At different times, about 7000 kinds of plants and hundreds of animals are used as food by human beings  The loss of species will reduce food diversity and make human beings rely on only a few major foods, thus breaking people's balanced diet  In addition, with the loss of species in the forest, the loss of species in the field may lead to an increase in the number of pathogens that are responsible for diseases in organisms
The relationship between species diversity and disease infection is subtle
 Some of the animals, plants and microbes that are most likely to become extinct are actually buffers for the spread of infectious diseases, which are responsible for many diseases on behalf of humans before they are infected