Helicobacter pylori as part of Microbiome

We leave our mother's womb without a single microbe. As we pass through our mother's birth channel, we begin to attract entire colonies of bacteria. By the time a child can crawl, he has been blanketed by an enormous cloud of microorganisms -- hundred trillion or
more. They are bacteria, mostly, but also viruses and fungi, and they come at us from all directions: other people, food, furniture,
clothing, cars, buildings, trees, pets, even the air we breathe. ...
We are inhabited by as many as ten thousand species,
which together weighs three pounds -- the same as our brain.
They are referred to as our microbiome and
play a crucial role in our lives.

Helicobacter pylori may be the most successful pathogen in human history.
While not as deadly as the bacteria that cause tuberculosis, cholera, and the plague, it infects more people than all the others combined.
H. pylori has been interwined with our human species for at least 200,000 years.
It occupies half the stomachs on earth.

In 1982, Barry Marshall and J. Robin Warren discovered
that H. pylori is the cause of gastritis and peptic ulcers
and won Nobel Prize in 2005.
It has since been associated with an increased risk of
stomach cancer as well.
H. pylori is shaped like a corkscrew and three microns long.
They live comfortably in the brutally acidic surroundings of the stomach.
So we can cure the disease by getting rid of the bacterium with antibiotics.
During the past 15 years, however, scientists have shown
that H. pylori performs beneficial functions
early in our lives, beginning in infancy.
There is evidence both in humans and animals that
it prevents asthma and obesity.
Scientists feel that without this organism, we are in real trouble.
When children don't carry this organism in their guts,
they often develop asthma and obesity.
This organism turns out to contol two stomach hormones, ghrelin and leptin,
which regulate our appetite.
As humans enter older ages, H. pylori may cause problems, causing ulcers, etc.

It is known that the cause of tooth cavities is streptococcus mutans,
which normally inhabits in the mouth, secrets acids
when we eat sweet things.
This bacteria proliferates excessively by the use of broadspectrum antibiotics.
It is also known that Lactobacillus sakei prevents sinusitis,
but they are killed by widespread use of antibiotics as well.

H. pyori is only one of ten thousand species of bacteria
inhabiting humans in our microbiome.
Human Microbiome Project researchers plan to define,
for the first time,
the normal microbial makeup of the human body.
This project has helped scientists identify many species
and learn which parts of our bodies they colonize.
But to understand what goes wrong when we are sick,
the researchers will need to determine how these organisms
interact with one another and with us.

Scientists are saying, "We have to stop looking at medicine as a war
between invading pathogens and our bodies.
"The human body turns out to be a vast, highly mutable
ecosystem. Each of us seems more like a farm, ....
We have to realize we are disturbing this microbiome
whenever we use antibiotics of some kind so that
we need to be a lot more careful than we ever were in the past.

....... The above is an excerpt by me from "Annals of Science, Germs Are Us,
Bacteria make us sick. Do they also keep us alive?"
by Michael Specter, The New Yorker, October 22, 2012