AN ILLUSTRATIVE VIEW OF THE GUT MICROBIOME
Functions of Gut Bacteria
Protection
The Barrier Effect
Protective effect of good bacteria
There is a HUGE number of bacteria in the gut. They cover the lining of the gut which is made up of epithelial cells and reduce the number of sites that bad (pathogenic) bacteria can bind to.
Nutrient Uptake
Bacteria present in the gut use up a lot of nutrients in the gut leaving very little for any invading pathogens. This mechanism reduces the chance of pathogen survival in the gut.
Anti-microbial Products
Bacteria in the gut synthesis anti-microbial products that function to kill invading pathogens.
Metabolism
Vitamin production by bacteria
Vitamin Synthesis
Bacteria have the ability to synthesis vitamins B and K. These are beneficial to us through aiding the replication and repair of our DNA as well as the production of proteins used in blood clotting.
Digestion
Bacteria ferment non-digestible carbohydrates to produce short chain fatty acids (SCFAs). SCFAs have a role in maintenance of the epithelial cells lining the gut through growth and repair. Therefore, they are beneficial in that they reduce damage that could lead to inflammation.
Bacteria digesting carbohydrates to produce SCFAs
Immune System Development
Development of Peyer's patches through exposure to bacteria
Recognising Bad Bacteria
In the first few years of life, interaction of mucosal bacteria and the gut-associated lymphoid tissue (GALT) is crucial for developing memory mechanisms that enable the innate immune system to discriminate between beneficial bacteria and harmful bacteria. Interaction with bacteria induces the growth of Peyer's patches which contain the immune cells that function to recognise specific elements on the bacterial surfaces, called antigens.