The human microbiota is gaining more importance in understanding the systemic health in the human body. This microbiota consists of several microorganisms living in our bodies and it has been well found that they participate in physiological and metabolic processes. How varied is this microbiota? The variety is huge. Just imagine: there are as many microorganisms as human cells in our body. Besides, there are a variety of microorganisms living in our bodies, making up for about a hundred times more distinct genes than our own. All of these different genes account for different metabolic functions that our cells are not capable of doing. The microorganisms live in different parts of our bodies, such as the respiratory system, the mouth, skin and the intestines. It is in the gastrointestinal system where the largest number of bacteria are found.
It has been found that the diet plays a special role in the microbiota living in the gastrointestinal system. People who eat highly-processed food, with a great amount of sugar and fat (also known as the Western diet), present alterations in the microbiota or also known as dysbiosis, compared to people who eat food high in vegetable fiber. In one study, the first group of people (eating more like the Western diet), presented more systemic inflammation compared to the second group. This inflammation due to the alteration of the microbiota has been associated with metabolic diseases, such as type 2 diabetes, metabolic syndrome, insulin resistance, inflammatory bowel disease, celiac disease, and cardiovascular diseases. The cell walls of gram-negative bacteria are mainly constituted by lipopolysaccharides (LPS), which induce inflammation. A high fat and sugar diet is correlated to an increase in LPS in the blood, which is caused by the permeability of this molecules from the gut. This permeability is mainly due to a dysbiosis. The increased levels of LPS have been correlated with metabolic endotoxemia. This has an effect in the inflammatory process in the body, contributing to developing or enhancing the metabolic syndrome.
A relationship has also been established between the non-alcoholic steatohepatitis (NASH) and the microbiota. It has been found in a study in people diagnosed with NASH, that the genes encoded by the intestinal microorganisms gradually deceases. This suggests that the bacteria living in the intestines become less diverse and this leads to metabolic issues related to inflammation, which leads to conditions as the ones mentioned before. In research that has been done, it has been found that people who present more kinds of favorable microorganisms, are less likely to develop systemic inflammatory diseases, unlike the individuals who have a less varied microbiome.
All of this information is leading us to research further the role of the microbiota in the human body. It seems that having a healthy and varied microbiome in our systems, helps prevent inflammation, and thus, diseases such as type 2 diabetes, metabolic syndrome, insulin resistance, and cancer. Probiotics and prebiotics will be playing an important role in this research and surely, we’ll be seeing more news regarding this in the pharmaceutical industry.