Yes, human body has a strong immune system which will automatically take care of all the pathogens and foreign body that enters it by killing them. It increases the body temperature which will act in its defense. Increased temperature of the body provides these pathogens unsuitable environment and thus they cannot sustain and multiply, thereby gradually decreasing them in number and eventually getting rid of them. An individual then can return back to his normal health. However, we do not want to go through whole procedure and since do not want to suffer from high temperature and want to readily cure our body, we go for medications which decreases body temperature as well as antibiotics which will help to get rid of microbes which have resulted in fever and infections.
Even slight infections like common cold which gets corrected by themselves are now treated by strong antibiotics. Our body's immune system itself can correct these sorts of infections which usually occur due to weather changes. Immune system produces antibodies and at the same time specialized cells in our body are triggered. Due to these changes, toxin producing micro-organisms in our body are destroyed or at least neutralized.
Antibiotics on the other hand cannot differentiate between good and bad micro-organisms and thus put an end to both. Our body needs good microbes for various activities and when next time pathogens make an entry in our body our immune system will become more weak as we have very less population of good microbes doing good to our body.
Antibiotics are making microbes resistant day by day. Thus, we are needing more and more powerful antibiotics with heavier dose. Microbes are passing resistance to their offspring and this resistance they have developed is difficult to cure with lighter dose of antibiotics. Viruses which are usually responsible for causing common cold, flu etc..... should never be treated with antibiotics because antibiotics are not meant to be targeted towards viruses. They are only meant for bacteria and other serious pathogens.
Harmful effects of excessive intake of antibiotics:-
1) Natural balance of gut gets disturbed thereby killing good bacteria which are very useful for the digestive purposes.
2) Harmful bacteria present in gut increases in number as the balance is disturbed and become resistant to antibiotics doing more harm to the body.
3) Good bacteria can turn into harmful one by antibiotics.
4) Antibiotic resistant gonorrhea is developing at a very rapid pace.
5) Resistance to antibiotics is responsible for increasing medical costs as prolonged and more expensive treatment demands is developing.
6) More and more people are suffering from diarrhea due to excess intake of antibiotics.
7) Pneumoccal infections like pneumonia, meningitis, ear infections, tuberculosis etc..... have become difficult to treat due to resistance offered by microbes.