Dr. Cox and the research team discovered that bacteria in the gut of mice changed when they received antibiotics at a very young age. The metabolism of the mice changed due to antibiotics exposure, which made them more vulnerable to an increase of weight.
Experiments were performed on mice for five years. The research team tested low doses of penicilline on three groups of mice. The first group received penicilline in the womb during the last week of pregnancy, the second group received antibiotics from birth on, while the third group received no antibiotics.
The two groups which received penicilline had a higher body fat mass, while the increase of weight was higher in the group of mice that received penicilline in the womb. According to Dr. Cox, this experiment shows that mice that receive antibiotics on an early age are more vulnerable to metabolic changes.
The next step in the study was questioning whether the increase in weight is caused by the changed gut bacteria, or by antibiotics. Bacteria of the gut were taken from mice which received antibiotics. These bacteria were transferred to the gut of very young mice. As a control group, the researchers transferred bacteria from the gut of mice which were not treated with antibiotics into the gut of the young mice.
The results showed that the mice which were treated with penicilline increased in weight, while the mice which received bacteria from mice that were not treated with antibiotics did not experienced an increase in weight.
According to Dr. Cox, the findings are important to not only understand the cause of obesity, but also to create solutions for this problem in the future.Source: Cell