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. 

V.H.POTTY

http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

  

RESISTANT STARCH-THE NEW LEAN BODY "MASCOT"!

Starch in foods contribute a major portion of calories in human diets and most of the population in the world depend on rice, wheat, and other cereals as their staple diet. Almost all cereals contain high levels of starch and normal starch, when digested in the gastrointestinal tract, yields readily utilizable glucose which is absorbed across the intestinal wall for serving as energy source for the living cells. It is only during the last 3-4 decades that sugar and other non-starch carbohydrates have become major sources of energy because of the predominance of industrially processed food products in the daily diet. The modern weight watching community has invariably targeted the starch in their attempts to cut down weight and they may be right in so far as all products from the industry contain refined starch ingredients devoid of the innate nutrients like germ, bran and others. But all starches do not deserve to be condemned and the importance of resistant starch, a form of starch molecules different in physical structure from the conventional ones, can be extremely healthy for humans as being brought out by many studies.

Many consumers may be unaware of the existence of resistant starch which is present in almost all foods one consumes to varying extent. The name is derived from the fact that it resists digestion in the small intestine and ends up in the large intestine for doing its good work. Many nutritional experts believe that resistant starch should be considered as the third form of dietary fiber, the other two being soluble and insoluble fibers. It is generally agreed that there are four different types of resistant starches, all capable of functioning as dietary fiber with varying efficiency. Starch that cannot be accessed physically from the sources like seeds, legumes and whole grains constitutes the first category known as RS1 while starch present in uncooked materials like uncooked potato, raw green banana flour and high amylose corn comes under RS2. During cooking or processing resistant starch is generated like in cooked legumes, baked bread, corn flakes and others, known as RS3 while chemically modified starches like etherized, esterified and cross bonded starches, not occurring in nature constitute the RS4 category.

In nature resistant starch occurs at varying levels in foods like cooked Navy beans ( 10 gm per half cup), raw banana (5 gm per one fruit), cold potato ( 3 gm per half inch diameter sample), cooked lentils (2.5 gm per half cup), cold pasta (2 gm per cup), pearled barley (1.5 gm per half cup) and in smaller amounts in many others. One of the beneficial attributes of these starches is that they help the friendly microbes in the large intestine to grow and produce the much needed short chain fatty acids including butyrates in abundance which are implicated in healthy growth of colon cells, acting as anti-inflammatory and anti-carcinogenic agents, abetting better absorption of Calcium and Magnesium, reducing cholesterol build up, over all reducing the intestinal pH and generation of potentially harmful secondary bile acids, ammonia and phenols.

The foods which are rich in resistant starch seems to have a role in aiding digestion since they provide fuel for bacteria in the colon that aid the process. Resistant starch has become a focal area of interest lately because they have been recognized by global agencies like the Food and Agricultural Organization (FAO) and World Health Organization (WHO). Some researchers even claim that resistant starch is able to cause shrinkage of fat cells in the human body, simultaneously increasing the muscle mass. According to the findings by scientists from University of Colorado based on a massive study those who consumed most of their carbohydrates from whole grains, fruits and vegetables were slim while others who ate the least carbohydrates tended to over-weight. If WHO findings are true, resistant starch may be the future "weight buster" and "Health Mascot" as it promotes satiety while decreasing the cravings for energy- and fat-rich foods.

V.H.POTTY

http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

POLYDEXTROSE-A DESIRABLE FOOD ADDITIVE?

The importance of fiber in the diet for maintaining good health has been recognized world over by now. Like water, fiber cannot be strictly classified as a nutrient essential for growth but while water is essential for the very survival, fiber consumption can dramatically influence the quality of life in many ways. The modern "mantra" about consuming whole grains, fruits, vegetables and nuts is based on the indisputable fact that they are rich sources of fiber. A daily intake of 25 gm for an adult is accepted in many parts of the world as essential for normal health..

The euphoria about dietary fiber has spawned many new businesses and there are thousands of products now available in the market claiming to be rich in dietary fiber that can control cholesterol, CVD, diabetes, hypertension and gastrointestinal afflictions. By far strongest evidence has come for the role of dietary fiber in reducing significantly the serum cholesterol level. The role of fiber in maintaining a healthy gut system and generating some nutrients like essential fatty acids are also well documented. Fiber contained in oat bran, whole wheat, beans, prunes and many plant foods are recognized as most effective in obtaining many of the benefits attributed to it.

Though there is distinct difference between soluble and insoluble fibers, both are required for good health. Recent differentiation between dietary fiber and functional fiber was necessary because of the tendency on the part of the industry to use some natural and others man-made substances in product formulations exhibiting some of the benefits of naturally occurring fiber sources. Two important sources of functional fiber are Polydextrose and Inulin,used widely by the food industry for boosting fiber content in processed foods. Polydextrose is made by vacuum melting of glucose with Sorbitol and citric acid resulting in a 3-dimensional structured molecule which resists action of gut enzymes that hydrolyzes starch and other carbohydrates. It is claimed as a soluble form of dietary fiber though every one does not agree that it is a true dietary fiber.

Polydextrose is water-soluble and is used in many beverages with a few advantages. It has a neutral, fresh taste, high solubility and good stability at a wide range of pH conditions. It is also stable at reasonably high temperature conditions without getting hydrolyzed easily. A solution of Polydextrose is clear and transparent in appearance with medium viscosity. Recently reports from China indicate that Polydextrose is an excellent additive for tea to modify the flavor and mouth feel liked by consumers besides contributing to higher levels of functional fiber. The low caloric value of only 1 kC per gm is an advantage while using in formulations with calorie restriction. The relatively low Glycemic Index, less than 7, makes it ideal for diabetic food formulations. Specialty foods incorporating sugar substitutes like aspartame need bulking agent or a carrier with least calorie content and Polydextrose fits into this role admirably.

With an E number of 1200, Polydextrose is widely used in many products where features like low caloric density, increased fiber level and reduced fat content are desired. Such products include beverages, cakes, candies, dessert mixes, breakfast cereals, frozen desserts, puddings, salad dressings etc. Being a humectant, stabilizer, thickening agent and a proven pre-biotic substance, Polydextrose offers opportunities for creating new foods with more diverse sensory characteristics. A few side effects attributed to this food additive include abdominal cramps, bloating of stomach and excessive generation of gas. Consumption of Polydextrose up to 90 gm a day does not cause laxative effect while other pollyols exerts such effects at levels less than 20 gm. Though it is proved to be safe for human consumption, having shown no deleterious effect so far by any scientific studies and approved for universal use as a food additive since 1981, considering that it is a synthetic product created out of chemical reaction, its use should preferably be restricted to specialty foods targeted at over weight, diabetic and diet conscious consumers.

V.H.POTTY

http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

THE 'NON- NUTRITIONA'L NUTRIENTS! THEIR IMPORTANCE

Water and dietary fiber( DF) are two components in any healthy diet and both of them are considered non-nutrients from conventional considerations. While water is absorbed by the body since it is the medium for all metabolic reactions, DF is not digested by the GI enzymes, contributing neither calorie nor any other major nutrient. Still both of them need to be present in food for normal health. From a relatively obscure position in the proximate composition tables, food fibers have captured center stage attention within a matter of two decades because of their sterling role in protecting human health. Most of the DF are non-starch polysaccharides(NSP) and are part of plant kingdom. Humans do not possess the necessary enzyme system to break them into sugar and therefore they pass through the GI tract without much change except for microbial action. If they do not have any metabolic role in human body why are they considered essential for good health?

By definition a fiber is a class of materials which are continuous filaments or indiscreet elongated pieces. Natural fibers hold tissues together in plants and animals. There can be vegetable fibers based on an arrangement of cellulose and lignin like cotton, hemp, jute, flax, sisal etc. Wood fibers are from tree sources which are delignified to make paper. Animal fibers include silk, wool and furs which are proteinacious in nature. Mineral fibers like asbestos, fiber glass etc are of industrial importance. Man made fibers are based on petrochemicals like polymers or cellulose based like rayon. Though the plant based fibers that are edible go through the GI tract without digestion, they can be acted upon by the gut microbes through fermentation, often producing nutrients like short chain fatty acids. DF with low fermentability include cellulose, hemicellulose, lignan, waxes and resistant starches. On the other hand beta glucans, pectin, natural gums, inulin, oligosaccharides and resistant dextrins are of high fermentability in the gut.

Potential advantages of DF include production of health promoting components during fermentation of soluble fibers and the property of of insoluble fibers to increase bulk, soften stool and shorten fecal transit time in the GI tract. A daily intake of 25 gm of DF is recommended for an adult consuming a 2000 kC diet. DF does not bind minerals or vitamins, as is assumed by many; on the other hand increased absorption of minerals has been reported when fermentable fibers are consumed. Probably phytates, not considered as a real DF do interfere with mineral absorption to some extent. Whole grains, bran from wheat and corn, nuts and seeds, lignans and vegetables are important sources of insoluble fiber while legumes like peas, soybeans, beans and others, oats ans rye, some fruits, some vegetables like broccoli, jerusalem artichokes and carrot, root vegetables like potato, plant gums like guar gum and acacia gum and psyllum seed husk contain significant levels of soluble fiber. High fiber containing foods include legumes (15-19 gm per serving), wheat bran (17gm per serving), prunes (12 gm per serving) Asian peas (10gm per serving). The exotic palmberry Acai is reported to be the richest source of DF, about 25-44% in its freeze dried version.

Importance of DF in human health has spawned a multibillion dollar industry and there are hundreds of products claiming to be rich in this 'non-nutritious' nutrient. Generally foods claiming to be high in DF must contain not less tha 5 gm per serving, between 2.5 and 4.9 gm qualifying for the 'good source' tag and at least 2.5 gm fiber to be incorporated during processing from external sources for claiming as 'more added fiber'. Such products are used to treat many disorders like hemorrhoids, diverticulosis, crohn's disease irritable bowel syndrome, abdominal discomforts etc. Proactive consumers take DF preparations to lower cholesterol levels in blood, reduce risks associated with cancers, lose weight and ensure regular bowel movement. Though modern food technology provides processing solutions for removing fiber from raw foods, it is only wise on the part of the consumer to shun regular consumption of such refined foods in the interest of his own health.

V.H.POTTY
http://vhpotty.blogspot.com/