I’ve definitely been enjoying the first few days of my break, I’ve been trying to write two blog posts a day to have them in my arsenal for the future… or maybe I could up to a few more than 2 posts a week during my winter break, what do you guys think?
My roommate drove down to Alabama for a climbing trip last night (I had to work ); I am already feeling a little lonely at my place lol… although I am keeping pretty busy with work, blogs and climbing, I’m just a little needy apparently lol. I’m excited to go home this Saturday (and also to give that high school presentation on Friday )
Here’s a picture taken of me at my climbing gym in the summer
Bacteria make up the bulk of the biomass in the human gut; identifying factors that control the diversity and health of our gut microflora has become an exciting area of research. So what’s the big deal? This blog post will be about our microbial inhabitants that reside in our large intestine. Hope you enjoy!
So let’s start from the beginning… Our guts are sterile at birth and rapidly develop as a result of environmental exposures and diet. Breast milk, for example, contains many antibodies and lactose which promotes the establishment of lactobacilli (which promotes a normal immune function).The first weeks, better yet, days is vital for gut colonization. Depending on our blood pH, nutrient availability and bacterial exposure, different floras will arise.
Microbe exposure results in a quickly changing gut flora in infants, it isn’t until about 3 years of age that the microbes stabilize. Since bacterial exposure is much different around the world, gut flora will consequently be much different in each individual. For example, people who live in poorer communities have drastically reduced incidence of allergies, autoimmune disorders and inflammation (even if they move to cleaner environments later in life); this is a result of many factors including their gut flora. Early development of our gut floras through infancy puts us at lower or higher risks for many disorders (including diabetes and obesity). Something to add, antibiotics may modify our gut microbiome and immune response, especially when taken in our early lives.
After weaning, fibre becomes very important- fibre, along with inulin and oligosaccharides (which are resistant to mammal food breakdown enzymes), pass into the large intestine where our gut flora resides. These non-digested carbohydrates become a major energy source for the bacteria; our diet determines which microbial species that will be successful. When there are lower carbohydrates and/or more refined carbohydrates in our diets, less undigested food will make it to the large intestine and thus less energy will be provided to the gut flora.
In animal models, gut flora can promote either extreme or minimal tendencies to gain weight. Furthermore, obese animals have microbiomes with a higher ability to harvest energy from high carb diets. The common north-American diet consists of highly refined carbs and fat and lower complex carbs; this has been linked to the rise of obesity. Fructose and artificial sweeteners have also been linked to this trend. These sugar compounds, particularly fructose, changes our microbiome with altered metabolic capacities. Furthermore, a procedure that replaces the bacteria in the large intestine of an obese individual with metabolic syndrome with that of a lean relative actually produces rapid improvements in insulin sensitivity (sustained for weeks!).
So you’ve probably heard of probiotics and prebiotics, what are they? Probiotics are microbial foods that are taken to correct our gut flora. Prebiotics provide suitable carbohydrates to preferentially stimulate a certain microbe. Effectiveness of pro and prebiotics is quite controversial and further research is definitely needed.
So some concluding thoughts; our gut microbiomes, largely determined by the first few years of our lives, puts us at different risks for many diseases including diabetes and obesity. Fibre is an important component to keep a healthy gut flora, as well as a reduction of refined carbs, fructose and artificial sweeteners. Although short term diet adjustments have been shown to improve gut flora temporarily, long term life style changes are the best way to support permanent beneficial changes. For this reason (and others), crash dieting is probably not the best way to get healthy but rather a permanent healthy lifestyle change.
Anyways, time to go to the library to do some more research , hope you all have a splendid Monday!
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Jackson AA, Gibson NR, Bundy R, et al. (2004) Transfer of (15)N from oral lactose-ureide to lysine in normal adults. Int J Food Sci Nutr.;55:455–462.
Ley RE, Lozupone CA, Hamady M, et al. (2012)Worlds within worlds: evolution of the vertebrate gut microbiota. Nat Rev Microbiol.;6:776–788.
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