The termite sundrome

[Guest guest]

Thought you folks might find this extract from an article in the NYT last

year of interest. It was published 13 August 2006.

Gordon first began studying the connection between the microflora and

obesity when he saw what happened to mice without any microbes at all.

These germ-free mice, reared in sterile isolators in Gordon’s lab, had 60

percent less fat than ordinary mice. Although they ate voraciously,

usually about 30 percent more food than the others, they stayed lean.

Without gut microbes, they were unable to extract calories from some of

the types of food they ate, which passed through their bodies without

being either used or converted to fat.

When Gordon’s postdoctoral researcher Fredrik Bhed transplanted gut

microbes from normal mice into the germ-free mice, the germ-free mice

started metabolizing their food better, extracting calories efficiently

and laying down fat to store for later use. Within two weeks, they were

just as fat as ordinary mice. Bhed and Gordon found at least one

mechanism that helps explain this observation. As they reported in the

Proceedings of the National Academy of Sciences in 2004, some common gut

bacteria, including B. theta, suppress the protein FIAF, which ordinarily

prevents the body from storing fat. By suppressing FIAF, B. theta allows

fat deposition to increase. A different gut microbe, M. smithii, was

later found to interact with B. theta in a way that extracts additional

calories from polysaccharides in the diet, further increasing the amount

of fat available to be deposited after the mouse eats a meal. Mice whose

guts were colonized with both B. theta and M. smithii as usually happens

in humans in the real world were found to have about 13 percent more body

fat than mice colonized by just one or the other.

Gordon likes to explain his hypothesis of what gut microbes do by talking

about Cheerios. The cereal box says that a one-cup serving contains 110

calories. But it may be that not everyone will extract 110 calories from

a cup of Cheerios. Some may extract more, some less, depending on the

particular combination of microbes in their guts. A diet has a certain

amount of absolute energy, he said. But the amount that can be extracted

from that diet may vary between individuals not in a huge way, but if the

energy balance is affected by just a few calories a day, over time that

can make a big difference in body weight.

But Elaine mentioned this to me back in 2002....

—

Marilyn

New Orleans, Louisiana, USA

Undiagnosed IBS since 1976, SCD since 2001

Darn Good SCD Cook

No Human Children

Shadow & Sunny Longhair Dachshund