.Both changes in diet and pathological conditions caused by an infectious agent, allergic or autoimmune inflammatory process, affect the biological rhythms of the digestive tract, which negatively affects the intestinal microbiota and increases the permeability of the intestinal mucosa. The altered microbiota potentiates inflammation and causes a “vicious circle”. The zonulin protein is the agent that modulates the density of intercellular connections. The review presents data on the biological role of zonulin, correction of its synthesis violation with the help of functional products for baby food.

На сегодняшний день в большинстве стран Европы и Северной Америки наблюдается неуклонный рост распространенности воспалительных заболеваний кишечника (ВЗК). Данных о взаимосвязи употребления молочных продуктов и развития ВЗК немного, несмотря на вероятные биологические механизмы, связывающие данные продукты с этиопатогенезом заболевания. Исключение из рациона молочных продуктов обычно связано с возникновением диспепсических симптомов при их употреблении, что может указывать на обострение воспалительного процесса в кишечнике или о наличии лактазной недостаточности. Для пациентов с ВЗК характерна высокая распространенность остеопороза, а ограничение употребления молочных продуктов оказывает еще большее негативное влияние на состояние минеральной плотности костей. В свою очередь, коррекция диетотерапии у пациентов с ВЗК при наличии у них непереносимости молочных продуктов должна быть важной частью процесса лечения и профилактики осложнений заболевания.

Lactose (β-galactosyl-1,4 glucose) is milk sugar, the main disaccharide of human and other mammalian breast milk. Lactase is intestinal disaccharidase that catalyzes the lactose hydrolysis. The lactase gene LCT controls biological function of the enzyme. The age-related genetically determined feature of disaccharide expression, epigenetic factors, and natural selection with persistent tolerance to milk sugar throughout lifetime has divided the human population according to the LCT gene into two phenotypes: lactase persistent and lactase non-persistent. There is conflicting evidence that the latter phenotype is associated with low calcium absorption and the development of osteoporosis. The regular use of fermented probiotic dairy products by individuals with the lactase non-persistence phenotype ensures the accumulation of peak bone mineralization and prevents osteoporosis.

Relevance of the research. Timing, order and sequence of complementary feeding remain the subject of discussion until now. The aim of the study. Estimate influence of different outlines of introduction of complementary foods on nutritional status and food behavior in children of first year of life. Materials and methods. Examined 96 children in age of 4-6 months during introduction of complementary foods. Main group – 50 children (27 breast-feed (BF) children and 23 on milk formulas (MF)), in whose diet were introduced only complementary foods, which were made in special factories. Comparison group – 46 children (33 – BF and 13 – MF) received complementary foods made at home and in special factories. Duration of follow-up was 3 months. Physical examination, mother’s diary analysis, evaluation of tolerance of complementary foods, bacteriological examination of feces. Results. On the background of introduction of complementary foods in the main group, increased the number of children with normal fatness (BF from 66.8% to 74.2%, MF from 82.7 to 88.4%), in comparison group, their number decreased (BF from 84.8% to 78.8%, MF from 69.3 to 62.3%). In the main group when a child refuses a product, mother continues offer it insistently. 61.5% of children began to eat unloved product at the end of first year of life. In comparison group, where mother changed unloved product at once, only 25% of children began to relate to it positively. In the main group dyspeptic disorders were mild in 4% of children. In in comparison group prevailed diarrheal syndrome, related to contamination with pathogenic strains of E. coli in 13% of children. Conclusions. Using of industrial made complimentary foods according to the optimal order, with determined mothers perseverance provides equalization of fatness, allows to form a correct food behavior and decreases risk of intestinal colonization by pathogenic microorganisms.

During evolution, microorganisms and humans have evolved to live in symbiosis with each other. The microbiome, in particular the intestinal microbiota that includes bacteria, archaea, fungi, viruses, their metabolites and genomic elements, plays an essential role in maintaining homeostasis. Alterations in the microbiome composition have been shown to affect the immune system of the host, triggering not only infectious, inflammatory or allergic intestinal pathology, but also frequent recurrent infections of the respiratory tract and ENT organs. Objective. To analyze intestinal microbiota and local immune response in the gastrointestinal tract among young children with frequent respiratory infections, who are in a difficult life situation (in an orphanage) in order to identify possible pathogenetic association between intestinal dysbiosis and inadequate immune responses. Patients and methods. In the period between October 2018 and May 2019, residents of the specialized psychoneurological orphanage (PNDR) in St. Petersburg were examined. To carry out the study, 46 respondents with health groups II-III aged from 11 to 36 months were selected. The average age was 21.2 ± 6.75 months. Among them were 25 (54.34%) boys and 21 (45.6%) girls. When analyzing the incidence of acute respiratory infections, we took into account the severity of each episode, its duration, complications, the need for antimicrobial therapy, and hospitalization of the child. All results were recorded on specially designed record forms. Results. The analysis of medical record confirmed that the incidence of acute respiratory infections in children living in the orphanage is higher than that among children living in families. Respondents with an altered state of the nose and oropharynx usually had longer episodes of respiratory infections and more frequent complications. These patients were also found to have severe diversification of the intestinal microbiota and less pronounced mucosal immune response of the intestinal mucosa as demonstrated by bacteriological examination of feces and testing of fecal filtrates using ELISA. We discuss the effectiveness of fermented dairy products enriched with probiotics and prebiotics with a proven effect on the local immunity. Conclusion. Our findings suggest possible association between dysbiosis and inadequate local and systemic immune response. Key words: intestinal microbiota, mucosal immune response, secretory immunoglobulin A (sIgA), children with frequent respiratory infections, fermented dairy products, probiotics, prebiotics

Lifestyle change, including diet changes, often lead to an impairment of biological rhythms regulating production of gastrointestinal hormones, enzymes, neuropeptides, and various cytokines that ensure proper functioning of the digestive tract. Such changes are almost always associated with microbiota disorders and increase permeability of the intestinal mucosa. Zonulin is a diagnostic marker regulating intestinal wall stability and modulating the density of intercellular connections. Its biological role and mechanism of action are being actively studied now. This literature review aims to summarize the results of latest studies published over the last five years analyzing the role of zonulin in various diseases and conditions. The article also covers some aspects suggesting that zonulin can be used as a marker of normal functioning of the intestinal barrier not only in therapeutic, but also in obstetric and pediatric practice. Key words: biomarker, inflammatory cytokines, gestation, depression, zonulin, intestinal barrier, metabolism, microbiota, intestinal wall permeability