Google receives thousands of searches around the gut every day. Here, we've answered some of the most common questions with an aim to educate on what's going on in your gut and why. 

What is the Gut Microbiome?

The gut microbiome exists in every person and consists of trillions of microorganisms - primarily good and bad bacteria.

The gut microbiome is involved in many primary bodily functions, and the health of the gut microbiome influences how well your body functions in terms of things like your immune system, cerebral function, digestive function, brain function, metabolism, body weight and skin health to name a few.¹

The gut microbiome exists in your digestive tract, with most bacteria living in your small and large intestines. The bacteria have an essential function; they help you digest the food you eat and use the nutrients within it.¹

Every person's gut microbiome is utterly unique in the types and quantities of each bacteria, but a healthy gut microbiome has trillions of good bacteria. If the bacteria is imbalanced, this causes the gut microbiome to be in a state of dysbiosis, which makes us more susceptible to disease, illness and health issues in the body.¹

What is in the Digestive Tract?

The digestive tract comprises “hollow” and “solid” organs that all work together to digest everything you consume.²

It stretches from your mouth to your anus, with the hollow organs being the mouth, oesophagus, stomach, small intestine, large intestine, and anus, and the solid organs being the liver, pancreas, and gallbladder.²

The small intestine is actually made up of 3 parts - The duodenum, the jejunum and the ileum. The large intestine comprises the appendix, cecum, colon and rectum.²

How do I Feed Good Bacteria?

The best way to feed good bacteria is to consume prebiotics- the best kind for the good bacteria is dietary fibre. Prebiotics act as food for the good bacteria in the gut microbiome, arriving at the bacteria relatively intact, making them a nutritious food source.

The good bacteria feast on the prebiotics' nutrients and allow them to grow stronger, thrive and multiply. By multiplying, they leave less room for the bad bacteria to do so, which maintains the health and balance of the gut microbiome.

If the good bacteria don’t have a food source, they can either die or feast on the intestinal lining, leading to inflammation and damage.

Why am I Bloated?

Bloating occurs when there is excess gas in the gut. Gas is used to help us digest food, so if the body is struggling to digest food, it may produce more gas to aid the process, which can cause bloating.

There can be many reasons your digestive tract struggles to digest food, but the most common cause is the foods you eat and when you eat them. If you eat late at night, your body may struggle to digest overnight, leading to bloating in the morning.

Eating foods you are intolerant of or overeating at once can cause digestive problems that lead to bloating. 

Why am I Constipated or have Diarrhoea?

Constipation also stems from digestive issues. It can be caused by not consuming enough fibre or being dehydrated. Fibre adds bulk to the stool; water helps to loosen the stool, making it move through the digestive tract more easily.

Diarrhoea can occur because the stool isn’t forming correctly and is moving through the digestive tract too quickly. Food intolerances can cause both of these issues, overeating, foods that aren’t nutritious, such as processed foods and fatty foods, or health conditions such as IBS or Crohn’s.

Why do I have Stomach Issues when I’m Stressed?

Complex signals are sent between the brain, and the gut, referred to as the gut-brain axis. The alerts allow them to communicate to keep the body functioning well. This means that if one of them is unhealthy, the other can also become unhealthy.³

Part of this communication process involves the central nervous system, which can deliver signals to the stomach regarding stress.

Stress is a natural body response to danger - feeling threatened or under pressure. 95% of serotonin is made in the gut, and when the brain becomes stressed, it encourages the gut to produce more serotonin than average which moves the food through the gastrointestinal tract faster.

This can lead to the sudden urge to go to the toilet or even accidents. A dysfunction in the nervous system, specifically the vagus nerve, can cause the body to feel stressed and increase gut motility.⁴

What is the Relationship between the Gut and the Immune System?

Our immune system comprises cells, roughly 70% of which are in the gut. This means that many of the cells that create antibodies designed to fight off germs are within the gut.

An imbalance between good and bad bacteria can cause inflammation, which the immune system then spends its time fighting off. This leaves us vulnerable to infections as the immune system has less time to concentrate on foreign invaders that may make us ill.^5,6

How do Antibiotics affect the Gut?

Antibiotics can be great at getting rid of bacteria that are making you ill, but unfortunately, they cannot specifically target the bacteria causing trouble.

Antibiotics kill all bacteria they come into contact with, including good bacteria. This can cause dysbiosis in the gut microbiome, as the diversity and quantity of bacteria can be severely limited.

If you need to take antibiotics, a probiotic supplement can help add new species of good bacteria into the gut microbiome whilst encouraging the existing good bacteria to repopulate. This limits the damage that antibiotics can do. 

How Does Alcohol Affect the Gut?

Alcohol can limit the variety and quantity of bacteria in the gut, leading to dysbiosis. The more you drink, the more the impact, so restricting alcohol intake will positively impact the diversity of your gut microbiome.⁷

Alcohol can also lead to leaky gut syndrome, which can lead to health issues due to food waste and toxins travelling out of the digestive tract.

Usually, our gastrointestinal tract is naturally permeable as it needs to allow nutrients to pass through the intestinal lining and arrive in your bloodstream so they can travel around the body.^8,9

This process also acts as a protective barrier to keep toxins out of your blood and maintain your immune health. Alcohol can weaken this barrier by damaging the cells that line the intestinal walls, which can cause chronic inflammation.^8,9

What Foods are Bad for The Gut?

Sugar is fine, in fact, necessary for our bodies. Our brain's primary energy source comes from glucose, but the type of sugar you eat is essential here.

Free sugars, or refined sugars like cakes, biscuits, and sugary drinks, often have far too much sugar for the body and are processed much faster than natural sugars.¹⁰

Natural sugars move through the body slower, allowing the gut to use the nutrients in it, whereas refined sugars fly through, and the good bacteria can’t gain what it needs from them. Excess sugar may also prevent good bacteria from surviving, leaving more room for bad bacteria to grow in the gut, leading to health issues.¹⁰

Additionally, a problem can occur when you overeat sugar. Consuming under 7 teaspoons of sugar means that it can all be processed in the small intestine and will not interact with all of the bacteria in the large intestine.

Our small intestine reaches a capacity of around 7 teaspoons of sugar, so any extra will travel down to the large intestine where it’s not supposed to be. When the sugar travels into the large intestine, it can eventually end up in the liver and the bloodstream.¹⁰

So, What Have We Learned?

Now that you know what the gut microbiome is and how the digestive tract works, you can be more conscious about how you treat it.

Understanding the brain-gut connection and the connection to the immune system gives you a broader understanding of how the body is connected.

Gut issues often stem from what we put into our body and when we consume it. Foods can be damaging when consumed in large quantities, and some foods are great for the gut microbiome. 

We hope that this insight into the gut helps you to take better care of yourself; remember, knowledge is power, and you can use that power however works best for you.