Lactic acid bacteria facts for kids
Lactic acid bacteria are tiny living things called bacteria. They are special because they make something called lactic acid. They do this by changing carbohydrates (like sugars) into lactic acid and energy. This process is called fermentation.
These bacteria belong to a group called Lactobacillales. Most of them are anaerobic, which means they don't need oxygen to live. They can also live in places that are quite acidic. You can find them in rotting plants and in milk products. They can be shaped like rods or like tiny balls.
Lactic acid bacteria are very common and important. There are about 40 different types, or genera, of these bacteria. Some types live inside the gut of animals, including humans. A few types can cause diseases, but many are helpful.
What They Do
Lactic acid bacteria have been used by humans for a very long time, even since the Stone Age. They help make food last longer and easier to digest. This is why they are used to make foods like cheese and yogurt.
Lactose Digestion
Long ago, adult humans could not digest milk products. This is because they were lactose intolerant. This means their bodies stopped making an enzyme called lactase after they were babies. Lactase is needed to break down lactose, the sugar in milk. Many animals, like cats, are still lactose intolerant after they stop drinking their mother's milk.
But some groups of humans developed a special ability called lactase persistence. This means their bodies continue to make lactase even as adults. This ability appeared about 10,000 years ago in groups of people who herded cattle. Being able to digest milk throughout life was a big advantage for them. However, most people around the world are still lactose intolerant.
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Streptococcus
See also
In Spanish: Cultivos lácticos para niños
