Intestinal microbiota and local immune response in the gastrointestinal tract among young children with frequent respiratory infections who are in a difficult life situation
Authors:   Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russian Federation, Bogdanova N.M. , Khavkin A.I. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Penkov D.G. ,   Specialized Children's Home No 3 (Psychoneurological) of Frunzensky district, Saint Petersburg, Russian Federation, Novikova V.P. ,   Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russian Federation
Published: February 2022

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