the gut glossary
Check out our one-stop-explanatory-shop for everything gut health below. We’ve even organised it A-Z for ya.
What is bacteria?
Bacteria are single-celled micro-organisms and can be found all over our bodies, including our mouths, skin and, of course, the gut (the ones we’re interested in!).
There are so many different species of bacteria in your gut. Think of the different species as having different job titles – they all do different things. Within a bacteria species (or job titles), there are ‘strains’. Strains are a further way of separating out the differences between bacteria belonging to the same species. For example:
Species: lactobacillus (music artist)
Strains: L. acidophilus (bassist)
- amylovorus (DJ)
- casei (singer)
- rhamnosus (backing vocalist)
What does it do?
Mostly, lots of great things, but sometimes the wrong type or too much/too little bacteria can cause problems.
The bacteria in your gut make up your microbiota.
The ratio of human to bacterial cells is thought to be 1.3:1. Scientists are continuing to research the true ratio but it makes up a big proportion of who we are!
What is bile?
Bile is a liquid produced in your liver and stored in your gallbladder. Your gut microbes can influence your bile and bile can influence your gut microbiota.
What does it do?
Bile helps us break down fats so we can absorb fat-soluble vitamins, such as vitamins A, D, E and K. It also gets rid of toxins we no longer need.
What is chyme?
Chyme is a cocktail of stomach acid, digestive enzymes, partially digested food and water.
What does it do?
Chyme allows for further digestion by enzymes and is a carrier of food and enzymes to the small intestine.
What is dysbiosis ?
Think of your gut microbiota as a country garden – you want a variety of different plants (beneficial microbes) and not too many weeds (less beneficial microbes) for a happy and healthy gut. We need our gut microbiota to be diverse and balanced, if our gut microbiota is in a state of dysbiosis, this means it is imbalanced or there is a disturbance in the normal composition of microbes, for example, decreased diversity of beneficial microbes.
What does it do?
Dysbiosis may negatively affect different aspects of your health, including your immune system, physical and mental health.
What are enzymes?
Digestive enzymes are crucial for good gut health! Your body produces lots of different digestive enzymes to support the digestion and absorption of fats, proteins, carbohydrates and micronutrients. For example, amylase is secreted by your salivary glands and pancreas to break carbohydrates down into glucose, which your body can use as fuel and lipase is secreted by the pancreas to support fat digestion.
What does it do?
Digestive enzymes help to break down our food so we can absorb it. If we don’t break down our food properly, this can affect our gut microbes.
What are faeces?
This is just another word for poo! Faeces are made up of water, bacteria, fats, protein, toxins and undigested food, including fibre, which helps bulk out your stool!
What does it do?
The purpose of having a poo is to rid your body of waste, toxins and other compounds.
What is fibre?
What does it do?
- Fibre bulks out and softens your stool by retaining water, which supports gut transit time and prevents constipation
- Certain types of fibre can be fermented by beneficial gut bacteria, which produce short chain fatty acids, which are a source of energy and also have other health benefits
- Fibre slows down the breakdown of sugars found in carbohydrates, which helps stabilise your energy levels
- Fibre promotes an environment favourable to beneficial gut bacteria
- A diet high in fibre can reduce the risk of developing high cholesterol, heart disease, diabetes and bowel cancer
What is GALT?
Yes, it is a bit of a mouthful, but GALT is extremely important and a huge part of your immune system! It consists of lots of immune cells lining your gut and it plays a fundamental role in defending your body against foreign invaders.
What does it do?
Protects you from pathogens such as bacteria and viruses. Your gut microbiota can influence how well your GALT works and vice versa.
What is the gut?
When we talk about the gut, we mean mainly your small and large intestine. Your small intestine has an average length of 3–6 metres! Your large intestine (where the majority of your gut bugs live) is around 1.5 metres long and makes up one fifth of your digestive tract. Your large intestine houses most of your gut bacteria. Your gut is supported by your stomach, liver, pancreas and gallbladder.
Find out more here.
What does it do?
Your gut has many functions, but the key ones are:
- houses the majority of your microbiome
- digests and absorbs nutrients
- supports immune function (approximately 70%)
- plays a role in producing chemicals that affect how we feel
In your lifetime, around 60 tonnes of food will pass through your gut!
What is the gut microbiome?
The trillions of microbes, their functions and genes (including bacteria, yeast, fungi and parasites) and their genetic material living within your gut. More than 1,000 species have been identified!
What does it do?
Our microbes do incredible things, here are our top picks:
- Produce vitamins, including vitamin K and B vitamins
- Produces short chain fatty acids, which fuel your gut cells
- Supports immune function and defends against pathogens
- Influence how often you ‘go’ to the loo
- Regulates health of gut
- Ferments fibre that your body cannot digest
- Influences mood and mental health
- Influences sleep
- Supports hormone regulation
- Regulates metabolism.
See more on the microbiome here.
What are gut microbiota?
The types of organisms (bacteria, viruses, parasites etc.) present in your gut. You might also hear the terms ‘microbiota’ or ‘microflora’ used interchangeably, but we use the term microbiota.
Diet, medication, environment and genes are just some of the factors that can influence your gut microbiota. Our microbiomes are unique to each and every one of us! Twins may have the same DNA, but their microbiomes will be different.
Our gut bugs can determine how well we manage different foods, from bananas to avocados.
What does it do?
Our microbes do incredible things, here are our top pics:
- Produce vitamins, including vitamin K and B vitamins
- Produces short chain fatty acids, which fuel your gut cells
- Supports immune function and defends against pathogens
- Influence how often you ‘go’ to the loo
- Regulates health of gut
- Ferments fibre that your body cannot digest
- Influences mood and mental health
- Influences sleep
- Supports hormone regulation
- Regulates metabolism.
Your gut microbes interact with almost all of your human cells!
What are gut mucosa?
The gut mucosa includes GALT (see above) as well as other immune cells and bacteria, which all work together to distinguish friend from foe in the gut. It allows dietary substances to cross into your bloodstream, but still stops pathogens from entering. Specific types of bacteria like to live in your gut mucosa, like our old friend Akkermansia.
What does it do?
An important part of our immune system, which provides a balance of beneficial bacteria and stops pathogens from getting in.
What are polyphenols?
Polyphenols are protective compounds found in plants, typically are found in higher quantities in brightly coloured vegetables. Your gut microbiota converts polyphenols from plants into something your body can use.
What does it do?
Polyphenols have antioxidant properties to help your microbes be their best selves and support overall health.
Food sources include brightly coloured vegetables, fruit, tea, coffee, dark chocolate, legumes and olive oil.
You can read more about polyphenols here.
What are prebiotics?
Prebiotics are a specific type of fibre, which can be broadly defined as non-digestible carbohydrates. Our gut bacteria like to ferment them, which can cause changes to our gut microbes.
The following are types of prebiotic fibre you might hear about:
- Inulin
- Oligofructose
- Galacto-oligosaccharides (GOS)
- Xylooligosaccharides (XOS)
Great sources of prebiotic food include onions, garlic, leeks, bananas, asparagus, artichokes, olives, plums, apples, plus wholegrains like oats, bran and nuts such as almonds.
What does it do?
Prebiotic foods can change the composition of your gut microbes by stimulating growth of beneficial bacteria.
You can read more about prebiotics here.
What are probiotics?
The term probiotic is banded around a lot! The true meaning is a live microorganism that, when administered in adequate amounts, confers a health benefit on the host. Probiotics can be in food or supplement form, but not all probiotics are created equal – different strains have different effects, and some might have no effect at all. It all depends on the individual.
Examples of food probiotics: yogurt, kimchi, sauerkraut, kefir, miso and kombucha. BUT if you are buying shop-bought versions, make sure you check for ‘live bacteria’ on the back of the pack.
What does it do?
Depending on the strain and the individual, probiotics can have lots of positive effects on the person consuming them. Some examples of what they can do:
- compete with other microbes in your gut
- effect your gut mucosal barrier
- support your immune system
Science is still learning exactly how different strains work so watch this space.
What are short chain fatty acids?
Most short chain fatty acids are produced within your large intestine by the fermentation of fibre by your gut microbes.
The main types are:
- Acetate
- Propionate
- Butyrate
Each have different functions in the body.
Fermented products may also contain short chain fatty acids. If we don’t eat enough fibre, this can decrease the amount of ‘food’ bacteria have to ferment and therefore reduce the number of short chain fatty acids produced.
What does it do?
Short chain fatty acids keep your gut healthy, are the primary source of energy for gut cells, are involved in the metabolism of nutrients, including carbohydrates and fat, support your immune system and may be protective against certain diseases.
We are still learning about the role of short chain fatty acids and health.
You can read more about probiotics here.
