Energy contributions of volatile fatty acids from the gastrointestinal tract in various species

1990 ◽  
Vol 70 (2) ◽  
pp. 567-590 ◽  
Author(s):  
E. N. Bergman
Keyword(s):  
Fatty Acids ◽  
Gastrointestinal Tract ◽  
Large Intestine ◽  
Volatile Fatty Acids ◽  
Animal Species ◽  
Ketone Bodies ◽  
Glucagon Secretion ◽  
Short Chain Fatty Acids ◽  
The Body ◽  
Peripheral Tissues

The VFA, also known as short-chain fatty acids, are produced in the gastrointestinal tract by microbial fermentation of carbohydrates and endogenous substrates, such as mucus. This can be of great advantage to the animal, since no digestive enzymes exist for breaking down cellulose or other complex carbohydrates. The VFA are produced in the largest amounts in herbivorous animal species and especially in the forestomach of ruminants. The VFA, however, also are produced in the lower digestive tract of humans and all animal species, and intestinal fermentation resembles that occurring in the rumen. The principal VFA in either the rumen or large intestine are acetate, propionate, and butyrate and are produced in a ratio varying from approximately 75:15:10 to 40:40:20. Absorption of VFA at their site of production is rapid, and large quantities are metabolized by the ruminal or large intestinal epithelium before reaching the portal blood. Most of the butyrate is converted to ketone bodies or CO2 by the epithelial cells, and nearly all of the remainder is removed by the liver. Propionate is similarly removed by the liver but is largely converted to glucose. Although species differences exist, acetate is used principally by peripheral tissues, especially fat and muscle. Considerable energy is obtained from VFA in herbivorous species, and far more research has been conducted on ruminants than on other species. Significant VFA, however, are now known to be produced in omnivorous species, such as pigs and humans. Current estimates are that VFA contribute approximately 70% to the caloric requirements of ruminants, such as sheep and cattle, approximately 10% for humans, and approximately 20-30% for several other omnivorous or herbivorous animals. The amount of fiber in the diet undoubtedly affects the amount of VFA produced, and thus the contribution of VFA to the energy needs of the body could become considerably greater as the dietary fiber increases. Pigs and some species of monkey most closely resemble humans, and current research should be directed toward examining the fermentation processes and VFA metabolism in those species. In addition to the energetic or nutritional contributions of VFA to the body, the VFA may indirectly influence cholesterol synthesis and even help regulate insulin or glucagon secretion. In addition, VFA production and absorption have a very significant effect on epithelial cell growth, blood flow, and the normal secretory and absorptive functions of the large intestine, cecum, and rumen. The absorption of VFA and sodium, for example, seem to be interdependent, and release of bicarbonate usually occurs during VFA absorption.(ABSTRACT TRUNCATED AT 400 WORDS)

Volatile Fatty Acids in the Gastrointestinal Tract of the Collared Peccary (Tayassu tajacu)

1989 ◽  
Vol 70 (1) ◽  
pp. 189-191 ◽  
Author(s):  
R. L. Lochmiller ◽  
E. C. Hellgren ◽  
J. F. Gallagher ◽  
L. W. Varner ◽  
W. E. Grant
Keyword(s):  
Fatty Acids ◽  
Gastrointestinal Tract ◽  
Volatile Fatty Acids ◽  
Collared Peccary ◽  
Tayassu Tajacu

Utilisation of the end products of ruminant digestion

1957 ◽  
Vol 1957 ◽  
pp. 3-15 ◽  
Author(s):  
D. G. Armstrong ◽  
K. L. Blaxter ◽  
N. McC. Graham
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Quantitative Data ◽  
Volatile Fatty Acids ◽  
Energy Requirement ◽  
The Body ◽  
Energy Requirements ◽  
Dietary Carbohydrate ◽  
Body Tissues ◽  
End Products

The work of the late Sir Joseph Barcroft and his collaborators (see Elsden & Phillipson, 1948) left little doubt that, in ruminants, the end products of the bacterial dissimilation of dietary carbohydrate included large amounts of the steam-volatile fatty acids—acetic, propionic and butyric acids. More recently, el Shazly (1952a, b) has shown that the steam-volatile fatty acids also arise together with ammonia during the bacterial breakdown of amino-acids in the rumen. Studies by Pfander & Phillipson (1953) and Schambye (1955) further indicate that the acids are absorbed from the digestive tract in amounts that suggest they make a major contribution to the energy requirement of the animal. Quantitative data relative to the amounts absorbed, however, are difficult to obtain. Carroll & Hungate (1954) have calculated that in cattle some 6,000-12,000 Cal. of energy are available from the acids produced by fermentation in the rumen. With sheep, Phillipson & Cuthbertson (1956) have calculated from the results of Schambye (1951a, b; 1955) that at least 600-1,200 Cal. of energy in the form of steam-volatile fatty acids could be absorbed every 24 hrs. Since the fasting heat production of the steer is about 6,500 Cal./24 hrs. and that of the sheep about 1,100 Cal./24 hrs. it is clear that if the fatty acids can be utilised efficiently by the body tissues, they could make a major contribution to the energy requirements, at least those for maintenance.

scholarly journals INDIGENOUS, NORMAL, AND AUTOCHTHONOUS FLORA OF THE GASTROINTESTINAL TRACT

1965 ◽  
Vol 122 (1) ◽  
pp. 67-76 ◽  
Author(s):  
René Dubos ◽  
Russell W. Schaedler ◽  
Richard Costello ◽  
Philippe Hoet
Keyword(s):  
Gastrointestinal Tract ◽  
Large Intestine ◽  
Animal Species ◽  
Healthy Adult ◽  
Bacterial Species ◽  
Bacterial Flora ◽  
Evolutionary Development ◽  
Adult Mice ◽  
Large Numbers ◽  
Characteristic Localization

The bacterial flora of the gastrointestinal tract differs qualitatively and quantitatively from one colony of mice to another. Certain components of this flora, however, are always present in large and approximately constant numbers in healthy adult mice, irrespective of the colony from which the animals are derived. Lactobacilli and anaerobic streptococci are extremely numerous in the stomach, the small intestine, and the large intestine. In contrast, organisms of the bacteroides group proliferate only in the large intestine. These three bacterial species persist at approximately constant levels in their characteristic localization throughout the life span of healthy animals. They are closely associated with the walls of the digestive organs, and are probably concentrated in the mucous layer. A few experiments carried out with rats and young swine indicate that lactobacilli are also present in large numbers in the stomach of these animal species. It is suggested that some of the components of the gastrointestinal flora have become symbiotic with their hosts in the course of evolutionary development and thus constitute a true autochthonous flora. The other components of the indigenous flora are acquired early in life either through accidental contact or because they are ubiquitous in the environment. The "normal" flora is that which is always present in the environment of the animal colony under consideration.

scholarly journals Rates of ketone-body formation in the perfused rat liver

1969 ◽  
Vol 112 (5) ◽  
pp. 595-600 ◽  
Author(s):  
H. A. Krebs ◽  
Patricia G. Wallace ◽  
R. Hems ◽  
R. A. Freedland
Keyword(s):  
Fatty Acids ◽  
Rat Liver ◽  
Ketone Bodies ◽  
Short Chain Fatty Acids ◽  
Diabetic Rats ◽  
Isolated Perfused Rat Liver ◽  
Perfused Liver ◽  
Perfused Rat Liver ◽  
Normal Range ◽  
Physiological Value

1. The rates of formation of acetoacetate and β-hydroxybutyrate by the isolated perfused rat liver were measured under various conditions. 2. The rates found after addition of butyrate, octanoate, oleate and linoleate were about 100μmoles/hr./g. wet wt. in the liver of starved rats. These rates are much higher than those found with rat liver slices. 3. The differences between the rates given by slices and by the perfused organ were much higher with the long-chain than with short-chain fatty acids. The increments caused by oleate and linoleate were 12 and 16 times as large in the perfused organ as in the slices, whereas the increments caused by butyrate and octanoate were about four times as large. 4. The rates of ketogenesis in the unsupplemented perfused liver of well-fed rats, and the increments caused by the addition of fatty acids, were about half of those in the liver from starved rats. 5. The value of the [β-hydroxybutyrate]/[acetoacetate] ratio of the medium was raised by octanoate, oleate and linoleate. 6. Carnitine did not significantly accelerate ketogenesis from fatty acids. 7. Oleate formed up to 82% of the expected yield of ketone bodies. 8. In the liver of alloxan-diabetic rats the endogenous rates of ketogenesis were raised, in some cases as high as in the liver from starved rats, after addition of oleate. 9. On addition of either β-hydroxybutyrate or acetoacetate to the perfusion medium the liver gradually adjusted the [β-hydroxybutyrate]/[acetoacetate] ratio towards the normal range. 10. The [β-hydroxybutyrate]/[acetoacetate] ratio of the medium was about 0·4 when slices were incubated, but near the physiological value of 2 when the liver was perfused. 11. The experiments demonstrate that for the study of ketogenesis slices are in many ways grossly inferior to the perfused liver.

Responses in milk yield and composition to the inclusion of ammonium salts of short-chain fatty acids in the drinking water of dairy cows

1970 ◽  
Vol 12 (3) ◽  
pp. 503-512 ◽  
Author(s):  
P. Jackson ◽  
J. A. F. Rook
Keyword(s):  
Fatty Acids ◽  
Drinking Water ◽  
Milk Yield ◽  
Volatile Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Rumen Ph ◽  
Long Term Experiment ◽  
Jersey Cows ◽  
Friesian Cows

SUMMARYThe effect of introducing a solution of fatty acids (consisting mainly of ammonium acetate) into the drinking water of Jersey and Friesian cows on the yield and composition of milk was investigated. In short-term experiments there were small increases in milk yield and in the yield of fat in Jersey cows receiving either a high-roughage or a high-concentrate diet and in Friesian cows receiving a high-concentrate diet. Friesian cows receiving a high-roughage diet gave no response. In a long-term experiment extending over 16 weeks of lactation with Jersey cows receiving a high-concentrate diet, there was no immediate effect on milk yield but a greater persistency and overall the yield of fat was increased by 5·9%.Inclusion of ammonia salts in the drinking water caused increases in the ammonia contents of rumen liquor and of blood but there was little effect on rumen pH or the volatile fatty acids of rumen liquor.

Nutritional Consequences of Large Intestinal Function in Health

1983 ◽  
Vol 2 (2) ◽  
pp. 111-114
Author(s):  
N. Ian McNeil
Keyword(s):  
Fatty Acids ◽  
Large Intestine ◽  
Fat Metabolism ◽  
Oral Intake ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Energy Requirements ◽  
Intestinal Function ◽  
Daily Oral Intake

The nutritional contribution of human colonic function has been poorly appreciated. As well as absorbing the equivalent of a daily oral intake of sodium and water, other minerals can be absorbed. Up to 10% of energy requirements may come from carbohydrate entering the colon, fermentation to short chain fatty acids that are absorbed being intermediate steps. The role of the large intestine in nitrogen and fat metabolism is unknown, as is its contribution to vitamin supplies.

scholarly journals Utilization of14C-labelledBacillus subtilisandEscherichia coliby sheep

1970 ◽  
Vol 24 (1) ◽  
pp. 129-144 ◽  
Author(s):  
N. J. Hoogenraad ◽  
F. J. R. Hird ◽  
R. G. White ◽  
R. A. Leng
Keyword(s):  
Escherichia Coli ◽  
Carbon Dioxide ◽  
Fatty Acids ◽  
Cell Walls ◽  
Volatile Fatty Acids ◽  
The Body ◽  
Air Plasma ◽  
Whole Cells ◽  
Total Glucose ◽  
Bacterial Preparations

1.Bacillus subtilisandEscherichia coliwere grown on14C-labelled glucose and used for the preparation of labelled whole cells, cell walls, cell contents and peptidoglycan.2. The radioactive samples were injected into the abomasum of sheep and the14C appearing in expired air, plasma glucose, urine and faeces was determined. Whole cells were also injected into the rumen and the incorporation of14C into volatile fatty acids was measured.3. All the bacterial preparations, including cell walls, were extensively digested and absorbed, Less than 15% of the radioactivity was recovered in the faeces.4. Up to 20% of the radioactivity injected was recovered in expired carbon dioxide with only 2.4–8.1% passing through the glucose pool.5. It has been calculated that under the conditions of the experiment 18.5 % of the total glucose entering the body pool of glucose in 24 h was derived from bacterial carbon.

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