In today's world, fermented foods have become a major part of human's diet. Therefore, the
science behind them is noteworthy.

Fermented foods are those foods that have been subjected to the action of enzymes or microorganisms, so that desirable biochemical changes cause significant modifications to the food. 

Yeasts, filamentous molds and bacteria constitute the microbiota in indigenous fermented foods and beverages, which are present on/in the ingredients, environment, or utensils. They are selected through adaptation to the substrate.

During the fermentation process, microorganisms like the lactic-acid bacteria (LAB) convert organic substrates into simple organic end products. Due to this process, food might have enhanced nutritional properties through the presence of potentially beneficial bioactive compounds.

Let’s take sourdough bread for example, naturally occurring microbes convert carbohydrates in milled grain into lactic acid and carbon dioxide, which makes the bread rise. This technique is used to make bread from a number of grains.

In fermented foods, live microorganisms and/or their metabolites are responsible for several health-promoting properties. A good example is lactic acid, the primary metabolite in non-alcoholic fermented cereal foods that demonstrates significant health benefits, by inhibiting pathogens causing human illnesses and food-borne diseases. 

In addition, fermented foods possess massive benefits. For instance, Kefir lowers cholesterol, reduce lactose intolerance symptoms, and stimulate the immune system among others.

Kimchi has anti-obesity, anticancer, antiaging, and anti-constipation effects. Findings from recent in vitro and animal models, as well as human intervention studies, support some of these claims.