Skip to content

Why everyone is switching to WeNatal. Read the science.

Understanding Infant Gut Health and Microbiomes | WeNatal

Understanding Infant Gut Health and Microbiomes | WeNatal
Health-conscious parents are likely to see a lot of information out there about infant gut health. That’s because scientists are learning more each day about the vital role our gut plays in our overall health. If you have seen terms like microbiome, gut bacteria, and probiotics, you may be wondering what it all means. Especially, since there are so many options in the marketplace that can make the topic confusing. This article will break it down for you—and answer your questions, so you can spend more time caring for your little one, and less time looking for peace of mind.

What is the gut microbiome? 

The microbiome is the community of organisms in and on our bodies. There are over 100 trillion bacteria, viruses and fungi in our microbiome. That is about 10 times the number of cells in the human body. The largest microbiome is found in the gut, more specifically in the large intestine or colon. 


In particular, the gut microbiome can have many beneficial jobs, including aiding digestion, nutrient absorption, disease prevention and immune system development. Your GI tract can be considered a tube with a large surface area that is exposed to the outside world and the gut systems help protect and educate the infant about the world around them. So, it makes sense that 80% of the human immune system is in our gut, and much of our body’s ability to fight diseases is determined in the first few months after we are born.

How do babies get their gut bacteria?

Babies are born with a naïve GI tract, meaning there are few microorganisms inside. During the birthing process, a baby’s microbiome begins to develop through exposure to their environment. Babies who are born vaginally have early exposure from the birth canal, mom’s skin, and even mom’s poop! Whereas cesarean section babies receive microorganisms mostly from mom’s skin flora. 


After birth, more bacteria enter the baby’s digestive system through human interaction and feeding. If mom is breastfeeding, her diet impacts her microbiome and her baby’s. In fact, mom’s breastmilk can have a considerable influence on which organisms thrive in the baby’s gut. 


Historically, babies were exposed to a specific good gut bacteria known as Bifidobacterium infantis. The job of B. infantis is to help babies digest the nutrients in breast milk, which are called human milk oligosaccharides or HMOs. Due to the unintended consequences of modern practices—c-sections, antibiotic use, and even daily showering—90% of babies in the U.S. do not have this important strain of bacteria.

Why is the gut microbiome so important?

Research shows that our gut health impacts many aspects of our overall health. Our microbiome provides signals to our neurologic, metabolic, and immune systems. In the first few years of life, it can be altered by our diet and environment until it becomes mostly established around three years of age. 


When babies are born, their bodies can be filled with “good” bacteria, such as B. infantis that promote healthy digestion and immunity, or “bad” bacteria that can cause inflammation and disease. Research suggests when a baby’s gut is filled with “good” bacteria, it supports the development of a stronger immune system throughout life. It also has been shown to reduce “bad” bacteria that can cause inflammation and disease. These “bad” bacteria have been linked to potential health issues such as allergies, autoimmune diseases, and baby ailments like colic, diaper rash and eczema.

Early introduction of probiotics can reduce the risk of dysbiosis and subsequent inflammation, leading to more comfortable and less fussy infants.

How do I know if my baby needs a probiotic?

Research shows that gut health influences the health of the entire body. Dysbiosis, an imbalance of good vs. bad bacteria of bacteria is caused by disruptions in the microbiome and can lead to various health conditions. Getting the good bacteria in early maximizes the power of your breast milk and gets the gut microbiome off to the right start. 


The most common signs of dysbiosis in infants are:

  • Gas/fussiness
  • Disrupted sleep
  • Diaper rash
  • Eczema


These symptoms can be related to an overgrowth of “bad” bacteria such as E. coliStaphylococcus, and Streptococcus, that cause inflammation and gas. Probiotic supplements can help fill the gut with healthy organisms that reduce harmful pathogens in the body. One particular strain of B. infantis called EVC001, actually colonizes the gut, adhering to the lining and replicating to provide lasting benefits, leaving less room for the unhealthy bacteria to live.


Inflammation and digestive issues such as dysbiosis are major contributors to colic, which affects almost 25% of babies. Nearly 1/3 of babies in the US are born via c-sections and are disproportionately likely to have dysbiosis, along with those who are exposed to antibiotics during or after birth. Early introduction of probiotics can reduce the risk of dysbiosis and subsequent inflammation, leading to more comfortable and less fussy infants.


One study also shows that babies with more B. infantis in infancy have lower rates of atopic disease at three years of life, such as atopic dermatitis and IgE-related food allergy.

How do I choose the right probiotic for my baby?

Probiotics are a broad and overwhelming category of supplements! Like antibiotics, probiotics serve different purposes depending on who is taking them and for what reason. For breastfed babies, Evivo is the only probiotic that contains B. infantis EVC001. While other probiotics may have different strains of B. infantis, Evivo is the only one that can fully consume all of the HMOs in breastmilk.


Evivo is unique because it colonizes up to 80% of the GI tract’s surface, leaving less room for bad bacteria to thrive. A recent study showed that babies given Evivo for the first month of life still had it in their GI tracts at one year of age.  Most probiotics shed after you stop taking them, which means you must keep taking them to be effective. More good bacteria for longer means less gas, less inflammation, and happier babies!


Studies also show that Evivo protects the mucin layer of the gut, leading to less mucus in stools. Parents of babies who received Evivo also reported less diaper rash and fewer, less watery stools per day.

What if my baby is getting some formula?
We believe in finding a feeding plan that is right for your baby and your family. More than 70% of families in the U.S. combination-feed with breastmilk and formula or use formula exclusively. B. infantis is good for all babies and the HMO found in breast milk and some formulas helps kick-start a healthy infant gut microbiome.

How do I give Evivo to my baby?
Babies can start taking Evivo as soon as they are taking breastmilk. Studies show that Evivo is effective and well-tolerated even in premature babies. For healthy full-term infants, Evivo comes in little powder sachets that you give once each day. The earlier you start, the more room your baby has for the beneficial bacteria to take over. 


Here are a few ways you can feed your baby Evivo:

  • Mix it with a few milliliters of breastmilk and offer via syringe.
  • Mix the powder with breast milk to form a paste and apply the paste directly to your nipple before nursing.
  • Put the powder directly into a bottle of breastmilk or formula that you know your baby will finish.


You can order Evivo directly from, and use the code WeNatal at checkout for 15% off!!

How do I know if Evivo is working?
Most of the benefits of a healthy gut microbiome are long-term, but parents report some exciting short-term benefits after starting Evivo: 

  • After one week of use, parents report decreased gas, diaper rash, colic, and improved sleep. 
  • Babies also usually have fewer and better formed, less watery stools–happier babies and fewer diapers!
  • Not all babies need a change in their bowel movements to indicate Evivo is working. If your baby is receiving Evivo and breastmilk daily, Evivo is working.

Share This Article

Payal Adhikari, M.D

Payal Adhikari, M.D. is a pediatrician and Clinical Implementation Director for Infinite Health. She grew up in the Chicago suburbs and lived in Singapore prior to settling in Chicago with her husband and two kids. She encourages her patients to have fun with parenting and believes in the power of the early microbiome to create healthier and happier babies.

Your Cart (0)

Your cart is empty

Funboy Product Image
Shipping & taxes calculated at checkout
International Orders: Shipping does not include import
duties and taxes from the destination country.