(2015·徐州市高三考前信息卷)Sometimes, we really want a chocolate bar or a cool sparkling drink. We usually have one, perhaps thinking, “My body really needs it!” But are you sure it’s really a demand from your body? It might just be bacteria in your stomach “cheating” you into thinking that way, scientists say.
Our gut and stomach are home to 10,000 species of bacteria which get energy from our halfdigested lunches. In return, they help us break down food and keep harmful bacteria out, The Atlantic reported. But a recent article in US journal Bio Essays suggests that these bacteria might tell us what to do and demand certain kinds of foods. The article, written by researchers from the University of New Mexico and the University of California, San Francisco, says that bacteria in our gut and stomach change our eating behavior to increase their fitness. For example, bacteria that specialize in sugar make us want sweet food. If we don’t give them what they want, they worry our minds until we eat sweet foods. The bacteria have some strategies to make us “listen” to them, the article suggests. They may change the expression of our taste receptors, making certain foods taste better. They may release hormones to make us feel hungry. Or they may use the vagus nerve (迷走神经), which connects the stomach to the brain, to control our eating behavior. In other words, our brain and moods might be hostages held by a hijacker called bacteria.