Benefits & Mischiefs from Normal Microbiota 1 Flashcards
Which type of bacteria is predominant in the gut?
gram negative bacteria
Are the bacteria in the gut predominantly aerobes or anaerobes?
anaerobes
In which part of the gut is most of the microbiota?
The colon
What are the most common aerobic microbiota in the gut?
staphylococcus, streptococcus, lactobacillus, enterobacteriaciae
What are the most common anaerobic microbiota in the gut?
bacteriodes, streptococcus, bifidobacterium, clostridium
What are the four main phyla in the gut?
Mostly bacteriodetes, firmicutes with some actinobacteria and few proteobacteria
What do the genes of the microbiota contribute to?
metabolic activity, development, immune system function and protection against pathogens
What factors influence gut microbiota?
mode of delivery (vaginal vs caesarian), age, diet, antibiotics, genetics, environment, chronic inflammation
Which phyla of bacteria is most prominent in the microbiota in the first few years of life?
fermicutes
At what age will there be sufficient microbiota to utilise plant base products?
a few months
At what age is the microbiota the same that it will be throughout the rest of life/
2.5 years
What diet changes affect microbiota?
changing from a high fat/low fibre diet to a low fat/high fibre diet
What will happen to the microbiota on an animal based diet?
There will be an increase in bile tolerant bacteria such as bacteroides
What will happen to the microbiota on an iron free diet?
There will be an increase in bifidobacterium and clostridium and a decrease in bacteroides
What happens to microbiota after antibiotic treatment?
It goes back to normal
Which antibiotic may effect the microbiota so that it doesn’t go back to normal after treatment is stopped?
vancomycin
What role does microbiota have in providing nutrition?
Directly supplying nutrients as well as altering metabolic machinery by inducing changes in genes and maintaining enterocyte differentiation
How do microbiota help with the metabolism of carbohydrates?
They break lactose and cellulose down into short chain fatty acids
Which vitamins are absorbed with the help of microbiota?
vitamin B2, vitamin K, biotin, folate
How do microbiota help break down bile acids?
By dehydroxylation which then allows reabsorption back into the liver
Which amino acids particularly need the help of microbiota?
lysine and threonine are broken down to urea
Why is important that bacteria degrades host glycans (such as mucin)?
Because it induces synthesis
What are some functions of short chain fatty acids as a product of metabolism by bacteria?
they maintain entrocyte differentiation and alter host genes to maintain angiogenesis
What are the main short chain fatty acids?
acetate, propionate and butyrate
