Could some types of obesity be caused by – a germ? It’s not as crazy as it sounds. A group of researchers think that viruses and bacteria that live in the human mouth may act as biological indicators of gaining excess weight, and may even participate in the disease process that leads to obesity.
The study, conducted by researchers from both Boston and Brazil, is based around the concept of obesity as an inflammatory disease. Since many inflammatory diseases can be caused by an infectious agent, the research focused on the possible role of oral bacteria as a factor contributing to obesity.
The researchers examined the microorganisms found in the saliva of a study group of overweight women. Saliva was collected from the women, and the type of bacteria found were noted and compared to those found in the saliva of a control group of healthy individuals. Sure enough, more than 98 percent of the overweight women were found to have a bacterium called Selenomonas noxia in their saliva, while the normal weight women didn’t – leading the researchers to theorize that bacterial species might somehow be related to obesity.
But how could bacteria make a person fat? The scientists behind the study suggest three possibilities: first oral bacteria may increase metabolic efficiency, reducing the amount of food the body burns – a speculative process called “infectobesity”.
Another possibility is that the oral bacteria can increase weight gain by increasing appetite – by stimulating your desire to chow down, the bacteria get more to eat, too.
A third hypothesis is that oral bacteria facilitate insulin resistance, screwing with your cellular metabolism so your body stores food as fat instead of burning it off.
Study researchers caution that they are nowhere near ready to conclude that oral bacteria can cause obesity. They do, however, think that a connection exists between the two – and urge that more research be done to find out what it is.
