This is not due to an increased calorie intake, but to a change in the composition of the intestinal flora after quitting smoking, as a study supported by the Swiss National Science Foundation (SNSF) suggests.
When smokers wave goodbye to their cigarettes, eighty per cent of them put on seven kilos on average. Their weight increases even if their calorie intake remains the same or even falls compared to the level before quitting smoking. What is the reason for this weight gain?
Researchers working with Gerhard Rogler of Zurich University Hospital attribute the cause to a changed composition of the bacterial diversity in the intestine. As they recently showed in PLoS One (*),the bacterial strains that also prevail in the intestinal flora of obese persons take the upper hand in people giving up smoking.
Comparison of stool samples
Rogler and his colleagues of the Swiss IBD cohort study examined the genetic material of intestinal bacteria found in the faeces and studied stool samples which they had received from twenty different persons over a period of nine weeks – four samples per person. The test persons included five non-smokers, five smokers and ten persons who had quit smoking one week after the start of the study.
While the bacterial diversity in the faeces of smokers and non-smokers changed only little over time, giving up smoking resulted in the biggest shift in the composition of the microbial inhabitants of the intestines. The Proteobacteria and Bacteroidetes fractions increased at the expense of representatives of the Firmicutes and Actinobacteria phyla. At the same time, the test subjects who had quit smoking gained an average of 2.2 kilos in weight although their eating and drinking habits remained the same (with the exception that, towards the end of the study, they drank on average a little more alcohol than before quitting smoking).
More efficient utilisation
Their results reflected those seen in previous studies conducted with mice, says Rogler. When other scientists transplanted the faeces of obese mice into the intestines of normal-weight mice some years ago, they saw that both the fractions of the Proteobacteria and Bacteroidetes in the gut flora as well as the weight of the mice treated increased. The new gut flora apparently used the energy contained in the nutrition more efficiently.
Rogler and his colleagues assume that the same effect also manifests itself in their test subjects. The composition of the diverse bacteria in the intestinal flora, which changes after giving up smoking, probably provides the body with more energy, resulting in new non-smokers gaining weight.(*) L. Biedermann, J. Zeitz, J. Mwinyi, E. Sutter-Minder, A. Rehman, S. Ott, C. Steurer-Stey, A. Frei, P. Frei, M. Scharl, M. Loessner, S. Vavricka, M. Fried, S. Schreiber, M. Schuppler and G. Rogler (2013). Smoking cessation induces profound changes in the composition of the intestinal microbiota in humans. PLoS One online.
Collagen nanofibrils in mammalian tissues get stronger with exercise
14.12.2018 | University of Illinois College of Engineering
New discoveries predict ability to forecast dementia from single molecule
12.12.2018 | UT Southwestern Medical Center
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
14.12.2018 | Power and Electrical Engineering
14.12.2018 | Physics and Astronomy
14.12.2018 | Physics and Astronomy