Which of the following best describes a side effect of antibiotics?

The development of superinfection is a well-documented side effect of antibiotic use. Antibiotics are designed to kill or inhibit the growth of pathogenic bacteria; however, they can also disrupt the natural balance of microorganisms in the body. This disruption can lead to an overgrowth of resistant bacteria or opportunistic pathogens, which may cause a secondary infection known as a superinfection. Common examples are infections caused by Clostridium difficile following antibiotic therapy, where the antibiotic kills off beneficial gut flora, allowing this pathogenic bacteria to proliferate.

In contrast, enhanced immunity, increased appetite, and improved digestion are not recognized side effects of antibiotics. While some individuals might experience various reactions to medications, these particular effects are not typical consequences of antibiotic treatment. Instead, antibiotics aim to target specific bacterial infections, rather than enhance the immune system or improve overall digestive health.