This new research , led by Dr. M Yansigawa, has found that certain protein generated by gut bacteria makes a big difference on how mice, and presumably humans, process food at the intestines. When present, the protein slows down digestion allowing for a much better absorption of food, while, when absent, digestion goes a lot faster and nutrients are wasted in a much larger ammount.
Obviously absorbing more food has pros and cons, it probably mproves a lot the survival rate when food is scarce but it causes other problems when food is aboundant, specially overweight and obesity. It is common knowledge that there are two exteme types in this aspect: people who can eat all they want and never seem to gain weight, and people who, even when eating little, always tend to be somewhat fatty. It would seem that this bacterial protein is at least one of the reasons in this dychotomy, what may offer in the mid-run new ways of treatment for obesity and also extreme thinness (surely not desirable either).