Improving the gut is beneficial for enhancing brain function

2023-10-25

The digestive tract is a special environment, seemingly in the body, but connected with the outside world, containing food are foreign "foreign substances". Food is digested and absorbed before it really enters the body.

We can think of the digestive tract as a deep cave that stores a variety of nutrients. They are digested into small molecules such as amino acids and simple sugars, pass through the stomach wall and intestinal wall into the blood and lymph, and then release energy during metabolism, synthesize the raw materials needed by cells, and continuously transform into human tissues.

The human digestive system includes the digestive tract and digestive glands. The digestive tract extends from the mouth to the pharynx, esophagus, stomach, small intestine and large intestine, which is a 10-meter-long muscle tube that is the only way for food; The digestive glands, including the salivary glands, stomach glands, intestinal glands, pancreas and liver, secrete up to 7 liters of digestive juices per day to break down food.

Food is first chewed by the teeth and finely crushed, then sent to the back of the mouth for swallowing, and through the throat into the esophagus.

The role of the esophagus is to carry food from the chest cavity into the abdominal cavity, and there is no digestive function. Next, the food enters the stomach, whose main task is to grind the food, a process called mechanical digestion, but also secreting some enzymes for chemical digestion. After the food passes through the stomach, it becomes a fine and soft chyme. The chyme enters the small intestine little by little through the pylorus of the stomach, and the large molecules in the food have become small molecules, which can enter the blood and lymph through the intestinal wall, and the absorption is completed.

What the small intestine cannot absorb is mainly dietary fiber, which is sent to the large intestine together with dead bacteria and digestive juices, and the large intestine absorbs the digestive juices back and excretes other residues. Food scraps are excreted through the large intestine to complete the journey of the human body. A daily meal takes about 24 hours to pass through the entire digestive tract, including 4-5 hours in the stomach, 3-8 hours in the small intestine, 10-20 hours in the large intestine, and the residence time and the content of dietary fiber in the food, living habits, etc. have a lot to do with it.

The digestive tract is made up of smooth muscle, which is not innervated by consciousness but is regulated by sympathetic and parasympathetic nerves. Eating can cause parasympathetic excitement, resulting in enhanced movement of the digestive tract, increased secretion of digestive juices, increased blood supply to the digestive system, and the human body is in a state of "replenishing energy", as if the mobile phone is charging. Most of the digestive tract walls are also rich in intramural plexuses, with a large number of sensory neurons, interneurons, and motor neurons, forming circuits with each other and completing simple reflexes. Mechanical or chemical stimulation of food can cause digestive tract movement and secretion by digestive glands through local reflexes, which is a regulatory mechanism unique to the digestive system. The intramural plexus, also known as the "gut brain," and both it and the central nervous system originate from the neural crest of the embryo.

Some people call the digestive tract "gut brain", will it think like the brain? In recent years, some studies have improved the mood and cognitive performance of patients by regulating the intestinal flora to treat Alzheimer's disease. There is no evidence that the intestinal flora can directly enhance intelligence, and there is no evidence that the "gut brain" can think, but by improving intestinal function, promoting the absorption of nutrients, and supplementing various raw materials needed by the human body, it will protect and enhance brain function to a certain extent.

To protect the digestive system, it is necessary to choose a variety of foods with appropriate proportions through a balanced diet and good eating habits, according to the model of a balanced diet pagoda recommended by the Chinese Nutrition Society, so that the intake of nutrients is comprehensive and balanced.

The intestine is the main place to absorb nutrients, and the intestinal flora is closely related to the absorption capacity. The human intestinal colony weighs 1.5 kilograms and has 500-1000 species of intestinal flora. They are not born, but gradually settle into the human intestine and colonize as babies breathe, breastfeed, and the addition of various complementary foods. Probiotics in the intestinal flora can promote food digestion, absorption of various vitamins, and form an immune barrier.

To protect probiotics, you can appropriately eat more vegetables, grains and other foods rich in dietary fiber, regular work and rest, three meals are timed and quantitative, and you can also eat some fermented foods rich in probiotics, do not abuse antibiotics.