A single molecule in the intestinal wall, activated by the waste products from gut bacteria, plays a large role in controlling whether the host animals are lean or fatty, a research team, including scientists from UT Southwestern Medical Center, has found in a mouse studyCan't wait for the day when I can tweak the types of bacteria that are living in my gut for optimum health.
Using mice, the researchers focused on two species of bacteria that break up dietary fibers from food into small molecules called short-chain fatty acids. Dr. Yanagisawa's team previously had found that short-chain fatty acids bind to and activate a receptor molecule in the gut wall called Gpr41, although little was known about the physiological outcome of Gpr41 activation.
The researchers disrupted communication between the bacteria and the hosts in two ways: raising normal mice under germ-free conditions so they lacked the bacteria, and genetically engineering other mice to lack Gpr41 so they were unable to respond to the bacteria.
In both cases, the mice weighed less and had a leaner build than their normal counterparts even though they all ate the same amount.
The researchers also found that in mice without Gpr41, the intestines passed food more quickly. They hypothesized that one action of Gpr41 is to slow down the motion that propels food forward, so that more nutrients can be absorbed. Thus, if the receptor cannot be activated, food is expelled more quickly, and the animal gets less energy from it.
via Science Daily