Microbiome Flashcards
What does the gut microbiome affect?
Gut microbiome affects a lot of things
Brain and behaviour
-Agression
digestion
Immune system
and more
Microbiome
The population of all the microbes in a given area (not just the bacteria)
Microbiota
The microbes that make up the microbiome
Homeostasis
In harmony or balance
Dysbiosis
Out of balance
Symbiosis
A mutually beneficial relationship
What do the microbes in the gut do?
When all is well, these are really helpful
-Provides nutrients
-Metabolites serve many functions
-Regulates immune system
-Also prevents colonization of microbial pathogens
-Influence metabolism and behavior
Which microbes live in the gut microbiome
Non-pathogenic bacteria, yeast, and even some protozoa
-Animals are born with these
Different if the birth is surgical birth or early antibiotics
Composition varies due to lot of factors
-Age
-Environment
-Diet
-Geography
Is germ free good?
NO
-Decreased learning ability
-Increased inflammation and auto-immunuty
-Increased fear, anxiety, depression and aggression due to the lack of metabolites
What causes dysbiosis
Caused by early life factors, genetics, diet, environment, other diseases, and antibiotics
This is multifactorial and has many different outcomes
Prebiotics
“Feed” the gut microbes: usually some type of solute fibre
-This is actually helpful
Fiber fermentation by microbiome increases short chain fatty acid production which in turn promotes immune system regulation, metabolic regulation, host cell proliferation
What is “leaky gut”
“Leaky gut” is a breakdown between the microbiome and the intestinal cell wall
Probiotics
Introduces “beneficial” bacteria into the gut
Prebiotics are better, why?
-Not much probiotics actually make it to the end product (doesn’t survive the freeze dry process
What is the main problem with probiotics
Not just any bacteria can move into the microbiome and establish - COLONIZATION RESISTANCE
-Most bacteria don’t really stay in the gut and colonize
-They don’t survive longer than 10-21 days
-Probiotics need to be taken continuously
-The species and subspecies that resolves dysbiosis varies between individuals
-Some studies even show negative effects of probiotics
How do we treat dysbiosis
It’s complicated
-Time
-Diet and environment (keep it hygienic)
-Control inflammation and-or autoimmunity
Why does microbiome dysbiosis cause so much trouble?
Dysregulation/activation of the local immune system - inflammation
-The macrophage may identify the microbiome microbes as a pathogen and attack
-Can become chronic and systemic, or lead to auto-immunity
Direct damage to the enterocytes (lining of the intestine)
Chronic enteropathy compounds dysbiosis
Allows pathogens to colonize
Give 3 examples
Outcomes of dysbiosis
Grain overload in horses
-Increased starch entering the cecum causes dysbiosis resulting in systemic inflammation - laminitis
Cecal dysbiosis in rabbits
-often causes death
Sudden changes of diet in dogs causes diarrhea due to the microbiome
-It’s good for dogs to change their diet fairly often for a diverse microbiome
Diarrheal disease in cattle
Increased susceptibility to pathogenic bacterial infection
Increased behavioural issues
The gut brain axis
The gut has a huge effect on behaviour and the brain
-Metabolites and other microbes produce things that your body needs to function
What do metabolites make that’s important
You are what your bacteria eat
“Metabolite produced by gut microbes contribute to Tryptophan production…a key amino acid that leads to serotonin synthesis”
Effects of Antibiotics on the microbiome
Antibiotics are both a blessing and a curse
The microbiome can take months to recover from antibiotic treatment
-Early life antibiotic treatment has the most detrimental effects
Solution: only use antibiotics only if indicated by clinical signs and diagnostics
-Use prebiotics when antibiotics are prescribed
-Avoid raw food and pea protein based/grain free diets
