We credit modern medicine with amazing discoveries that are improving our health. But once in a while we're humbled by what ancient cultures knew about healing.

In this case, we're talking about antibiotics. And the scientist who had always gotten credit for discovering this wonder drug in the 1920s was Alexander Fleming.

But we were wrong!

The Nubian people began using antibiotics sixteen hundred years ago.

Excavated bones of ancient Nubians, who lived along the Egyptian-Sudanese border, prove that they regularly ingested the antibiotic, tetracycline. The first hint of this came from a study in 1980 when a bioarcheologist discovered the bones glowed under UV light.

That's because tetracycline fluoresces with a unique yellow-greenish color.

The antibiotic tends to bind with the calcium and phosphorus in our bones, so that even small amounts stay for many years.

But few people believed the 1980 report, skeptical that the Nubians could have stumbled onto such a modern marvel. Yet soon, another scientist provided more proof by extracting the antibiotic from the bones and showed that it could still kill bacteria.

The best evidence was just published. In the new study, the bone samples were dissolved in acid and analyzed by mass spectrometry, which can identify unknown compounds.

This technique proved the bones contained tetracycline and that exposure was over long periods of time.

So, where and how did the ancient Nubians consume this antibiotic? Well, tetracycline producing bacteria called Streptomyces naturally occurs in the soil there. Researchers believe the Nubians, knowing its therapeutic effects, used it along with their grain to produce beer.

Most Nubians, starting at two years old, drank the brew. Researchers believe it would have cleared up bacterial infections and symptoms like diarrhea.