Old Friends Hypothesis (fka as Hygiene Hypothesis) and Umami Hypothesis

[PaleoPhil]

The Old Friends Hypothesis:

In the mid 1960s scientists made the observation that MS was more common in those who had had very clean childhoods. In 1986 Godfrey published in the Lancet what would become known as the hygiene hypothesis, based on his observation that allergies were less common in later siblings in large families. He reasoned that their increased exposure to infectious organisms throughout their childhoods via their elder, numerous, siblings was the cause.

Since then hundreds of scientific papers have been published looking at this issue and the majority confirm or extend his ideas. The result had been to refine and expand the Hygiene Hypothesis is to produce the Old Friends Hypothesis (OFH).

The OFH suggests that the immune response to infection, particularly by large multi-celled and complex organisms like helminths , is effective in moderating immune response in large measure because we and our immune systems (and by we I mean all large complex organisms) have co-evolved with every organism that has parasitized or infected us long term.

The case for immunotherapy based on the use of benign infectious organisms for the treatment of immunological disorders
http://www.gather.com/viewArticle.action?articleId=281474977623982

If childhood infections do not protect and home hygiene does not correlate, what might be the protective factors associated with pets, farms, and day care centres? The answer might lie in certain relatively harmless microorganisms (including helminths, saprophytic mycobacteria, and lactobacilli) that have been present throughout mammalian evolution. We have called this the “old friends” hypothesis.1 Contact with “old friends” is greatly diminished in rich countries but increased on farms, in cowsheds, and through contact with pets. A number of reports have provided evidence for this interpretation. Allergic disorders are less frequent in individuals with helminth infections, and atopic sensitisation increases after treatment of intestinal helminths.15 Similarly, there are less lactobacilli in the guts of children with allergies,16 and a preliminary clinical study suggests that high doses of lactobacilli may inhibit development of atopic eczema in genetically high risk children.17 Finally, the saprophytic mycobacterium M vaccae, originally isolated, as its name suggests, from a cow shed, potently drives maturation of Treg that will treat pre-existing allergy in a mouse model18 and has given encouraging results in clinical trials in allergic disorders.19,20

Microbes, immunoregulation, and the gut
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1774411/

The Umami Hypothesis:

"We like foods with sour, umami, and complex tastes/flavors.  My evolutionary explanation: these preferences increased microbe intake, which increased health. Fermentation, which increases microbes, easily produces all three of these characteristics. They are not easily produced otherwise (in the absence of lemon trees). As a result, until recently these three characteristics were  correlated with the microbe content of food. For example, until recently, the more sour a food, the more microbes. Seeking out sourness caused us to eat foods with more microbes. It’s easy to see this correlation today. As milk becomes yogurt, it becomes more sour and more microbe-rich at the same time. As juice becomes vinegar, same thing. The Chinese character for sour connects it with fermentation. As meat ages, it gets a stronger umami flavor and becomes more microbe-rich. For example, umami in dry-cured hams increases with time. Umami flavor is produced by glutamate molecules. They increase in concentration when proteins break down into components. Nowadays meat is aged because it tastes better aged than fresh. The flavor improvement with age presumably caused our ancestors to age their meat. Microbes add complexity to flavor because they produce many byproducts. Many experiments support the idea that our food preferences are a guide to what we should eat. When children chose their own food, they turned out very healthy."

- Seth Roberts, The Umami Hypothesis: We Need to Eat Microbes
http://blog.sethroberts.net/the-unami-hypothesis-why-i-believe-fermented-foods-are-necessary-for-health/

A raw Paleo diet fits well with these hypotheses, as it provides more of the "old friends" (and umami taste) in the raw and raw fermented foods and a Paleo/ancestral type lifestyle also promotes more exposure to the old friends.

[Dorothy]

What a wonderful name: Old Friends Hypothesis. I'm going to call all my starters, scobies etc. "old friend" from now on!

[cherimoya_kid]

Fascinating.  I had no idea that fermenting meat increased the umami flavor.

[TylerDurden]

Thanks PP, I'll save the above link in one of the sticky threads.

[PaleoPhil]

If your healthcare practitioner won't prescribe a GI microbiome test or other microbiome test, to see how well your Old Friends are doing, there are some Internet options:

Jeff C says:
April 17, 2014 at 9:49 pm
You can order many Metametrix tests through mymedlab.com. They have physicians on staff that will approve the test and the result is sent to them. They’ll do a quick review of the results then notify you that it’s available for download. We’ve ordered several Metametrix tests using them and the turnaround time is very good. No insurance allowed, the costs are out of pocket.

You can also order tests through Crohns.net with a similar system though I’ve never used them.

http://www.fathead-movie.com/index.php/2014/04/17/revisiting-resistant-starch-part-two

[cherimoya_kid]

Good finds, Phil.