More and more health experts and scientists are highlighting the importance of the microbiome and the role it plays in preventing disease and illness. This article will answer some of the most common questions you may have about what the microbiome actually is, why you need to support it and how your nutrition can be central to this support.
What is the microbiome?
The term ‘microbiome’ refers to the trillions of bacteria, viruses and fungi that comprise the intricate and incredible ecosystem of your gut. While it may worry you to have so many of these things that often have negative associations inside you, they are actually what allow us to break down and absorb nutrients from the food we eat. They are also responsible for supporting our immune system by attacking pathogens and they play a role in regulating the hormones that control our mood and energy levels.
So it is clear that without a microbiome we could not survive. But what is becoming more clear to researchers is the damage that can be caused when the delicate balance of the microbiome is interrupted. When the microbiome is out of balance, numerous important mechanisms cease to function, potentially causing digestive issues, mood swings, metabolism disfunction, blood sugar problems and all the illnesses that can accompany these. The bottom line is that without a healthy gut it is impossible to have a healthy body.
To understand why this is the case, it is useful to understand the basics of digestion.
Digestion 101
When we talk about the digestive system, we are referring to the continuous tract that runs from the mouth to the anus and includes the esophagus, stomach, and the large and small intestines. The liver, pancreas and gallbladder also play important roles in digestions, via their bile and enzyme secretions, however they are not directly part of the digestive path through which our food travels.
Digestion starts in the mouth. When we chew, our food is broken down by our teeth and is combined with saliva, which creates a mash called ‘bolus’, which we swallow. The more you chew, the less intensely the rest of your digestive system will have to work to break your food down to an absorbable level, so it is very important not to rush this stage. Experts recommend chewing each bite around 30 times before swallowing.
After swallowing, the bolus moves down through the esophagus and into the stomach. The stomach is a large pouch that contains many digestive acids, which break the bolus down further into a kind of frothy liquid called ‘chyme’. It is important that the stomach acids are working correctly so that large, indigestible food particles are not left over and passed into the intestine. If you are noticing recognisable pieces of food in your stool, it could be a sign that you are not producing enough stomach acid, however it could also be a sign that you have not sufficiently chewed your food. Stomach acids also neutralise many toxins and pathogens that could cause issues further down the digestive tract.
From the stomach, the chyme is passed into the small intestine, which is where most of the nutrients from your food are absorbed into the body. The small intestine is actually around 20 feet long in an adult, so there is plenty of time for pancreatic juices and bile from the liver and gallbladder to break down the various proteins and emulsify the fats.
From the small intestine, the remaining chyme gets passed into the large intestine, where residual water is extracted and the resulting waste is compacted to produce feces, which is then pushed out through the anus. The large intestine contains many billions of bacteria that metabolise the waste as it travels towards the end of the digestive tract.
If you want to understand and support your biome, it is important to grasp the basics of how your digestive system works, so read this section as many times as you need to.
The role bacteria plays in your microbiome
The billions of bacteria and microbes within your digestive tract play an essential role in maintaining good health. There are 30 or 40 main types of bacteria, which each have different jobs, including:
supporting and stimulating activity in the immune system
breaking down food particles
neutralising toxins
maintaining and repairing the intestinal lining
synthesising vitamins including B vitamins and vitamin K
The microbes within your digestive system produce ‘metabolites’ which, as their name suggests, are responsible for processes of metabolism, the chemical processes that make life itself possible. Taken as a whole, the metabolites in the gut are known as the ‘metabolome’. A well balanced metabolome supports good digestion, whereas too many, too few, or the wrong ratio of metabolites can mean the digestive system begins to malfunction.
The third vital part of your gut, working alongside the microbiome and metabolome, is the layer of cells that form the gut lining. You may have heard the term ‘leaky gut’ in the media or even elsewhere on this site. This refers to a common condition where a number of factors, including stress, diet or an unbalanced microbiome, cause a loosening of the junctions between the cells. The gut lining then becomes ‘permeable’, meaning that toxins, food particles bacteria and metabolic waste can escape into the bloodstream instead of being excreted. Leaky gut can cause numerous health issues, which you can read more about in this article.
The importance of the microbiome
The microbiome refers to the trillions of microbes, including bacteria, fungi, viruses and yeasts, that reside in the gut, most of which are in the large intestine. A healthy microbiome does not just require the presence of these microbes, but also that they are able to properly interact with each other. Having the right combination of bacteria in the right proportions can assist with many of the body's most important functions, including:
Immunity
Metabolic function
Skin health
Blood sugar balance
Weight regulation
Mood stabilisation
On the other hand, an unbalanced microbiome has been linked to a number of unpleasant symptoms, including:
Increased frequency of illness
Slow metabolism
Bloating or tendency to be gassy
Diarrhoea or constipation
Poor skin health (rashes, acne, eczema etc.
Difficulty controlling weight
Brain fog
Mood fluctuations
Hypoglycaemic or hyperglycaemic
How to balance your microbiome
Our understanding of the microbiome is expanding all the time, but according to what we currently understand, the manageable factors that have the greatest effect on its health are:
Diet
Environment
Stress
Exercise
Resilience
Poor diet, environmental toxins and stress have all been found to impact digestive secretions, transit time and absorption in the gut, while diet also determines which nutrients and microbes are introduced to the gastrointestinal tract, either beneficial or pathogenic. The ideal diet for a healthy microbiome is one that includes clean proteins, gluten-free grains, fresh vegetables and low-GI fruits. Since a wide variety of microbes are required to run the gut, it is best to include as wide a variety of healthy foods as possible, aiming to regularly rotate the fruit and veg that form part of your daily diet.
Everyone is slightly different when it comes to nutritional requirements but sticking to the above principles will help to ensure that you give your microbiome the best chance of getting what it needs. Look out for an upcoming article on FODMAPS to further understand how your nutrition can impact your microbiome.
Regular exercise and movement of any sort can support microbiome health. Studies have found that exercise may induce microbial changes in the gut which improve immune responses, lower inflammation and alleviate the symptoms of metabolic disorders. Exercise does not need to be exhausting or painful. Try to think of any movement as exercise and work out ways of introducing more movement into your day. Modern life with its labour-saving devices is designed to remove as much physical movement as possible. What we are learning now is that it is absolutely vital to recover that lost movement in whatever way we can. Try working standing up or parking further away from work and walking part of the way into the office. In terms of cardiovascular exercise, the important thing is to find something that is fun so that you look forward to doing it.
Resilience refers to our ability to effectively manage and respond to stress. Prolonged activation of the stress response can be disruptive to microbiome balance, so learning how to avoid stress when possible, and to manage it when it is inevitable, is an important way of supporting gut health. Your stress response and your microbiome have a symbiotic relationship, meaning that they affect each other. Stress causes a disrupted microbiome, while the microbiome affects mood. Therefore having regular and proven stress-management techniques is an important way to prevent this relationship from becoming toxic. To learn more about stress management and how nutrition can play a role in this please read this detailed article on lifestyle hacks to lower your stress levels.