Exploring the Role of Human Microbiome Beyond Digestive Health

Did you know that the number of bacterial cells in and on our bodies is equal to or greater than that of human cells? These tiny organisms significantly impact our well-being, living in various parts of our bodies, including our gut, skin, and mouth. Surprisingly, they can communicate with other body systems like the immune system and the brain.

Although people often associate the microbiome with digestive health, its influence extends far beyond that, affecting aspects like mood, dental health, and exercise.

The human microbiome is an incredibly complex and dynamic ecosystem. Many factors, such as diet, environment, genetics, and medication use, can influence it. Thanks to recent advances in high-throughput sequencing technologies, we can now study the human microbiome in unprecedented detail. This has revealed much about these microorganisms' diversity and functional capacity.

It has become increasingly clear that changes to the human microbiome composition and function can significantly impact our health. In particular, dysbiosis (a disruption of the average balance of microorganisms in the microbiome) has been linked to various diseases, including inflammatory bowel disease, obesity, diabetes, and even cancer. This is because dysbiosis leads to inflammation, immune dysregulation, and altered metabolism.

Human microbiomes are the crucial and multifaceted ecosystem of microorganisms that inhabit the human body. These microorganisms regulate our immune system and produce antimicrobial compounds that prevent autoimmune diseases. Recent studies have demonstrated that the microbiome can also significantly impact brain development and function, potentially contributing to certain psychiatric disorders. By occupying specific niches, the microbiome effectively keeps harmful bacteria at bay and maintains a healthy balance, making it an indispensable component of our overall health and well-being.

Let's explore 5 potential roles of these microbiomes beyond digestive health:

Skin microbiome

Despite harsh physical conditions, the human skin maintains a diverse community of microbes essential for our health. These microorganisms also found in our digestive and urogenital tracts, play a critical role in maintaining the skin's health. They help protect against pathogens, regulate the immune response, and influence skin barrier function and hydration.

The skin microbiome is subject to change over time, just like our insides, and can be influenced by factors such as gender and environmental exposures.

The skin is often considered the body's primary defence mechanism. However, recent studies have revealed that our skin microbiome can also act as the first line of defence for our skin. A lack of beneficial microbes can result in skin problems such as atopic dermatitis, chronic wounds, and acne. Over the last decade, research has shown that maintaining a healthy balance of microbes on the skin is critical to its ability to function as a barrier. In the case of acne, for example, bacteria such as Propionibacterium acnes and Malassezia species can disrupt this balance, making it crucial to support the skin's barrier function by keeping harmful bacteria at bay. Skin conditions can lead to serious health issues like staph infections, sepsis, or blood poisoning. Overgrowth of staph on the skin may be due to a lack of friendly microbes.

Oral microbiome

The human mouth contains diverse microorganisms, including bacteria, fungi, viruses, and protozoa. These microorganisms form biofilms, which offer protection against external agents. Bacteria like Streptococcus mutans, Actinomycetes, and Prevotella can cause tooth decay by producing acid when they stick to teeth. This acid comes from fermentable carbohydrates. Imbalanced oral bacteria can also lead to inflammation and bone loss. Poor oral health impacts multiple systems, including cardiovascular, digestive, and endocrine. Periodontal disease is linked to endocarditis, diabetes, rheumatoid arthritis, and Alzheimer's. Caries and periodontal disease are both serious concerns.

Diet, smoking, antibiotics, and hormonal changes during pregnancy can all impact the makeup of oral microbiomes, increasing the risk of diseases like caries and periodontal disease. Pregnant women should be especially mindful of their oral health.

Microbiome and immunity

The gut microbiome is crucial for the development of a healthy immune system. Without exposure to the microbiome, our immune system becomes ineffective and dysregulated. The gut contains the highest concentration of microorganisms in contact with immune tissue, making it essential to protect ourselves from harmful pathogens entering the body through the gut. The interaction between the gut microbiome and the immune system involves the microbes and metabolites released into our cells and tissues.

The microbiome contains MAMPs, which are examples of microbe-associated molecular patterns. Our immune system gathers information about the diversity of MAMPs in the microbiome. This helps the immune system to protect the body against harmful microbes efficiently. Essentially, it's like having a microbial surveillance system that the immune system can learn from and adapt to.

Lung microbiome

The lung microbiota refers to the diverse community of microorganisms that inhabit the lower respiratory tract, specifically the mucous layer and epithelial surfaces. This complex microbiota includes bacteria, fungi, viruses, and bacteriophages, with the bacterial component being the most extensively researched. The core bacterial genera consist of Prevotella, Sphingomonas, Pseudomonas, Acinetobacter, Fusobacterium, Megasphaera, Veillonella, Staphylococcus, and Streptococcus, which can function as both aerobes and anaerobes. The composition of microbial communities is highly variable among individuals, with approximately 140 distinct families. The bronchial tree, for example, contains an average of 2000 bacterial genomes per cm2 surface. Respiratory specimens routinely detect harmful or potentially harmful bacteria, including Moraxella catarrhalis, Haemophilus influenzae, and Streptococcus pneumoniae, which are known to cause respiratory disorders.

The lung microbiome plays an important role in maintaining the health of the respiratory system, and recent research has suggested that changes in the lung microbiome may be associated with a range of respiratory diseases.

Here are some of the roles of the lung microbiome:

Protection against infection: The lung microbiome is believed to play a crucial role in protecting the respiratory tract against pathogenic bacteria and viruses. The presence of healthy microorganisms in the lung can help to prevent harmful bacteria from colonizing the respiratory tract, thus reducing the risk of infection.

Immune system regulation: The lung microbiome may also regulate the immune response within the respiratory tract. Studies have shown that the microorganisms within the lung can interact with immune cells and influence the production of immune proteins, such as cytokines, which help to fight infection and inflammation.

Lung development and function: Studies have shown that changes in the lung microbiome during early childhood may increase the risk of developing respiratory diseases later in life.

Metabolism and nutrition: The microorganisms within the lung microbiome can break down complex compounds and produce nutrients essential for the respiratory tract's health. This can help to maintain the balance of nutrients and prevent the growth of harmful bacteria.

Vaginal microbiome and women health

The vaginal microbiome consists of billions of microorganisms, mostly from the Lactobacillus genus. These microorganisms maintain a healthy environment by producing antimicrobial and anti-inflammatory compounds like lactic acid and hydrogen peroxide. They also regulate the pH levels in the vagina to protect against infection. Microorganisms in the vagina can be disturbed by various internal and external factors. A woman's hormones fluctuate throughout her life, and her immune system and environment change. Antibiotic therapy, infections, exposure to microbes, and active sexual life can disrupt this fragile ecosystem.

UTIs are common in women and are usually caused by bacteria from the intestine entering the urinary tract. Elderly people may be at higher risk due to factors like diet or obstruction. Lactobacillus bacteria in the urogenital system can help prevent UTIs by interfering with the adhesion of E. coli. This means that Lactobacilli may be a possible solution for managing recurrent UTIs.

For optimal health benefits, it is crucial to provide good nutrition to the tiny organisms that make up the human microbiome due to their diverse role.

Eat healthy for your microbiome

Various factors can have either positive or negative effects on the gut microbiota. Among them, dietary composition and habits are the most influential in regulating the dynamic gut microbiota. The primary components of our diet, including proteins, carbohydrates, fats, and fibres, significantly influence the gut microbiota and our overall health. However, certain diets that lack diversity can lead to dysbiosis within the gut ecosystem and even cause inflammation.

To maintain a healthy microbiome, consuming a balanced and varied diet that includes plenty of fibre-rich fruits, vegetables, and whole grains is essential. These foods provide the prebiotics that feeds the beneficial bacteria in the gut, promoting their growth and activity. In addition to prebiotics, it's also important to consume probiotics, which are live bacteria and yeasts that can be found in fermented foods like yogurt, kefir, kimchi, and sauerkraut. These foods help to introduce beneficial bacteria into the gut, promoting a healthy balance of microorganisms.

Nutrients like vitamins A, C, D, E, and zinc are important for maintaining a healthy microbiome. These nutrients regulate the immune system, support gut barrier function, and promote beneficial bacteria growth and activity.

On the other hand, consuming a diet high in sugar, saturated fat, and processed foods can disrupt the balance of microorganisms in the gut, leading to an overgrowth of harmful bacteria and an increased risk of chronic diseases.