Bacteria lurking in food can make it delicious or deadly. Why are some bacteria in food safe and even beneficial, while others are harmful and can cause illness?
“Over millions of years, bacteria have evolved into different types, some of which have developed beneficial relationships with us, and some of which have evolved into more toxic forms,” explains Maria Tucker, a registered dietitian and nutrition educator at Duke University. “This evolution has actually led to some bacteria being beneficial to us and some being harmful to us.”
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Beneficial bacteria
Fermented foods—yogurt, kefir, tempeh, miso, sourdough bread, and some cheeses, to name a few—owe their unique and delicious flavors to the bacteria that live there.
Bacteria break down certain food components. This creates new flavors and textures. Sometimes germs are captured from the air (as in homemade sauerkrautfor example), and sometimes a certain group of microbes is added (as in yogurt).
lactobacilli And Bifidobacterium are well-known examples of beneficial bacteria in foods, but there are many others. According to journal research food, Some of these microbes, known as probiotics, have been shown to improve health by, among other things, increasing the bioavailability of nutrients and generating compounds that help reduce inflammation, regulate the immune system, and support gut and metabolic health.
However, in recent Advances in nutrition In a study on fermented foods, the authors note that some people should use caution when consuming fermented and probiotic foods. Pregnant people, people with weakened immune systems, and people with irritable bowel syndrome or bacterial overgrowth in the small intestine should be especially careful. The authors also warn that in many cases, marketing claims lack scientific support.
Read more: It doesn't take long to restore your gut health with small lifestyle changes.
Harmful bacteria
However, as Tucker notes, some microbes can cause a lot of trouble. According to the World Health Organization, more than 600 million people worldwide fall ill every year after eating contaminated food. Of these, about 420,000 die. Young children and the elderly are most at risk.
Some of the more well-known killer food bacteria are: Escherichia coli, listeria, Salmonella, ShigellaAnd Staphylococcus aureus, – says Tucker. These bacteria are not added to food or encouraged to grow, unlike beneficial bacteria. Instead, they slip somewhere between the truss and the plate.
Escherichia coli, Shigella, And Salmonella occur as a result of fecal contamination of food products. Sometimes meat products get bacteria from the animal's intestines or skin, Tucker says.
“That's why you sometimes see a recall of ground beef, because there was coli in it.”
Animal products are not the only types of food that can be contaminated. Vegetarians should also be careful. Many dangerous bacteria live in the soil, fall into the hands of people, and get into food during harvesting or packaging.
How to prevent the spread of harmful bacteria
Luckily, protecting yourself and your family is easy. Tucker says to remember four important steps: peel, separate, cook and chill.
- Clean: Wash your hands dishesand kitchen surfaces often. “Wash your produce, too,” Tucker says. Even pre-washed lettuce can be rinsed well.
- Separate: Store raw meat, poultry, seafood and eggs separately from other foods. Always use separate cutting boards for meat and vegetables.
- Prepare: Make sure food is cooked to the appropriate temperature. Tucker suggests using a kitchen thermometer. According to her, some of them indicate safe cooking temperatures for various foods.
- Cold: Immediately place leftovers in the refrigerator. That means, Tucker says, within an hour or two at most. Better yet, she says, freeze them. Leftover food only lasts two to three days in the refrigerator.
Fermented foods tend to last longer, but even with foods that contain beneficial bacteria, you need to be careful about introducing harmful bacteria. And for foods that smell bad even when they're good (I'm looking at you, kimchi), it can be hard to tell when they've gone bad.
Tucker advises keeping an eye out for changes in texture or color—for example, pink or gray in the usually orange kimchi, or a slimy texture.
Your food can contain both good and bad bacteria. If you want to stay healthy, embrace the good and avoid the bad.
This article does not contain medical advice and should be used for informational purposes only.
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