Thursday, December 3, 2015

The bacteria that controls the hunger-A new twist to satiety and hunger in humans.

Thousands of words have been written about the importance of consuming a balanced diet in moderate quantities and many workshops have taken place to impress upon people the need to exercise regularly for maintaining good health. Unfortunately consumers do not seem to be paying too much attention to these cautionary advices as evidenced by the gross indiscipline seen among the consumers regarding their choice of foods. With massive promotion of nutrient light and calorie rich junk foods by the industry, consumers are tempted to go in for foods which are cheap, tasty and satisfying ignoring costlier options like fruits, vegetables, whole grains based products and others. The result is the galloping trend of uncontrolled weight gains often tending to cross the obesity rubicon! Who is to be faulted for this population degeneration-the industry, government or the consumer.? The answer depends on who is going to reply! The industry says that consumer must do necessary exercise to maintain good health, government has not much of an opinion on this and the consumer cannot decide what to eat. With sugary and salty foods now being bracketed with tobacco and alcohol as addictive substances, the onus seems to be on the consumer to shun these types of foods for their own good. But how can they do this unless there is strong will which cannot be expected from every body. Now comes another twist to this food addiction story narrated by some scientists who opine that it is actually the gut bacterial composition that determines the hunger and decision to eat how much. Read further below to get a better idea about the new postulations made by them.   

"Gut microbes could be the one responsible for telling people that dinner is done. Researchers of a new study have found chemical clues suggesting that when certain bacteria in the stomach already had enough to eat, they inform the brain it is time to push away the plate. In animal experiments, researchers found evidence suggesting that certain microbes in the body have a way of letting the brain know they have had enough nutrients. The signals they send also appear to have the ability to turn on and off the hunger of their host. For the new study published in Cell Metabolism, Serguei Fetissov, from Rouen University in France, and colleagues looked at the proteins produced by the E.coli bacteria, which are prevalent in the human gut, and noticed that about 20 minutes after feeding and multiplying in number, the bacteria switch from producing a set of proteins to another. When Fetissov and colleagues injected small doses of the post-meal proteins into rodents, they noticed that they reduced their food intake regardless if they were previously fed or kept hungry. Further analysis likewise revealed that one protein stimulated the release of a hormone that play a role in satiety.  "Our study shows that bacterial proteins from E. coli can be involved in the same molecular pathways that are used by the body to signal satiety, and now we need to know how an altered gut microbiome can affect this physiology," Fetissov said. Once they are provided with nutrients, the bacteria were found to produce more or less a billion more of their kind. Interestingly, they stop growing after producing about one billion and then start producing new proteins that inhibit the effect of appetite. The researchers said that E.coli could be hijacking a molecular pathway to produce signals that make animals feel full. By doing so, the bacteria also find a way to self-regulate their populations. The findings of the study show the microbes have a crucial role in the physiology of appetite and may even help people who suffer from eating disorders. "These data show that bacterial proteins produced after nutrient-induced E. coli growth may signal meal termination," the researchers wrote. "Continuous exposure to E. coli proteins may influence long-term meal pattern."

E.coli is a microorganism not liked by the hygiene scientists and its presence in any food is taken as indication of fecal contamination. This surmise is based on the fact that there are over 500 species of microorganisms which inhabit the human gut. Naturally among these colony of bugs there could be good ones as well pathogens depending on the source of fecal contamination. Thus E.coli is more known as a marker microbe for the microbiological quality of any food. However the revelation by the French scientists that it may be playing a role in controlling the hunger is indeed startling and by this score it deserves our respect. There may be significant implications of these findings for future research on obesity control. A natural question that arises in this context is whether inclusion of favorable nutrients of E.coli in human diet can bring in satiety faster and there fore lesser intake of food? This is a gray area requiring further studies. Of course the results of the animal experiments itself need not be applicable to humans in all cases and naturally the research opens up wide vistas for further studies in the coming years. If confirmed by human trials, there is even the possibility of growing E.coli under controlled conditions for producing the typical protein that is implicated in satiety and including the same in the diet for creating quicker satiety.


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