Changes

A number of animal factors impact carbohydrate digestion. These include '''age related changes in enzyme activities''' as well as '''inherent species differences in metabolic pathways'''. Lactase activity is highest in puppies and kittens and decreases with age<ref>Kienzle E. (1993)''' Carbohydrate metabolism in the cat. 4. Activity of maltase, isomaltase, sucrose, and lactase in the gastrointestinal tract in relation to age and diet.''''' JAPAN'' 1993;70:89-96.</ref><ref>Buddington RK, ''et al.'' (2003)''' Activities of gastric, pancreatic, and intestinal brush-border membrane enzymes during postnatal development of dogs. '''''AJVR '' 2003;64:627-634.</ref>. In contrast, pancreatic amylase activity increases with age. Low fructokinse activity in cats means they can develop galactosuria or fructosuria if given these monosaccharides.<ref>Kienzle E. (1994)''' Blood sugar levels and renal sugar excretion after the intake of high carbohydrate diets in cats.''''' J Nut'' 1994;124:2563S-2567S.</ref> Overall carbohydrate [[Nutrition Glossary#Digestibility|digestibility]] decreases with age in otherwise healthy dogs and cats.<ref>Strasser A, ''et al.'' (1993)''' The effect of aging on laboratory values in dogs.''''' J Vet Med'' 1993;A40:720-730.</ref><ref>Burkholder WJ. (1999) '''Age-related changes to nutritional requirements and digestive function in adult dogs and cats. '''''Vet Med Today'' 1999:215:625-629.</ref>

A number of animal factors impact carbohydrate digestion. These include '''age related changes in enzyme activities''' as well as '''inherent species differences in metabolic pathways'''. Lactase activity is highest in puppies and kittens and decreases with age<ref>Kienzle E. (1993)''' Carbohydrate metabolism in the cat. 4. Activity of maltase, isomaltase, sucrose, and lactase in the gastrointestinal tract in relation to age and diet.''''' JAPAN'' 1993;70:89-96.</ref><ref>Buddington RK, ''et al.'' (2003)''' Activities of gastric, pancreatic, and intestinal brush-border membrane enzymes during postnatal development of dogs. '''''AJVR '' 2003;64:627-634.</ref>. In contrast, pancreatic amylase activity increases with age. Low fructokinse activity in cats means they can develop galactosuria or fructosuria if given these monosaccharides.<ref>Kienzle E. (1994)''' Blood sugar levels and renal sugar excretion after the intake of high carbohydrate diets in cats.''''' J Nut'' 1994;124:2563S-2567S.</ref> Overall carbohydrate [[Nutrition Glossary#Digestibility|digestibility]] decreases with age in otherwise healthy dogs and cats.<ref>Strasser A, ''et al.'' (1993)''' The effect of aging on laboratory values in dogs.''''' J Vet Med'' 1993;A40:720-730.</ref><ref>Burkholder WJ. (1999) '''Age-related changes to nutritional requirements and digestive function in adult dogs and cats. '''''Vet Med Today'' 1999:215:625-629.</ref>

In both dogs and cats, starch digestibility is also affected by the source and type of carbohydrate present<ref>Bach-Knudsen KE and Hansen I. (1991)''' Gastrointestinal implication in pigs of wheat fractions. I. Digestibility and bulking properties of polysaccharides and other major constituents.''''' Br J Nutr ''1991;65:217-232.</ref> as well as the degree of processing of the carbohydrate.<ref>Camire ME, ''et al.'' (1990)''' Chemical and nutrition changes in food during extrusion. '''''Food Sci Nutr'' 1990;29:35-57.</ref><ref>Marsaman GJ, ''et al.'' (1997)''' The in vitro accessibility of untreated, toasted, and untoasted soybean meals for proteases and carbohydrases.''''' J Ag Food Chem ''1997;45:4088-4095.</ref> The type and amount of non-absorbable carbohydrate (i.e. [[Fibre - Nutrition|fibre]]) present in the diet will also influence the post-prandial glycaemic response in both dog and cats. The presence of high soluble, fermentable fibre content in the diet will slow carbohydrate digestion and absorption resulting in dampened post-prandial blood glucose in both healthy<ref>Muir HE, ''et al.'' (1996)''' Nutrient digestion by ileal cannulated dogs as affected by dietary fiber with various fermentation characteristics. '''''J Anim Sci ''1996;74:1641-1648.</ref><ref>Nguyen P, ''et al.'' (1998)''' Glycemic and insulinemic response after ingestion of commercial foods in healthy dogs: Influence of food composition. '''''J Nutr'' 1998;128:2654S-2658S.</ref> and diabetic animals.<ref>Nelson RW. (1989)''' The role of fiber in managing diabetes mellitus. '''''Vet Med ''1989;84:1156-1160.</ref><ref>Nelson RW, ''et al''. (2000)''' Effect of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus.''''' JAVMA ''2000;216:1082-1088.</ref> Ground, cooked and extruded starches are almost 100% digestible in both dogs and cats,<ref name="Morris" /><ref name="Hilton" /><ref>Murray SM, ''et al. '' (1999) '''Evaluation of selected high-starch flours as ingredients in canine diets. '''''J Anim Sci'' 1999;77:2180-2186.</ref><ref>Kendall PT and Holme DW. (1982) '''Studies on the digestibility of soybean products, cereals, cereal and plant-based products in the diets of dogs. '''''J Sci Food Agric ''1982;33:813-822.</ref> while digestibility of raw (uncooked) starches varies from 0-65% depending on type of starch. Resistant starches are formed when solubilised dietary starch recrystallize upon cooling forming a structure that is resistant to pancreatic amylase.<ref>Berry SC. (1986) '''Resistant starch: Formation and measurement of starch that survives exhaustive digestion with amylolytic enzymes during determination of dietary fiber. '''''J Cereal Sci'' 1986;4:301-304.</ref> Undigested starches and resistant starch can then be fermented by intestinal bacteria,<ref>Rerat A, ''et al.'' (1978)''' Digestion and absorption of carbohydrates and nitrogenous matters in the hindgut of omnivorous nonruminant animals.''''' J Anim Sci ''1978;46:1808-1837.</ref><ref>Washabau RJ, ''et al.'' (1986)''' Evaluation of intestinal carbohydrate malabsorption by pulmonary hydrogen gas excretion. '''''AJVR ''1986;47:1402-1406.</ref><ref>Muir P,'' et al.'' (1991)''' Evaluation of carbohydrate malassimilation and intestinal transit time in cats by measurement of breath hydrogen excretion. '''''AJVR'' 1991;52:1104-1109.</ref> which may contribute to [[Antibiotic Responsive Diarrhoea#Clinical Signs|clinical signs of bacterial overgrowth]]. Maldigestion and malabsorption of dietary starch are believed to be a feature of [[Inflammatory Bowel Disease|inflammatory bowel disease]].<ref>Ugarte C, ''et al''. (2004) '''Carbohydrate malabsorption is a feature of feline inflammatory bowel disease but does not increase clinical gastrointestinal signs. '''''J Nutr ''2004;134:2068S–2071S.</ref>

In both dogs and cats, starch digestibility is also affected by the source and type of carbohydrate present<ref>Bach-Knudsen KE and Hansen I. (1991)''' Gastrointestinal implication in pigs of wheat fractions. I. Digestibility and bulking properties of polysaccharides and other major constituents.''''' Br J Nutr ''1991;65:217-232.</ref> as well as the degree of processing of the carbohydrate.<ref>Camire ME, ''et al.'' (1990)''' Chemical and nutrition changes in food during extrusion. '''''Food Sci Nutr'' 1990;29:35-57.</ref><ref>Marsaman GJ, ''et al.'' (1997)''' The in vitro accessibility of untreated, toasted, and untoasted soybean meals for proteases and carbohydrases.''''' J Ag Food Chem ''1997;45:4088-4095.</ref> The type and amount of non-absorbable carbohydrate (i.e. [[Fibre - Nutrition|fibre]]) present in the diet will also influence the post-prandial [[Nutrition Glossary#Glycaemic Response|glycaemic response]] in both dog and cats. The presence of high soluble, fermentable fibre content in the diet will slow carbohydrate digestion and absorption resulting in dampened post-prandial blood glucose in both healthy<ref>Muir HE, ''et al.'' (1996)''' Nutrient digestion by ileal cannulated dogs as affected by dietary fiber with various fermentation characteristics. '''''J Anim Sci ''1996;74:1641-1648.</ref><ref>Nguyen P, ''et al.'' (1998)''' Glycemic and insulinemic response after ingestion of commercial foods in healthy dogs: Influence of food composition. '''''J Nutr'' 1998;128:2654S-2658S.</ref> and diabetic animals.<ref>Nelson RW. (1989)''' The role of fiber in managing diabetes mellitus. '''''Vet Med ''1989;84:1156-1160.</ref><ref>Nelson RW, ''et al''. (2000)''' Effect of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus.''''' JAVMA ''2000;216:1082-1088.</ref> Ground, cooked and extruded starches are almost 100% digestible in both dogs and cats,<ref name="Morris" /><ref name="Hilton" /><ref>Murray SM, ''et al. '' (1999) '''Evaluation of selected high-starch flours as ingredients in canine diets. '''''J Anim Sci'' 1999;77:2180-2186.</ref><ref>Kendall PT and Holme DW. (1982) '''Studies on the digestibility of soybean products, cereals, cereal and plant-based products in the diets of dogs. '''''J Sci Food Agric ''1982;33:813-822.</ref> while digestibility of raw (uncooked) starches varies from 0-65% depending on type of starch. Resistant starches are formed when solubilised dietary starch recrystallize upon cooling forming a structure that is resistant to pancreatic amylase.<ref>Berry SC. (1986) '''Resistant starch: Formation and measurement of starch that survives exhaustive digestion with amylolytic enzymes during determination of dietary fiber. '''''J Cereal Sci'' 1986;4:301-304.</ref> Undigested starches and resistant starch can then be fermented by intestinal bacteria,<ref>Rerat A, ''et al.'' (1978)''' Digestion and absorption of carbohydrates and nitrogenous matters in the hindgut of omnivorous nonruminant animals.''''' J Anim Sci ''1978;46:1808-1837.</ref><ref>Washabau RJ, ''et al.'' (1986)''' Evaluation of intestinal carbohydrate malabsorption by pulmonary hydrogen gas excretion. '''''AJVR ''1986;47:1402-1406.</ref><ref>Muir P,'' et al.'' (1991)''' Evaluation of carbohydrate malassimilation and intestinal transit time in cats by measurement of breath hydrogen excretion. '''''AJVR'' 1991;52:1104-1109.</ref> which may contribute to [[Antibiotic Responsive Diarrhoea#Clinical Signs|clinical signs of bacterial overgrowth]]. Maldigestion and malabsorption of dietary starch are believed to be a feature of [[Inflammatory Bowel Disease|inflammatory bowel disease]].<ref>Ugarte C, ''et al''. (2004) '''Carbohydrate malabsorption is a feature of feline inflammatory bowel disease but does not increase clinical gastrointestinal signs. '''''J Nutr ''2004;134:2068S–2071S.</ref>

==References==

==References==