Can Obesity Spread Like Other Infectious Diseases?

Researchers at the Wellcome Trust Sanger Institute believe that certain diseases could be passed, not just through human genetics, but also via the microbiome.

According to the new study, certain bacteria transmitted from one host to another can cause an imbalance in the new hosts gut microbe system. The imbalance can lead to medical problems, including obesity.

"When there is an imbalance in our gut microbiome we may acquire diseases such as obesity, Inflammatory Bowel Disease, Irritable Bowel Syndrome and allergies," the author notes in a press release.

As explained by the researchers, there are certain bacteria that forms spores in the gut. These spores allow some bacteria to remain dormant for a period of time before travelling via air to a new host.

If in case, some kind of bacteria ingested disrupts one's gut microbiome, certain diseases can manifest.

Such in the case of Clostridium difficile (C. difficile), a bacteria that causes diarrhea and is known to spread from person to person via air.

Current treatment for C. difficile infection can involve transplants of feces from healthy people, to culture the gut.

Though the study did not directly say that obesity can be contagious it emphasized that the gut bacteria transfer may lead to manifestations of certain diseases. Thus, the study can lead to more understanding of biology and relationship between health and disease.

"Being able to cast light on this microbial ‘dark matter' has implications for the whole of biology and how we consider health," says Dr. Trevor Lawley of the Sanger Institute on the press release.

Meanwhile, a separate study conducted in 2007 found out obesity can spread from person to person. The team has come up with this conclusion after studying a a large social network of 12,067 people who had been closely followed for 32 years, from 1971 until 2003. According to Dr. Nicholas Christakis, the lead author, a physician and professor of medical sociology at Harvard Medical School weight gain is influenced by each other's perception of fatness.

"You change your idea of what is an acceptable body type by looking at the people around you," Dr. Christakis told New York Times.

The study, he said, "highlight the importance of a spreading process, a kind of social contagion, that spreads through the network."

Independent UK notes UK has the highest level of obesity in Western Europe, with one in four adults being obese.

Findings were published in Nature.