
A deadly gut infection may come down to a sugar in ice cream - ALee
https://arstechnica.com/science/2018/01/the-curious-case-of-a-boring-sugar-that-may-have-unleashed-a-savage-plague/
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randomdrake
Study: Dietary trehalose enhances virulence of epidemic Clostridium difficile

Citation: J. Collins, C. Robinson, H. Danhof, C. W. Knetsch, H. C. van
Leeuwen, T. D. Lawley, J. M. Auchtung & R. A. Britton. Nature 2018-01-03
online.

Link:
[https://www.nature.com/articles/nature25178](https://www.nature.com/articles/nature25178)

DOI: 10.1038/nature25178

Abstract: Clostridium difficile disease has recently increased to become a
dominant nosocomial pathogen in North America and Europe, although little is
known about what has driven this emergence. Here we show that two epidemic
ribotypes (RT027 and RT078) have acquired unique mechanisms to metabolize low
concentrations of the disaccharide trehalose. RT027 strains contain a single
point mutation in the trehalose repressor that increases the sensitivity of
this ribotype to trehalose by more than 500-fold. Furthermore, dietary
trehalose increases the virulence of a RT027 strain in a mouse model of
infection. RT078 strains acquired a cluster of four genes involved in
trehalose metabolism, including a PTS permease that is both necessary and
sufficient for growth on low concentrations of trehalose. We propose that the
implementation of trehalose as a food additive into the human diet, shortly
before the emergence of these two epidemic lineages, helped select for their
emergence and contributed to hypervirulence.

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stevebmark
Don't overlook that first paragraph, fluoroquinolones are some of the most
dangerous antibiotics available, but prescribed for common infections (which
they shouldn't be). Fluoroquinolones kill most human gut bacteria
(irreversibly) _except_ c.diff, leading to overgrowth.

~~~
cableshaft
I got prescribed Ciproflaxin once, a fluoroquinolone, and was just told it was
an antibiotic, not warned about any potential side effects from the doctor,
just acted like it was just like every other antibiotic I ever took, and I was
to take it for 30 days straight.

I thought it was weird when the information page that came with the pills said
"do not exercise while taking this medication and for at least a month
afterwards", as well as a long list of side effects.

I took the first dose, and the very next day I started feeling tingly
neuropathy in my extremities. I kept taking the medication for a few days
while being worried about it, and it started spreading to other parts of my
body. I started reading anecdotes online about how Cipro destroyed people's
bodies, snapped tendons (especially the achilles tendon, one of the weaker
tendons apparently, hence the don't exercise warning), and has side effects
that last for years afterwards and getting even more paranoid about it.

Day 7 I start feeling the tingling in my face, and that prompted me to call
the doctor. They got me on a non-fluroquinolone for the rest of the 30 days.

I have had periods of neuropathy on and off for years after that, including in
my face, for the past four years since. It seems to have become less frequent
recently though, finally. Mind you, this is after taking only 7 pills total
four years ago.

It's so dangerous, and pretty much every doctor I've told this too since have
been surprised that it could cause such problems.

FDA had to issue a warning (unfortunately after I was prescribed), telling
doctors not to prescribe it for minor infections, and saying it had
potentially permanent serious side effects, involving tendons, muscles,
joints, nerves, and central nervous system:
[https://www.fda.gov/Drugs/DrugSafety/ucm500143.htm](https://www.fda.gov/Drugs/DrugSafety/ucm500143.htm)

~~~
ramphastidae
I had almost the same exact experience after just three days taking the
medication. Dizziness, passing out, burning and tingling of extremities. I’m
still really freaked out by the experience.

PLEASE make sure you know the risks before taking ciproflaxin.

~~~
stevebmark
I can't tell if it's your intention, but your phrasing blames patients for
taking drugs prescribed by doctors. We need the medical community to
understand this and stop prescribing. Fluoroquinolones have misleading and
false safety profiles that make it hard for a patient to truly evaluate the
risk. Doctors need to understand how these drugs work, because if they did,
they wouldn't prescribe them.

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dwills
A missing piece of information is that trehalose is a rather new additive. It
was very expensive to manufacture until about 20 years ago when a new cheaper
process to make it was found. And voilà, because it appears safe and is
somewhat useful, it starts showing up in all sorts of products without any
labeling indication. And the fallout is just now being noticed. One of the
commenters used the phrase "food science" ... hah! We're the guinea pigs!

~~~
bunderbunder
Not missing. In paragraphs 5 and 6, the article explains how, just before c.
diff infections started to get more common, a new method for producing it that
dropped the price by over 99% was developed.

~~~
sjg007
I wonder if Japan had higher c.diff rates before global use since trehalose
was common there first.

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philipodonnell
I notice they had to add the bacteria to the mice to do the test. I wonder if
some of the instances when drugs work on mice but not in human trials are due
to the different gut bacteria at work?

~~~
bastawhiz
There are any number of reasons why drugs don't work on humans when they do
work on other animals. It could be gut bacteria, but it could just be that the
animal has some other physiological trait that causes the drug to be more or
less effective.

In this case, they weren't testing a drug, they were testing the deadliness of
the bacteria. It doesn't matter _how_ toxic the bacteria is to humans relative
to mice, it only matters that the bacteria is more deadly (or less deadly) to
the mice when the sugar is present.

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stmfreak
Just goes to show how little the FDA can even imagine to protect us against.

~~~
slack3r
In general, the FDA over-regulates rather than under regulates.

A comment is too short to summarize the reasons why, but I would refer
interested people to Eliezer Yudkowsky's Inadequate Equilibria ― there is a 50
page dialogue between two humans and an alien visitor on the FDA.

~~~
freddie_mercury
Here is a link to what this poster is talking about:
[https://equilibriabook.com/molochs-
toolbox/](https://equilibriabook.com/molochs-toolbox/)

It appears to be another in a long line of entries in the "undergraduate
economics solves all the world's problems" genre.

~~~
PhasmaFelis
In this particular case it's "self-taught AI enthusiast solves all the world's
problems," but yeah, same thing.

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justinph
WOW!

I had c. diff (it sucked, a lot) and this really fills in some gaps for me.
Before my gut was destroyed by c. diff, I used to eat more ice cream, no doubt
containing this sugar. Obviously I can't say for certain, but I can see how
this helped the pathogen gain a hold in my gut.

~~~
nickpsecurity
You said you "had" c. diff. How did you get rid of it?

~~~
justinph
Ended up getting the FMT.

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m3kw9
So am I right to summarize that because of the type of sugar used which allows
the ice cream to stay solid at a higher temperature, it was easier to have the
deadly bacteria thrive on the type of sugar used?

~~~
QAPereo
Rather, two strains of _C. Diff_ have enhanced trehalose metabolism. It’s 5e
trehalose you eat which feeds it well, in your gut. The ice cream itself
was/is safe in terms of pathogens.

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smnplk
We sure are guinea pigs. Maybe this kind of shit caused my thyroid autoimmune
disease.

~~~
DrewRWx
It was living downwind of a pesticide-ridden cabbage field that did it for me.

~~~
smnplk
Hey, sorry for late reply. How are you managing your condition ?

~~~
DrewRWx
Sorry for my even later reply. It took a couple surgeries to remove my thyroid
and lymph nodes it had spread to. And a few rounds of radioactive iodine
treatment and scans to get the parts that had spread through my lymphatic
system. My last treatment was 10 years ago during high school and I've
thankfully scanned clean since.

Management has been staying on a relatively high thyroid hormone replacement
dose and periodic radioactive iodine scans. Worst case scenario, the scan
requires a grueling couple weeks off of my medication and on a low-iodine diet
so that any remaining thyroid cells are completely starved and ready to absorb
the radioactive dose. Best case, the recombinant thyroid-stimulating hormone,
Thyrogen, is available and my insurance is willing to pay for it because it
reduces prep to a pre-scan injection.

