Lecture 19 - Gut microbiome and ageing Flashcards
the majority of species in the gut microbiome belong to which 2 species of bacteria?
bacteriodetes and firmicutes
how many genes make up the gut microbiome?
316 million
name the 7 major functions of the gut microbiome
pathogen protection, synthesis of vitamins, immune system development, fat storage, SCFA production, modulation of CNS, intestinal angiogenesis
name the 8 roles of SCFAs
provide energy for colonocytes and hepatocytes, contribute to intestinal barrier integrity, protect against inflammation, reduce risk of colorectal cancer, increase insulin secretion, help DNA homeostasis, regulate skeletal muscle metabolism, modulate CNS
how do SCFAs in the gut contribute to intestinal barrier integrity in 2 ways?
upregulate expression of tight junction proteins and mucus production
which cranial nerve carries signals between brain heart and gut?
vagus nerve (CNX)
name 4 diseases linked to dysbiosis in the gut microbiome?
IBS, type 2 diabetes, obesity, cardiovascular diseases
which chemical, which gets translocated to the immune system has hormones which affect memory function, reduce inflammation and reduce ageing/permeability of the BBB?
butyrate
butyrate (SCFAs) has beneficial effects to which 4 neurological/neurodegenerative disorders?
autism, depression, alzheimer’s and parkinson’s
which peptides does butyrate disrupt in alzheimer’s disease?
AB
which aggregates does butyrate disrupt in parkinson’s?
alpha-s
which lysine derivative found n proteins has been found to affect microglia in old mice? what does it increase the production of which can damage DNA?
CML, increases ROS
name the 3 types of starch which are prebiotic, giving an example of each?
rapidly digested starch (amyloidose), resistant starch (amylose), raw legumes (amylose)
what is the gut bacteria associated with inflammatory bowel disease such as Chron’s and ulcerative colitis?
helicobacter hepaticus
which gut bacteria is associated with GI cancer?
H.pylori
which gut bacteria is presrnt as babies are breastfed still?
bifidobacteria
in the ageing gut, which type of cells die as cells become more senescent?
enterocytes
give the 4 species of aerobic gut bacteria
Bacteroides, Firmicutes, Prevotella, Ruminococcus
give the 4 species of anaerobic gut bacteria
Peptostreptococcus, Bifidobacterium, Lactobacillus, and Clostridium
togther the aerobic and anaerobic species of gut bacteria prevent the overgrowth of what? by competing for what?
harmful bacteria, nutrients and attachment sites to gut mucus membrane
When fibre is not available,
which species of aerobic bacteria feed on the protective mucus layer that lines the gut? what can this trigger?
bacteroides, immune response
name the 2 metabolites during ageing
phenols and indoles
phenols are gut bacterial degradation products of which two substances?
phenylalanine and tyrosine
indoles are gut bacterial degradation products of which amino acid?
tryptophan
name 4 ways which can alleviate gut inflammation in the elderly?
diet change/add probiotics and polyphenols, faecal mater transfer, oral SCFAs, modulate immune system
