Bacterial imbalances in the semen microbiome may cause a reduction in semen and sperm quality, according to a new study.
- Semen has its own
microbiome, and bacterial imbalances may impact sperm count and quality,
according to a new study.
- The researchers found
unusually high levels of the bacteria Lactobacillus iners in
males with low sperm motility.
- The link between the health
of the semen microbiome and gut microbiome remains unclear.
- Experts say healthy
lifestyle choices that promote a healthy gut could also support the health
of the semen microbiome.
Globally, there is a
reported decrease in male sperm count or the number of viable
sperm within semen.
Some research points
toward pollution as a factor contributing to male infertility,
but this does not explain why an estimated 30% of semen is considered abnormal.
A new reproductive study
of semen examined the impact of the health of the semen microbiome on sperm motility,
which is the sperm’s ability to swim successfully through the female
reproductive system to reach and potentially fertilize an ovum or egg.
The study finds that high levels of the
bacteria Lactobacillus
iners (L. iners) are
associated with low sperm motility.
This study represents
the first time a distinct semen microbiome has been suggested and investigated,
and the first in which L. iners has been linked to a
lowering of sperm motility.
The study is published
in Scientific Reports.
Balance
of bacteria in semen microbiome affects sperm health
Along with “sperm
helpers,” such as enzymes, fructose, and citric acid,
there is a community of bacteria within semen.
In addition to L.
iners, the most prominent bacteria found in semen include:
- Enterococcus
faecalis
- Corynebacterium
tuberculostearicum
- Staphylococcus
epidermidis
- Finegoldia
magna
For the study, the semen
of 73 males seeking treatment for reproduction issues or vasectomies was
analyzed.
The researchers found that 27 males with
reproduction issues all exhibited higher amounts of L. iners compared
to the 46 males seeking vasectomies who had already successfully reproduced and
who had healthy semen.
The males with abnormal
semen also had comparatively higher levels of the bacteria Pseudomonas
stutzeri and Pseudomonas fluorescens. They had lower
levels of Pseudomonas putida than those with normal semen.
How
does bacteria impact human infertility?
The study’s first
author, Dr. Vadim Osadchiy, an academic urologist specializing in
men’s health and infertility, explained how the L. iners bacteria
present in males and females may affect infertility:
In females, “this
microbe can act as a symbiotic organism, meaning it helps maintain the healthy
vaginal microbiome and prevents bad players from taking over,” Dr. Osadchiy
said.
However, some
studies suggest that, at times, the bacteria may “predispose a person
to developing bacterial
vaginosis or even sexually
transmitted infections,” he added.
Dr. Osadchiy noted
the L. iners bacteria may also impact success rates for
people undergoing fertility treatments.
“There is some
data suggesting worse assisted
reproductive technology outcomes when this microbe is found in higher
abundance in the vaginal microbiome,” he said.
“This microbe has never really been studied within
the context of male factor fertility, or really within the context of men’s
health.”
Is
there a link between the semen microbiome and gut microbiome?
The relationship, if
any, between the lesser-known semen microbiome and the gut microbiome is
unclear, but experts have a few theories.
“I think the farther
away you get from the reproductive tract, anatomically speaking, the more
tenuous the relationship becomes between the semen microbiome and the various
other microbiomes in our bodies,” Dr. Osadchiy suggested.
“We know there is an intimate relationship between
the urinary and semen microbiome as the reproductive and urinary tract are
interconnected [although] the two microbiomes are certainly distinct,” Dr.
Osadchiy added.
Dr. Menka Gupta, a
functional medicine doctor with NutraNourish, not involved in the study,
suggested it may be possible to improve semen microbiome health but
prioritizing gut health.
“I can potentially see a
connection between the gut and the semen microbiome through lifestyle factors
such as diet, level of stress, [and] exposure to toxins,” Dr. Gupta said.
Dr. Osadchiy noted it
may be possible that a gut microbiome with inflammation could “result in
conditions that favor a pro-inflammatory semen microbiome.”
“I’m not sure if there
is too much definitive data on this yet, but that would be my hunch,” he said.
More
research on the semen microbiome needed
Dr. Gupta said further
exploration of the role of the semen microbiome in fertility outcomes is
needed, which could lead to “new treatments to improve sperm parameters and
male fertility.”
Dr. Osadchiy agreed,
noting there’s still much to learn about the body’s microbiomes in general,
specifically the semen microbiome.
“We
know that microbial community interactions can be just as important as the
actions of individual players, so work to understand microbial communities in
semen would help contextualize our findings. There are still so many questions
related to the semen microbiome. More exploratory work but larger sample sizes
and greater geographic diversity may help us better characterize what is
expected variability since it’s likely there isn’t just one ‘good’ semen
microbiome and not just one ‘bad’ microbiome.”
— Dr.
Vadim Osadchiy, first study author
Dr. Osadchiy said a
deeper understanding of the relationship between the semen microbiome and
infertility is also needed, and researchers currently lack “a good sense of
what sort of factors are under our control to positively (or negatively) impact
the semen microbiome.”
“I wouldn’t be surprised if what is good for the
body in general is also good for the semen microbiome,” Dr. Osadchiy added.
Despite the lack of
understanding of the relationship between the semen and gut microbiome, both
Dr. Osadchiy and Dr. Gupta recommended prioritizing healthy lifestyle choices
to improve sperm quality and motility. These include:
- exercising regularly (cardio
and strength training)
- minimizing stress (mindfulness and
meditation)
- avoiding processed food
- increasing fiber intake
Dr. Gupta also noted the
value of abstaining from alcohol and smoking and
following a diet rich in antioxidants and probiotic foods.
No comments:
Post a Comment