What is fermentation?

Fermentation is a natural process by which various microorganisms, such as yeasts and bacteria, convert carbohydrates – starch and sugar – into alcohol or acids (lactic acid, acetic acid, etc.).

The range of fermented foods is large and includes yogurts, cheeses, pickles, cold cuts and drinks. Many factors affect fermentation, including the type of microorganisms and their metabolites. For example, yogurt is made by fermenting milk from lactic acid-producing bacteria.

Fermentation differs from the decomposition of food, although microorganisms are responsible for both processes. A cabbage that is left out of the refrigerator for some time begins to change color as bacteria and fungi feed on it and in a few weeks it acquires a rotten appearance. However, removing oxygen and adding a little salt inhibits the growth of decay-related germs while other lactic acid-producing bacteria grow. The result is a nutritionally enhanced diet.

Their effect on the intestine

Many fermented foods are full of beneficial bacteria, probiotics. These living microorganisms colonize the gut, improving its functions. However, a fermented food or drink does not necessarily mean that it contains probiotics. Bread, beer, wine and distilled spirits require yeasts to be produced but the microorganisms are either deactivated by heat (eg in bread and some beers) or removed by filtration or other means (e.g. in wine).

The modern diet contains much less probiotics than pre-industrial diets. This is partly due to the use of processed foods that contain artificial sweeteners and preservatives, rather than fresh fruits and vegetables. [1]

Some scientists believe that fermented foods containing probiotics can significantly improve the health of most people and especially the digestive system. Probiotics have been used to prevent diarrhea due to antibiotics or as an adjunct to acute diarrhea. They can reduce the symptoms of irritable bowel syndrome, a common digestive disorder. [2]

A probiotic called Bifidobacterium found in dairy products helps relieve the symptoms of irritable bowel syndrome. Also, the sugar fungus boulardii helps fight diarrhea and other digestive problems. A six-week study of 274 adults with irritable bowel syndrome found that daily consumption of 125 grams of fermented milk improved symptoms. [3]

In addition, fermented foods can reduce the severity of diarrhea, bloating, gas and constipation [4]. Other studies have shown that they have antioxidant, anti-inflammatory and anti-diabetic properties and can protect against infections. Yogurt (but also kefir) seems to have a positive effect on the immune system. In a randomized controlled trial, consumption of live yogurt (when unheated) for one year was found to reduce allergic symptoms. [5]

Fermented foods are considered more nutritious than their non-fermented form because microorganisms synthesize vitamins and minerals. It also increases the digestibility of proteins and carbohydrates as well as the bioavailability of phytochemicals.

Possible side effects

Fermented foods are often considered safe but there are some caveats. For example, fermented vegetables have a salt content of about 2%, so you need to be careful as salt raises blood pressure in many people.

Start consuming fermented foods gradually to see if you tolerate them well. Avoid them if you have a serious illness that causes immunosuppression. If you have recently had gastric, liver problems consult your doctor first. If you can not tolerate fermented foods, you can improve the health of your gut through the prebiotic route: a diet high in fiber.

At Vita4you.gr you can find a great variety of food supplements with probiotics!

References

1. A Meta-Analysis of Probiotic Efficacy for Gastrointestinal Diseases.
2. Systematic review: probiotics in the management of lower gastrointestinal symptoms – an updated evidence‐based international consensus.
3. Effect of a fermented milk containing Bifidobacterium animalis DN-173 010 on the health-related quality of life and symptoms in irritable bowel syndrome in adults in primary care: a multicentre, randomized, double-blind, controlled trial.
4. Systematic review and meta-analysis: the effects of fermented milk with Bifidobacterium lactis CNCM I-2494 and lactic acid bacteria on gastrointestinal discomfort in the general adult population.
5. Health benefits of yogurt consumption. A review. International Journal of Food Properties.