- The ‘gut’ is the gastrointestinal system, comprising the mouth, oesophagus, stomach, and small and large intestines, and accessory organs
- Its role is to provide an external surface to absorb nutrients from food
- It is also critically important for the modulation of inflammation and immunity
What is gut health?
When people talk about the ‘gut’, they’re referring to the gastrointestinal system, also known as the digestive system or digestive tract. This system includes the mouth, oesophagus, stomach, and the small and large intestine. It also includes the accessory organs which aid digestion by helping to break down larger particles of food into absorbable particles (i.e. the tongue, salivary glands, pancreas, liver, and gallbladder). Having a healthy digestive system allows us to absorb nutrients optimally and helps to reduce inflammation, support immunity, and even plays a role in helping us to feel better mentally.
Why is gut health important?
Because it’s exposed to the external environment, the digestive system is an external organ by which we absorb the nutrients that make up the body’s structures, chemical messengers, and fuels. Because it’s exposed to the outside environment, it is also a potential site of infection from pathogens (disease-causing microbes) and pollutants in food and water and so, is part of our innate defences against disease and disorder that has an important relationship with the immune system of the body.
Is gut health a fad?
Because the role of the gut is so important for both nourishment and immunity, ‘gut health’ couldn’t be called a fad. Having a healthy gut is an essential component of wellbeing! However, there can be dubious claims made about supplements and diets for gut health that aren’t backed by strong evidence.
What is the microbiome?
The microbiome is the community of microbes found in the body. Technically, microbiome refers to collective genomes of these microbes with microbiota used to describe the communities of microbes but in general use, these terms are used synonymously. Usually, the microbiome in common usage refers to the community of bacteria in the gut but it also includes other microbes like fungi, protozoa, and viruses and there is distinct microbiota of the skin, oral cavity, and other surfaces.
What are probiotics?
Probiotics are microbes (usually bacteria) that can be taken as a supplement to help improve the balance of the microbiome.
What are prebiotics?
Prebiotics are fuels that feed (beneficial) microbes in the gut. Usually, these are fibres and resistant starches that feed particular bacteria.
Effects of the gut on health
Gut health and the microbiome play an important role in our overall health. Poor gut health caused by disturbances to the balance of ‘good’ and ‘bad’ microbes in the gut can affect both nourishment and growth and metabolic conditions like obesity and type 2 diabetes.1
The key role of the gastrointestinal tract is to absorb nutrients from food. So, having a gut that functions correctly (that can also keep out any ‘nasties’) and absorb nutrients from food is essential to achieving optimal health. The microbiome also contains bacteria that produce nutrients, like short-chain fatty acids which feed cells of the digestive wall, other bacteria, and can be taken up into the body to use as fuel. These and other chemicals produced by bacteria in the gut also act as messengers that provide a ‘metabolic interaction’ between the host (you) and the microbiota and digestive environment.2
Inflammation and immunity
Far more than just being an organ to absorb nutrition, the gut is essential for the regulation of systemic inflammation, and plays a role in inflammatory conditions like psoriasis.3 Interestingly, in people with inflammatory conditions there is typically a reduced diversity and abundance of bacteria in the gut,4-6 and reduced diversity and abundance of bacteria in the gut is also associated with increased inflammation.7
1. Wilson AS, Koller KR, Ramaboli MC, Nesengani LT, Ocvirk S, Chen C, et al. Diet and the Human Gut Microbiome: An International Review. Digest Dis Sci. 2020;65(3):723-40.
2. Yadav M, Verma MK, Chauhan NS. A review of metabolic potential of human gut microbiome in human nutrition. Archives of Microbiology. 2018;200(2):203-17.
3. Damiani G, Bragazzi NL, McCormick TS, Pigatto PDM, Leone S, Pacifico A, et al. Gut microbiota and nutrient interactions with skin in psoriasis: A comprehensive review of animal and human studies. World J Clin Cases. 2020;8(6):1002.
4. Hidalgo-Cantabrana C, Gómez J, Delgado S, Requena-López S, Queiro-Silva R, Margolles A, et al. Gut microbiota dysbiosis in a cohort of patients with psoriasis. British Journal of Dermatology. 2019;181(6):1287-95.
5. Alesa DI, Alshamrani HM, Alzahrani YA, Alamssi DN, Alzahrani NS, Almohammadi ME. The role of gut microbiome in the pathogenesis of psoriasis and the therapeutic effects of probiotics. J Family Med Prim Care. 2019;8(11):3496-503.
6. Coit P, Sawalha AH. The human microbiome in rheumatic autoimmune diseases: A comprehensive review. Clinical Immunology. 2016;170:70-9.
7. van den Munckhof ICL, Kurilshikov A, ter Horst R, Riksen NP, Joosten LAB, Zhernakova A, et al. Role of gut microbiota in chronic low-grade inflammation as potential driver for atherosclerotic cardiovascular disease: a systematic review of human studies. Obesity Reviews. 2018;19(12):1719-34.