How to improve intestinal flora

What is it?

Intestinal flora is the set of bacteria that live in the gut. The vast majority of these are not harmful to health, and many are beneficial. It is calculated that in the body we have 2,000 different bacterial species, of which only 100 they can be harmful and cause serious infections.

Specifically, in the human intestinal flora there are more than 400 different species of bacteria that coexist in relative harmony and perform important functions, both for the health of the digestive system and for the rest of the body. In fact, by intestine It is called "the cradle of the immune system”Since, on the one hand, the intestinal microflora prevents the invasion of harmful germs and prevents intestinal infections. And, on the other hand, the small percentage of Pathogenic bacteria of the intestine keeps the immune system in a state of alert, which stimulates the constant defense production.

Ally of our health

Many animal species depend very closely on their intestinal flora. In the human being it benefits us in different ways:

• They stimulate the peristaltic movements of the intestine and improve digestion. In addition, they help prevent gas and constipation.
• They are essential for synthesis de certain compounds, such as vitamin K and some B complex vitamins
• They promote lactose tolerance, by degrading the part ingested through food and supplying something of the deficiency of the lactase enzyme that intolerant people possess.
• They help the absorption of calcium, since the lactic acid they produce creates the right environment for it to be assimilated.
• They protect the liver, by neutralizing certain harmful substances, and help thanks to the use of fiber from food.

What can alter the intestinal flora?

All intestinal bacteria form a complex ecosystem that regulates itself and remains in balance. But the balance is broken and proliferates the group of pathogenic versus beneficial bacteria It can lead to problems such as making intestinal transit difficult and causing constipation. Likewise, these bacteria, by fermenting food waste, produce gas and bloating, and also nitrosamine, which has been shown to possess carcinogenic action.

Each animal or each person has a different population of bacteria that depend on their lifestyle, especially their diet. An international project is underway to learn about the genome of these bacteria (human microbiome), which may play an important role in metabolic diseases and influence the immune system.

The flora of the adult is influenced by a series of intrinsic factors (intestinal secretions, hereditary predisposition) and extrinsic (aging; diets rich in processed and refined foods, fried, sugar, coffee ..., but low in fresh products of plant origin; stress; tobacco; alcohol; antibiotic treatments) that can cause an alteration of the intestinal flora.

Being composed of microorganisms, the intestinal flora is very sensitive to antibiotics, which are the main causes of its destruction, when it occurs. However, it is able to regenerate periodically and quickly, excreting dead microorganisms through the feces.

Good food

In addition to trying to control the factors that cause the deterioration of the intestinal flora, it is good to know that we have some foods that contain two allies of its balance.

Prebiotics

Prebiotics are substances present in food capable of stimulate the growth and / or activity of intestinal bacteria beneficial to the intestine (such as lactobacilli and bifidobacteria). In general, these are usually indigestible carbohydrates such as lactulose (composed of fructose and galactose), the dietary fiber, the fructooligosaccharides and the inulin (present in garlic, onion, artichoke and spinach). Other foods that contain prebiotics are bananas, soybeans, or corn.

Indeed, all these molecules can form part of the intrinsic composition of foods or be added to them (functional foods). Prebiotic foods are used in the food industry as sugar and fat substitutesThey tend to provide food with texture, stabilize foaming, improve the sensory qualities of fermented dairy products, cookies, jams, bread and milk.

Probiotics

Probiotics, as defined by the World Health Organization (WHO), are «live microorganisms which, when supplied in adequate quantities, promote benefits in the health of the body who receives them. Ingested in sufficient doses, therefore, they could have beneficial effects, such as contributing to the balance of the intestinal bacterial flora and boost the immune system. They usually contain probiotics fresh yogurts and others fermented milks like kefir. It should also be borne in mind that probiotic dairy products are better tolerated by people with lactose intolerance.

Types of probiotic bacteria

• Bifidobacteria: a group of bacteria that normally live in the intestines. They can be grown outside the body and later ingested. They belong to a group of bacteria called lactic acid bacteria and are found in like yogurt and cheese.
• Lactobacilli: they are also found in foods such as yogurt and in dietary supplements. There are doubts about the quality of certain lactobacillus products. Some of those labeled acidophilus lactobacillus do not actually contain it or possess a different strain of lactobacillus such as Lactobacillus bulgaricus.

Are probiotics really beneficial?

Although they have been extensively studied, they still the exact mechanism of action of probiotics is not known which, in addition, can vary a lot between different probiotics and also from one person to another. In addition, there are few studies that have evaluated its effects on the general state or well-being in healthy people and with variable results, which is why its systematic use with the aim of "improving the general state" is not justified. Therefore, more studies are needed to recommend its consumption in cases of digestive or general disorders.

In some research centers in Barcelona it has been possible to transplant intestinal flora among mice. This could be the first step to find new ones such as obesity or chronic inflammatory bowel diseases, but it is research that is still in the experimental phase.

• Beneficial: the intestinal flora is essential to maintain the healthy digestive system and prevent disease.
• It is altered by ... age, unbalanced diets, alcohol, tobacco, stress, abuse of antibiotics ...
• Allies: probiotic foods (yogurts and fermented milks) and prebiotics (garlic, onion, artichoke, spinach, banana, soy, corn ...).

Dra. Elisabeth Herrero i Vila Family and Community Medicine Specialist Master in Clinical Gerontology Bedside Medicine