Can gut health improve male fertility?

While it is a known fact that male fertility issues related to low sperm parameters constitutes around 50% of couples experiencing fertility struggles, what is less well known is that research has shown that taking a daily friendly bacteria supplement can help to support healthy sperm motility.  

Common causes of male factor infertility include a variety of genetic, immunological and anatomical reasons, to which inflammation in the male genital tract is a major contributor. Inflammation can be associated with reduced semen quality via several pathways, including the impaired secretory capacity of the accessory glands, oxidative stress, anatomical obstruction of the seminal tract, or via microorganisms acting directly on spermatozoa.

Male semen, being a mixture of sperm and secretions of sexual accessory glands, containing nutrients (such as lipids, proteins, glycans and inorganic ions), is an ideal environment for microbe growth. While in the past it was thought that the presence of bacteria in the semen was a sign of infection, the use of next-generation sequencing-based approaches has revealed that the human semen is not sterile and hosts a specific microbiota.

To date, the functions of this resident microbiota in maintaining a healthy status in men has not been completely understood, and it seems that the semen microbiota could be involved in the modulation of inflammatory and immune responses, which have important roles in successful reproduction and in protecting against microbial invasions. 

Research has shown that semen quality (measured according to WHO guidelines by semen volume, sperm count and concentration, sperm motility and proportion of normal sperm) is higher in Lactobacillus-predominant semen samples, and Lactobacilli have been shown to prevent sperm lipid peroxidation, preserving sperm motility and viability.

A recent study of three homogeneous groups of males in terms of motility (<60%) has established a link between sperm health and probiotics. The control group was fed with a normal standard diet. The other received supplements: One group (control) was fed with maltodextrin and the other received a probiotic preparation based on a mixture (1:1) of Lactobacillus rhamnosus CECT8361 and Bifidobacterium longum CECT7347. The study duration was 21 days and the probiotic was shown to improve sperm motility, DNA fragmentation and level of ROS.

As awareness of the incredible health benefits provided by probiotics has become more widespread, much has been written about how this daily supplement can help with health in general, but these findings underline the connection between using probiotics and enhanced male fertility and that sperm is significantly more likely to be healthy when the semen microbiome has large amounts of beneficial Lactobacillus strains.