Fat mice: that’s why Harvard University scientists sent Peter Ferket, professor of poultry science, a jar of mouse poop. 

The study Ferket conducted concluded two mice could eat, exercise, excrete and behave the same way with only one becoming obese.

According to Ferket, it began with Harvard scientists trying to see if the mouse that ate more was told to eat less and would become more like the thinner mouse. Ninety days later, the scientists at Harvard realized something was off.

“They ate the same, they looked at their behavior and one didn’t change in terms of activity; they were both the same in activity,” Ferket said. “They stuck it in a calorimeter that measures the body heat and activity and the respiration. From there they realized the caloric use was no different. So they were still asking the question why the certain mice were getting fatter if what goes in the mouse is no different.”

Ferket said that was when the scientists came to him for help.

“We in poultry science, because feed efficiency is really important, want to make sure whatever a chicken eats causes them poop the least amount,” Ferket said. “With this, more of the nutrients going to the meat which is the part we eat. … in fact all agricultural animals whole terms of digestibility are extremely important because it has an impact on resource uses, energy uses, environmental concerns.”

With the use of an instrument called a bomb calorimeter, Ferket is able to measure the energy going on the animal and the energy going out. According to Ferket, there are very few laborites in the country that can actually preform this study with this type of equipment and have the expertise to do so.

“They asked me what they should do,” Ferket said. “That’s when I suggested that we needed to take a look at the energy, what the digestibility was. We needed to figure out if they really were digesting the food better. Maybe they had better enzymes.”

Ferket usually works with anywhere from a gram or .5 grams of feces to properly measure enzyme activity. To make an accurate conclusion, Ferket said he would have to do multiple replications of his findings.

“I told them, ‘Go ahead, send me some mouse feces,’” Ferket said. “They sent it to me in a little jar and in the bottom of the little jar there were maybe five or six pellets. I didn’t have enough so I had to come up with a way to measure the mouse feces using my analytical constraints.”

To make up for the small amount of feces he was given, Ferket decided to take wheat flour and determine its energy content. Ferket was able to turn the wheat flour into pellets that and burn it to determine the pellets’ calories.

“We went over to our mouse colony and said, ‘Give us all the mouse poop you’ve got!’” Ferket said. “We could see that this was how regular mouse feces should have energy and we blended it with the flour doing a bomb calorimetry on that.”

After six weeks of working on the bomb calorimetry and retuning his findings to the scientists at Harvard that a possible conclusion was reached dealing with the MRAP2 gene. This particular gene works as an activator turning on and off.

“That’s where it started a whole new thought process,” Ferket said. “Up until now obesity has been considered a behavioral problem. Based on this research and some on this gene it may not be the case. There are some people that have the same kind of variance in the MRAP2 receptor. They’re different in humans but there’s some kind of similar issue that may indicate that for some people, not everyone, who are morbidly obese that it’s not their fault.”

Ferket said that while this finding sounds specifically technical, there is a heavy social aspect to the research.

“When you step back and you think about it, this is something I always encourage everyone to do, there’s a social aspect,” Ferket said. “There are some people that just can’t help it … behavior can impact it but that’s not always the case.”

Ferket said that the interesting part of this type of research is the solutions for these kinds of problems.

“For those patients maybe it’s as simple as a drug,” Ferket said. “To take it even further maybe there are new things like gene therapy. We have to think about some people who have this genetic defect that maybe this really is a disease.”

The possibility for companies to start looking at new drugs or new medical applications to help, Ferket said, is an exciting idea.

“We’re entering into this whole aspect of customized medicine and customized nutrition,” Ferket said. “The more information that we have about our genes and what they do the more likely we can find some more custom things for people whether in nutritional ways or therapies and things like that.”