Abstract
Carob (Ceratonia siliqua) supplements can increase sperm quality. This study aimed to summarize the available evidence about the effects of carob (Ceratonia siliqua) supplements on sperm quality and reproductive hormones in infertile men. Systematic searches of five databases were conducted from inception to October 20, with the last update on November 20, 2023. Randomized clinical trials (RCTs) that compared carob (Ceratonia siliqua) supplements with nonintervention control groups on infertile man. Risk of bias and certainty of evidence were assessed by the Cochrane risk of bias tool 2. Summary effect size measures were calculated using a random-effects model estimation and are reported as standardized mean differences and 95% confidence intervals. Reporting followed the PRISMA guidelines. The analysis included four studies involving 236 infertile men. It was found that sperm motility of infertile men improved after carob intervention (MD:11.30, 95% CI:5.97 to 16.64, Z = 4.15, p < 0.00001), and there was a significant difference compared to control groups. The effect size of carob on semen quantity in infertile men was positive, and the relationship was statistically significant (MD:5.42, 95% CI:1.58 to 9.42, Z = 2.77, p = 0.006). When hormone parameters of infertile men were analyzed, the MDA (malondialdehyde) value decreased compared to the control group (MD = -4.81, 95% CI: -10.18 to 0.56, Z = 1.76, p = 0.08), and there was a significant difference between them. Carob (Ceratonia siliqua) supplements was associated with improvement in sperm quality compared with nonintervention control groups in infertile man. However, high-quality, larger RCTs are required to draw more definitive conclusions.