Bacteria, Humans, and Food

Bacteria, Humans, and Food Photo Credit: Clipart.com


Our ancestors did not have refrigeration and did not know sterile technique. And that is good news because all of the great cuisines of the world have benefited from those deficiencies. Fresh foods (fresh peas, fresh strawberries, freshly caught salmon) are delicious. After a few days without refrigeration, however, food either becomes inedible or becomes something new and different with subtle, interesting, savory smells and flavors thanks to the activities of fermenting microbes. We are in competition with many of them for the same nutrients. Sometimes the microbes win—the food gets tossed out and they continue to enjoy it in the compost heap. Sometimes we humans win—the food becomes even more delicious; it becomes our distinctive cultural cuisine. The microbes win too, in that case because humans have made great efforts to maintain and domesticate the valuable bacteria and fungi that create their cheeses, bean and fish sauces, sour dough breads, wines, and beers. Also, many of the culinary microbes are perfectly content to end up in our intestines after we have ingested them.

Thus, it is no coincidence that many of the benign bacteria found in and on our bodies are the same as those participating in the enhancement of food and drink. Contact of our bodies with our food would have readily (almost unavoidably) transferred those bacteria.


Go to and read Fermentation and Food on the Exploratorium website. As you read this resource, think about answers to these questions:

  • What does it mean to ferment something?
  • Describe fermentation in these different foods: pickled vegetables, wines, breads, and cheeses.

This esheet is a part of the The Ecology of Your Skin 3: The Body Food Connection lesson.

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