
Body fat link to bacteria in feces - gm-conspiracy
http://www.bbc.com/news/health-37452630
======
elsherbini
A recent meta-analysis came out and claimed to show that we don't have
evidence right now for a link between obesity and what we've measured so far
about the human microbiome [0].

I can imagine a regime where two people with the same diet but with very
different bacterial communities would have different health outcomes. It
toally makes sense to me that if you have bacteria that are better at breaking
down long fats into absorbable molecules, that you'd be getting more effective
calories from the same food compared to someone without those bacteria. In
fact, this has been shown to work in mice in 2006 [1].

However, in the real world, you aren't living in a sterile cage. You can
sample bacteria from the environment and your microbiome is allowed to change
in response to your diet. It's possible that in this regime, your diet impacts
your microbiome much more than your microbiome impacts the outcome of your
diet.

[0]([http://mbio.asm.org/content/7/4/e01018-16](http://mbio.asm.org/content/7/4/e01018-16))
- Looking For a Signal in the Noise - Revisiting Obesity and the Microbiome
Sze and Schloss, mBio 2016

[1]
[http://www.nature.com/nature/journal/v444/n7122/abs/nature05...](http://www.nature.com/nature/journal/v444/n7122/abs/nature05414.html)
An obesity-associated gut microbiome with increased capacity for energy
harvest Turnbaugh et. al., Nature 2006

~~~
gadders
Animals used for meat production are bred for their feed conversion ratio [1]
i.e. how much body mass can they produce for a given amount of food. If this
can vary within other mammals, I don't see a reason why it couldn't happen in
humans. I'm not sure if it would necessarily be microbiome related.

[1]
[https://en.wikipedia.org/wiki/Feed_conversion_ratio](https://en.wikipedia.org/wiki/Feed_conversion_ratio)

~~~
hammock
Surprised this isn't referenced more when people bring up "calories in,
calories out"

edit: see my child comment if you somehow think I am arguing against the
concept

~~~
jtuente
Probably because it's still irrelevant to CICO. CICO doesn't tell you how much
calories go in or out, rather it tells you to measure them wherever possible
and make adjustments based on your weight changes.

~~~
hammock
It is relevant. You might have thought I meant it debunks it (or supports it),
what I meant was it adds color to it. Conversion ratio allows you to quantify
the difference from one person to another (the "adjustments based on weight
change" you refer to)

~~~
WorldMaker
I still think calories in health science are the last bastion of phlogiston in
any of the sciences. It's a deeply over-simplifying metric that implies a
false equivalency. We estimate the calories in food by the amount of heat
equivalent they create when burnt. We estimate the calorie usage of a human
body by the heat it produces during the effort. None of those estimates do
justice to the complex biology and chemistry processes at work: not all
calories are equal, they never have been, they never will be. (Humans aren't
just heat-producing machines. Digestion is nothing at all like producing raw
heat from food.)

ETA: It's the health science equivalent of the physics spherical cow fallacy
writ large and taken dogmatically.

~~~
jtuente
Good job, you've expounded on the obvious short-coming of "simplification".
Most people have a hard enough time with algebra, how do you expect them to
handle the many complexities of human biology and the digestive process. CICO
is meant as a starting point in a diet, not a be-all, end-all encompassing
idea. The spherical cow exists to simplify ideas so they can be more easily
grasped and learned.

~~~
WorldMaker
The problem with an over-simplification, _especially_ one that leads to a
false equivalence (in this case calories != calories because it's an indirect
measurement of energy by way of an energy by-product heat), is that it leads
to drawing the wrong conclusions. Using CICO as a starting point in a diet is,
best case, mostly harmless. On the other hand, it has been shown to be
actually harmful to people's self-esteems and generally leads exactly to where
we are with a steady stream of CICO "fad of the month diets" that don't
produce general, reproducible results and can easily victim blame because
"they weren't counting right".

Great, CICO might be a useful superstition for you. I'm not going to stop you
from using it just as I'm not going to stop people from consulting their
astrology charts. I do take umbrage at anyone that thinks CICO is good
science; it really is about as much science as astrology.

~~~
jtuente
> harmful to people's self-esteems

Hoo boy, that's what we need, more people with self-inflated self-esteem
issues. I think what you mean is that it's harmful to their immediate
gratification response.

> CICO "fad of the month diets"

Could you point one of those out to me, because the only CICO diets I'm aware
of are things like Jenny Craig and Weight Watchers (oh and maybe Nutrisystem).
Shit like South Beach, Atkins, Low-GI, Keto aren't focused on CICO, but on
some other aspect of nutritional content.

~~~
WorldMaker
From what I've read, and I know I'm veering towards stuff I don't have the
place to discuss, both Jenny Craig and Weight Watchers seem to go through fad
periods themselves, measurement revamps, have different scoring systems
between each other, etc.

There are blogs and tumblrs devoted to the cycles that Jenny Craig and Weight
Watchers tend to go through and the abusive victim blaming to people that
occurs within their programs, especially to "repeat customers". You might not
care anything about that sort of abuse (and in fact from many of your
responses seem more than happy to fat shame), but it is a real problem that is
hurting real people, compassion would go a long way...

~~~
jtuente
For as long as those two have been around, I would expect that they have had
to adjust their system based on the changes in nutritional science and to
better balance their scoring systems (much like video games often do).

Abusive victim blaming? Really? You mean people don't like being told they're
fat. That the only reason they aren't losing weight is because they aren't
staying true to their diet. Don't get me wrong, some people are downright
abusive, but that falls on the individual not the diet system. On the other
hand if you're a repeat customer to something like this, it really shows you
aren't learning how to control your diet on your own (which should be the
ultimate goal of these programs, I don't know).

I don't put any stock in blogs that dedicate themselves to finding these
stories to share (I consider them something akin to conspiracy websites, very
different from, say, Yelp). A program so focused on customer abuse should have
closed up shop long ago from a lack of customers.

~~~
WorldMaker
For as long as those two have been around I'd expect they'd have solved weight
loss entirely if it was truly as simple as CICO. I'd assume they would have
worked themselves out of a business model. They are both for-profit companies
and their revenues rely as much on that fact that they don't actually solve
the problem as they do on revamping the system every few years to score new
customers or returning old customers.

------
acjohnson55
This strikes me as a classic place to consider whether this link is a
correlation or a causation. It's really easy for me to imagine that diets
likely to produce a great deal of body fat also produce a home for particular
sorts of gut bacteria.

It's less obvious, but it's also not such a stretch to imagine mechanisms for
positive feedback, in which some of these bacteria reinforce chemical signals
that lead to consumption of more of the food they thrive on.

~~~
neximo64
There have been studies that show stool transplants can suddenly cause massive
weight changes in individuals. As is often the case with treatments to IBS. It
matches up a lot with this study.

In addition a similar study has been tried on genetically identical twins. The
difference being the bacteria.

How someone cultivates these bacteria, still a mystery. It could be
antibiotics as much as potato starches.

~~~
vanderZwan
> There have been studies that show stool transplants can suddenly cause
> massive weight changes in individuals.

Which is weird, because:

> "The researchers found the strongest links with visceral fat, participants
> with a high diversity of bacteria in their faeces had lower levels of
> visceral fat."

A stool sample _decreasing_ biodiversity sounds counter-intuitive to me

~~~
gr33nman
The "massive weight changes" from stool transplants are most often weight
loss, to my knowledge.

If so, this would be consistent with increased biodiversity (from the stool
transplant) correlating with reduced visceral fat.

At any rate, the interaction is probably more complex than our current
understanding, as this is a very new area of research.

~~~
DougWebb
It works both ways, but once people doing FMT realized that transplanting
feces from an obese person to a thin person makes the thin person gain weight,
they stopped doing that. All of the stool banks now screen for obesity and
won't accept donors with high BMI. So now you should only see weight loss
after FMT, or no significant change.

~~~
gm-conspiracy
That is very interesting.

Can you provide any links for this FMT screening process?

~~~
DougWebb
Sure, here's one: [http://www.openbiome.org/stool-
donation/](http://www.openbiome.org/stool-donation/)

~~~
gm-conspiracy
$40 per stool. Nice.

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ruffrey
If you eat only fruit, veggies and lean meat, it makes sense that your gut
bacteria would be different from someone who eats high levels of processed
carbs and sugars. The things you eat already are known to cause body fat.

Links like this do not seem like a leap forward, to me.

Did they control for the critically important variable: the subject's diet?

~~~
nestlequ1k
That's assuming that slim people are always people who eat perfectly healthy.
Yet seems we all know that one skinny person who eats the worst food ever, and
never gets fat.

~~~
jtuente
Probably because that one skinny person eats jack-all outside of the times you
are observing them.

~~~
Domenic_S
No, it's that some extreme outliers have insane BMRs. It's still a calories-
in-calories-out situation, it's just their _base_ calories out is so high
without doing anything special it's like a superpower. I've only met a few,
but it's a real thing! Most of us go through something similar (but to a
lesser extent) in our teen years. A few seem to keep it forever.

~~~
semi-extrinsic
I'm curious whether anyone can provide some scientific evidence supporting the
theory that these people actually burn calories faster? Seems like it should
show up very clearly on their core body temperature (thermodynamics and all).

An alternative hypothesis would be that these people have a less efficient
digestive system, so more of the calories just pass through.

~~~
Domenic_S
Here ya go:

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4535334/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4535334/)

~~~
semi-extrinsic
Oh neat, they use oxygen consumption as a proxy for metabolism rate. That's
actually really clever.

Still would be interesting to see whether it's correlated with body
temperature, or if people with high metabolism naturally shed heat faster.

------
brianbreslin
What was the name of the startup that would analyze your biome?

~~~
mox1
[http://ubiome.com/](http://ubiome.com/)

There may be others...

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gm-conspiracy
Anybody with fecal transplant experience care to comment?

~~~
justinph
I had one after having a c. diff infection. Didn't turn into a fatso. I did
lose 25 lbs from the c. diff, though, now mostly gained back. We're very
unclear about how the microbiome affects us; to be a FMT donor you must be in
perfect health: not fat, no mental illness, etc.

A FMT is not a panacea for everything that ails. It can cure c. diff, but the
results of it for anything else are much less clear. We don't really know why
it works and the long term effects of such a dramatic treatment are unknown.

~~~
DougWebb
I don't know that I'd call FMT a _dramatic treatment_. It doesn't seem any
more dramatic than a course of antibiotics, which we know wipes out most of
your microbiome and tends to lead to IBS and weight gain, or taking probiotics
which are intended to introduce bacteria strains into your microbiome.

~~~
gm-conspiracy
Take a look at this book, _he Second Brain : The Scientific Basis of Gut
Instinct and a Groundbreaking New Understanding of Nervous Disorders of the
Stomach and Intestines_ :

[http://amzn.to/2dmlrM4](http://amzn.to/2dmlrM4)

It touches on how the enteric nervous system has similar structures to the
brain and also produces neurochemicals.

Interesting perspective.

------
_of
I still have not managed to find the original paper.

~~~
swehner
There are some here,
[https://kclpure.kcl.ac.uk/portal/michelle.beaumont.html](https://kclpure.kcl.ac.uk/portal/michelle.beaumont.html)

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chriogenix
Isn't it possible that families tend to eat similar foods/diets and this
social construct creates the obesity to begin with?

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anotherarray
As a mere reader of this article, my only question is:

Couldn't the bacteria be instead the result of a high body fat percentage?

~~~
nibs
The gut biome is self reinforcing. If you eat nothing but sugar (simplified
example) the bacteria that thrive will be the ones that most resourcefully
consume sugar. Other strains will wither away entirely or to a very
insignificant state. Some, like yeast, actually kills 95% of the colony and
the other 5% eat it, so it can take years to bring under control in people
with immunocompromise (autoimmune disease, AIDS). If you eat nothing but
fibrous vegetables (another simplified example) then your biome will be very
different. And part of what makes you hungry is the nutrients the bacteria in
your gut desire in order to maintain the colony. So you eat the right foods,
then your body desires the right foods. You can re-program your biome to an
extent by eating differently. And that goes for eating good or bad food. So I
suspect (but cannot prove) that this is where the effect comes from.

~~~
DougWebb
An FMT jumpstarts that process, by introducing a bunch of colonists from a
healthy microbiome all at once. Then you just need to nurture the new arrivals
with proper diet, which you'll start to desire thanks to their influence.
That's easier than changing your diet first (fighting what your microbiome
wants) and hoping to pick up enough different bacteria for them to establish
themselves.

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khattam
Give me any bacteria and I will keep the body fat low... you know, by just
eating as much as my body needs?

