Final answer:
Antibiotics target specific features of bacterial cells that are different from human cells, allowing them to fight infections without harming our cells. However, they can disrupt beneficial bacteria in our bodies, sometimes necessitating treatments like fecal transplants to restore gut flora balance.
Step-by-step explanation:
Antibiotics are medicines specifically designed to fight bacterial infections. They target and kill prokaryotic cells, such as bacteria, without harming human cells. The reason antibiotics do not hurt our healthy cells lies in their selective mechanism of action. Antibiotics often attack parts of bacterial cells that are different from human cells, such as the bacterial cell wall, their protein synthesis machinery, selective enzymes, or their DNA replication process. Since human cells don't have cell walls and have different enzymes and ribosomes for protein synthesis, antibiotics can target these bacterial features without harming us.
However, despite their specificity, antibiotics can also affect the good bacteria in our bodies. For instance, the normal gut flora, essential for our digestion and immune system, can be disrupted by antibiotics. This can lead to complications like overgrowth of Clostridium difficile, causing severe gastric problems. In such cases, treatments like fecal transplants from healthy donors are used to reestablish the balance of the gut microbial community. So, while antibiotics are effective against bacterial pathogens, they also highlight the importance of our body's microbiome and the risks associated with the overuse of antibiotics.