STEM Tuesday: Obesity and the Human Microbiome

Two mice; the mouse on the left has more fat s...
Two mice; the mouse on the left has more fat stores than the mouse on the right. (Photo credit: Wikipedia)
Thanks everyone for the the positive feedback on my STEM Tuesday posts.

With the weather getting warmer, many of us are getting on the excercise and dieting as we anticipate baring more skin.  Me too.

Does the Human Microbiome impact our efforts? Guess what?  Big time.

Chemistry tells me that a calorie is a calorie, no matter where it comes from.  Eating fewer calories and moving more is the only way to be slimmer and trimmer.

“Eat less, Move more. That’s the key to staying thin,”

Doctor Heart told me. He’s correct, but that’s only part of the story.

Thin people have different microflora than obese people.

You know that old saying?

You are what you eat”

It’s sort of  true, but not in the way you might think.

What we eat greatly impacts what kind of microorganisms make up our microflora.  The same people given a high fat Atkin’s type diet have vastly a vastly different gut flora than the same people switched to a vegan type diet.  The bacteria that are our friends when we eat a “bacon and egg” diet love to digest fat. That sounds logical.  These same bacteria change our body chemistry producing more inflammation and increasing insulin resistance. In other words, we become more susceptible to heart disease and diabetes.

These little micro-demons create an environment in our guts that make us actually extract more energy from the food we eat.  Obese people need to eat less to get the same amount of caloric benefit as thin people.Wow. Now that’s not fair!

It’s not just that the microbes are different.  They turn on different genetic responses in us.

This response starts right at the beginning: in our mouths.  The microflora is markedly different in lean compared to obese people in the mouth, stomach, small intestines, and large intestine.

Scientists can predict with 90% accuracy whether a person is obese from examining their micro flora.

Children remaining lean at age 7 had higher levels of certain bacteria from infancy.  Scientists believe the flora comes first, the the inclination for lean vs obese.

Our Microflora may affect gut hormones.

Gut hormones communicate with the brain to tell us when we are full and when we are hungry.

You can change your micro flora in a short amount of time, just by changing your diet.  You can also go radical and get some “Poop Pills.” These pills are probiotics from a healthy, lean gut.  Yes, a microbial cocktail, from real poop from real people, put into capsule that will made to melt in the gut and deliver the lean gut microbes.

Perhaps most important, lean people have a much more diverse microflora.

The type of microbes found in obese guts are from a group called Bacteroidetes. These bacteria are found in soil, water, and of course, poop from warm-blooded creatures. Think of it like planting a new garden. The seeds must be planted in the right soil before it can thrive. So what we eat remains important, that”s what creates the soil. And, of course calories still play a part.

So… Eat food, not too much, and mainly plants.

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And Dr. Heart is still right about at least one thing.

Move more.

Exercise is  still a good way to keep a healthy heart and lungs and to burn calories.

And don’t worry so much about getting dirty.

Diversity is Key.

Here’s an academic paper that’s very interesting, even if it is very, well, very academic, by Ruth E. Ley from Cornell.

Here’s a video by Robynne Chutkan describing her experience.  It’s a little long.  Still, I think you’ll enjoy her good sense of humor.