Gut-Brain axis Flashcards
the gut is called the 2nd brain because there is bi-directional
communication between
the gut and the ???
CNS/brain
ANS comprises the sympathetic and
parasympathetic branches and is in control of unconscious stuff like:
???, ???, ???
- Breathing
– Heartbeat
– Digestion
The vagus nerve is the 10th
cranial nerve or CN X and
interfaces with parasympathetic control of the heart, lungs and
???
digestive tract
TRUE or FALSE: Vagus nerves are NEVER paired
False, they are often paired, even though they are referred to as one nerve
the ??? nerve is a mixed nerve composed of 80% afferent and
20% efferent fibres.
vagus nerve
Afferent is communication from gut to brain OR from brain to gut?
from gut to brain
Efferent is communication from brain to gut OR from gut to brain?
from brain to gut
the vagus nerve is able to sense the microbiota metabolites through its
afferents OR efferents? and to transfer this gut information to the CNS and then to generate an adapted and/or inappropriate response
afferents
A cholinergic anti-inflammatory pathway has been described
through VN’s fibres, able to dampen peripheral inflammation and decrease intestinal permeability. This can or can’t impact microbiota?
can impact it == very
probably modulating microbiota composition.
TRUE or FALSE: Stress inhibits the VN and damages the gastrointestinal tract and microbiota. It is involved in the pathophysiology of GI disorders such as IBS and IBD which are
both characterised by a dysbiosis
TRUE
dysbiosis refers to a ??? or maladaptation on or inside the body, such as an impaired microbiota
microbial imbalance
enteric (intestine) nervous system is largely responsible for gut functions such as
– Motility
– Control of ???
fluid movements
The GI tract has the densest concentration of immune cells in the body and is in constant communication with ??? in the gut
microbes
what serves to facilitate communication between the gut and immune system through the recognition of self and non-self antigens in order to prime the immune system to identify harmful pathogens?
Hint: goblet cells secreting…. Which interact with…
goblet cells secreting a mucous layer which interacts with host microbiome and an exchange of molecules through the mucous layer and epithelium occurs
two best known Enteroendocrine cells
– Enteroendocrine L cells
– Enterochromaffin cells
have a long or short lifespan?
long lifespan
Enteroendocrine L cells secrete glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) in post-prandial state
– Obese people have low levels of GLP-1 and PYY, WHY?
because both GLP-1 & PYY can stimulate satiation and inhibit eating
(control food intake, body weight and metabolism)
Enterochromaffin cells (ECs) produce the majority of serotonin (5-HT) from dietary tryptophan (amino acid)
– 5-HT mediates many GI functions including intestinal ???, ???, pain reception, and inflammatory responses
peristalsis, electrolytes excretion
TRUE or FALSE: neurotransmitter Histamine is responsible for mediating host-microbe cross talk
TRUE
gamma-aminobutyric acid (GABA) synthesised from glutamate (by host and gut bacteria) is the chief inhibitory neurotransmitter in the developmentally mature mammalian CNS. Its principal role is reducing ??? throughout the nervous system
neuronal excitability
Deficits in bile acid levels have been associated with small intestine bacterial overgrowth, activation of inflammation, and subsequent
damage to the epithelium. WHY?
Bile acids help to limit the expansion of bacterial population in the GI tract. Bile acids can exert antimicrobial effects directly due to their membrane – solubilising properties
what is the most examined gut
microbial-derived metabolites, of which 95% consist of acetate, propionate and butyrate
SCFA (short-chain fatty acids)
TRUE or FALSE: Acetate is the only SCFA found in the brain. It promotes an expression profile of regulatory neuropeptides that favour appetite
suppression = less appetite –> less consumption of food
TRUE
TRUE or FALSE: Vast majority bacteria is NOT in colon
False, it IS in colon
