Intestine, a second brain

We now often hear about the microbiota and the brain as two parts of the body that are closely linked to each other, which have a strong impact on health in general.

It is no coincidence that Dr. Michal D. Gershon , professor of pathology and cell biology at Columbia University,  coined the term “second brain” to indicate the intestine, home to the microbiota.

This organ, in fact, often neglected, performs important functions that contribute not only to physical, but also to psychological well-being.

Microbiota and brain, a two-way relationship

The intestine contains millions of neuronal cells and fibers that make up a real autonomic nervous system.

In addition to assimilating the vital nutrients for our health , the intestine  is able to process external and internal stimuli received by the body, interacting with the central nervous system through an exchange of information.

Communication between the intestine and the brain takes place along the vagus nerve by means of neurotransmitters, such as serotonin, which plays a fundamental role in regulating mood and is 95% produced by cells found in the intestinal mucosa.
This communication has the task of mediating functions such as peristalsis and secretion, as well as the sense of nausea.

Through the vagus nerve these signals are transmitted by serotonin to the brain which associates them, for example, with the sensation of satiety.

It is important to underline that the relationship between the two organs is absolutely two-way : the state of health of the brain is also reflected in the intestine.

Strong stress, anxiety and fear cause an increase in intestinal motility and sensitivity with alterations in peristalsis and consequent episodes of constipation, colitis and production of acids, enzymes, hormones.

Even too restrictive diets, for example, alternate mood by increasing the level of stress, with consequent repercussions on the intestinal system.

What is meant by intestinal microbiota

The intestinal microbiota is the set of microorganisms present in the digestive tract where there are four million different types of bacteria, which live in close contact with the intestinal mucosa.  

Its composition is strongly influenced by nutrition starting from the type of breastfeeding (breast or artificial), weaning and, subsequently, by daily eating habits. 

The main bacteria that are part of the microbiota are bifidobacteria, lactobacilli and eubacterium, but there are numerous other species, and all together carry out essential functions such as:

• Support intestinal peristalsis ;
• protect the intestinal mucosa from aggression by pathogenic microorganisms;
• facilitate the availability of certain nutrients and the metabolization of calories;
• synthesize vitamins ;
• regulate the immune system in the intestinal mucosa.

The intestinal epithelium (the surface that covers the walls of the intestine) works in close contact with the microbiota.

Together they form a real barrier , whose state of health is closely correlated with our well-being: a healthy intestinal barrier will allow a functional exchange, while a damaged or suffering one will not be able to perform its vital functions at best, with consequent processes of malabsorption and with repercussions on health.

For example, an unbalanced diet, foods poorly tolerated by the intestine, imbalances in the intestinal bacterial flora,psycho-physical stress and unbalanced lifestyles are all factors that can cause dysbiosis, or even important alterations of the microbiota.

Taking care of the gut: nutrition, lifestyle and probiotics

” Let food be your medicine and medicine be your food “: already well over 400 years before the birth of Christ, Hippocrates , father of medicine, understood the importance of nutrition in relation to psycho well-being -physicist. 

And that’s right: nutrition and lifestyle are the main ones responsible for maintaining the balance of the intestinal flora . It is therefore essential to follow a healthy and balanced diet and also pay attention to the reaction of the intestine to certain foods or drinks that can irritate it the most (fried, fats, acids, carbonated and sugary drinks).

A correct diet with the right amount of fiber allows you to maintain the balance of the intestinal microbiota. In any case, if this is not enough, it may be useful to resort to food supplements based on probiotics, valid allies both to restore the bacterial flora and to support the immune system.

The brain also wants its part : performing regular physical activity and having a correct sleep-wake rhythm, in addition to keeping the body healthy, has positive effects on mood, helping to reduce anxiety and stress and consequently to keep the body under control. gastrointestinal system.