The 4 types of microbes

Gram-positive cocci and rod-shaped bacteria are the predominant microorganisms found in the small intestine. The bacterial flora provide regulatory signals that enable the development and utility of the gut. Overgrowth of bacteria in the small intestine can lead to intestinal failure. This form of testing is also often preferable to more invasive techniques, such as biopsies.

The 4 types of microbes

Rafa Alvarez Advertisement For the 35 percent of American adults who do daily battle with obesity, the main causes of their condition are all too familiar: In recent years, however, researchers have become increasingly convinced that important hidden players literally lurk in human bowels: Throughout our evolutionary history, the microscopic denizens of our intestines have helped us break down tough plant fibers in exchange for the privilege of living in such a nutritious broth.

Yet their roles appear to The 4 types of microbes beyond digestion. New evidence indicates that gut bacteria alter the way we store fat, how we balance levels of glucose in the blood, and how we respond to hormones that make us feel hungry or full. The wrong mix of microbes, it seems, can help set the stage for obesity and diabetes from the moment of birth.

Expertise. Insights. Illumination.

Fortunately, researchers are beginning to understand the differences between the wrong mix and a healthy one, as well as the specific factors that shape those differences. They hope to learn how to cultivate this inner ecosystem in ways that could prevent—and possibly treat—obesity, which doctors define as having a particular ratio of height and weight, known as the body mass index, that is greater than Imagine, for example, foods, baby formulas or supplements devised to promote virtuous microbes while suppressing the harmful types.

Keeping our gut microbes happy could be the elusive secret to weight control. An Inner Rain Forest Researchers have long known that the human body is home to all manner of microorganisms, but only in the past decade or so have they come to realize that these microbes outnumber our own cells 10 to one.

Each of us begins to assemble a unique congregation of microbes the moment we pass through the birth canal, acquiring our mother's bacteria first and continuing to gather new members from the environment throughout life. By studying the genes of these various microbes—collectively referred to as the microbiome—investigators have identified many of the most common residents, although these can vary greatly from person to person and among different human populations.

The 4 types of microbes

In recent years researchers have begun the transition from mere census taking to determining the kind of jobs these minute inhabitants fill in the human body and the effect they have on our overall health.

An early hint that gut microbes might play a role in obesity came from studies comparing intestinal bacteria in obese and lean individuals. In studies of twins who were both lean or both obese, researchers found that the gut community in lean people was like a rain forest brimming with many species but that the community in obese people was less diverse—more like a nutrient-overloaded pond where relatively few species dominate.

Lean individuals, for example, tended to have a wider variety of Bacteroidetes, a large tribe of microbes that specialize in breaking down bulky plant starches and fibers into shorter molecules that the body can use as a source of energy.

Documenting such differences does not mean the discrepancies are responsible for obesity, however. To demonstrate cause and effect, Gordon and his colleagues conducted an elegant series of experiments with so-called humanized mice, published last September in Science.

First, they raised genetically identical baby rodents in a germ-free environment so that their bodies would be free of any bacteria. Then they populated their guts with intestinal microbes collected from obese women and their lean twin sisters three pairs of fraternal female twins and one set of identical twins were used in the studies.

The mice ate the same diet in equal amounts, yet the animals that received bacteria from an obese twin grew heavier and had more body fat than mice with microbes from a thin twin.

As expected, the fat mice also had a less diverse community of microbes in the gut. Gordon's team then repeated the experiment with one small twist:In biology, there are four distinguishable types of microorganisms.

These organisms are proven to be harmful or helpful to humans, plants and animals alike. The film "Contagion" provides an excellent opportunity to learn about infectious disease, how it spreads and which organizations would be involved in tracking and controlling a dangerous outbreak.

Scientific American is the essential guide to the most awe-inspiring advances in science and technology, explaining how they change our . The Littlest Organisms Let's study the wee ones of the world known as the microbes or the microorganisms. If you spend your life studying them, you would be a are the smallest of the small and the simplest of the simple.

Microbes in the human body According to a recent National Institutes of Health (NIH) estimate, 90% of cells in the human body are bacterial, fungal, or otherwise non-human.


Although many have concluded that bacteria surely enjoy a commensal relationship with their human hosts, only a fraction of the human microbiotahuman microbiomeHuman . A scientific overview of the association of microbes with cheese, through the lens of select cheese varieties that result due to surface mold ripening, internal mold ripening, rind washing, cave aging, or surface smear rind development.

The 4 types of microbes
How Gut Bacteria Help Make Us Fat and Thin - Scientific American