Three days is a long time to a bacterium. E coli has a generation time of 20 minutes, Staph aureus is about 30. So we're looking at a hundred generations or so. It's not nothing.
It is certainly something when only focused on individual bacteria.
But the whole system including gut flora and human body changes. And that takes more time. 3 days a different diet? Not a lot to see much change in the body.
Would you trust any diet related study that only lasts three whole days?
The test is to see the impact on whole system health, which is determined by the slowest constituent parts, not the fastest.
Certainly, colonic flora has super high generation time, but the health of the system cannot measurably change over a three day period without changes in measurements falling well within error tolerance. Even if health did improve, the time span chosen is not long enough to sufficiently determine correlation, let alone causation.
Although it sounds like an amazing experience, I'm not really sure if we should be impressed with the results of the experiment. How much of the increase in floral biodiversity was just from going somewhere far away from home? That is, if he'd eaten food for three days in Pretoria or Bangalore, would he have seen the same increase? Or is there something special about a hunter/gatherer diet?
(...and yeah, for the purposes of this comment, I'm setting aside the n=1 problem. It's not really supposed to be a scientific experiment, obviously, but the writeup sure sounds like it's supposed to prove a point.)
It doesn't answer all the questions I have but I think it is rational.
> Mounting evidence suggests that the richer and more diverse the community of microbes in your gut the lower your risk of disease.
So this is the main law from science pertinent to the article. My impression is that many people are interested in this law today.
> What we didn’t know is whether a healthy stable gut microbiome could be improved in just a few days.
This is the empirical question that the experiment explores. If the article is honest, then the reader has some food for thought. Science would be better served with a better study.
Building on this article, for those who are interested in some science on the subject, what you eat greatly influences your biome. A vegan diet has been shown to substantially change your flora [1] in as little as a day [2]. I also found this video on the role of fiber, our gut flora, and our immune system interesting [3].
> Conclusions: Maintaining a strict vegan or vegetarian diet results in a significant shift in the microbiota while total cell numbers remain unaltered.
Studies should almost never use the term "vegan diet" to arrive at any conclusions. A vegan diet can be potato chips and oreos, whole foods high carb, whole foods high fat, 100% raw, etc. I assume most of them would produce significantly different results.
Of late I have been enthralled by this show called 'Life Below Zero' (It's on Netflix and I really recommend watching it) - it's a reality TV show which profiles folks living in the Alaskan Bush. It primarily revolves around 4-5 different folks who live in various extreme remote parts of Alaska.
Reading this article, it really reminded me of one of the lead characters, Glenn Villeneuve (http://channel.nationalgeographic.com/life-below-zero/articl...), who lives a very spartan and primitive (by his own choosing) hunter-gatherer lifestyle in the Brooks Range (Chandalar, AK). He hunts for all his food and just boils them mostly (and often times eats them raw). He doesn't not use seasoning at all. I am guessing his gut microbes must be pretty robust and diverse.
Main difference between Hadza and his place is that food sources are very spread out and thin in Chandalar. Most of the show is just following him trying to find his food.
[OT: I generally dislike watching reality TV shows (and also TV in general). But this show has made me change my opinion on reality TV. Or it could just be because Alaska has a special place in my heart :)]
I really liked Alone, which reminded me a lot of Survivorman. The contestants are dropped off far apart, and told to survive on their own for as long as they can, while filming themselves.
The amount of effort varied hugely. Some tapped out and left on the very first night - either due to psychological issues ("oh my GOD there's a bear") or physical ("hey let's drink some of this stagnant water and throw up all night"). Some lasted a long while, but seemed to have a very, very hard time finding enough calories day to day, and at best lived on a feast-and-famine schedule (with "feast" being maybe a whole fish.)
A few contestants did so well that their biggest problem was finding things to do to entertain themselves. One completely moved his camp and rebuilt it from scratch, built himself a boat, and made a guitar. Another one made a variant on a chess set that allowed him to play a solitaire game for amusement.
And these folks were all separated by less than ten miles.
It is. The last person to give up wins the cash prize. (Obviously, they're not told how many people have quit so far; each person, when they're "tapping out", has no idea whether they've won or not.)
I really recommend the first season; while there's some tropes of "oh my god what was that noise <cut to commercial>", there's a lot of focus both on the physical tasks required for survival, and on what the contestants go through, psychologically.
It's hard to come to a conclusion without knowing their actual ages. If their healthy-looking elders are all of 45, and nobody seems to be much above that, then an entirely different conclusion could be drawn.
There's also very likely selection bias involved. The photographer likely chose that photo because it was appealing, not to show a representative sample of the population.
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[ 2.9 ms ] story [ 59.8 ms ] threadThree weeks would be more noteworthy, but really get back to me after three months or three years.
But the whole system including gut flora and human body changes. And that takes more time. 3 days a different diet? Not a lot to see much change in the body. Would you trust any diet related study that only lasts three whole days?
Certainly, colonic flora has super high generation time, but the health of the system cannot measurably change over a three day period without changes in measurements falling well within error tolerance. Even if health did improve, the time span chosen is not long enough to sufficiently determine correlation, let alone causation.
(...and yeah, for the purposes of this comment, I'm setting aside the n=1 problem. It's not really supposed to be a scientific experiment, obviously, but the writeup sure sounds like it's supposed to prove a point.)
> Mounting evidence suggests that the richer and more diverse the community of microbes in your gut the lower your risk of disease.
So this is the main law from science pertinent to the article. My impression is that many people are interested in this law today.
> What we didn’t know is whether a healthy stable gut microbiome could be improved in just a few days.
This is the empirical question that the experiment explores. If the article is honest, then the reader has some food for thought. Science would be better served with a better study.
[1]: http://www.nature.com/ejcn/journal/v66/n1/full/ejcn2011141a....
[2]: http://www.nature.com/nature/journal/v505/n7484/full/nature1...
[3]: http://nutritionfacts.org/video/prebiotics-tending-our-inner...
Studies should almost never use the term "vegan diet" to arrive at any conclusions. A vegan diet can be potato chips and oreos, whole foods high carb, whole foods high fat, 100% raw, etc. I assume most of them would produce significantly different results.
Reading this article, it really reminded me of one of the lead characters, Glenn Villeneuve (http://channel.nationalgeographic.com/life-below-zero/articl...), who lives a very spartan and primitive (by his own choosing) hunter-gatherer lifestyle in the Brooks Range (Chandalar, AK). He hunts for all his food and just boils them mostly (and often times eats them raw). He doesn't not use seasoning at all. I am guessing his gut microbes must be pretty robust and diverse.
Main difference between Hadza and his place is that food sources are very spread out and thin in Chandalar. Most of the show is just following him trying to find his food.
[OT: I generally dislike watching reality TV shows (and also TV in general). But this show has made me change my opinion on reality TV. Or it could just be because Alaska has a special place in my heart :)]
The amount of effort varied hugely. Some tapped out and left on the very first night - either due to psychological issues ("oh my GOD there's a bear") or physical ("hey let's drink some of this stagnant water and throw up all night"). Some lasted a long while, but seemed to have a very, very hard time finding enough calories day to day, and at best lived on a feast-and-famine schedule (with "feast" being maybe a whole fish.)
A few contestants did so well that their biggest problem was finding things to do to entertain themselves. One completely moved his camp and rebuilt it from scratch, built himself a boat, and made a guitar. Another one made a variant on a chess set that allowed him to play a solitaire game for amusement.
And these folks were all separated by less than ten miles.
surely this is not the actual time constraint.
I really recommend the first season; while there's some tropes of "oh my god what was that noise <cut to commercial>", there's a lot of focus both on the physical tasks required for survival, and on what the contestants go through, psychologically.
A lot of parts are very surprisingly funny.