Present in the digestive tract and concentrated in the colon, the microbiota , or intestinal flora, has been the subject of countless research for fifteen years. Thanks to new techniques to decipher their genes one by one, we know that it is composed of more than 100,000 billion micro-organisms, that it can include up to 1000 different bacteria and that it varies from an individual to another. We also know his roles better. It produces vitamin B8, B9, B12 and K . It digests the fibers and gives rise to compounds that nourish the intestinal cells and prevents the bad germs – those, for example, causing infections – from entering the body. It boosts the immune system, three quarters of them in the digestive tract. Finally, this “second brain” even conditions our mood, interacting with the more than 100 million neurons in the intestine.
Microbiota: why you must take care of it
Studies show that when it is unbalanced or not very diversified, multiple diseases can occur: intestinal diseases ( irritable bowel , Crohn’s disease …), allergies, depression, type 2 diabetes … It is even involved in overweight, with an overrepresentation of bacteria (firmicutes) capable of extracting maximum calories from food residues reaching the colon or disrupting the production of hormones regulating hunger and satiety .
Fresh fruits and vegetables every day
The composition of the microbiota depends on genetic factors, but also largely on the alimentary mode. Studies show that diets rich in plants (cereal products, fresh and dry fruits and vegetables), and thus in fiber , favor its richness and diversity. Results confirmed by researchers at INRA (National Institute of Agricultural Research), who tested in volunteers, meals providing different amounts of fiber. They have shown that it is enough to boost the intake to 40 g per day for 5 days to obtain positive changes. Only downside, the diet must be continued for long, otherwise the good bacteria disappear again.
Prebiotic fiber, a favorite food
Certain fibers, called ” prebiotics “, stimulate the development in the intestine of microorganisms favorable to health.
– Resistant starches: starch is the carbohydrate (sugar) of starchy foods. When it resists digestion thanks to specialized enzymes (amylases), it reaches intact in the colon, which it feeds in good bacteria. This is the case when it is raw (banana still green), cooked and then cooled (pasta, rice or potatoes) or trapped by a high fiber content (pulses).
– Fructans: which are concentrated in certain vegetables: garlic, artichoke, asparagus, banana, chicory , onion, dandelion, leek, salsify, rye, Jerusalem artichoke.
– Beta-glucans: found in oats , barley, rye and sorghum.
– Polyphenols: which are not fibers but are nevertheless beneficial, because of their antioxidant and anti-inflammatory effects . They are abundant in coffee, tea, cocoa, spices, fruits and vegetables. There are several thousand, so the ideal is to vary its menus to enjoy the max.
The 3 enemies of the microbiota
The modern diet , poor in plants and too rich in meat and animal fats, sweets and industrial products loaded with additives, promotes the development of firmicutes (involved in overweight and diabetes), as well as bacteria involved in infections ( Escherichia Coli …).
Physical inactivity. According to studies, the least active people have the least diverse microbiota.
Excess antibiotics. If they eliminate the bacteria responsible for infections, they also destroy part of the microbiota. Several successive treatments would result in a definitive imbalance.