Health experts have long worried about the increasing rate of obesity in kids. It's an important concern: Being weight or obese during childhood can lead to serious problems normally seen in adults, such as diabetes and high blood pressure. Poor diets and a lack of exercise are usually the causes. But would you ever have imagined there might be a connection between the bacteria that lived in your guts  when you were a baby and the chance that you would become overweight? Scientists in Finland recently found just such a link. In a recent study, they showed that overweight kids had different species of bacteria living in their guts. You probably think of bacteria only as germs that can make you sick. While it's true that some bacteria can make people ill, your body actually depends on some types of bacteria to help you digest food and extract nutrients from it. These "good" bacteria live in your guts, where they process the food you eat. Human babies get these bacterial helpers from their moms. When a baby is born, some of the bacteria in the mother move into the baby's body. Growing babies get additional "good" bacteria from the milk their mothers produce. And it turns out the bacteria might play an important role in regulating weight just six years later. So how could these bacteria affect weight? The researchers still haven't tested that question, but future tests might lead to an answer. The purpose of writing this passage is to   _  .
introduce the role of bacteria in children's weight analyze the influence of obesity on kids give advice on how to lose weight quickly explain the function of bacteria in foods
Question: Health experts have long worried about the increasing rate of obesity in kids. It's an important concern: Being weight or obese during childhood can lead to serious problems normally seen in adults, such as diabetes and high blood pressure. Poor diets and a lack of exercise are usually the causes. But would you ever have imagined there might be a connection between the bacteria that lived in your guts  when you were a baby and the chance that you would become overweight? Scientists in Finland recently found just such a link. In a recent study, they showed that overweight kids had different species of bacteria living in their guts. You probably think of bacteria only as germs that can make you sick. While it's true that some bacteria can make people ill, your body actually depends on some types of bacteria to help you digest food and extract nutrients from it. These "good" bacteria live in your guts, where they process the food you eat. Human babies get these bacterial helpers from their moms. When a baby is born, some of the bacteria in the mother move into the baby's body. Growing babies get additional "good" bacteria from the milk their mothers produce. And it turns out the bacteria might play an important role in regulating weight just six years later. So how could these bacteria affect weight? The researchers still haven't tested that question, but future tests might lead to an answer. The purpose of writing this passage is to   _  .
A. introduce the role of bacteria in children's weight
B. analyze the influence of obesity on kids
C. give advice on how to lose weight quickly
D. explain the function of bacteria in foods
Answer: