Bacteria Fight Obesity

Gut microbes may be another way to tackle  obesity, new research suggests.

Could a transplant of gut bacteria be the key to tackling obesity?


Scientists found that by altering the levels  of gastric bugs in mice, they were able to induce rapid and significant weight  loss.

The change occurred after bacteria from obese  mice that had undergone gastric bypass surgery were transplanted into ordinary  animals.

Surgery had the effect of altering the  make-up of the gut flora, introducing a different balance which promoted  slimming.

Surgery to transplant different bacteria into the gut - altering the make-up of the gut flora - promoted slimming, say researchers
Surgery to transplant different bacteria into the gut –  altering the make-up of the gut flora – promoted slimming, say researchers

When this new mix of microbes was transferred  to non-obese mice, the weight loss benefits were transferred too.

The U.S. research shows that gastric bypasses  do more than prevent food being digested. Much of their impact is due to altered  ecology in the gut.

‘It may not be that we will have a magic pill  that will work for everyone who’s slightly overweight,’ said study leader Dr  Peter Turnbaugh, from Harvard University, Boston.

‘But if we can, at a minimum, provide some  alternative to gastric bypass surgery that produces similar effects, it would be  a major advance.’

Gastric bypasses work by rearranging the gut  so that it accommodates less food.

The research showed that after surgery  different kinds of microbe began to take over. In particular, the gut became  dominated by verrucomicrobia and gammaproteobacteria. In contrast levels of the  Firmicutes family of bugs fell.

It took less than a week for the rebalancing  to occur, and the effect continued for months afterwards.

The new population of bugs appeared to drive  weight loss, and continued to do so when transferred to a non-obese group of  mice that had not undergone a gastric bypass.

An altered balance of microbes in the gut can lead to weight loss
An altered balance of microbes in the gut can lead to  weight loss

‘Simply by colonizing mice with the altered  microbial community, the mice were able to maintain a lower body fat and lose  weight – about 20 per cent as much as they would if they underwent surgery,’  said Dr Turnbaugh.

He suspected an even more dramatic result  would have been seen if the mice receiving the bugs had been fattened up  beforehand.

How particular populations of microbes induce  weight loss remains unclear.

The answer may be linked to waste products  the bugs excrete, according to the research published in the journal Science  Translational Medicine.

Along with the altered microbes, the  scientists found changes in the concentration of certain short-chain fatty  acids. Previous studies have suggested the molecules may trigger signals that  cause the body to speed up metabolism, or store fewer calories as  fat.

‘A major gap in our knowledge is the  underlying mechanism linking microbes to weight loss,’ said Dr Turnbaugh. ‘There  were certain microbes that we found at higher abundance after surgery, so we  think those are good targets for beginning to understand what is taking  place.’

Co-author Dr Lee Kaplan, from Massachusetts  General Hospital in Boston, said: ‘We need to learn a good deal more about the  mechanisms by which a microbial population changed by gastric bypass exert its  effects, and then we need to learn if we can produce these effects – either the  microbial changes or the associated metabolic changes – without  surgery.

‘The ability to achieve even some of these  effects without surgery would give us an entirely new way to treat the critical  problem of obesity, one that could help patients unable or unwilling to have

Attribution: Anna Hodgekiss, Mail Online