adult Gut Health
Gut Health and Fatigue: How Your Microbiome Affects Energy
Frequently asked questions
Why is gut health important? Is testing really worth it?
Emerging microbiome research has shown the importance of gut health to our overall health. The science links 80% of our immune system to the gut. So, taking steps to improve gut health supports lifelong wellness.
There are many tools and strategies to help improve your gut health. These include eating the best
foods and taking supplements for gut health, or working with a gut health coach. Yet there is no one-size-fits-all approach to gut health. For example, taking a probiotic for the gut may be beneficial for some individuals. In others, it could do more harm than good. Imagine there’s already high levels of a beneficial microbe in your gut. Taking a probiotic could boost those levels to a point where they are too high, resulting in low diversity in the gut microbiome.
Taking a gut microbiome test is the best way to determine if there are any imbalances in your gut that need course correction. Testing helps educate you on the best actions for your unique microbiome. And you can retest to track if dietary changes and gut health supplements or probiotics are having the intended effect.
Is it too late to test? Are microbiome tests beneficial at any age?
In short, it’s never too late to test! Gut health matters at every age. And the sooner you have a baseline sample, the better.
During the first year, a baby’s microbiome sees dramatic shifts. This path sets the trajectory for their health, all the way through adulthood. For this reason, we encourage parents to sample as soon as possible, from age 0 to 3 years old and beyond.
A child's gut is still maturing until the age of 3 to 5 years old. Up to this point, you have the best opportunity to check in on your little one’s gut health and make changes, if needed.
Even if your child’s gut has reached maturity, you can still take steps to influence their health! For older children and adults, gut health testing can reveal a lot. For example:
- Hidden inflammation that can lead to leaky gut
- Bacteria that make anti-inflammatory short-chain fatty acids
- Microbiome diversity, and
- Biomarkers for immune health and fiber digestion.
No matter your age, it's a good idea to test your gut. Identifying even low levels of chronic inflammation can help you take steps to prevent disease later in life. And microbiome research in older adults shows that longevity has links to gut health.
All Tiny Health gut tests come with a detailed report and steps to take to optimize your microbiome. Our experts recommend diet, supplement, and lifestyle changes based on your age and unique results. Select your test to get started.
My doctor has never heard of this type of microbiome testing. Why should I take a test?
Conventional medical providers usually are not trained in microbiome testing and probiotics, since these things aren't currently standard of care in those settings. In addition, many conventionally trained physicians also have limited nutritional training, and diet is one of the most powerful ways you can optimize microbiome health. While conventional medicine can have lots of insight into sick care, it isn't always the best at wellness and prevention. Plus it can take 10-15 years for the medical field to put new academic research into practice !
But that doesn’t mean that it’s something to wait on. Enter Tiny Health.
Our team of leading pediatric scientists and physicians are on the cutting edge of microbiome health. We are prevention and wellness focused. We've developed tests to give families access to this innovative science right now.
What does a Tiny Health test look for? What is included?
Tiny Health screens for over 120,000 microbes. This includes bacteria, fungi, parasites, viruses, and archaea found in the microbiome. Each microbiome test kit includes a mess-free stool or vaginal swab with instructions. You return your kit in the pre-paid mailer, which goes to our CLIA-certified and CAP-accredited laboratory partner for microbiome sequencing. In 3-4 weeks, you receive a precision report of your results. This includes personal, evidence-based suggestions to improve your gut or vaginal health.
Summary + Expert Highlight
Your summary gives you a bird’s eye view of your gut or vaginal health report. This includes a customized plan prepared by one of our microbiome experts.
The expert highlight guides you through the results. We help you understand what the data means and which actions to take first.
Key Insights
Learn about current imbalances that are important for your specific age. This means a 4-month old gets different metrics from a 12-month old. And a 2-year old gets different metrics than a 40-year old.
Microbiome Breakdown
You receive a comprehensive list of all microbes found in your sample. We categorize them as beneficial, unfriendly, variable, or unknown and provide detailed descriptions of each microbe. You can see how much of each microbe is present, down to a 0.05% abundance level. (No other baby gut test does this!)
Conditions
This section of the report identifies if you have microbiome signatures for certain conditions. These markers could predict an increased risk of developing that condition.
Action Plan
We provide personal, evidence-based suggestions based on your test results and survey responses. Our suggestions may include actual products and brands that we recommend. You'll also receive useful diet, supplement, and lifestyle tips.
Curious? Explore a Sample Report
Can a gut test help with eczema, allergies, or asthma?
Eczema, allergies, and asthma are inflammatory conditions. Tiny Health microbiome tests help you identify inflammation at its source, your gut. With deep insights into your gut microbes, you can take action and help prevent or reduce inflammation in your body.
Here are two ways caring for your microbiome can help with inflammatory conditions:
1. In our first few years of life, our gut microbes help train our immune system how to behave. Without proper training, our immune system can contribute to long term issues with inflammation (e.g., eczema, allergies, asthma). The goal is to address imbalances early. That way, the immune system has proper education. This may even help prevent inflammatory conditions from developing.
2. At any age, the microbiome can become unbalanced. This may trigger inflammatory symptoms in our bodies. This can weaken the gut lining, cause leakiness or inflammation, and trigger the immune system. It is important to address these imbalances. Better gut health is possible at any age.
Tending to your gut health is beneficial for overall health and wellness. But your gut may not be the only factor contributing to inflammatory conditions. Many families have successfully reduced or eliminated symptoms by testing and taking action. When you use Tiny Health tests, you can rest assured that a team of gut health specialists are here to support your health journey.
Can a microbiome test tell me about lactose, dairy intolerance, or specific food allergies?
No, a gut microbiome test kit cannot detect lactose intolerance or specific food sensitivities.
At Tiny Health, we can help you understand your gut health and how it may contribute to symptoms of these food sensitivities.
Lactose intolerance refers to trouble digesting the milk sugar, lactose. It is different from cow milk protein allergy, which involves an immune response. Cow milk protein allergy is somewhat common in babies. But lactose intolerance is very rare in children under the age of 5 years old.
There are two types of lactose intolerance:
1. Primary lactose intolerance: This is rare in babies and all about genetics. In this case, the body cannot make enough of the enzyme lactase. This is the enzyme that helps break down and digest the lactose milk sugars.Primary lactose intolerance is not caused by gut microbes. But symptoms may improve with helpful bacteria like Streptococcus thermophilus.
2. Secondary lactose intolerance: This is all about damage to the gut lining. Lactose digestion takes place in the small intestine. Damage to the lining of the small intestine can lead to secondary lactose intolerance. Usually this happens in adults, after a long period of gut inflammation.
Gut microbes can cause lactose intolerance if they are are causing gut inflammation. Repairing the gut and clearing inflammation can help support lactose digestion.
If you or your child is having issues with a food sensitivity, talk to a healthcare provider. It is important to understand the root cause. Specific food allergies and sensitivities are often determined by a blood test.
However, for children who are reactive to a wide variety of foods, the common cause may be related to an imbalance in the microbiome, and less the individual foods. Inflammation in the gut may damage the gut lining, and gut leakiness may permit dietary triggers to get into the rest of the body, triggering reactions. For some children, healing the gut can reduce their reactivity to foods.
Get $20 OFF to kickstart your microbiome health journey
Get exclusive offers and gut health tips for the whole family straight to your inbox
Unlock $20 Off
Get $10 OFF to kickstart your microbiome health journey
🎉 Thank you! Your report and coupon are on their way to your inbox
Oops! Something went wrong while submitting the form.
Get exclusive offers and gut health tips for the whole family straight to your inbox
Unlock $20 Off
Low levels of unfriendly E. coli are actually a good thing! They help train your baby’s immune system. Just don’t let it dominate your baby’s gut.
Close
For the best immune health, it's ideal for your baby to have 30-80% bifidobacteria.
Close
justone.ai
justone.ai is blocked
This page has been blocked by an extension
- Try disabling your extensions.
ERR_BLOCKED_BY_CLIENT
Reload
This page has been blocked by an extension