Do antibiotics make us fat?

the human gutAcross our population, the widespread use of antibiotics may have encouraged a set of bugs that increases obesity.

Roger Highfield at the Telegraph reports that there is a link between gut bacteria and obesity where antibiotics may play a significant role.

Bacteria make it possible to digest our food. The human digestive system is home to about 100 trillion bacteria – around 10 times the number of cells in the major organs (there are another 25 trillion red blood cells, plus a few trillion brain cells). “Good” bugs, such as lactobaccili, alter the way that fats are emulsified in the upper gut, making them less available to the body.

“We never dine alone: our microbes are able to sit at the dining room table together with us, consume for their own purposes the nutrients that are available, notably those we cannot digest on our own, and share the bounty with us,” said Professor Jeffrey Gordon at Washington University School of Medicine.

“This raises the question of whether differences in the mix of bacteria in our guts predispose some of us to obesity: the number of calories harvested from a serving of cereal may not be the same for everyone – some people may extract slightly more than others and over time this will add up.”

Jeremy Nicholson of Imperial College London studies bacteria and fat digestion. He’s thinking that obesity could be linked to antibiotic use and misuse. “Mapping the change in population obesity in the US over the last 20 years looks rather like the spread of an infectious disease.”

Roger Highfield asserts,

“You would be nothing without these microbial minions milling around inside your large intestine, performing crucial functions that your fancy, complicated human cells haven’t a clue how to do.

“The ecology of the human gut is at least as complex as that in soils or seas.”

The University of Maryland achieved the first large-scale gene sequencing of the human gut. The findings should lead to a better understanding of how microbes in the gut contribute to health and diseases.

Most of what is known about the microbes that live in the human gut has been learned from samples grown in a Petri dish. But only one percent of bacteria is able to grow in a Petri dish. We can now look at bacteria that we couldn’t see before. By looking straight at the environment, we can see all of the organisms, even those we can’t culture.