An interesting read from the The Scientist magazine about Horizontal gene transfer in the gut. To put it in plain words – the bacterial flora in the human gut acquires certain sets of genes from the bacterial population present in the food that we consume which in-turn help the bacteria (in our gut) to easily break down the food.
In broad strokes, the human digestive system function’s with the assistance of the bacteria in the gut and these bacterial flora seem to be specialized to the kind of food that we consume. Sterilizing food materials thoroughly may not be the most intelligent thing to do! ..