Gut microbiota involved in spermatogenic function of Sancai Lianmei granules in obese mice

Obesity is a well-established cause of reduced fertility and semen quality in men. Current evidence suggests that Sancai Lianmei granules (SCLM) effectively improve sexual function and semen quality in diabetic patients, while the gut microbiota can influence disease metabolism through various mechanisms. However, the effect of SCLM on the obesity-induced decrease in semen quality and on the gut microbiota is unclear. This study aimed to investigate the effects of SCLM on spermatogenic function and gut microbiota in obese mice. Obese mice were induced by a high-fat diet, and lipid metabolism, spermatogenic function, inflammatory factors, oxidative stress, and autophagy were analyzed to determine the effects of SCLM and SCLM-fecal microbiota transplantation (FMT). In addition, changes in the gut microbiota of mice were analyzed. SCLM and SCLM + FMT could effectively reduce the levels of total cholesterol (TC), high-density lipoprotein (HDL), and low-density lipoprotein (LDL); decrease the expression of oxidative stress products malondialdehyde (MDA) and 8-hydroxyde-oxyguanosine (8-OHdG); and increase sperm density and sperm viability in obese mice while inhibiting the inflammatory responses and excessive cellular autophagy, indicating that SCLM and SCLM + FMT exerted a protective effect on spermatogenic functions. Furthermore, SCLM affected the gut microbiota composition in mice. This study determined that obesity can lead to reduced sperm motility and affect the composition of the gut microbiota, while SCLM can regulate blood lipids in mice directly or indirectly by regulating gut microbiota changes, and may improve sperm motility in obese mice by reducing oxidative stress and autophagy. In addition, FMT enhanced this effect, which may be related to the diversity of gut microbiota.