Understanding the rules of life

Bioscience for sustainable agriculture and food

Bioscience for an integrated understanding of health

Category: CASE Studentships

The effect of the microbiome and microbial bioactives on semen quality and reproductive health

Project No. 2152

Primary Supervisor

Dr Gary Robinson – University of Kent


Dr Peter Ellis – University of Kent


The composition and influence of the microbiome has become a major focus of research in many areas of biomedicine in humans and many other species.

Different microbes within the microbiome may modify their environment (e.g. maintain a lower pH – Lactobacilli) or produce compounds that are bioactive (e.g. antimicrobials such as Streptomyces) therefore perturbing host processes. It was long assumed that both the male and female reproductive tracts are largely sterile environments in the absence of pathogenic infection, but this has been shown not to be true. Each are different in composition, have been shown not to be sterile and be altered when subject to dysbiosis. Understanding the normal and abnormal reproductive microbiomes and their effects on sperm function is likely to lead to diagnostic and treatment breakthroughs for both natural and assisted reproduction. Such insights can be extended to microbial bioactives (i.e. potential contraceptives or fertility supplements) that affect factors such as sperm motility and physiology.

Aims and objectives

The present proposal is focused on the mammalian reproduction, using sperm as the principal experimental system, and asks three related questions:

  • How do the normal male and female reproductive microbiomes affect sperm quality?
  • How does dysbiosis (i.e. clinical or subclinical infections) affect sperm quality?
  • Can microorganisms – whether ordinarily resident in the reproductive tract or not – produce modulators of sperm quality?

This study will be facilitated by a newly-established diagnostic suite within the School of Biosciences capable of studying sperm vitality, motility, DNA fragmentation and DNA oxidation.