Gut-testis axis: microbiota-(n-3) PUFA improving semen quality in type 1 diabetes

Gut dysbiosis and type 1 diabetes (T1D) are closely related, and gut dysbiosis and male infertility are correlated, too. Moreover, most male T1D patients are of active reproductive age. Therefore, it is crucial to explore possible means for improving their semen quality. Here, we found that fecal microbiota transplantation (FMT) from alginate oligosaccharide (AOS) improved gut microbiota (A10-FMT) significantly decreased blood glucose and glycogen, and increased semen quality in streptozotocin-induced T1D subjects. A10-FMT improved T1D-disturbed gut microbiota, especially the increase in small intestinal lactobacillus, and blood and testicular metabolome to produce n-3 polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) to ameliorate spermatogenesis and semen quality. Moreover, A10-FMT can improve spleen and liver function to strengthen the systemic environment for sperm development. FMT from gut microbiota of control animals (Con-FMT) produced some beneficial effects; however, to a smaller extent. Thus, AOS improved gut microbiota may be a useful protocol for improving semen quality and male fertility in T1D patients. ImportanceClinical data suggest that male reproductive dysfunction especially infertility is a critical issue for type 1 diabetic patient (T1D) because most of them are at the reproductive age. Gut dysbiosis is involved in T1D related male infertility. However, improved gut microbiota can be used to improve spermatogenesis and male fertility in T1D remains incompletely understood. We discovered that alginate oligosaccharide-improved gut microbiota (A10-FMT) significantly ameliorated spermatogenesis and semen quality. AOS-improved gut microbiota (specific microbes) may serve as a novel, promising therapeutic approach for the improvement of semen quality and male fertility in T1D patients.