A healthy gut flora produces short-chain fatty acids that strengthen the intestine and supports your general health. This can be ensured by eating a diet rich in fibre.
In recent years, research has shown that an unbalanced gut flora can be linked to a variety of diseases. We should therefore focus on finding out what causes imbalances in the gut flora and which methods we can employ to counteract or treat these imbalances.
But just as an unbalanced gut flora can have a negative health impact, a healthy gut flora can contribute to your general health in several important ways. One of the beneficial functions of the gut flora is its ability to produce short-chain fatty acids such as acetic acid, propionic acid and butyric acid. These short-chain fatty acids consist of fewer than six carbon atoms and are a residual product that is created when the intestinal bacteria in the large intestine ferment fibres.
Scientific studies have shown that butyric acid, in particular, strengthens the intestinal barrier. A dense and stable mucous membrane decreases the risk of leakage and inflammation in the intestine. Such a membrane allows the immune system to focus on attacking pathogenic bacteria and viruses, instead of using immune cells to maintain an unnecessary state of inflammation in the intestinal mucosa. An increased concentration of short-chain butyric acid in the body seems to affect the formation of both inflammatory and anti-inflammatory substances in the body.
You can affect the gut flora’s ability to create short-chain fatty acids by optimising the conditions in your gut. These fatty-acids are formed when the microflora of the large intestine is provided with fibres such as resistant starch, which is a form of carbohydrate that can pass the small intestine without being broken down. It is thus your choice of diet that determines the amount of short-chain fatty acids that are formed. The more of the food you eat that reaches all the way down to the colon without being broken down, the better the ability of the good gut bacteria to create short-chain fatty acids becomes.
Fructose, saccharides (FOS), inulin and pectin are examples of the types of fermentable dietary fibres that occur naturally in plant foods. Inulin is found in artichokes, garlic, leeks, onions and asparagus, while oligosaccharides are found in various fruits and vegetables. Apples, apricots, carrots and oranges contain pectin, and resistant starch is found in barley, rice, beans, green/unripe bananas, legumes and potatoes that have been boiled and then cooled. According to researcher Stacey Lockyer, who summarised recent years’ research on resistant starch published in the British publication The Nutrition Bulletin, ingesting 30 grams of resistant starch a day protects you against a number of chronic diseases. So the bottom line is that it’s worthwhile to keep your house – or rather; your gut flora – in order, and to make sure to feed both yourself, and the intestinal bacteria, good food.
Risk and benefit profile, The Swedish National Food Administration
Stacey Lockyer, Health Effects of Resistant Starch, Nutrition Bulletin