MICROBIOTA 2 Flashcards
how does diet affect gut microbiota
major driver of diversity
different types of diets influence community composition
obese individuals have a distinct gut microbiome from lean individuals
several confounders exist: diet, genetics, environment etc
how can those different gut microbiota be studied when relating to obesity?
studies on MZ or DZ twins
(MZ are more similar) and mouse models, where you can control the genetics and the diet
how does leptin affect obesity?
leptin: hormone made by fat cells that regulates the amount of fat stored in the body, the “satiety” hormone
ob/ob mutants are obese
mice are used as animal model of type 2 diabetes
how do obese mice have a different gut microbiota?
obese mice and wild type mice were fed the same diet and there was amplicon sequencing (variable region of 16S rRNA)
following microbiome transfer, there was a higher ratio of fimicutes:bacteriodetes in the recipient mice
the recipient mice who received feces from obese mice had more body fat after 2 weeks despite the same amount of food eaten
how was it determined that the microbiota influenced obesity?
the obese mice had bacteria that were more efficient at absorbing energy from the carbohydrates, but they didn’t need this extra energy so they stored it as fat
how were this mice obesity microbiota studies translated to humans?
how do antibiotics affect gut microbiota diversity?
lower the diversity, select for only one type of bacteria
even after 24 months the diversity remains low
particularly disruptive during early childhood
at sub-therapeutic doses, antibiotics can promote weight gain
what are the unintended effects of antibiotics?
clindamycin: antibiotic
characteristics of C.difficile infections
antibiotic associated diarrhea
what is the 1st line treatment for C.difficile infection?
what is fecal microbiota transplant and how can it be used for C.difficile
infusion from healthy donors was demonstrated to be an effective method in treating recurrent C.difficile
study was stopped because it was considered unethical to not offer FMT to everyone
what are some concerts about FMT?
what are some considerations/applications when it comes to microbiota transplants?
what are some other ways to manipulate the microbiome?
probiotics, prebiotics, diet, bacteriophages
what are short chain fatty acids (SCFAs)?
what is the gut brain axis
immune cells and cytokines can cross the BBB and can regulate neurological functions, including the hypothalamic pituitary adrenal axis (HPA)
all these molecules are active in the brain and the gut
what are some body wide microbial interactions in diseases?
