Glossary - G

GALT (gut-associated lymphoid tissue)

The gut-associated lymphoid tissue, or GALT, comprises of several types of lymphoid tissue that work to protect the body from invasion. These lymphoid tissues include Peyer’s patches, tonsils and adenoids.

Gamma-aminobutyric acid (GABA)

GABA is an amino acid found in the brain, that functions as an inhibitory neurotransmitter. It has a calming effect on nerve impulses in the brain, making it a natural ‘relaxation agent’. A deficiency of GABA can lead to feelings of anxiety, tension headaches and even reduced cognitive function as the nervous system becomes over-stimulated and agitated.

Gastrointestinal health

Referring collectively to the stomach and small and large intestines. The commonly used abbreviation for gastrointestinal is GI.

Gastrointestinal tract

The gastrointestinal tract, or simply ‘gut’, refers to the entire passage between a human’s mouth and anus, including the oesophagus and stomach. This system of organs takes in food, digests it to extract energy and nutrients, and expels the remaining waste.

Gastro-oesophageal reflux disease (GORD)

Gastro-oesophageal reflux disease (GORD), or simply acid reflux disease, is caused by stomach acids escaping the stomach into the oesophagus, causing mucosal damage of the oesophagus lining or chronic symptoms; the most common being frequent heartburn.
The condition usually occurs due to a spontaneous and unnecessary opening of the barrier muscles between the stomach and oesophagus. Possible reasons for this have been cited as a hiatal hernia or abnormal relaxation of the lower oesophageal sphincter.


Gastroenteritis, or gastric flu, is an infection of the gut (usually the stomach or intestines). The infection can be viral, bacterial or parasitic; and is often caused by consumption of contaminated food or drinks. Symptoms include diarrhoea, abdominal cramping, bloating, nausea and vomiting.
Having a healthy balance of friendly bacteria in the gut is thought to lessen the risk of gastroenteritis, as well as relieving symptoms and quickening recovery.


A genus is a group of related or similar organisms and can be referred to as a ‘family’. A genus contains one or more species. Examples of probiotic genera include Bifidobacterium and Lactobacillus.


Gluten-free means that a product does not have any gluten-containing ingredients. Gluten is a family of proteins (primarily glutenin and gliadin) found in grains such as barley, rye and wheat, which form a sticky substance and help to make the dough elastic. Gluten causes an auto-immune reaction in people with coeliac disease. It is also thought to cause a reaction in people suffering from non-coeliac gluten sensitivity. All ProVen Probiotics products are gluten-free.

GOS (Galactooligosaccharides)

Galactooligosaccharides (or GOS) are carbohydrates that form prebiotic fibre to feed the friendly bacteria (probiotics). GOS is naturally present in breast milk and is thought to help feed the friendly bacteria to help the development of the baby’s microbiome. GOS can also be derived from the lactose in milk.

Gram-negative bacteria

This group of bacteria are known as ‘gram-negative’ as they don’t change colour when coming into contact with a staining method known as Gram’s method. This method is used to classify different types of bacteria. Gram-negative bacteria usually have thin cell walls and include members of the E. coli genus.


This group of bacteria is known as ‘gram-positive’ as they change colour when coming into contact with a staining method known as Gram’s method. This method is used in order to classify different types of bacteria. ‘Gram-positive’ bacteria have a thick cell wall (made out of peptidoglycan) which take on the purple stain.

Gut-brain axis

The gut-brain axis refers to the physical and chemical connections between your gut and brain. Neurotransmitters and other chemicals produced in your gut also affect your brain. By altering the types of bacteria in your gut, it may be possible to improve your brain health.

Gut flora

‘Gut flora’ refers to the microorganisms that live within the body’s digestive tract, mostly comprised of bacteria, including both probiotics and pathogenic bacteria.

Gut friendly

Foods such as plain live yoghurt, fruits, vegetables, pulses, nuts and wholegrain foods are considered to be gut friendly as they feed healthy bacteria in the gut. Highly-processed foods, cigarette smoking and alcohol (which do not constitute being gut-friendly) contain ingredients that either suppress ‘good’ bacteria or increase ‘bad’ bacteria.

Gut health

Gut health relates to the balance of microorganisms within the GI tract. This balance of bacteria, fungi and viruses is largely attributed to what we eat, how we sleep and our lifestyle habits such as exercise and alcohol consumption.

Gut integrity

Gut integrity refers to the health of the structure of the intestinal lining. An impairment of this gastrointestinal lining increases the risk of developing GI diseases, food intolerances, inflammation in the body and infections. Gut integrity can be damaged by a number of things prominent in modern life such as antibiotics, parasites, an unhealthy diet, and sugar.

Additions to our Probiotics Glossary

If you come across a term you feel should be within our Probiotics Glossary, please do not hesitate to reach out to us and we will endeavour to research and add them. Email us at: [email protected]/uk

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