YSM Issue 93.4 Full Magazine

Microbiology
FOCUS
significant changes just from interacting
with soil. While children from the natureoriented
daycares had much higher
microbial diversity initially, the microbial
diversity of children in the intervention
group increased to nearly comparable levels
by the end of the twenty-eight-day period.
Notably, the relative abundance of bacteria
associated with IBD decreased, while the
diversity of bacteria known to help maintain
the lining of our intestines increased.
These shifts in bacterial communities then
initiated significant downstream effects on
the children’s immune systems. While we
are far from understanding the complete
web of interactions that comprise an
immune system, there are a few key markers
that point towards the overall state of one’s
immunological health. For instance, they
tracked the frequency of autoimmune disease
preventing regulatory T cells in children.
Additionally, the researchers investigated
the proportion of the anti-inflammatory
interleukin-10 (IL-10) to the inflammatory
interleukin-17 (IL-17) as well as the amount
of anti-inflammatory cytokine Transforming
growth factor-Beta1 (TGF-β1). In general,
all three of these signaling molecules bind to
different receptors on immune cells which,
in turn, provokes the cells to produce either
pro- or anti- inflammatory proteins.
By the end of the study, children in
the intervention group presented higher
IL-10 to IL-17A ratios, increased levels
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of TGF-β1, and higher frequencies of
regulatory T cells—all signs of a less proinflammatory
immune system. Thus, it
seems that just as the children in daycare
centers were learning how to interact
with others and navigate the world,
their immune systems were receiving an
education of their own. This intervention
study sheds light on the crucial link
between our health and our environment,
providing a glimpse of a future where
deliberate steps could be taken to create
and curate healthy immune systems.
Additionally, in a parallel study focusing
on the qualitative effects of the natural
intervention at daycares, researchers at the
University of Helsinki found that children’s
motivation to learn, activity levels, and
overall well-being also increased.
While millions of dollars have been
justly awarded to fund research seeking to
treat inflammatory diseases that arise from
microbial dysbiosis, recent results have
started to point to possibly inexpensive
and easy ways to prevent such diseases
from occurring at all. For instance, in
another recent study, researchers at the
University of Helsinki designed a widespectrum
microbial inoculation mixture
that could reproduce the slow-growing
and elaborate agglomeration of ancient
microbes in forest soil. Engineered to leave
out any naturally occurring pathogens,
this inoculate could safely be integrated
into our urban soils and landscapes in
order to increase microbial diversity and
potentially mitigate the risk of immunemediated
diseases in urban populations.
Unfortunately, there are ideological
barriers to implementing such programs.
“People are afraid of microbes because
there are some bad microbes,” Posland
said. Intuitively, the thought of bacteria
conjures up ominous images of fuzzy
cylindroids infested with infectious
diseases. “Current legislation requires
that many products do not contain
microbes. Creating policy change
requires collaboration between many
organizations and that the decision
makers understand the science and value
of maintaining a healthy microbiome.
It’s a slow process to change the way
that things are currently done in urban
planning, green infrastructure and so
on, ” Sinkkonen said.
While we have made leaps and bounds
in our scientific understandings of
germs since the days of Louis Pasteur,
trying to conquer disease by completely
eradicating bacteria from our food,
living environments, and bodies may
no longer be the best course of action.
Recent research, coupled with the rise
of immunological disorders in Western
populations, has proven that health is
not always synonymous with sterility. It
seems that we have reached a point of
inflection where science and modern
technology should be used to understand
and reconnect us to—not separate us
from—nature. Perhaps the next era of
medicine and healthcare will engage a
more nuanced conversation with the
lifeforms that have evolved alongside us
for time immemorial, allowing us to step
towards a healthier world. ■
Roslund, M.I., Puhakka, R., Grönroos, M., Nurminen, N., Oikarinen, S., Gazali, A.M.,
Cinek, O., Kramná, L., Siter, N., Vari, H.K., Soininen, L., Parajuli, A., Rajaniemi, J.,
Kinnunen, T., Laitinen, O.H., Hyöty, H., Sinkkonen, A., 2020. Biodiversity intervention
enhances immune regulation and health-associated commensal microbiota among
daycare children. Science Advances.. https://doi.org/10.1126/sciadv.aba2578
December 2020 Yale Scientific Magazine 31