15 January 2022 | New Scientist | 15More Insight online
Your guide to a rapidly changing world
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IMAGESBacteriophages (light
blue) attack an E. coli
bacterium (yellow)Extending shelf life would
not only benefit producers and
consumers, but also help save
biodiversity and limit carbon
emissions by reducing food waste.
Food production is a major cause
of emissions and habitat loss.
Lastly, many teams hope to use
phages to treat diseases in animals
and plants. This could help reduce
antibiotic use by farmers.
“One of the biggest issues we’ve
had with antibiotic resistance has
been the horrible abuse in the
food and agricultural industries,”
says Ben Temperton at the
University of Exeter, UK. “If we
can increase the amount of phage
use and decrease antibiotics that
can only be a good thing.”
But using phages on farms
is trickier than applying them
to food. When they are given to
animals that are moving around
and swapping bacteria, resistance
can rapidly evolve and spread,
says Sulakvelidze.
With plants, resistance is
less of an issue, says Blackwell,
whose team is developing phage
treatments for potato blackleg,
a bacterial disease that attacks
the stems of the plants.
However, phage resistance isn’t
as serious a problem as antibiotic
resistance. If phage resistance
appears, you simply look for other
phages that the bacteria cannot
resist – and doing so is much
cheaper than finding new
antibiotics, says Temperton.
As regulators and companies
become more comfortable using
phages on food, it could also help
with their adoption for treating
antibiotic-resistant infections
in people, says Temperton.
“The familiarisation of using
these as an antimicrobial can
only really serve the clinical use
of phages positively,” he says.
“If people see it working in food
and it’s kind of normalised that EY
E^ OF^ SCIENCE/SCIENCE^ PHOTOLIBRARYin Kenya on phage treatments
for chickens just before slaughter,
to reduce meat contamination
with campylobacter.
An additional challenge is
storage, she says, as phages need
to be kept cold, but a team in
Canada has developed a way of
turning phages into dry powders
that don’t need refrigeration.
Preventing food poisoning isn’t
the only thing phages are being
developed for. Several teams wantto make food last longer, by killing
the bacteria that make it rot.
“We have a pipeline of products
targeting the spoilage pathogens
of potatoes, mushrooms, salads,
anything which is of commercial
interest,” says Alison Blackwell,
chief executive of UK-based
company APS Biocontrol.way, I definitely think that’s going
to be a big, big positive.”
This is already happening in
the US, says Sulakvelidze. He says
Intralytix decided to focus on food
uses because it would have run
out of money trying to get human
therapies approved back in 1998
when it was founded. US regulators
now have the understanding and
processes in place to deal with such
phage therapies, and Intralytix
plans to launch three clinical trials
within the next year or two.Not just food
“There’s clearly a renaissance
in phages, and phage biocontrol
and therapy, which hopefully will
lead to some human therapeutic
products in the not-too-distant
future,” he says.
Intralytix also wants to launch
phage “nutraceuticals” that people
can buy, for instance to get rid of
undesirable components of their
microbiome, such as bacteria
associated with obesity. The firm
is exploring skincare and oral
hygiene products too.
But in Europe, the use of
phages hasn’t really progressed.
APS Biocontrol, for one, has been
waiting several years for approval
to use phage products on farms,
says Blackwell. “The US is really
ahead of Europe,” she says.
The one exception is Belgium,
where phage therapy can be
prescribed. The approach is being
pioneered at the Queen Astrid
Military Hospital in Brussels.
All in all, it looks as if phage
therapy might finally go
mainstream. “In the last five years,
we’ve seen so much growth it’s
unbelievable,” says Nagel. The
bad news is that it is happening
because we are fast running out
of alternatives due to growing
antibiotic resistance. “I think it’s
desperation,” she says. ❚“ We have products
targeting the spoilage
pathogens of potatoes,
mushrooms and salads”
10
31
Estimated number
of phages on Earth10
15
Number of phages thought
to be in your gut100m
Number of light years all the
phages on Earth would stretch
if stacked end to end