Chinese researchers have shown that, in addition to the vagus nerve's known regulation of gastric motility and digestive processes, chemically inactivating its dorsal motor nucleus in mice reduces intestinal fat absorption, causing them to lose body weight. Likewise, activating this same nucleus causes the opposite effect, increasing intestinal fat absorption and body weight.
But the most novel and surprising thing that researchers have observed is that when a certain group of neurons in that same nucleus is deactivated, specifically those that project to the jejunum, a part of the small intestine, the length of the microvilli in the intestinal wall is shortened, which reduces its surface area and thus the place in whose blood capillaries fat absorption occurs. The brain thus regulates this absorption by controlling the length and surface area of the intestinal spaces in which it takes place.
But that is not all, because the Shanghai researchers have completed their excellent and complex research by showing that puerarin, a substance used to treat vascular diseases of the brain, increases the excretion of fecal fats and weight loss by also inhibiting certain neurons in the dorsal motor nucleus of the vagus nerve, which makes this substance a regulator of intestinal fat absorption and, consequently, a promising treatment to control body weight in humans as well.
