Question 13
1 pts
You are interested in learning more about how the bacteria living in your gut affect your
metabolism and your weight. You start researching the topic and read about a study where
two different experimental groups of mice were given different types of gut bacteria. Then
the mice in both groups were fed the exact same diet. After several weeks, both groups of
mice gained weight, but mice in group 1 had gained less weight than mice in group 2. What
conclusion can be drawn from this result about how different types of mutualistic gut bacteria
influence host metabolism and weight gain?
Note: We will discuss this experiment during the Wk6A class.
Group 1 mice gained less weight than group 2 mice because the gut bacteria given to group 1 directly
inhibited any nutrient absorption from occurring in the mouse digestive system.
In group 2, their gut bacteria had higher metabolic efficiency; these gut bacteria were better at
breaking down food, which produced metabolites that were readily absorbed by the mouse digestive
system.
The results of greater weight gain in the group 2 mice was due to a greater consumption of food
overall, regardless of their gut bacteria.
Because the gut bacteria in group 2 had less efficient metabolism, more food remained undigested
and unavailable for absorption by mouse's digestive system, leading to greater weight gain.
The results indicate that gut bacteria have no impact on weight gain; weight differences are solely due
to genetic factors of the mice.
