https://onlinelibrary.wiley.com/doi/10.1111/obr.13321
Our gastrointestinal system is full of bacteria that can change a variety of things from how our body deals with food (metabolism) to what food cravings we have. On a similar note, antibiotics are designed to kill bacteria and during a course of antibiotics there can be a change in the bacteria within our gut (microflora). This study looked at how taking antibiotics as a child was linked to obesity as an adult. They found that a high level of antibiotic use (4 prescriptions) increased the chance of developing obesity by 30% whilst low antibiotics use (1 prescription) had an increase of 8% compared to people who had no antibiotics. This shows that the more antibiotics that are used as a child the higher the chances of developing obesity as an adult.