20 years since the International Society of the Ageing Male (ISSAM) was founded

Abstract

Nowadays, the old hypothesis about the important influence of the human intestinal microbiota (IM) on the mental and somatic health, expressed in the second half of the 19th century, received its scientific confirmation. Back then, Mechnikov predicted the discovery of the infectious agents responsible for carcinogenesis and for the development of the “sugar disease”. The results of the recent years’ long-term researches alter the traditional picture of the pathogenesis of many diseases and initiate more profound and deep investigation of the human IM. These achievements were facilitated by the development of the novel technologies of the molecular genetics, which make possible the identification of various bacterial species previously not available for cultivation and for traditional microbiological research methods. As a result, at the moment researchers have no doubt about the contribution of the microbiota into the development of many pathologies: metabolic, autoimmune, allergic, functional, oncological, cardio-vascular, etc. Essential contribution to the studies of the IM made the “Human Microbiom” project (HMP). One of the main goals of the project was the decoding of the genomes of more than 1000 bacteria from all biotopes of the human body contacting with the environment. The intestinal microbiome contains 100 times more genes than human genome. Each person has his own unique microflora []. IM is not only a large metabolic organ, but also a largest organ of the human body. Its mass can be up to 2.5–3 kg. However, Ley and coauthors proved that factors of the diet could lead to the changes in the IM content. Moreover, the levels of bifidobacterium and faecalibacterium have correlations with the anti-age effects. Due to widely spread metabolic syndrome and connected pathologies, like obesity and type 2 diabetes in the last decades, the role of the IM in the development of all pathogenic stages of the “20–21 century epidemic” is in the focus of the attention of the researchers. Essential difference in the IM content of the persons with under-weight and overweight allows one to suppose the importance of the role of IM in the development of obesity. Particularly, Cani and coauthors have shown that the decrease in the diversity of the gram-positive butyrate-producing anaerobic bacteria is associated with the endotoximia, chronic inflammation and development of the insulin resistance in mice. Ley and coauthors have found the changes in the ratio of the concentrations of Bacteroidetes and Firmicutes (decrease of the former and increase of the latter) in mice with obesity. The increase of the body mass in mice with obesity is connected with the additional extraction of energy by the colon microbiota from the meal polysaccharides. Thus, there is substantial progress in the research of the IM and in the understanding of its influence on the human health, particularly in its role in the pathogenesis of obesity and diabetes type 2. Although, many questions are still open and are the subjects for further research, but applying the methods of the IM correction such as special diet, probiotics and prebiotics, aiming at normalization of the IM facilitates the reduction of insulin resistance, normalization of the glycemic background and body mass, improvement of the other indexes of the metabolic syndrome.