Exploring the role of gut microbiome in male reproduction

Abstract

Background: The impact of the gut microbiome on the organism has become a growing research focus with the development of 16S rRNA sequencing. However, the effect of the gut microbiome in male reproduction has yet to be investigated. Objective: To overview on possible mechanisms by which the gut microbiome could affect male reproduction and therapeutic opportunities related to the gut microbiome. Methods: Authors searched PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane Library for medical subject headings terms and free text words referred to “male infertility” “testis” “gut microbiome” “insulin resistance” “erectile dysfunction” “therapy” “sex hormones” and “genital diseases” until December 2, 2021. Results: Evidence suggests that immune system activation caused by the gut microbiome translocation not only leads to testicular and epididymal inflammation but can also induce insulin resistance together with gastrointestinal hormones such as leptin and ghrelin, which in turn affects the secretion of various sex hormones such as LH, FSH, and T to regulate spermatogenesis. In addition, the gut microbiome can influence spermatogenesis by controlling and metabolizing androgens as well as affecting the blood–testis barrier. It also promotes vascular inflammation by raising trimethylamine-N-oxide (TMAO) levels in the blood, which causes erectile dysfunction. The testicular microbiome and gut microbiome can interact to influence male reproductive function. This study discusses therapeutic options such as probiotics, prebiotics, and fecal microbiota transplantation, as well as the challenges and opportunities behind ongoing research, and emphasizes the need for additional research in the future to demonstrate the links and underlying mechanisms between the gut microbiome and male reproduction. Therapeutic options such as probiotics, prebiotics, and fecal microbiota transplantation are potential treatments for male infertility. Discussion and conclusion: Gut microbiota may have a causal role in male reproduction health, therapeutic strategies such as supplementation with appropriate probiotics could be undertaken as a complementary treatment. In the future, additional research is needed to demonstrate the links and underlying mechanisms between the gut microbiome and male reproduction.