A new study has raised concerns about the widespread and irregular use of antibiotics in Nigeria, which may be linked to changes in sperm quality among men experiencing infertility.
Researchers have investigated the growing problem of antibiotic resistance in the country to determine whether exposure to commonly used antibiotics also affects male reproductive health.
The report, published in the Journal of Xenobiotics, indicated that commonly prescribed antibiotics detected in urine samples were associated with changes in sperm count, motility, and morphology, the key indicators of male fertility.
They reported that three antibiotics, ampicillin, chloramphenicol, and tetracycline, were independently associated with sperm quality in infertile men.
The study was a prospective case-control investigation involving 290 men recruited from five hospitals in southern Nigeria. Of these, 136 were diagnosed with infertility, while 154 were confirmed to be fertile.
Semen samples were analysed to assess sperm quality, while advanced laboratory techniques were employed to detect the presence of antibiotics in the participants’ urine.
According to the study, the presence of ampicillin in the urine was associated with a significant decline in sperm count, with infertile men exhibiting an average reduction of more than 3 million sperm per millilitre. This effect was not observed in the fertile control group.
They reported that chloramphenicol exposure was also associated with reduced sperm motility and abnormal sperm morphology in infertile men, further emphasising its potential impact on reproductive health.
In addition, among men with infertility, the presence of tetracycline in the urine was independently associated with increased sperm motility. However, no significant relationship between tetracycline exposure and sperm quality was observed in fertile men.
Also, the other antibiotics detected in urine samples, metronidazole and ciprofloxacin, showed no association with sperm characteristics.
They suggested that antibiotic exposure may affect sperm characteristics differently depending on the underlying fertility status, given that antibiotics have previously been shown to influence fertility outcomes in animal studies and in a few studies involving humans, particularly in low- and middle-income countries.
According to the researchers, although the study did not establish a definitive cause-and-effect relationship, exposure to these antibiotics may be associated with various sperm parameters and overall sperm quality in Nigerian males.
They stated the need for more controlled research and enhanced regulation of antibiotic use to understand better and mitigate potential risks to reproductive health.
‘Further studies are required to determine the direction of these relationships and to identify the full range of antibiotics that may be involved,’ they said.