For example, metagenomic analyses have identified more than 700 candidate glucohydrolase genes of bacterial origin in the hindgut paunch of Nasutitermes termites, most of which have predicted capacity to degrade cellulose and xylans (462), and a remarkable 27,755 putative carbohydrate-active genes have been detected in the metagenome of the cow rumen contents, most of which are bacterial in origin, have less than 75% sequence identity with previously described genes, and many of which are likely active against cellulose (210). Starck JM, Beese K. Structural flexibility of the intestine of Burmese python in response to feeding. Fish amylases and glucose transporters appear to be molecularly closely related to those in mammals and to have comparable characteristics (165, 269). Posthatch changes in SI activity also seemed correlated with changes in SI mRNA, suggesting that SI expression is transcriptionally controlled (446). In addition, preexisting pools of transporter proteins, probably localized in the cytosol, are likely localized to the membrane; this can achieve more rapid changes in transporter activity than changes in gene expression. Postnatal ontogeny of intestinal GCPII and the RFC in pig. Canavoso LE, Jouni ZE, Karnas KJ, Pennington JE, Wells MA. Shiraga T, Miyamoto K, Tanaka H, Yamamoto H, Taketani Y, Morita K, Tamai I, Tsuji A, Takeda E. Cellular and molecular mechanisms of dietary regulation on rat intestinal H+/Peptide transporter PepT1. Development of digestive enzymes in common dentex. McWhorter TJ, Green AK, Karasov WH. As the name suggests, this system is responsible for circulating blood and nutrients throughout the body. Human Anatomy and . Eisert R. Hypercarnivory and the brain: Protein requirements of cats reconsidered. For example, locusts Locusta migratoria feeding on diets with excess protein or carbohydrate display reduced activity of digestive -chymotrypsin and -amylase, respectively (93) (Fig. A genomic view of the human-Bacteroides thetaiotaomicron symbiosis. In Drosophila, the activity of amylase in the midgut is significantly higher in larvae feeding on starch diets than sugar diets, and the 5 cis-regulatory region that regulates gene expression of the amylase genes has been identified (226). Evolutionary structural and functional conservation of an ortholog of the GLUT2 glucose transporter gene (SLC2A2) in zebrafish. Transport across the basolateral membrane is also mediated by amino acid exchange, for example, y+L for efflux of cationic amino acids, or by facilitative diffusion, for example, transporters of the L and T system for efflux of neutral and aromatic amino acids, respectively. Secondary metabolites (SMs) are compounds produced and/or sequestered by plants and animals that do not appear to play a major role in their primary nutritional or regulatory metabolism. (307) provide a recent review of impacts of polyphenolics on intestinal absorption of organic cations, thiamin, folic acid, and glucose. Dyer J, Al-Rammahi M, Waterfall L, Salmon KS, Geor RJ, Boure L, Edwards GB, Proudman CJ, Shirazi-Beechey SP. Apparent transcription control of SP activity was also demonstrated in the scarabaeid beetle Costelytra zealandica (306). Each bar represents the mean of three independent repeats of the experiment. Lowry JB, McSweeney CS, Palmer B. Developmental regulation of a turkey intestinal peptide transporter (PepT1). Which animal has strongest digestive system? Krogdahl A, Hemre GI, Mommsen TP. There are four basic types of digestive systems: monogastric, avian, rumi- nant, and pseudo-ruminant. Diacylglycerol generated by PLC2, together with the high Ca2+, activates PKCII, permitting the insertion of GLUT2 into the apical membrane and the resultant high capacity uptake of glucose and fructose. In most mammals lactase activity is high at birth and declines sharply around weaning. Evolution and adaptive significance of larval midgut alkalinization in the insect superorder Mecopterida. Skopec and Karasov (408) predicted that phloridzin would inhibit glucose absorption at the whole animal level when administered at ecological concentrations (they used 10 mmol/L), and that the effects would be more pronounced in nonflying mammals that rely on mediated pathway(s) for glucose absorption than birds that rely more on a nonmediated, paracellular pathway. Manichanh C, Reeder J, Gibert P, Varela E, Llopis M, Antolin M, Guigo R, Knight R, Guarner F. Reshaping the gut microbiome with bacterial transplantation and antibiotic intake. Usnic acid, a secondary metabolite of lichens and its effect on, Pankoke H, Bowers MD, Dobler S. Influence of iridoid glycoside containing host plants on midgut beta-glucosidase activity in a polyphagous caterpillar, Spilosoma virginica Fabricius (Arctiidae). Amino acid transporters are also expressed in the apical membrane of the insect hindgut epithelium, where they mediate the uptake of amino acids in the primary urine produced in the Malpighian tubules. Jia L, Betters JL, Yu L. Niemann-pick C1-like 1 (NPC1L1) protein in intestinal and hepatic cholesterol transport. (B-D) Mean utilization efficiencies for animals in different taxa eating different types of food. The stomach has complex glandsin its wall. 2). Fat metabolism in insects. Brzek P, Kohl KD, Caviedes-Vidal E, Karasov WH. Modeling has also contributed to understanding impacts of temperature change (297, 474) that could improve predictions of animal responses to climate change (13). A core gut microbiome in obese and lean twins. Under conditions of high luminal glucose content, however, GLUT2 in rodents is inserted into the apical membrane, where it mediates the high flux of glucose into the enterocyte (254). Cellulase (cellulose is hydrolyzed by the concerted action of three types of cellulases: endocellulases, exocellulases, and -glucosidases). Developmental adjustments of house sparrow (. Another set of phenolics, catechins, which are monomeric flavanols, are reported to inhibit cholesterol absorption, perhaps by reducing micellar solubility and precipitating cholesterol (222), and they are reported to interact with lipid bilayers (336), which could lead to alterations in transport. In that tissue, lysozyme and other bactericidal proteins called defensins are secreted by Paneth cells located at the base of intestinal crypts (367). Tiemann TT, Avila P, Ramirez G, Lascano CE, Kreuzer M, Hess HD. (248). Nevertheless, ABCG5/G8 does not function exclusively in relation to cholesterol. Absorptive capacity may be limiting in some developing animals because of scarcity of certain transporters (148). Zhang JZ, Zhang YP, Rosenberg HF. Mechanistic bases for differences in passive absorption. Nutritional development of feeding strategies in arctic ruminants: Digestive morphometry of reindeer. But, there was more to the story because some populations (e.g., in sub-Saharan Africa and Saudi Arabia) that lacked the variant T-13910 nonetheless had a high prevalence of lactose tolerance. Dietary and developmental regulation of intestinal sugar transport. Yet this multi-faceted system involves many complex interactive functions.The goal of this paper is to describe the organs involved in digestive and biological functions (Figure 1). Gut size changes in relation to variable food quality and body size in grasshoppers. The intraepithelial metabolism of SCFAs contributes to the high-energy demands of these cells. An ecological and evolutionary perspective on human-microbe mutualism and disease. Fuller RC, Baer CF, Travis J. Ontogenesis of digestive functions and nutritional requirements in marine fish larvae. Comparative utilization of phytoplankton and vascular plant detritus by the cockle Cerastoderma edule: Digestive responses during diet acclimation. Pig's teeth are 44 in number, most being molars and some incisors. Remis MJ, Dierenfeld ES. Absorbed amino acids and simple sugars are taken directly to the liver via the portal vein. Camara VM, Prieur DJ. Effect on colonic fermentation and faecal output. Sundset et al. The birds were hand-fed on either 0-starch diet (mimicking insect food), comprising 20% corn oil and 59.63% casein; or +starch containing 25.4% corn starch, 8% corn oil, and 46.23% casein designed to mimic a mixture of insects and plant (seed) material. Altmann SW, Davis HR, Jr, Zhu LJ, Yao X, Hoos LM, Tetzloff G, Iyer SP, Maguire M, Golovko A, Zeng M, Wang L, Murgolo N, Graziano MP. But, microbes potentially provide their hosts more than those energy-rich fermentation products. The microbiota breakdown cellulose and other cell-wall material relatively slowly, and if herbivores retain material in their gut for less than 4 to 8 h the extent of cell-wall digestion is relatively low. Developmental changes in glucose transport, lipid composition, and fluidity of jejunal BBM. McWhorter TJ, Caviedes-Vidal E, Karasov WH. Induction of digestive alpha-amylases in larvae of. Geurden I, Aramendi M, Zambonino-Infante J, Panserat S. Early feeding of carnivorous rainbow trout (, Ghadamyari M, Hosseininaveh V, Sharifi M. Partial biochemical characterization of alpha- and beta-glucosidases of lesser mulberry pyralid, Glyphodes pyloalis Walker (Lep. The pig in the first photograph below is laying on its dorsal side. (Diet did have a significant effect on gut size, but the effect was on cecal and large intestine size.) The coupled functions of electrogenic K+ transport and K+/amino acid uptake are mediated by different cells, presumably because the high emf generated by the goblet cells could compromise the function of the SL6 and other transporters. Composition of bacterial species at different life stages of Drosophila melanogaster. This design minimizes the competition between animal and resident microorganisms for ingested nutrients that can be processed readily by the animal. The integrated processing response in herbivorous small mammals. These advances have been especially marked in studies of changes in carbohydrases coincident with inclusion of starchy foods and milk products in the human diet. Morais S, Lacuisse M, Conceicao LEC, Dinis MT, Ronnestad I. Ontogeny of the digestive capacity of (S. Moran AW, Al-Rammahi MA, Arora DK, Batchelor DJ, Coulter EA, Ionescu C, Bravo D, Shirazi-Beechey SP. The suite of reactions responsible for the transformation of complex carbohydrates to SCFAs is mediated by consortia of multiple bacteria with complementary capabilities (156), with cross-feeding of intermediate metabolites among bacteria with different capabilities (Fig. Flint HJ, Duncan SH, Scott KP, Louis P. Interactions and competition within the microbial community of the human colon: Links between diet and health. Because birds typically achieve higher paracellular absorption with less intestinal length and surface area than do similar sized nonflying mammals, there apparently are differences in intestinal permeability per unit intestinal tissue. Active transport of 3-O-methyl-glucose by the small intestine in chronically catheterized rats. Skopec MM, Green AK, Karasov WH. Metagenomic discovery of biomass-degrading genes and genomes from cow rumen. In three precocial species [chickens (33, 348), wild jungle fowl (231), ducks (256)] tissue-specific enzyme, and transport rates were constant or declined with age but overall digestive and absorptive capacity increased, along with intestine mass, in direct proportion to metabolic body mass, which was the pattern described for mammals. The oesophageal region is located at the entrance of the stomach from the oesophagus. Among birds, examples of cytoplasm consumers would be plant cutters (genus Phytotoma) that feed almost exclusively on young leaves (with low cell-wall contents) (46) whereas hoatzins (Ophistocomus hoazin) and some species of grouse consume leaves, buds, and tips of woody twigs and may digest a lot of the cell-wall material (195). The heart of a pig is four-chambered. These compounds occur in plant foods typically as glycosides. There is evidence that some flavonoid glycosides may be transported by SGLT-1 (10, 82, 274, 459), which could potentially lead to competitive inhibition of glucose transport. Kellett GL, Brot-Laroche E, Mace OJ, Leturque A. Skin breakdown and blisters from senna-containing laxatives in young children. In vertebrates, the absorption of lipid hydrolysis products and sterols is dependent on their incorporation into micelles formed in the lumen of the small intestine. Interestingly, the Atlantic cod genome does not seem to contain colipase (386) that typically is essential for pancreatic lipase activity. Common cutworms (Spodoptera litura; Lepidoptera), a highly polyphagous pest of subtropical and tropical crops, can be used to illustrate a pattern that is probably common (488). A proportion of the SCFAs taken up is metabolized to lactate and ketonic acids (including acetoacetate and 3-hydroxybutyrate); these products are transported from the basolateral membrane of epithelial cells, probably via MCT1, to the blood. Dierenfeld ES, Hintz HF, Robertson JB, Van Soest PJ, Oftedal OT. But, another fascinating aspect of lysozymes is that they have been recruited as digestive enzymes over evolutionary time in several vertebrate and invertebrate taxa including foregut fermenting mammals and birds (248), insects (64, 166, 167, 375) and arachnids (Acari) (141). A shift from insectivory to nectarivory or frugivory (addition of plant sugars to the diet) was accompanied by a significant increase in sucrase (Fig. Other SMs directly damage GIT mucosa, such as lectins (451), proanthocyanidins (2), and hydrolysable tannins (251). Ontogenetic changes in digestive enzyme activity of the spiny lobster. This review has uncovered numerous areas for future research focused on important gaps in the comparative physiology of the GI tract. With the exception of SCFAs, these products are absorbed principally distal to the gastric region of the alimentary tract, for example, small intestine of vertebrates and midgut of insects. However, limited microbial enzymes activity does occur in the large intestine, which forms VFAs (volatile fatty acids). de Oliveira JE, Druyan S, Uni Z, Ashwell CM, Ferket PR. There is overwhelming evidence that the digestive and absorptive function of the GI tract of animals can vary with diet composition. However, the transport proteins responsible for SCFA/HCO3 exchange have yet to be identified, raising the possibility that SCFA is coupled to HCO3 via multiple transporters, for example, SCFA/H+ cotransport and Cl/HCO3 exchange (99). the crop of the cockroach Periplaneta americana, can also occur (63, 447). Chan AS, Horn MH, Dickson KA, Gawlicka A. Digestive enzyme activity in carnivores and herbivores: Comparisons among four closely related prickleback fishes (Teleostei: Stichaeidae) from a California rocky intertidal habitat. Meleshkevitch EA, Robinson M, Popova LB, Miller MM, Harvey WR, Boudko DY. A large number of studies of GI development in at least a dozen fish species have been published in the past decade (59, 67, 96, 104, 187, 191, 200, 213, 224, 225, 240, 260, 264, 269, 273, 281, 327329, 359, 481, 484, 485) due to their importance in aquaculture, and many studies include newer molecular and gene expression approaches (109, 272). Niemann-Pick C1 Like 1 protein is critical for intestinal cholesterol absorption. Regulation of the fructose transporter GLUT5 in health and disease. Ingestion of large amounts of lactose post-weaning normally results in escape of undigested lactose to the distal GI tract where it is fermented, leading to production of gases (CO2, H2, and methane) and sometimes osmotic diarrhea. Cipollini ML. You have remained in right site to begin getting this info. (C) Changes related to homeobox gene of the caudal family (cdxA): protein and mRNA from reference (405). However, modeling approaches have still guided research and enhanced understanding in some taxa that have specialized features of digestion that are not necessarily captured in the simplest reactor models. Henning (208) provides a good overview of GI development in mammals, especially in the laboratory rat, the most studied of about a dozen mammalian species that have been surveyed to date (3, 17, 49, 56, 57, 65, 134, 196, 219, 238, 263, 294, 323, 347, 362, 390, 394, 397, 433, 471, 483, 489, 490, 492). Dietary protein level and stage of development affect expression of an intestinal peptide transporter (cPepT1) in chickens. Mutualistic fermentative digestion in the gastrointestinal tract: Diversity and evolution. As a first approximation, conversion or extraction efficiency can be expressed as: Digesta retention time can be measured using inert markers fed to both vertebrates and invertebrates (248). Physiological energetics. Meissner B, Boll M, Daniel H, Baumeister R. Deletion of the intestinal peptide transporter affects insulin and TOR signaling in Caenorhabditis elegans. Likewise for digestive enzymes, it seems typical to find significant positive relationships between carbohydrases and dietary carbohydrate but not between proteases/peptidases and dietary protein, at least for fish (179), and in birds (261). In: Lawrence IG, Kostas I, Sarjeet SG, editors. Price DR, Tibbles K, Shigenobu S, Smertenko A, Russell CW, Douglas AE, Fitches E, Gatehouse AM, Gatehouse JA. They did not ascribe the difference to any major difference between rat and robin in the types of intestinal glucose transporters, because birds and mammals appear to share the similar suite of intestinal sugar transporters (292, 332). Nicotine, for example, has a MW of 162 Da, its cationic forms are water soluble, and it was found to be absorbed by the paracellular pathway in cell culture (TR146 cells) (343). Neal JJ. [Data from reference (475)]. 8A). Uldry M, Ibberson M, Hosokawa M, Thorens B. GLUT2 is a high affinity glucosamine transporter. Based on expression profiling and measures of activity, species in both groups have at hatch the full suite of enzymatic, pancreatic, and intestinal activities to digest fat, carbohydrate, and protein [e.g., references (74, 184, 186, 292, 407, 480)]. Some species (e.g., poultry and ducks) are precocial in development, possessing advanced locomotory, and thermoregulatory features at hatch compared with other species that are altricial (e.g., perching or passerine birds). Rossi GD, dos Santos CD, Cardoso MD, Correa AD, de Abreu CMP, Paiva LV. They can interact with proteins and other macromolecules in vitro through hydrogen bonding and hydrophobic bonds, and thus bind enzymes and their nutrient substrates. Sather BT. In: Halter F, Winton D, Wright NA, editors. Based on genetic patterns and analysis of Neolithic human skeletons, it seems that the ancestral human condition is lactose intolerance, but in a number of locations (i.e., cultures) humans consumption of dairy products created a strong selection pressure for evolution of genes that support digestion of lactose (8). Sodium/glucose cotransporter-1, sweet receptor, and disaccharidase expression in the intestine of the domestic dog and cat: Two species of different dietary habit. Peptidoglycan in G(+) bacterial cell walls, Terrestrial plant material (flowers, seeds, fruits, leaves, twigs), Aquatic/marine plant materials (green and brown, diatoms, seaweeds, Plant exudates (saps, resins, latexes, gums), Phenols and terpene derivatives, hemicellulose, other complex -linked polysaccharides, Increased time between defecations (slower transit? The key glucose transporters in mammals and birds (184) are a Na+/glucose cotransporter SGLT1 (a member of the Na+/solute symporter family) and the facilitative transporter GLUT2, which transports glucose, fructose, mannose, and galactose with low affinity and N-acetyl-glucosamine with high affinity (444). By contrast, peptides are taken up by a single transporter with very low selectivity, as considered at the end of this section. The site is secure. The large ontogenetic increases in glucose and fructose transport in rats can occur in the absence of any dietary signal (and are thus sometimes called hard wired), but early introduction of fructose during weaning in rats will induce earlier expression of GLUT5 mRNA, protein, and fructose transport. Guilloteau P, Zabielski R, Hammon HM, Metges CC. You can view other papers presented at Swine Profitability Conference 2009 by clicking here. Large changes occur posthatch in intestine size and digestive capacity as birds grow. The next system to go over is the integumentary system-the skin. [SGLT1 expression has not been found to be influenced by cdx in mammals (405)]. The allele that carries the T-13910 variant was subsequently found to correlate with many global populations with lactose tolerance, and a variety of functional studies have revealed some of the molecular steps by which the allele controls the expression of lactase in intestinal cells (138). The interpretation is that species in both groups absorb most glucose, but that birds relied more on the passive, paracellular route. Developmental study of a-methyl-D-glucoside and L-proline uptake in the small intestine of the White Leghorn chicken. Fully reversible phenotypic plasticity of digestive physiology in young house sparrows: Lack of long-term effect of diet composition. Is intestinal peptide transport energized by a proton gradient? Wallace RJ. Subsequent sections cover mechanisms and patterns of variation across taxa in chemical digestion by animals and their microbiota, and absorption of breakdown products. Ito Y, Hirashima M, Yamada H, Imoto T. Colonic lysozymes of rabbit (Japanese white) - recent divergence and functional conversion. Paracellular transport refers to movement between cells of the gut epithelium, while the transcellular route involves transport across the apical cell membrane of gut epithelial cells, transit across the cell (for some molecules with metabolic transformations in the cell), and then export at the basolateral membrane. Muegge BD, Kuczynski J, Knights D, Clemente JC, Gonzalez A, Fontana L, Henrissat B, Knight R, Gordon JI. There is also evidence that SGLT1 and GLUT transporters contribute to intestinal glucose absorption in nonmammalian vertebrates, including fish (72, 269). In vitro ruminal fermentation of tanniniferous tropical plants: Plant-specific tannin effects and counteracting efficiency of PEG. Frank DN, St Amand AL, Feldman RA, Boedeker EC, Harpaz N, Pace NR. Much remains to be learned about the mechanisms that vertebrate hindgut fermenters use to take advantage of their GIT microbes. Brzek P, Kohl K, Caviedes-Vidal E, Karasov WH. Many advances have relied on new molecular techniques. Whelan CJ, Brown JS, Schmidt KA, Steele BB, Willson MF. The difference in paracellular absorption between birds and nonflying mammals is not simply explained by mediated absorption in birds of the carbohydrate probes that are presumed to be absorbed passively. Under high glucose conditions, the inward flux of Na+ ions via SGLT1 results in depolarization of the membrane and Ca2+ influx, which, in turn, causes a large-scale reorganization of the cytoskeleton, facilitating access of proteins to the apical membrane. 30 generations) of cecal valves, which slow down food passage and provide for fermenting chambers, among lizards (Podarcis melisellensis) that were introduced onto an island where they consumed eight times more vegetation than did individuals in their source population. Jongsma MA, Bolter C. The adaptation of insects to plant protease inhibitors. It can be seen that the human digestive tract is relatively small. Low-diversity bacterial community in the gut of the fruitfly Drosophila melanogaster. Purification and partial characterization of a midgut membrane-bound alpha-glucosidase from. The discovery of efflux transporters over the past 2 to 3 decades across many animal phyla revealed another process by which passive absorption of lipophillic SMs might be limited. In contrast, the anthraquinone, emodin, which tends to speed digesta through the gut of humans (137), appears to have the opposite effect on the frugivorous bird the Yellow-vented bulblul, and increases the birds apparent digestive efficiency on emodin-containing fruit (440). The biochemical flexibility is generally considered to maximize the acquisition of carbon for energy production and essential nutrients for maintenance and growth, while protecting against the acquisition of excessive, potentially toxic, amounts of certain dietary constituents (e.g., iron). As in humans, the integumentary system of the pig includes the skin, hair, fingernails, and toenails. Ferreira AHP, Ribeiro AF, Terra WR, Ferreira C. Secretion of beta-glycosidase by middle midgut cells and its recycling in the midgut of. For example, glucose transporter function in vertebrates tends to be higher and more flexible to diet in herbivores and omnivores than in carnivores (246). Effects of diet quality on phenotypic flexibility of organ size and digestive function in Mongolian gerbils (. There is now overwhelming physiological and molecular evidence for carrier-mediated uptake and also efflux across the apical membrane (Fig. These sterols have the tetracyclic ring structure and side chain at C17, as in cholesterol, but the side chain in phytosterols is alkylated at C-24 (e.g., with ethyl substituent in sitosterol), and some phytosterols (e.g., stigmasterol) also have double bonds in the side chain. In pigs, the stomach is significant during growth. White and green tea polyphenols inhibit pancreatic lipase in vitro. There are small differences in a few organs. Once the chyme passes though the duodenum, the digestion process is in full swing. Hindgut fermentation, either in the cecum or large intestine/colon, occurs in many clades of mammals, birds, and reptiles. 7). Fructose is transported principally via the facilitative transporter GLUT5 (126). Many details remain to be elaborated, such as the location and magnitude of lysozyme capacity. Most mammals and birds have a single gene copy that codes for lysozyme. Digesta passage, digestibility and behavior in captive gorillas under two dietary regimens. The Gut as a Model in Cell and Molecular Biology. A comparative survey of the hydrolytic enzymes of ectoparasitic and free-living mites. However, activities in domesticated silkworms (Bombyx mori), which are mulberry specialists, are not affected whereas activities in Eri silkworms (Samia ricini), which are generalist insect herbivores, were inhibited by very low concentrations of the alkaloids (212). German DP, Horn MH. For example, female Aedes aegypti mosquitoes feed on both sugar-rich nectar and protein-rich vertebrate blood. Johnston DJ. Effect of age and diet on total and paracellular glucose absorption in nestling house sparrows. Ryan CA. Chemicals from many of the major groupings of SMs (e.g., alkaloids, phenolics, and terpenoids) inhibit animals intrinsic mechanisms of breakdown of carbohydrates, fats, and proteins (Table 4). These esterified products are incorporated into apolipoprotein (apo)B48-containing chylomicrons in a microsomal triglyceride transport protein-dependent manner. But, excessive retention time would either limit food intake rate or impose costly increase in size of the GI tract, or both, and this would be selected against in animals maximizing their growth or reproductive rate. Due to the differences in the digestive systems, cattle can utilize different types of feeds than pigs. Pregastric fermentation chambers have evolved rarely, and are apparently restricted principally to mammals, with five independent evolutionary origins [in the Artiodactyls (in the ruminants, camels, and hippos), in the colobine monkeys, and the Macropodidae (kangaroos)]; the remarkable S American bird, the hoatzin, also has a pregastric fermentation chamber (188, 476).