[news.bbc.co.uk]

You should put 'probably' in that sentence.

13 swallows does not make a summer - or rather a finding in 13 people is not conclusive. The article does only say it is possible but very interesting all the same.

Very interesting, so they are talking about the cultivation of healthy gut flora, the enzymes produced by certain bacteria that can break down the cell walls of this red algae, so when the Japanese eat traditional raw nori they are eating the beneficial bacteria which then become part of the gut flora.

"Algal cell walls

"...Algal cell walls contain cellulose and a variety of glycoproteins.

"Manosyl form microfibrils in the cell walls of a number of marine green algae including those from the genera, Codium, Dasycladus, and Acetabularia as well as in the walls of some red algae, like Porphyra and Bangia." [www.answers.com]


The enzymes could be digesting the cellulose or the glycoproteins (or both) of the cell wall and then gaining entry to more good stuff inside.

The answers.com article mentions Porphyra (Nori) along with Codium. Codium is the species I see the most of when foraging and it does seem easy to digest.



Edited 1 time(s). Last edit at 04/12/2010 11:48AM by loeve.

Sooooo, this is suggesting that by eating raw nori, we could supply ourselves with the algal-digesting enzymes that Japanese people already have a genetic propensity for? Flipperjan is right--it's interesting, but it's not conclusive until they actually take a large population of non-Japanese people and observe the effects on their guts of a high porphyrase diet.

Thanks for posting.

Our "second genome" --

"The human gut holds microbes containing millions of genes, say scientists.

"In fact, there are more genes in the flora in the intestinal system than the rest of our bodies. So many that they are being dubbed our "second genome".

"A study published in the journal Nature details the analysis of the genes, carried out to better understand how the gut flora is affected by disease.

"Basically, we are a walking bacterial colony," said Professor Jeroen Raes, one of the researchers involved.

"There is a huge diversity. We have about 100 times more microbial genes than human genes in the body. We also have 10 times more bacterial cells in our body than human cells," he told BBC News. Most of the microbes present in our bodies live in the gut."

[news.bbc.co.uk]

loeve,

Hmmmmmm, I see a through-road to proving someday that Homo sapiens is supposed to be primarily a plant eater.

Gut--the Final Frontier. These are the voyages of the European MetaHIT Consortium. Its 5 year mission: To explore strange old organs, to seek out new life and new organ purposes, to boldly go where no geneticist has gone before! la-laaaaaa-la-la-la-laaa-la-laaaaaaaa-la-la-la-laaa . . . .

..primarily meant to be a plant eater, and the more one eats of them the more the body adapts to that type of food, and there's no reason to wait generations for the adaptations to come (maybe).

"Un-sterile" foods was another point. The bacteria/genes/enzymes have to be eaten intact for the body to incorporate them into its gut flora.


PubMed has the abstract of the study. "May" does seem to be the operative word. I thought marine bacteria could simply take up residence in the human gut, but they are talking the possible transfer of genes from marine bacteria to gut bacteria. Hmmm...

Transfer of carbohydrate-active enzymes from marine bacteria to Japanese gut microbiota.
Hehemann JH, Correc G, Barbeyron T, Helbert W, Czjzek M, Michel G.

Université Pierre et Marie Curie, Paris, France.

Comment in:

Nature. 2010 Apr 8;464(7290):837-8.

Abstract
Gut microbes supply the human body with energy from dietary polysaccharides through carbohydrate active enzymes, or CAZymes, which are absent in the human genome. These enzymes target polysaccharides from terrestrial plants that dominated diet throughout human evolution. The array of CAZymes in gut microbes is highly diverse, exemplified by the human gut symbiont Bacteroides thetaiotaomicron, which contains 261 glycoside hydrolases and polysaccharide lyases, as well as 208 homologues of susC and susD-genes coding for two outer membrane proteins involved in starch utilization. A fundamental question that, to our knowledge, has yet to be addressed is how this diversity evolved by acquiring new genes from microbes living outside the gut. Here we characterize the first porphyranases from a member of the marine Bacteroidetes, Zobellia galactanivorans, active on the sulphated polysaccharide porphyran from marine red algae of the genus Porphyra. Furthermore, we show that genes coding for these porphyranases, agarases and associated proteins have been transferred to the gut bacterium Bacteroides plebeius isolated from Japanese individuals. Our comparative gut metagenome analyses show that porphyranases and agarases are frequent in the Japanese population and that they are absent in metagenome data from North American individuals. Seaweeds make an important contribution to the daily diet in Japan (14.2 g per person per day), and Porphyra spp. (nori) is the most important nutritional seaweed, traditionally used to prepare sushi. This indicates that seaweeds with associated marine bacteria may have been the route by which these novel CAZymes were acquired in human gut bacteria, and that contact with non-sterile food may be a general factor in CAZyme diversity in human gut microbes.

[www.ncbi.nlm.nih.gov]



Edited 1 time(s). Last edit at 04/12/2010 03:07PM by loeve.

Brenaj,
I think I see now, enzyme genes from raw seaweed and the bacteria on it can transfer to bacterial flora in the human gut making seaweed easier to digest --

"Bacteria lack the membrane-bound nuclei of eukaryotes; their DNA forms a tangle known as a nucleoid, but there is no membrane around the nucleoid, and the DNA is not bound to proteins as it is in eukaryotes. Whereas eukaryote DNA is organized into linear pieces, the chromosomes, bacterial DNA forms loops. Bacteria contain plasmids, or small loops of DNA, that can be transmitted from one cell to another, either in the course of sex (yes, bacteria have sex) or by viruses. This ability to trade genes with all comers makes bacteria amazingly adaptible; beneficial genes, like those for antibiotic resistance, may be spread very rapidly through bacterial populations. It also makes bacteria favorites of molecular biologists and genetic engineers; new genes can be inserted into bacteria with ease."

[www.ucmp.berkeley.edu]

Thanks for the article.