Tuesday, November 25, 2014

The mysterious Bilophila wadsworthia -A gut bug with monstrous potential to damage health of excessive meat eaters!

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. 

Dietary fiber which is considered a "glamorous" ingredient in human diet is undigested by the metabolic system in human intestine and therefore not considered a nutrient in the true sense. But their role in promoting the growth of microbiota in intestine is universally recognized because many bacteria residing in the gastrointestinal (GI) tract are beneficial for improved health in many ways. Imagine how crowded is our intestine when it is found that more than 500 species of bacteria have settled down there with a 100 trillion cell count, almost 10 times more than human cells! As it is a question of co-existence between man and his intestinal crowd, latter must also receive appropriate foods in sufficient quantities to nourish and prosper. Since all food ingredients except fiber is digested by the powerful digesting enzymes in the GI tract, gut microbes depend largely on fiber, semi digested and undigested food that slip into the large intestine. Hence the importance of dietary fiber in human system.  

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 of a person while in the long term such changes can be significantly injurious to the health. The major difference in the diets of carnivores, omnivores and herbivores can be attributed to the fiber content in the food they eat. While carnivores depend mostly on animal foods containing practically no fiber, omnivores take a mixed diet containing animal and plant foods. It is the herbivores who consume mostly plant based foods and materials like whole food grains and fruits and vegetables are rich in fiber, both soluble as well as insoluble types which are now being eulogized for their health supporting role in human lives. Microbiota works on these fiber components when they reach the large intestine and act on them to generate a host of metabolites including acetates, propionates and butyrates, short chain fatty acids which are implicated in many beneficiary action supporting good health.  

We are presently on the threshold of a major discovery about the importance the foods we eat and how such decisions can bring about dramatic changes in the microbiota in the GI. It is becoming increasingly clear that these tiny creatures have lot to do in influencing our body weight, immunity and behavior. Interest on studying the links between diet and the human microbiome appears to be growing. In a more recent study scientists tested the effect of two extreme diets, one overwhelmingly based on meat and cheese while the other one based on plant based food and it became apparent that the bacteria in the gut showed contrasting changes within 2-3 days. Microbes that belonging to the Bilophila species started to dominate the guts of the carnivores and this species can influence the inflammation level dramatically in the intestine. Earlier another study last year had confirmed that blooms of Bilophila in the gut can cause cause inflammation and colitis in experiments with animals. However no data is available regarding the levels of inflammation caused in the above study. 

Bilophila wadsworthia, the most conspicuous from this species is an anaerobic, gram negative, rod shaped bacteria which is present to the extent of 0.01% in the gut microbiota of a normal person. This appears to have the ability to ferment under appropriate conditions substrates like bile, mostly from the meat and similar animal derived foods and produce hydrogen sulphide prolifically. They are slow to grow unless very favorable conditions are obtained and adhere to human cells waiting for an opportune time to bloom. Increased numbers of this microbe have been found in clinical samples of persons affected by diseases like sepsis, liver abscesses, cholecystitis, empyema, osteomyelitis, etc. Gut disorders like Intestinal Bowl Syndrome (IBS) and Crohn's disease are also suspected to be associated with this microorganism. With such abundance of insight into this unique bacteria further studies are bound to be undertaken for expanding our present knowledge about the role played by gut bacteria in human health.

This Blog does not wish to deprecate those consuming meat but only wants to caution them regarding excessive eating and probably suggesting that they need to balance their diet by including more and more and more fiber rich foods like whole food grains, fruits, and vegetables. Same applies to vegetarian consumers with tendency to gorge on cheese and paneer who have to exercise some moderation on these tasty foods. As further studies are bound to follow a clear picture will emerge only when there is a unanimity on the findings and conclusions presented in this Blog piece. 


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