Dietary probiotic supplement positively affects sperm motility in obese murine models

Obesity in adult men in recent years has inconsistently been associated with low semen quality and sub-fecundity. Probiotics have gained high interest as alternatives to pharmacological compounds. However, their possible effect on male fertility has been less investigated. This study aimed at assessing the use of L.Rhamnusus on obese male fertility characteristics. We proposed that this probiotic can not only reduce the weight but in parallel would enhance sperm motility in obese male mice.
Diet-induced obese C57BL/6NTac mice were randomly assigned to 2 groups and treated with a single daily dose (1x109CFU) of L.Rhamnusus (test group) or physiological saline (control group) for 4 weeks. Sperm motility and kinematics were assessed by the Sperm Class Analyzer (SCA).
The control group maintained a raising trend in weight gain leading to a significant difference on week 5 continuing to week 8 whereas the DIO mice in the test group did not gain significant weight after the start of probiotic test. The test group showed a significantly higher progressive motility compared to the control group after 4 weeks of receiving the probiotic treatment.
L.Rhamnusus supplementation demonstrated a higher percentage of progressive sperm, suggesting a possible increase in pregnancy. The effect mechanism of L.Rhamnusus could be either through direct influence on sperm motility or indirectly due to the promotion of weight loss. The latter hypothesis is due to the fact that weight-loss leads to scrotal temperature decrease and hormonal balance affecting sperm kinetics and kinematics during maturation in the epididymis. These hypotheses require further investigation.