There are many different types of antibiotics. Some are broad-spectrum, meaning that they act on a wide range of disease-causing bacteria. Others are designed to kill certain species of bacteria.
Both types can have a number of side effects, including tiredness and antibiotic associated diarrhoea (AAD) caused by an overgrowth of diarrhoea producing bacteria. They have a negative effect on our gut bacteria (microbiota) and taking too many antibiotics can drastically change the amounts and types of bacteria in our gut, potentially leading to an overgrowth of the ‘bad’ types of bacteria and causing an imbalance known as dysbiosis.