I have come across an interesting study conducted by Shanghai
Jiao Tong University that has demonstrated in a trial on mice how a particular bacterium
isolated from an obese human’s intestines can induce obesity and insulin resistance
in mice who are fed a high fat diet. Mice exposed to the same bacterium but
which were fed a normal diet did not develop obesity. A further control group
was fed a high fat diet but this group was not exposed to the bacterium and the
members of the group did not develop obesity or insulin resistance.
This is not the first time that scientists have proposed
that gut bacteria may play a role in obesity. I remember reading study a few
years back from scientists at Washington University School of Medicine that
postulated a link but it was unable to demonstrate a causative effect.
The study by the scientists at the Chinese university where
the latest research was conducted are not advancing the theory that this particular
bacterium is the sole bacterium that may have an impact on obesity and much
more work needs to be done but they have managed to demonstrate that an
endotoxin-producing bacterium appears to have a role. When the human volunteer
from whom the bacterium was isolated in the first place was put on a special diet
of probiotics, whole grains and some Chinese medicinal products, the
concentration of the enterobacter levels fell from 35% to undetectable levels
at the end of the 23 week trial. Over the same period, the volunteer lost 51
kg.
While this study is fascinating, there was only
one human volunteer. We would really need to see a much larger study that
replicated the controls in the mouse study before we could be satisfied that
there really is a connection between endotoxin-producing bacterium and obesity.