5 March 2022 | New Scientist | 15GIVING omega-3 supplements to
pregnant women with low levels
of this fatty acid could prevent
about 14 per cent of early preterm
births, according to data from an
Australian trial. The finding has
inspired a world-first screening
and treatment programme for
omega-3 deficiencies in pregnant
women in South Australia.
Omega-3 fatty acids are found
in fish and are known to protect
heart and brain health, and
there is evidence that they are
also important in pregnancy.
For example, observational
studies have shown that eating
fish regularly during pregnancy
seems to lower the risk
of premature birth.
A few years ago, Maria Makrides
at the South Australian Health and
Medical Research Institute and her
colleagues ran a trial in which they
randomly assigned 5500 pregnant
women to have either 1 gram of
Health
Alice Klein
MARK
WIEN
ER
/ALAMYOmega-3 supplements could cut
the number of preterm births
Omega-
fish oil can be
taken as daily
supplementsAnimal behaviour
SLUGS may be important dispersal
vehicles for fungal spores, spread
through their faeces. The molluscs
deliver spores from a wide range
of forest fungi to microhabitats
perfect for new fungal colonies.
Nobuko Tuno and Keiko
Kitabayashi at Kanazawa University
in Japan collected mantleslugs
(Meghimatium fruhstorferi) in
a forest, briefly keeping them
captive so they could collect
droppings. They used microscopes
to detect any spores in the faeces
and DNA analysis to identify the
fungal species present.
Nearly three-quarters of the slugs
had fungal spores in their faeces.
The researchers detected the
DNA of dozens of different fungal
species in the droppings of eight
slugs. Most of the fungi were
wood-rotting varieties, but there
were also pathogenic species and
ones that form beneficial symbiotic
relationships with trees (Ecology
and Evolution, doi.org/hh43).Many spores didn’t experience
any decline in their germination
rate after being excreted. In fact,
some appeared to start germinating
while in the guts of the slugs. Tuno
thinks moisture in the digestive
tract and in fresh droppings may
speed the process.
Researchers also tracked themovement of five slugs through
their forest habitat at night for
several hours, marking the position
of each every 30 minutes. They
found that the molluscs tend to
move through leaf litter and wood
debris well-suited to new fungal
colonies, something made more
likely by the quantity of spores
in slug droppings.
“The overwhelming number
of spores being dispersed in a
germinated state” would be
an advantage over competing
decomposer species, says Tuno. ❚Meet the slug hunter with a new way
to keep molluscs at bay, page 48Slug faeces help
mushrooms start
new colonies
Jake BuehlerNOBUKO
TUNOYoung mantleslugs
feeding on oyster
mushrooms“Finding ways to prevent
premature birth is one of
the highest priorities in
maternal and child health”omega-3 per day in the form of fish
oil capsules or a placebo, starting
any time before 20 weeks of
gestation (NEJM, doi.org/ghbsx8).
They found that in women
who started out with low levels
of omega-3 in their blood,
supplements of omega-3 fatty
acids reduced the risk of birth
happening before 34 weeks of
gestation by 77 per cent. The
placebo had no effect on the risk
of such early premature birth.
But for women who already
had high omega-3 levels, taking
the omega-3 supplements actually
increased their risk of thesepreterm births. This suggests
that the supplements should only
be recommended to pregnant
women with low omega-3 levels,
although multivitamins
containing small omega-3 doses
are fine for women who already
have high levels, says Makrides.
On the back of these results,
Makrides has helped launch a
screening programme in the
state of South Australia that offers
free blood tests to all pregnant
women to identify and treat those
who are low in omega-3. About
3000 women have been screened
since May 2021 and so far 17 per
cent have been found to have
low omega-3 levels.
Based on the earlier clinical trial
results, Makrides and her team
estimate that recommending
omega-3 supplements to these
women with low omega-3 levels
could prevent 1 in 7 early preterm
births across South Australia.Currently, there are few effective
ways to prevent premature births,
which increase the risk of death or
disability in babies, says Makrides,
who will present the first results
of the screening programme at
the annual scientific meeting of
the Royal College of Pathologists
of Australasia on 6 March.“Finding ways to prevent
premature birth is one of the
highest priorities in maternal
and child health,” she says.
It isn’t clear why omega-
fatty acids protect against
preterm birth, but there is
some evidence that it influences
pre-labour changes to the
cervix and contractions of
the uterus, says Makrides. ❚