The world of the fetal microbiome

Background and Aim : The study of the human microbiome has evolved significantly, showingthat the microbiome plays a variety of significant roles in our bodies. In light of this information,it is crucial to determine the commencement of microbiome colonization. The microbiota of themother, the placenta, and the fetus all affect fetal growth and undoubtedly play a significant rolein the healthy development of the newborn child.We show evidence that, contrary to popularbelief, the fetus is not sterile and contains a microbial ecosystem. This article also discusses thelink between hormones, immunity, and microbiome alterations.Methods : We conducted an organized examination of the literature in PubMed, Medline, andGoogle Scholar using specific search criteria. Because of the novelty of this method, few types ofstudies have been conducted in this field. We restricted the time period to ۲۰۱۹–۲۰۲۲, and we onlyallowed English. The search returned ۶۸ relevant items; five articles were reviewed afterduplicates were eliminated.Results : It is still debatable where microbial colonization starts. This concept has been discussedwhen microbial elements have been discovered in many samples of fetuses even afterstraightforward pregnancies with healthy term-born neonates. For example, Stinson et al. reportedthe first comprehensive ۱۶S rRNA gene study of meconium and amniotic fluid. They employedPacBio SMRT cell technology. Their findings imply that bacterial metabolites and DNA aredetectable inside the fetus. There is proof that our microbiota, immune system, and pregnancyhormones interact differently. A low-grade pro-inflammatory state can be triggered by alterationsin the host immune system of the intestinal mucosa as well as metabolic hormone levels.Progesterone lowers bacterial richness but enhances the growth of Faecalibacterium, Bacteroides,and Bifidobacterium, among other bacteria. The scientists discovered that estrogen administrationcaused mucosal growth of regulatory B-cells and M۲ macrophages, exhibiting a limited protectiveimpact. Also, the microbiota may regulate the number of sex hormones produced, providinganother degree of intricacy.Conclusion : In conclusion, evidence shows that, in contrast to earlier assumptions, scientists nowhave some data suggesting that the uterus is not sterile. Pregnancy-related immunological andmicrobiological changes make distinguishing between cause and effect challenging.

کلیدواژه ها:

Microbiome ، Fetus ، Pregnancy