Lately, we can’t seem to get away from talk about microbes. With terms like good bugs, bad bugs, fermented foods, probiotics, antibiotic resistance being used often – it’s enough to make your head spin! The good news is, we’re learning more and more on these topics and our knowledge is growing. With so much information available around you, where do you start? Let us help you out with some basics on these topics.
What is the gut microbiota?
The best place to start in answering this question is to define the word “microbiota.” Simply put, a microbiota is the community of microbes in a given area. Microbes include bacteria, viruses, and other very small (‘micro’) organisms. When it comes to humans, bacteria usually come to mind when we think about microbes. Bacteria are incredibly diverse, and almost every type of environment on earth can support certain bacteria. Bacteria are basically everywhere!
In fact, trillions of bacteria live with humans. The number of bacteria in and on a human body can outnumber human cells by up to 10 times, because they’re so small and numerous.
By far, most of the bacteria that live with humans are in the digestive tract. These bacteria are part of the gut microbiota. Types and amounts of bacteria change as you go through the digestive tract. The large intestine, or colon, has the most density and diversity of bacteria in the entire human gut.
The bacteria in our guts are extremely diverse. Just like fingerprints, the composition of your gut microbiota is unique to you (although we share some similar features). You have unique amounts and types of bacteria in your gut and, unlike fingerprints, the gut microbiota can change because the types and amounts bacteria shift over time.
Gut bacteria are very complex, but most are harmless. We sometimes think of certain ones as “good” (beneficial bacteria) and others that can be potential pathogens if the circumstances are right as “bad.” Some factors that impact the bacteria in our gut include genes, age, environment, health, antibiotics, and diet. This is why your gut microbiota can and do shift over time.
How is the gut microbiota important?
A long time ago, medicine didn’t think much of bacteria. In fact, there was a time when it was believed they were mostly harmful, or at least not helpful. Times sure have changed! We’ve learned a lot about the importance of gut microbes in both gut and immune health. The gut microbiota plays an important role in the normal function of the body, including:
- Helping the body digest certain foods
- Producing some vitamins
- Defending against harmful pathogens
- Playing a role in metabolism
- Sending signals to the immune system
Since the gut microbiota can shift, and it’s composed of a range of “good” and “bad” bacteria, the more balanced the gut microbiota is - with more “good” microbes - the better it can perform the above roles in the body.
The gut microbiota is important in early life. In fact, the gut microbiota is more flexible in the first few years: It isn’t until about three years of age that the gut microbiota becomes relatively stable. The types and amounts of microbes in the gut in those first few months and years are influential, and have been linked to later health.
The development of a “healthy” and balanced gut microbiota in infancy is a key episode in early life. It’s hard to define what a “healthy” gut microbiota is, but the goal for infants is what the gut microbiota typically looks like for healthy, breastfed infants. For those infants, a balanced gut microbiota is typically dominated by bifidobacteria. Breast milk can be a source of bifidobacteria for breastfed infants, and provides nutrition that supports the growth of bifidobacteria.
What can happen if the gut microbiota isn’t in balance?
This has been tough to answer because gut microbes are so diverse, unique, and can shift. However, a growing body of research highlights the link between health and the gut microbiota. Scientists came up with a clever way to explore this. They’ve looked at the gut microbiota of infants and watched the health of the infants as they grew up. This let them look for clues that could link gut microbes with various health conditions.
Scientists have looked at lots of different health conditions, but we’re going to focus on the link between the gut microbiota and allergies. Here is a summary of some of what the research has found:
- A link between the gut microbiota in infancy and later food allergies
- A link between the gut microbiota in infancy and some later food allergic conditions
- A link between the gut microbiota in infancy and atopic dermatitis later in childhood
This body of research suggests that imbalances in the gut microbiota - a.k.a. “gut dysbiosis” - in early infancy may come before immune conditions, including food allergy and atopic dermatitis. It’s important to note that we don’t yet know the full extent of the link between the gut microbiota and these allergies. For example, we don’t know if one can cause the other, or if they just tend to occur together.
How does nutrition influence the gut microbiota?
You might be interested to know that what we eat and drink has a huge effect on the types and amounts of microbes in our gut. The reason is that every microbe has to “eat” – or consume – something. Let’s call this their “food.” Most of the food available to our gut microbes is the leftovers of the foods that we eat. In other words: after our gut digests and absorbs what it can from our snacks and meals, most of the rest is eaten by our gut microbes.
But every microbe prefers specific foods. When the food that a given microbe likes is available, that microbe grows and thrives and is present in high numbers. When that microbe’s preferred food isn’t around, the microbe may be in our gut, but in very low numbers. Many good microbes grow best on various fibers, whereas other microbes might grow well on fat or protein compounds.
For adults, eating a diet rich in fruits, vegetables and whole grains – all sources of fiber – can support a diverse gut microbiota. For infants, research has shown that human breast milk contains fiber-like compounds – human milk oligosaccharides – that support bifidobacteria. Bifidobacteria are the most common gut microbes in healthy, breastfed infants, but are much less common in older children and adults.
The gut microbiota in infants with food allergies
Research has found that infants with cow milk allergy and multiple food allergies can have an imbalanced gut microbiota. That means that there are differences when compared to infants without food allergies. Specifically, infants with cow milk allergy and multiple food allergies have been found to have fewer bifidobacteria in their gut compared with healthy, breastfed infants.
Infants with milk allergy and multiple food allergies who need formula to supplement or replace breast milk must use a hypoallergenic formula. Research with older hypoallergenic formulas found that they helped resolve food allergy symptoms, but didn’t shift the imbalance in gut microbiota.
Neocate® Syneo® Infant is the first and only hypoallergenic formula that is shown to help balance the gut microbiota of food-allergic infants to be closer to that of healthy, breastfed infants. That’s because Neocate Syneo Infant contains both prebiotics and probiotics, specifically designed for allergic infants.
A diagram explaining the difference between prebiotics and probiotics:
Who Is This Formula For?
Neocate Syneo Infant is specially formulated for the dietary management of infants with cow milk allergy (CMA), multiple food allergies (MFA) and related GI and allergic conditions, including food protein-induced enterocolitis syndrome (FPIES), eosinophilic esophagitis (EoE) and gastroesophageal reflux (GER). It's important to always contact a healthcare professional before making any changes to your baby's diet. Neocate Syneo Infant should be used under medical supervision.
Rob McCandlish is a registered dietitian nutritionist (RDN) who joined the Nutricia team in 2010. Rob has years of experience at Nutricia following food allergy research, working with Neocate products, talking with Neocate families and learning about the science behind Neocate and food allergies. Rob has two nephews who both used Neocate for their cow milk allergies!
Nutricia North America supports the use of breast milk wherever possible.