By: Rose Mustafa, dietetic-student volunteer, Food, Nutrition, and Health program at UBC, reviewed by Mantala Milembamane, RD and the JM Nutrition Team
In recent years, the gut microbiome has become a hot topic in the scientific community. The gut microbiome refers to the diverse community of microorganisms. This includes bacteria, fungi, viruses, and archaea, that reside in the gastrointestinal tract (Sender, Fuchs, & Milo, 2016). These microbes play an essential role in a range of biological processes that are vital for our health. This ranges from digestion to immune function and even brain development (Marchesi et al., 2016).
While the gut microbiome has been studied in adults, its role in children’s health is an area of intense research, as early-life microbiome development has significant long-term implications. The composition and diversity of the gut microbiome in childhood has a tremendous impact. It can influence immune system development, metabolic health, brain function, and even behaviour.
Understanding the gut microbiome’s impact on children’s health is crucial, not only for treating health problems but also for prevention and improving quality of life.
As such, we will explore the complex ways in which the gut microbiome affects children, its role in their development, and why it matters.
Before we explore how the gut microbiome affect children and why it matters, let’s take a closer look at what the gut microbiome actually is.
What is the Gut Microbiome?
The human gut microbiome is a complex ecosystem of microorganisms that inhabit the gastrointestinal (GI) tract. In a healthy individual, the microbiome consists of trillions of microbes, with diverse species of bacteria being the most abundant. These microbes perform numerous essential functions, including:
- Digesting food: Certain bacteria help break down complex carbohydrates, fibres, and other nutrients that human enzymes cannot digest. This process releases energy and helps the body absorb key nutrients (Bäckhed et al., 2015).
- Synthesis of vitamins: Gut bacteria produce essential vitamins like vitamin K, biotin, and some B vitamins, all of which are necessary for the body’s functioning (Bäckhed et al., 2015).
- Regulation of the immune system: The microbiome influences immune cell development and helps regulate immune responses, ensuring that the body can effectively fight infections without overreacting to harmless substances (Gensollen et al., 2016).
- Metabolism: The microbiome influences how the body processes and stores energy from food. It also helps modulate fat storage and the balance of glucose and insulin in the body (Rooks & Garrett, 2016).
- Protection from pathogens: Beneficial bacteria outcompete harmful microbes for space and resources, thereby preventing infections and maintaining gut health (Lloyd-Price et al., 2016).
In children, the gut microbiome undergoes significant development from birth onwards. The first few years of life are particularly important for establishing a stable and balanced microbiome, as the microbial community in the gut influences many aspects of a child’s growth and health status.
How the Gut Microbiome Affects Children’s Health
The gut microbiome is intricately linked to various aspects of a child’s health. This ranges from immune function to mental health.
In this section, we will explore how the microbiome influences several key areas of children’s well-being.
1. Immune System Development and Protection
The gut microbiome plays an instrumental role in shaping the immune system. A healthy and diverse microbiome supports the development of immune tolerance, helping the body distinguish between harmful pathogens and harmless substances. It also promotes the production of regulatory immune cells, which help prevent autoimmune diseases and allergies (Gensollen et al., 2016).
At birth, an infant’s immune system is immature and requires microbial input to develop properly. The microbiome influences the maturation of immune cells and helps train the immune system to respond appropriately to different environmental challenges (Rautava et al., 2012; Belkaid & Hand, 2014).
Children with a more diverse microbiome tend to have better immune responses, while those with a disrupted microbiome are at increased risk for infections, allergies, asthma, and autoimmune disorders (Arrieta et al., 2014; Wopereis et al., 2014).
Research has shown that early microbial exposure plays a pivotal role in preventing allergic diseases.
For example, infants who are born via Cesarean section or who are not breastfed are at a higher risk of developing allergies and asthma. This is because they miss out on the natural microbial exposure provided by vaginal birth and breastfeeding (Zhao et al., 2022). Vaginal delivery allows the baby to be colonized by beneficial bacteria from the mother’s birth canal, and breast milk provides additional protective microbes and prebiotic compounds that help nurture the infant’s microbiome (Fernández et al., 2022).
Related: prenatal and postnatal dietitian support
By promoting a healthy microbiome from an early age, parents can help protect their children against a range of immune-related conditions.
2. Digestive Health and Nutrient Absorption
The gut microbiome plays a significant role in digestive health. Gut bacteria break down fibre and other complex carbohydrates that the body cannot digest on its own. This produces short-chain fatty acids (SCFAs) like butyrate, which provide energy for gut cells and help maintain a healthy intestinal lining (Rooks & Garrett, 2016). SCFAs also have anti-inflammatory properties and support the integrity of the gut barrier, preventing harmful substances from leaking into the bloodstream (Koh et al., 2016).
In children, a healthy gut microbiome is essential for proper digestion and nutrient absorption. Certain strains of bacteria help synthesize essential vitamins like vitamin K, folate, and B vitamins, which are critical for a child’s growth and development. For example, deficiencies in vitamin K can lead to bleeding disorders, while a lack of folate can result in developmental delays or neurological issues (Rothschild et al., 2018; Milani et al., 2017).
An imbalanced microbiome in children can lead to digestive problems such as constipation, bloating, diarrhea, and colic (Rautava et al., 2012).
It can also contribute to more serious conditions, such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) (Kostic, Xavier, & Gevers, 2014).
These conditions can have a significant impact on a child’s quality of life and overall health. Maintaining a balanced microbiome is therefore crucial for optimal digestive health and nutrient absorption in children.
3. Brain Development and Emotional Regulation: The Gut-Brain Axis
One of the most exciting and emerging areas of research is the connection between the gut microbiome and the brain, known as the gut-brain axis. This two-way communication system links the gut to the brain through multiple pathways, including the vagus nerve, immune molecules, and the production of neurotransmitters by gut bacteria (Dinan et al., 2015).
Related: dietitian’s support for brain health
In children, the gut-brain axis plays a critical role in brain development, cognition, and emotional regulation. Early disturbances in the gut microbiome can influence brain development and behaviour, potentially leading to neurodevelopmental disorders such as autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and anxiety (Davenport et al., 2017).
For example, gut bacteria produce neurotransmitters such as serotonin, dopamine, and gamma-aminobutyric acid (GABA), which are involved in mood regulation and cognitive function. A healthy microbiome supports balanced levels of these neurotransmitters, helping children manage stress, emotions, and mental health. In contrast, an imbalanced microbiome may lead to an overproduction or underproduction of these important chemicals. Consequently, this may contribute to mood disorders or cognitive difficulties (Wang et al., 2023).
There is also evidence that gut bacteria influence sleep, memory, and learning. Undoubtedly, these are essential for a child’s academic success and emotional well-being. By supporting the development of a healthy gut microbiome, parents can help improve their children’s emotional and cognitive outcomes (Wang et al., 2023).
4. Metabolic Health and Obesity Prevention
The gut microbiome is deeply involved in regulating metabolism. This includes energy balance, fat storage, and glucose metabolism. Children with an imbalanced microbiome are at an increased risk for obesity and metabolic diseases like insulin resistance and type 2 diabetes (Ridaura et al., 2013).
Research has shown that the composition of the gut microbiome can influence a child’s weight and metabolism.
For example, children with obesity often have a less diverse microbiome and a higher proportion of bacteria associated with the fermentation of carbohydrates and fat storage (Zhao et al., 2022). These microbial patterns may promote weight gain and increase the risk of metabolic disorders.
Additionally, disruptions in the microbiome during infancy, such as those caused by early antibiotic use, Cesarean delivery, or poor dietary habits, may set the stage for obesity later in life. A balanced microbiome, supported by a healthy diet and lifestyle, can help maintain a healthy weight and reduce the risk of metabolic disorders in children (Zhao et al., 2022).
Factors that Influence the Gut Microbiome in Children
To better understand how the gut microbiome affects children, it’s important to know the factors that help shape it.
Several factors shape the gut microbiome in children. These factors include:
- Mode of delivery: vaginal birth vs. Cesarean section
- Breastfeeding vs. formula feeding
- Antibiotic use
- Diet factors: eating lots of fruits, vegetables, and fibre helps grow good bacteria, while eating many sugary and processed foods can lower the number of helpful microbes (Milani et al., 2017).
- Environmental factors: The environment also matters—children who grow up with pets, play outside often, or live in rural areas tend to have more diverse microbes in their gut (Tamburini et al., 2016).
Why the Gut Microbiome Matters: Long-Term Implications for Children’s Health
The early development of the gut microbiome has far-reaching implications for children’s health. Disruptions to the microbiome during infancy and childhood can contribute to a range of health problems. This includes increased risk of allergies, asthma, autoimmune diseases, mental health disorders, obesity, and metabolic disorders.
Therefore, maintaining a healthy gut microbiome in childhood can help mitigate these risks and improve children’s long-term health and quality of life.
How the Gut Microbiome Affects Children and Why It Matters Final Thoughts
The gut microbiome plays a critical role in the health and development of children. From immune function to brain development, the gut microbiome influences nearly every aspect of a child’s growth and well-being.
Understanding the importance of the microbiome and promoting healthy practices, such as breastfeeding, a balanced diet, and minimizing unnecessary antibiotic use, can help foster a healthy gut microbiome in children and set the stage for lifelong health.
By nurturing the microbiome from an early age, we can help ensure that children grow up strong, healthy, and resilient.
Conclusion
We hope that the information presented herein shed some light on how the gut microbiome affects children and why it matters.
If you’re interested in receiving personalized nutrition counselling with one of our dietitians and nutritionists for digestive health or pediatric nutrition, book a free consultation and we will gladly lend a hand.
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