What Is the Gut Microbiome and Why Is It So Important?
Gut Health

What Is the Gut Microbiome and Why Is It So Important?


When it comes to gut health, many of us may have heard about the importance of the gut microbiome. But what actually is the microbiome in the gut and what does it even do?! From playing a major role in digestion, to brain health and even a healthy immune system, let us count the many (and we mean many!), ways.

What is the human gut microbiome?

Our amazing bodies are home to trillions of microorganisms. Our gut alone houses around 100 trillion of them, particularly bacteria, fungi, protozoa and even viruses. Collectively, these make up what is known as the gut microbiome.

Approximately 10,000 different species of gut microbes call the human gut home, however, most of these are thought to be bacteria. While each of these organisms play a very specific role within our body, gut bacteria and their various roles have been the most studied.

"Good bacteria" vs "bad bacteria"

There are around 1,000 different types of bacteria in the gut, each playing a unique role in our health. While most types of bacteria work to benefit our health in some way, there are some organisms that may work against us and contribute to disease, particularly when they become out of balance.

When it comes to the terms "good bacteria" and "bad bacteria", it’s best to think of these tiny microbes as beneficial and opportunistic instead. Where an imbalance occurs between the two – known as gut dysbiosis - this can lead to not only poor digestion, but can compromise our overall health as well.

Research suggests that an imbalance of gut bacteria has been linked to health concerns such as weight gain, heart disease, and even mental health disorders such as anxiety and depression. While there’s still so much to understand about the gut microbiome, there’s no doubt that supporting a healthy balance of gut bacteria is vital to our total wellbeing.

Functions of the gut microbiome

Our gut microbiome develops early in life, and is influenced by things like how we were born (for example, a vaginal birth versus a caesarean section), whether we were breastfed, our genetics, age, what and how we eat, plus things like stress, medication use and even the environment we live in. Over time, each of us has developed our own unique community of gut organisms that live within us, and every single one of them has a role to play.

One function of the gut microbiome is to help our bodies break down and digest food. Special types of gut bacteria produce something called short chain fatty acids, which serve as a main source of energy for the cells in our colon. They also work to break down and digest fibre from the food we eat, which can help to prevent concerns such as cardiovascular disease, diabetes, as well as help maintain body weight.

Other functions of our gut microbiota include:

  • Production of nutrients. Approximately half of our daily vitamin K needs are produced from our gut bacteria alone. On top of this, certain strains of gut bacteria are also able to produce some B vitamins including B1, B2, B5, biotin and folate.
  • Regulating our immune system. Around 70% of our immune system lies within our gut. Our bacteria play a crucial role in the development and function of the immune system and communicates with special immune cells to control how our body responds to infections. Imbalances of gut bacteria have also been linked with autoimmune disorders, such as rheumatoid arthritis and gut-related autoimmune diseases like ulcerative colitis and Crohn’s disease.
  • Supporting metabolism. Research suggests that an imbalance of gut bacteria can lead to weight gain. One study showed that supporting the gut with probiotics can assist with weight loss, however the exact way in which they do this is not yet fully understood. Some evidence suggests that beneficial bacteria strains from probiotics may support weight loss by regulating appetite, reducing fat storage proteins and inhibiting the absorption of fat through food.
  • Protecting our heart health. Studies have shown that the gut microbiome has a role in supporting good cholesterol levels which is important for the health of our heart. On the other hand, certain strains of unhealthy gut bacteria can produce certain chemicals which can block arteries and lead to heart disease.
  • Supporting brain health. Known as the “second brain”, our gut is connected to our brain through millions of nerves. This two-way street allows the gut and brain to communicate with each other, sending messages back and forth.

    Research suggests that certain gut microbes can help to produce neurotransmitters such as serotonin that can help with overall mood. A number of other studies have also shown that probiotic supplements can help improve our mental health, with specific strains of probiotic bacteria helping to reduce symptoms of depression and anxiety.

What causes imbalances in the gut microbiome?

A number of factors can lead to a reduction of gut flora as well as an imbalance of good and bad bacteria in the gut. When dysbiosis occurs, this can lead to issues with our digestion and absorption of food, our immune system, and put us at risk for disease. Things that affect our gut microbiome include:

  • Antibiotics. Antibiotic medications are important to help treat infections when we do get sick. But while they help to kill off the bad bacteria, they also kill off a lot of our beneficial bacteria too. This can result in an imbalance of gut bacteria and unfortunately affect us long term. In fact, one study showed that just a 7-day course of antibiotics resulted in long-term impacts on gut bacteria balance for up to 2 years.
  • Artificial sweeteners. Artificial sweeteners are often used as a replacement for sugar, however, studies show that these may stimulate the growth of unhealthy bacteria in the gut. While sweeteners don’t contain any sugar, evidence suggests that their effects on the microbiome can not only cause dysbiosis, but issues with blood sugar control, leading to increased risk of metabolic diseases like type 2 diabetes and obesity.
  • Alcohol intake. Alcohol is a gut irritant and excessive intake has shown to harm the balance of our gut bacteria, as well as affect intestinal permeability.
  • Processed foods. The typical Western diet is often high in processed foods. This concoction of sugar and salt laden foods along with additives, preservatives, colours, flavourings and artificial sweeteners is a perfect recipe to disrupt our bacteria balance and put us at risk for inflammation and disease.
  • Stress. Along with diet, high stress levels have also shown to have a major impact on the health of our gut and balance of gut microflora. Managing stress through self-care practices is therefore really important not only for mental wellbeing, but for our digestion and overall health too.

How to improve your gut microbiome

There are many ways that we can support a balanced microbiome and good gut health. These include:

  • Eating a wide variety of whole foods. By eating a wide range of different foods, this helps to promote diversity in our gut microflora. The more diverse our gut bacteria species are, the greater the health benefits.
  • Fermented foods. Fermented foods such as yoghurt, sauerkraut, miso and kimchi are naturally rich in beneficial probiotic bacteria. By eating these foods regularly, this can help support a balanced gut microbiome and reduce the number of unfriendly bacteria in the intestines that may contribute to disease.
  • Fibre rich foods. Eating a range of fruits, vegetables, beans and legumes is a great way to get in a host of nutrients and fibre to help our good bacteria thrive. Research also shows that a diet high in fruit and vegetables can influence our gut microbiome by reducing harmful bacteria linked to cardiovascular disease.
  • Natural herbs. Herbs such as slippery elm and marshmallow can help to support digestion and good gut health by soothing the gut lining, reducing irritation and encouraging diversity within the gut microbiome. Studies have shown that slippery elm has the ability to improve gut flora balance as well as reduce inflammation and protect against more harmful, opportunistic bacteria. Two Islands Happy Gut has been specifically formulated with a high dose of both slippery elm and marshmallow, alongside other soothing digestive herbs such as chamomile and ginger to help ease digestive discomfort and support a good balance of gut bacteria. Together, this specialised blend of herbs plus glutamine and apple fibre helps to nourish the gut lining, reduces bloating and supports healthy and regular bowel motions.

Overall, a healthy balance of gut bacteria is key to our total health and wellbeing. By eating a varied diet of fresh fruits and vegetables, limiting processed foods and alcohol plus taking lifestyle factors into account to manage stress, we can help to promote a balanced microbiome and a happy gut.

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