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RawNut
Sun, Dec-01-13, 19:21
tracing a chain of ideas

Sometimes the assumptions that scientists start with about what is “good”, “healthy”, or “normal” can cause them to interpret results in a completely different way than someone starting with different assumptions would have. Then, the resulting conclusions become the assumptions in the next round of interpretation, leading to a chain of logic in which one questionable assumption leads to another.

We recently read a paper in which the authors made a series of logical steps, and it became almost comical to us how at each step we would have interpreted their results in an opposite way than they did.

When the results of their experiment are looked at from our perspective, it suggests an intriguing hypothesis:

Maybe some of the health benefits a ketogenic diet are due, not just to the diet being low in digestible carbohydrate and thus leading to ketosis, but also to being low in indigestible fiber and thus starving certain gut bacteria.

Or, to phrase the same hypothesis differently, maybe one mechanism by which a glycolytic or high-fiber diet causes health problems is that it feeds harmful gut bacteria, and the presence of those bacteria causes the health problems.

If that hypothesis were true, it would imply that if you are eating a low-carb diet, then including a lot of low-carb vegetables would feed these hypothesized harmful gut bacteria and reduce some of the potential health benefits of a low-carb diet.


in brief

The purpose of this article is two-fold:



First, to compare the authors' interpretations of the observations to ours, given what we know about the metabolic effects of ketogenic diets.

We draw attention to the fact that the metabolism of germ-free mice is strikingly similar to that of ketogenic dieters. This similarity holds at the whole-body level in terms of behaviour and physical characteristics, as well as the level of mitochondrial energetics. We show that these characteristics appear to be beneficial.

Second, to raise the following questions:

Are some of the benefits of a ketogenic diet mediated by starving gut bacteria, and if so, does eating fiber (i.e. low-carb vegetables) reduce some of the health benefits of a keto diet? Would eating a carbohydrate- and fiber- free diet confer some keto-like benefits even in the absence of ketosis?




Continued here: http://www.ketotic.org/2013/11/similarities-between-germ-free-mice-and.html

inflammabl
Sun, Dec-01-13, 19:39
The problem I have with gut bacteria explanations is you can make up anything you want and it makes sense. I'm not saying these authors are wrong. I think there are too many plausible hypotheses.

For all of that angst, I am a believer in gut bacteria mechanisms. I just don't know what to believe.

WereBear
Mon, Dec-02-13, 10:48
I'm fascinated, thanks so much for this article!

I find that when I skip vegetables I seem none the worse for it, and there are stretches where I don't bother at all, except for leafy greens, which I do love, and seem the "least toxic" in many ways.

Because after all, white Anglo-Saxons who adopted the Inuit diet didn't just survive, they thrived. So that takes care of the nonsense about being genetically adapted to it, if you ask me.

RawNut
Tue, Dec-03-13, 15:56
It may be similar to how whole grains are better than refined grains but no grains is best. Good gut bacteria is better than the bad but getting rid of it altogether or reducing it as much as possible may be best.

Some people don't get as much benefit on LC until they eliminate all plant foods. I had thought it may have been phyto-chemicals that were responsible but it may actually be gut bacteria.

aj_cohn
Tue, Dec-10-13, 18:11
Because after all, white Anglo-Saxons who adopted the Inuit diet didn't just survive, they thrived. So that takes care of the nonsense about being genetically adapted to it, if you ask me.

They thrived for a short period (1 year) while cutting out all the crap that makes people sick. It's hard to tell which part of that experiment made the difference. It also tells you nothing about the long-term effects of an Inuit diet on Caucasians who evolved at lower latitudes.

RawNut
Tue, Dec-10-13, 21:47
They thrived for a short period (1 year) while cutting out all the crap that makes people sick. It's hard to tell which part of that experiment made the difference. It also tells you nothing about the long-term effects of an Inuit diet on Caucasians who evolved at lower latitudes.

But their sh*t didn't stink. ;)
The principal observations were as follows: The fecal specimens during the period of the meat diet consisted of finely divided material with a mild acid, aromatic odor, generally inoffensive, and with a reaction varying from neutral to moderately acid ( $P_H$ 7 to 6). Direct microscopic counts of bacteria showed within from seven to ten days a decrease of about 50 per cent in the total number of bacteria.
http://www.jstor.org/pss/30081508