7.8 Introduction to the Gut-Brain Axis Flashcards
What is the gut brain axis
The gut brain axis describes interactions between the gut and the brain, where signals can be sent from both directions and signals can be from the entire gut
What is the microbiota
The microbiota are all the microorganisms in the gut.
What is the microbiome
The microbiome is the genetic code of all the microbiota
What is the metabolome
The patterns of metabolites found in bodily samples
What are some ways that bacteria in the gut help humans
They provide metabolic functions that the humans have not evolved themselves. They educate the human immune system. They influence the human risk of non communicable disease
What is the benefit of understanding the gut microbiome
Understanding the gut microbiome helps with understanding disease. Understanding the mechanisms behind disease, being able to predict the risk of disease, diagnosis, altering microbiome composition so as to reduce risk of disease or treat the disease etc
What is a key area that has strong links with the microbiota composition
Diet
Describe the hygiene hypothesis
The hygiene hypothesis is the idea that a lack of exposure to a diverse range of microorganisms can lead to overactive immune systems, causing autoimmune disorders and allergies.
What are some factors that influence microbiome composition
events in early life, genetics, digestive disease, interaction with immune system, antibiotics, diet, probiotics ,geography, ethnicity
Describe the early colonisation of the gut
infants are born with a sterile, immature gut and an immature immune system. In the first 4 days, the gut gains lots of bacteria from the mother and the environment. Early colonisation of the gut depends upon factors like breast feeding, whether birth is vaginal or caesarean, perinatal antibiotics, geography, genetics, prenatal stress, perinatal antibiotics and weaning.
Describe the opportunities for gut colonisation throughout life
at birth- the infant is exposed to vaginal bacteria in the birth canal and the mother’s faecal bacteria
in the first weeks- the infant is exposed to bacteria in the local environment as well as through breast feeding
in infancy and childhood- exposed to bacteria in the environment and in food
in adulthood- exposed through diet, probiotics, antibiotics, surgery, faecal transplants etc
What are some barriers to gut colonisation
gastric acid, pancreatic enzymes, the existing gut microbiome, competition in the gut for nutrients, competition in the gut fro binding sites, bacteriocins, pH and various bacterial metabolites
What is needed to study the gut microbiome
To study the gut microbiome, samples are needed. Gut content and gut mucosal samples are good to use, but instead often people end up using faecal samples which are not that representative of the upper colonic and mucosal bacteria. Urine and blood samples are also used for metabolomics
Describe the interconnected nature of bacteria in the microbiome
Bacteria live in niches such as the mucosa, mucus and biofilms. They communicate to each other with cross talk as well as communicating with human cells. The metabolism changes in biofilms as species accumulate and bacteriocins are produced
