Dysbiotic changes in the intestines under the influence of exogenous biological determinants

Introduction. Data were obtained on the difference in the quantitative and specific composition of intestinal microbiota bacteria in practically healthy individuals with subclinical invasions by pathogenic intestinal protozoa Lamblia intestinalis, Blastocystis hominis. Сhanges in bacterial composition were shown to have characterological features and species-specific «targets» of intestinal microbiota destruction.

Material and methods. Bacteriological and parasitological research methods were used. For a comparative analysis of quantitative and specific changes in the symbiotic microflora, there were formed two groups: “Yes” and “No” for each type of pathogenic protozoa, bacteriological indicators were ranked by quantitative content — CFU “0–10³”, CFU “10³–10^max”, CFU “10^max”. Statistical differences in research results were determined by the Chi-square calculation method.

Results. Antagonistic activity of unicellular protozoa in relation to the symbiotic bacterial intestinal microflora in the examined population groups has a different degree of severity depending on the type of invasion. Parasitic pathogens were shown to inhibit up to 40% of the quantitative and 50% of the species composition of the intestinal microflora and are an aggressive biogenic factor in the destruction of biota. There are no limitations of the study.

Limitations. The studies had no methodological or administrative restrictions.

Conclusion. For the first time, significant statistical material has confirmed that asymptomatic parasitosis is a strong biogenic determinant of the development of destructive changes in the integral structure of the symbiotic microflora and the formation of a subclinical form of dysbiosis in an “almost healthy contingent” of the population. The asymptomatic carriage of Blastocysts spp. was found to have a more pronounced antagonistic effect on the bacterial composition of the intestinal microbiota than the presence of L. intestinalis, Blastocysts spp., form intestinal dysbiosis more aggressively, which indicates a greater pathogenic potential of B. hominis in the formation of intestinal pathology in humans.

Compliance with ethical standards. The studies were approved by the decision of the local ethical commission to use anonymized, de-identified, non-re-identifiable samples (protocol of the Federal State Budgetary Institution “CSP” of the FMBA of Russia No. 3 of 2013).

Contribution of the authors:
Kuznetsova K.Yu. — concept and design of the study, writing the text;
Sergiev V.P. — research concept and design, editing;
Kuznetsova M.A. — collection and processing of material, statistical processing;
Aslanova M.M. — collection and processing of material, writing text;
Zagaynova A.V. — collection and processing of material;
Fedets Z.E. — collection and processing of material;
Kovalchuk M.V. — statistical processing.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version. 

Acknowledgment. The research was carried out within the framework of the research work “Development of technologies for cryopreservation and archiving of biological samples of human microecological resources (code“Cryobank”)”. 

Conflict of interest. The authors declare no conflict of interest.Received: May 19, 2021

Accepted: July 27, 2021
Published: April 28, 2023