Many of these bacteria help build molecules
that let you digest food, they keep harmful microbes at bay, and they
can even feel your emotions. In fact, the bacteria in your gut are
responsible for producing about 90% of the serotonin in your body, which
is sometimes referred to as the ‘happy hormone’ because it plays a
crucial role in regulating one's mood.
In 2009, microbiologist John Cryan of
Ireland’s University College Cork found that rats stressed from birth
later showed signs of both irritable bowel syndrome (IBS) and mood
disturbance. These findings were in tune with doctors’ previous
observations that many patients with digestive symptoms also had mental
health issues, and vice versa.
When researchers at Cryan’s lab sampled and sequenced the gut bacteria
from stressed rats, they came to a surprising conclusion: stressed
animals — those more prone to mental health issues — had a less diverse
assortment of gut microbes, or microbiome, than their more healthy
counterparts. In the following decade, more labs started reporting that
gut bacteria indeed produce a variety of compounds and acids that can
influence the mind both positively and negatively.
Rather than passing from the gut to the brain via the bloodstream, some
of these chemicals influence the brain through intermediate channels,
like the central nervous system, namely the vagus nerve, which functions
as a communication route between the brain, the gut, and other organ
systems in the human body. This connection is called the gut-brain axis
(GBA).
What is currently known about probiotics' efficacy against depression?
Now that we understand how the gastronomical tract and the brain are
connected, it’s easy to see why scientists think that probiotic-based
treatments could be potentially beneficial for those suffering from
depression. As we mentioned, existing research on the topic is largely
promising, but many of the studies are very small. This makes it hard to
draw distinctive conclusions on just how effective probiotics are.
In a small 2016 study, people with major
depression took a probiotic supplement containing three bacteria strains
for eight weeks. At the end of the study, most had lower scores on the
Beck Depression Inventory, a common method of evaluating depression
symptoms. A separate study from 2017 even suggested that a diet higher
in beneficial bacteria can banish depression in more than a third of
people.
The authors of each of these studies generally agree that full-scale
clinical trials are needed to understand how probiotics boost mental
well-being and how they can be utilized as a regulated mental-health
treatment.
One issue is that probiotics aren’t identical. Certain types of bacteria
will have more profound effects on the brain than others, and there is
no ‘magic strain’ that works for everyone.
How can I try probiotics for depression?
Until there is an official probiotic treatment, probiotics can be
obtained through your diet or supplements. If you’re considering trying
probiotic supplements for depression, it’s highly recommended that you
talk to your healthcare provider first. Probiotics are considered safe
to use, but it’s generally a good idea to get professional advice before
trying any new supplement or medication.
Foods like sauerkraut, yogurt, and kefir are known to naturally contain
bacterial strains tied to anti-depressive effects.
If you decide to take a supplement, make
sure to follow the manufacturer’s recommendation for dosage. If you
experience stomach pain, persistent gas, bloating, or other
gastrointestinal distress, it’s a good idea to stop using the probiotic
and talk to your doctor before trying it again.
It is important to stress that while probiotics may be a helpful
addition, they are not a replacement for therapy, medication, or other
treatments recommended by your doctor. They are part of the treatment
and not a standalone cure.
The bottom line is that probiotics are a promising potential treatment
for depression and other mental health conditions. At the same time,
more extensive research to confirm its efficacy. However, there is no
harm in trying to take probiotics. It could prove beneficial for both
your mood and gut health!