Sunday, November 23, 2014

Diets that change gut bacteria- The implications.

Many of us associate bacteria with negative things as most pathogens causing a host of diseases belong to this group of microorganisms. But it is not a correct perception because there are many species friendly to man doing many things to support our health. Human microbiome which involves bacteria that thrive in and on human beings have received focused attention only recently and whatever has been unfolded is both exciting and scary. Exciting because it opens up avenues for maneuvering them for greater benefits and disease amelioration in humans. Scary because inappropriate food consumption habits and reckless diet can ruin them inviting disaster in the long run. The early recognition about the importance of dietary fiber was due to the role these fibers play inside the gut in providing a great service in avoiding many diseases including CVD, diabetes and obesity. According to one of the recent studies changes in the diet can change the gut profile of bacteria within a matter of 2-3 days causing some damage to the well being while in the long term such changes can be significantly injurious to the health. Here is a take on this important development.

"Scientists are just beginning to learn about how our decisions at the dinner table — or the drive-through — tweak our microbiome, that is, the communities of bacteria living in our bodies. But one thing is becoming clear: The critters hanging out in our intestine influence many aspects of our health, including weight, immunity and perhaps even behavior. And interest in studying the links between diet and the human microbiome is growing. Previous research in this field had turned up tantalizing evidence that eating fiber can alter the composition of gut bacteria. But these studies had looked at diets over long periods of times — months and even years. David and his colleagues wanted to know whether fiber — or lack of it — could alter gut bacteria more rapidly. To figure that out, the researchers got nine volunteers to go on two extreme diets for five days each. The first diet was all about meat and cheese. "Breakfast was eggs and bacon," David says. "Lunch was ribs and briskets, and then for dinner, it was salami and prosciutto with an assortment of cheeses. The volunteers had pork rinds for snacks." Then, after a break, the nine volunteers began a second, fiber-rich diet at the other end of the spectrum: It all came from plants. "Breakfast was granola cereal," David says. "For lunch, it was jasmine rice, cooked onions, tomatoes, squash, garlic, peas and lentils." Dinner looked similar, and the volunteers could snack on bananas and mangoes. "The animal-based diet is admittedly a little extreme," he says. "But the plant-based diet is one you might find in a developing country." David and the team analyzed the volunteers' microbiomes before, during and after each diet. And the effects of all that meat and cheese were immediately apparent. "The relative abundance of various bacteria species looked like it shifted within a day after the food hit the gut," David says. After the volunteers had spent about three days on each diet, the bacteria in the gut even started to change their behavior. "The kind of genes turned on in the microbes changed in both diets," he says. In particular, microbes that "love bile" — the Bilophila — started to dominate the volunteers' guts during the animal-based diet. Bile helps the stomach digest fats. So people make more bile when their diet is rich in meat and dairy fats. A study last year found that blooms of Bilophila cause inflammation and colitis in mice. "But we didn't measure levels of inflammation in our subjects," David says. "That's the next step."

Though the above study was carried out with a very small number of subjects, the significance of its findings cannot be belittled. It is a dire warning from these little creatures who live within us not to take them light and convey a message that co-existence means satisfying their needs also. If your gut microbiome profile is sound, your health also will be sound! Probably the carnivorous community may see red in this study as it frowns upon eating meat regularly but even the lacto vegetarians are forewarned that too much intake of dairy products at the expense of fiber rich plant foods can be disadvantageous. Only further studies by multiple agencies on the lines done under this limited trials can only dispel any lingering doubts about the help by our "friends" in our guts. 


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