Antibiotics and the food we eat

I can't recall taking any antibiotics since I was in high school. Not that I haven't tried of course. When I was in graduate school, I had a cough, and ear infections for a long time. I also had crummy insurance and so when I went to the doctor, they told me to drink more water and sleep more. It was probably good advice, but I was really sick. I wavered between shooting myself up with lab antibiotics and talking to a pharmacist. I decided to go to the pharmacist and asked what to do. Pharmacists turn out to be really cool. Besides dispensing drugs, they know A LOT, and they are usually happy to share their knowledge. The pharmacist told me to take pseudofed to help drain my ears and I got better. I apparently didn't need antibiotics after all. Since then, I have just steered clear of antibiotics and although I have been really sick a few times since then, it was always viral and I didn't need an antibiotic. So I felt pretty good about myself. You know, since I research antibiotic resistance, it's the least I can do to not contribute to the problem that I am trying to help solve. But then I found out about antibiotics and the food we eat. Horror of horrors! I contribute to the problem after all because I eat food.

Antibiotics are used heavily in the food industry. They are used both for plants and animals. It is probably impossible to eliminate them entirely from agriculture because plants and animals get sick with bacterial infections. Since agricultural organisms are often in close contact with each other, diseases can spread rapidly so it's usually necessary to treat the entire population to get rid of the disease entirely.
However, sometimes antibiotics are used for purposes other than the treatment of diseases. They are used to enhance the growth of animals. This practice is mainly used in pigs but has also been used in chickens. The reason that antibiotics are thought to increase the growth of food animals is that by killing off some of their gut microbial flora, there isn't as much competition for the food between the animals and their microbes. It might also help eliminate pathogens from the animals.
In the 90s, growth enhancing use of antibiotic accounted for about half the use of all antibiotics. More recently than that, we have learned that many antimicrobials don't break down during the sewage treatment process and so they hang around in the environment selecting for antimicrobial resistance bacteria long after they have passed through whatever organism they were used to treat. The antibiotics used in animals are similar to those used in humans. Resistance to animal antimicrobials is related to resistance to human antimicrobials. At this point, pharmaceutical companies aren't making many new antibiotics, so it's important to make the ones we have last.
In Europe and in Korea, the use of growth promoting antibiotics has been banned because those countries have decided to prioritize human use of antibiotics over growth promotion. (Antibiotics can still be used to treat diseases in animals). In the US however, this hasn't happened yet. I would suspect that the reasons it hasn't happened are that the lobby by the agricultural industry is intensely opposed to this, and there is a huge demand for inexpensive pork.

I know which side of the problem I am on (I don't eat much meat anyway, so if the price goes up, I'll survive). If you are also on the side of prioritizing antimicrobials for humans over growth promotion in animals, you can write to your congressman demanding that antibiotics be eliminated as growth promoters in the agricultural industry so that they will remain effective longer in human populations. You can also eat less pork.