A multielement male nutritional supplement (AlphaSperm®) induces novel epigenetic changes in sperm DNA

Male fertility supplements reduce oxidative stress, but whether they improve fertility is controversial. Since sperm epigenetic patterns correlate with fertility potential, we investigated whether a male fertility supplement (AlphaSperm^®) impacts semen parameters or sperm epigenetics. In a prospective, multi-institutional, within-subject study, 3 groups were evaluated: young healthy men < 25 years old (C, n = 11), young infertile men < 40 years old (YI, n = 10), and older infertile men > 40 years old (OI, n = 10). While on daily AlphaSperm^® supplementation, subjects provided serial semen samples. Conventional WHO semen parameters, sperm DNA fragmentation, and sperm DNA methylation were assessed at baseline and after 9 months of treatment. Beta values were generated from methylation array data, and differences in regional sperm DNA methylation with treatment were reported as differentially methylated regions (DMRs) by paired sliding-window analyses. The Stanford GREAT gene ontology tool revealed biological pathways associated with DMRs. SpermQT, a clinical diagnostic, was performed on all subjects. AlphaSperm^® supplementation did not significantly alter semen parameters or sperm DNA fragmentation within groups. Regional sperm DNA hypermethylation was observed in all groups (eFDR < 0.0001), and mean methylation changes at DMRs ranged from 0.1% to 4.3%. Gene ontological analysis revealed 29 biological pathways significantly altered with treatment in the OI group (adjusted p < 0.05), though their functional significance needs validation. Supplement-induced DMRs included 5 genes whose methylation statuses are correlated with male infertility that were hypermethylated in the OI group; 1 was hypermethylated in the C group. Thus, although semen parameters and DNA fragmentation were largely unaltered, male fertility supplementation induced novel regional sperm DNA hypermethylation, most obvious in older infertile men. This study provides novel insights into the potentially large epigenetic effects of nutritional supplements occurring independent of semen analysis changes. Limitations include small sample size and lack of placebo controls.