In his acceptance speech for the Nobel Prize in 1945, Scottish scientist Alexander Fleming warned that his discovery of penicillin, the world’s first antibiotic, held an inherent problem: misuse of the drug would lead to new concerns including bacterial resistance.
The benefits of antibiotics are well-known. They have helped manage serious infections that used to be potentially lethal, including pneumonia, cellulitis and gangrene. Predictably, the widespread use of these ‘wonder drugs’ since WWII has led to unanticipated consequences. One of these is allergic reactions. Today, an estimated 10% of the US population is allergic to drugs in the penicillin family, and allergy and anaphylaxis have been reported with many antibiotics.
There are dozens of antibiotic drugs that are used worldwide, in animals and in humans, and they work in different ways. Penicillin kills bacteria by damaging the cell walls of the microbe. Other types of antibiotics work by disrupting bacterial DNA or RNA (quinolones and rifampin), protein synthesis (aminoglycocides, chloramphenicol, tetracyclines, and macrolide antibiotics), or metabolism (trimethoprim and sulfonamides).
Humans have about the same number of bacteria to human cells. (please reference this instead. These bacteria are part of our diverse microbiome, which helps our immune system develop tolerance, and is important in helping prevent allergies. A direct consequence of antibiotic use is gut dysbiosis, but there are also inter-generational effects. Studies have reported changes in children whose mothers had significant exposures to these drugs.
Animals on US factory farms are fed 80% of that country’s antibiotics. As predicted, this intensive application has given rise to ‘super bugs’ that are resistant to the drugs. Antibiotic resistant bacteria cause 2.8 million infections and 35,000 deaths each year in the US.
While antibiotics have saved millions of lives and are an important part of the modern world, there is growing recognition of the need to be better stewards of the global microbiome, to ensure that benefits outweigh harms, and to prevent resistance so that they remain effective when we need them most.