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PubMed1985

Delayed protein digestion in the alligator following carbonic anhydrase inhibition.

Small alligators were injected with a carbonic anhydrase (CA) inhibitor (dichlorphenamide) and a day later they were fed large amounts of lean beef. The rate of protein digestion was determined and compared with that in controls fed the same amount. The controls began digestion at once, while in the CA-inhibited ones, digestion was blocked for over 10 hr. The inhibitor decreased gastric HCl production to one-third that in controls and delayed activation of pancreatic and intestinal proteases. After 15 hr, digestion began in the inhibited group and proceeded to completion. Once digestion began, further injections of the inhibitor could not block it. It seems that CA inhibition blocks digestion (for a time) by reducing HCl synthesis. NaHCO3 to neutralize the acid chyme in the intestine, was derived from that in the plasma.

Acetazolamide↗
PubMed2005

Quantitative changes in the digestive gland cells of the snail Helix aspersa after exposure to the fungicide copper oxychloride.

This study investigated the relationship between accumulated copper in the digestive gland of Helix aspersa, after exposure to the fungicide copper oxychloride, and quantitative changes in the digestive gland cells of this snail. Snails were exposed to 80 and 240 microg g(-1) copper oxychloride for 6 weeks. Histological sections of digestive glands were analyzed by means of computer-assisted image analysis. Results indicate that copper is strongly accumulated in the digestive gland and that this organ is the main site of copper accumulation in the snail body. Also, as a result of copper accumulation in the digestive gland, measurable changes in epithelium cell height and area of this organ occur. In the case of cell height, these changes are dose-related. It is concluded that changes in digestive gland cells, as a result of copper oxychloride exposure, may possibly serve as biomarkers of exposure to this fungicide.

Animals↗
PubMed2005

Morphological and enzymatic analysis of the midgut of Anopheles darlingi during blood digestion.

The midgut of adult female Anopheles darlingi is comprised of narrow anterior and dilated posterior regions, with a single layered epithelium composed by cuboidal digestive cells. Densely packed apical microvilli and an intricate basal labyrinth characterize each cell pole. Before blood feeding, apical cytoplasm contains numerous round granules and whorled profiles of rough endoplasmic reticulum. Engorgement causes a great distension of midgut. This provokes the flattening of digestive cells and their nuclei. Simultaneously, apical granules disappear, the whorls of endoplasmic reticulum disassemble and 3h post bloodmeal (PBM), nucleoli enlarge manyfold. An intense absorptive process takes place during the first 24 h PBM, with the formation of large glycogen inclusions, which persist after the end of the digestive process. Endoproteases activities are induced after bloodmeal and attain their maximum values between 10 and 36 h PBM. At least two different aminopeptidases seem to participate in the digestive process, with their maximum activity values at 36 and 48 h PBM, respectively. Coarse electrondense aggregates, possibly debris from digested erythrocytes, begin to appear on the luminal face of the peritrophic membrane from 18 h PBM and persist during all the digestive process, and are excreted at its end. We suggest that these aggregates could contain some kind of insoluble form of haem, in order of neutralize its toxicity.

Animals↗
PubMed2006

Digestible and indigestible carbohydrates: interactions with postprandial lipid metabolism.

The balance between fats and carbohydrates in the human diet is still a matter of very active debate. Indeed, the processing of ordinary mixed meals involves complex processes within the lumen of the upper digestive tract for digestion, in the small intestine mucosa for absorption and resecretion, and in peripheral tissues and in the circulation for final handling. The purpose of this review is to focus on available knowledge on the interactions of digestible or indigestible carbohydrates with lipid and lipoprotein metabolism in the postprandial state. The observations made in humans after test meals are reported and interpreted in the light of recent findings on the cellular and molecular levels regarding possible interplays between carbohydrates and lipid moieties in some metabolic pathways. Digestible carbohydrates, especially readily digestible starches or fructose, have been shown to exacerbate and/or delay postprandial lipemia, whereas some fiber sources can lower it. While interactions between dietary fibers and the process of lipid digestion and absorption have been studied mainly in the last decades, recent studies have shown that dietary carbohydrate moieties (e.g., glucose) can stimulate the intestinal uptake of cholesterol and lipid resecretion. In addition to the well-known glucose/fructose transporters, a number of transport proteins have recently been involved in intestinal lipid processing, whose implications in such interactions are discussed. The potential importance of postprandial insulinemia in these processes is also evaluated in the light of recent findings. The interactions of carbohydrates and lipid moieties in the postprandial state may result from both acute and chronic effects, both at transcriptional and posttranscriptional levels.

Cholesterol↗
PubMed2003

Digestive efficiency of a generalist avian feeder, the Cape White-eye (Zosterops pallidus).

Digestive processes determine whether the particular diet of a bird is utilized efficiently and whether energetic demands are met. Assimilation efficiency is often used as an index of whether a diet is digested optimally. Studies on the digestive processing of generalist feeders are scarce. Cape White-eyes (Zosterops pallidus) have a diverse diet of fruit, nectar and insects. The nutrient contents of these three diets vary considerably and require quite different digestive processing. This study compared the digestive efficiencies of Cape White-eyes on these three diets by measuring transit times and assimilation efficiency. Cape White-eyes lost body mass significantly when fed fruit, while they maintained and gained body mass on nectar and mealworm diets, respectively. Assimilation efficiency varied significantly between the three diet types (nectar>mealworms>apples). When given a choice of diets, Cape White-eyes selected the diet, which was most efficiently digested and yielded the greatest energetic reward. Diet preference trials further showed that Cape White-eyes regulated daily energy intake. Assimilation efficiency depends on the accessibility of nutritional contents of a diet. Cape White-eyes did not maximize assimilation efficiency. Instead, they adjusted transit time to maximize the rate of energy gain per gram of food in order to maintain energy balance.

Animals↗
PubMed1995

Effect of forage digestibility and type of concentrate on nutrient utilization by lactating dairy cattle.

Six lactating dairy cows were used in a three period, part balanced changeover design experiment to investigate the effects of forage digestibility and concentrate composition on the efficiency of nutrient utilization in lactating dairy cows. Six treatments comprising three forage regimens and two concentrate types (starch v. fibre) were examined in a 3 x 2 factorial design. The three forage regimens were high digestibility grass silage offered ad lib. (HA) or restricted to 6.5 kg dry matter/d (HR) and a low digestibility grass silage offered ad lib. (LA). Within each forage regimen animals were offered 10 kg/d of supplements containing either high-starch or high-fibre concentrations. Experimental periods lasted 28 d with a 10 d recording period, during which animal performance, ration digestibility and nitrogen and energy utilization were measured. Respiratory exchange measurements were made over a 72 h period using indirect open-circuit calorimetry. Throughout the experiment, there were no significant forage x concentrate interactions in any of the intake, production or nutrient utilization results. Milk yield was significantly influenced by forage regimen (24.1, 21.7 and 21.9 kg/d for HA, HR and LA respectively) and concentrate type (21.6 and 23.5 kg/d for high-starch and high-fibre respectively). Concentrate type also significantly influenced milk protein concentration (32.8 and 30.9 g/kg for high-starch and high-fibre respectively). Forage regimen significantly influenced the efficiency of utilization of metabolizable energy (ME) for milk production (k1) with values of 0.62, 0.64 and 0.59 for HA, HR and LA respectively. Concentrate type had no significant effect on ME intake, heat production or k1, although animals receiving the high-fibre concentrates synthesized proportionately 0.11 more milk energy per unit of available energy (ME intake--heat production) than those receiving the high-starch concentrates. Interpolation of the values obtained with the two high digestibility forage regimens indicated that at similar ME intakes there was a trend towards a higher k1 with the diet based on high digestibility silage, and this was in line with the higher metabolizability of the overall diet with this silage.

Animal Feed↗
PubMed2001

Assessment of degradation and intestinal cell uptake of carotenoids and chlorophyll derivatives from spinach puree using an in vitro digestion and Caco-2 human cell model.

Although numerous studies have demonstrated the health benefits of chlorophyll derivatives, information regarding the digestion, absorption, and metabolism of these phytochemicals is quite limited. To better understand the digestion of these pigments, green vegetables including fresh spinach puree (FSP), heat- and acid-treated spinach puree (HASP), and ZnCl(2)-treated spinach puree (ZnSP) were subjected to an in vitro digestion method which simulates both the gastric and small intestinal phases of the process. Native chlorophylls were converted to Mg-free pheophytin derivatives during digestion. Conversely, Zn-pheophytins were completely stable during the digestive process. Transfer of lipophilic chlorophyll derivatives, as well as the carotenoids lutein and beta-carotene, into the aqueous micellar fraction from the food matrix was quantified. Micellarization of total chlorophyll derivatives differed significantly (p < 0.05) for FSP (37.6%), HASP (17.2%), and ZnSP (8.7%). Micellarization of chlorophyll a derivatives was determined to be significantly more efficient than chlorophyll b derivatives in FSP and HASP (p < 0.01), but not in ZnSP (p > 0.05). Intestinal cell uptake of micellarized pigments was investigated using HTB-37 (parent) and clonal TC7 lines of human Caco-2 cells. Medium containing the pigment-enriched fraction generated during digestion was added to the apical surface of fully differentiated monolayers for 4 h. Pigments were then extracted from cells and analyzed by C18 HPLC with photodiode array detection. Both Caco-2 HTB-37 and TC7 clone cells accumulated 20-40% and 5-10% of micellarized carotenoid and chlorophyll derivatives, respectively. These results are the first to demonstrate uptake of chlorophyll derivatives by human intestinal cells and to support the potential importance of chlorophylls as health-promoting phytochemicals.

Biological Availability↗
PubMed2002

Digestibility of food allergens and nonallergenic proteins in simulated gastric fluid and simulated intestinal fluid-a comparative study.

Information on the comparative digestibility of food allergens and nonallergenic proteins is crucial when stability to digestion is to be used as a criterion to assess the allergenic potential of novel proteins. In this work, we compared the digestive stability of a number of food allergens and proteins of unproven allergenicity and examined whether allergens possess a higher stability than nonallergenic proteins of similar cellular functions, and whether there is a correlation between protein digestibility and allergenicity. The stability of groups of storage proteins, plant lectins, contractile proteins, and enzymes, both allergens and proteins with unproven allergenicity, in a standard simulated gastric fluid and a standard simulated intestinal fluid was measured. Food allergens were not necessarily more resistant to digestion than nonallergenic proteins. There was not a clear relationship between digestibility measured in vitro and protein allergenicity.

Allergens↗
PubMed2006

Digestive Stability, micellarization, and uptake of beta-carotene isomers by Caco-2 human intestinal cells.

While isomeric profiles of carotenoids found in food often differ from those in body fluids and tissues, insights about the basis for these differences remain limited. We investigated the digestive stability, relative efficiency of micellarization, and cellular accumulation of trans and cis isomers of beta-carotene (BC) using an in vitro digestion procedure coupled with human intestinal (Caco-2) cells. A meal containing applesauce, corn oil, and either water-soluble beadlets (WSB) or Dunaliella salina (DS) as a BC source was subjected to simulated gastric and small intestinal digestion. BC isomers were stable during digestion, and the efficiency of micellarization of cis-BC isomers exceeded that of all-trans-BC isomers. The cellular profile of carotenoids generally reflected that in micelles generated during digestion, and intracellular isomerization was minimal. These data suggest that cis isomers of BC are preferentially micellarized during digestion and transferred across the brush-border surface of the enterocyte from mixed micelles with similar efficiency as all-trans-BC at the concentrations of the carotenoids utilized in this study.

Caco-2 Cells↗
PubMed2006

Available (ileal digestible reactive) lysine in selected cereal-based food products.

True ileal total lysine digestibility was determined and compared with true ileal reactive lysine digestibility when applied to 20 cereal-based breakfast foods. Semisynthetic diets each containing a breakfast cereal as the sole protein source were formulated and fed to growing rats. Titanium dioxide was included as an indigestible marker. Digesta were collected from the rats and total (conventional amino acid analysis) and reactive (guanidination) lysine were determined in both diets and digesta. The true ileal reactive lysine digestibility ranged from 53 to 108% and was significantly higher than the true ileal total lysine digestibility for most of the breakfast cereals. Available lysine content (digestible reactive lysine content) ranged from 0.21 to 3.5 g/kg across the breakfast cereals. The conventional measure of digestible total lysine content significantly overestimated (on average 37%) available lysine for the majority of the cereals. Breakfast cereals undergo a significant degree of lysine modification probably as a result of processing during manufacture.

Animals↗
PubMed2000

Perspectives into factors limiting in vivo digestion of legume proteins: antinutritional compounds or storage proteins?

The in vivo protein digestibility of raw and cooked common bean (Phaseolus vulgaris L.) and faba bean (Vicia faba L.) and of protein fractions extracted from them was determined with growing rats. Overnight-fasted rats were intubated with a protein suspension or fed the same amount of protein added to a basal diet. The rats were killed 1 h later, the contents of stomach and small intestine were washed out, and their protein contents were measured. The in vivo digestibility of proteins of raw common bean flour was 72.4% and not significantly improved after cooking. In contrast, the digestibility of faba bean proteins was decreased from 86.5 to 60.6% by the thermal treatment. Globulins from either species had similar digestibilities (approximately 70%). Proteins in the soluble fraction of cooked beans were more digestible than those in the insoluble fraction, which contained the bulk of the proteins. Hemagglutination assay and trypsin inhibitor determination indicated that after the thermal treatment only very low, nonharmful, levels of both lectin and inhibitor remained. Faba bean contained more polyphenols than common bean samples, with most of the polyphenols being bound to globulins. However, protein-bound polyphenols were markedly decreased after cooking. SDS-PAGE characterization of the gastrointestinal digesta of globulins and amino acid analysis of undigested proteins of whole cooked common bean and faba bean suggested that it is mainly the structural properties of the storage proteins and not their binding of polyphenols, which determines the extent of protein aggregation on autoclaving and may therefore be responsible for their low digestibility.

Animals↗
PubMed2001

Evaluation of the feeding value of palm press fibre using in vitro digestibility techniques.

Palm press fibre (PPF) was obtained from two sources, a small-scale oil palm processing unit and a large-scale factory processing unit, and its chemical composition was determined. In vitro digestibility techniques were used to assess the feeding value of untreated, defatted and sodium hydroxide-treated PPF. For the NaOH treatment, 0.5 g oven-dried PPF was treated for 24 h with 5% NaOH in three ways: treated and not washed (NaNW); treated and washed (NaW); and treated after milling (NAD). The results indicate that, on a dry matter basis, PPF is low in nitrogen (12-13 g/kg), moisture (37-90 g/kg) and ash (53-62 g/kg), but high in ether extract (269-355 g/kg), neutral detergent fibre (532-768 g/kg), acid detergent fibre (375-548 g/kg) and lignin (219 g/kg). The in vitro dry matter digestibility values were low for the samples from both sources, but the large-scale factory-processed PPF had higher in vitro dry matter digestibility (0.215 vs 0.166) and in vitro organic matter digestibility (0.196 vs 0.145). Defatting the PPF and treating it with 5% NaOH solution significantly (p < 0.01) improved both the dry matter and organic matter digestibility. Washing the NaOH-treated PPF resulted in a higher digestibility of dry matter as against NaNW or NAD. These results suggest that defatting and treatment with 5% NaOH would improve the feeding value of PPF.

Animal Feed↗
PubMed2004

Drug solubilization behavior during in vitro digestion of suspension formulations of poorly water-soluble drugs in triglyceride lipids.

PURPOSE: The purpose of this study was to characterize the solubilization and precipitation characteristics of a range of poorly water-soluble drugs during the in vitro digestion of long-chain or medium-chain triglyceride (TG) lipid suspension formulations. METHODS: TG suspensions of model drugs (present at double their equilibrium solubilities in the respective lipid) were digested in vitro and the drug solubilization and precipitation pattern in the resulting digests analyzed. RESULTS: For griseofulvin, diazepam, and danazol, solubilization of the small mass of drug originally presented in the TG lipid was efficient with only a small proportion of the dose precipitating and being recovered in the pellet phase after digestion of the TG lipid. For the more lipophilic and lipid-soluble drugs (cinnarizine, halofantrine), in which higher drug loadings were possible, significant enhancement in drug solubilization in the postdigestion aqueous phase was not apparent compared with simple TG lipid solutions. CONCLUSIONS: Suspensions of drugs, which are poorly soluble in water and TG lipid, may prove beneficial as the relatively high solubilizing capacity of the colloidal phases produced on TG digestion will likely exceed the mass of drug that could have been administered as a simple lipid solution. However, for more lipid-soluble drugs, suspension formulations may offer little benefit as sufficiently high drug loadings can otherwise be achieved with simple solution formulations that still provide for adequate solubilization after TG digestion.

Cinnarizine↗
PubMed2004

Rapid carbohydrate digestion rate produced lesser short-term satiety in obese preschool children.

OBJECTIVE: To examine whether high carbohydrate meals with different carbohydrate digestion rates have an effect on the short-term satiety in normal and obese preschool children. SUBJECTS AND SETTING: In total, 48 children of both gender, 24 normal and 24 obese, according to body mass index, aged between 3 and 6 y, were selected from children who were attending to a day-care center where they consumed three meals in the day. INTERVENTIONS: Rapid (potato-based meal) and lente (spaghetti-based meal) carbohydrate digestion rate meal were given at lunch, matching energy intake, carbohydrate, protein and fat levels, and then the preschool children's energy intake at the subsequent mealtime was observed. In this last mealtime, the children received varied types of high-acceptability foods in higher quantities than the normal serving. RESULTS: At lunch, a significant higher energy intake, lesser satiation, was observed in both groups, normal-weight and obese children, when they consumed the potato-based meal. In the subsequent mealtime, a significant effect of carbohydrate digestion rate was demonstrated, but only in obese preschool children, being higher in the meal with rapid digestion rate carbohydrates. CONCLUSIONS: Rapid carbohydrate digestion rate meal produced a significative lesser satiation in normal-weight and obese children. However, only in obese children a significant lesser satiety was observed after consumption of the rapid carbohydrate digestion rate meal, indicating a decreased capacity of energy regulation in obese children. The finding of the present work could provide dietary strategies required for decreasing prevalence in overweight and obesity in preschool children.

Anthropometry↗
PubMed2001

Feed intake, growth, digestibility of dry matter and nitrogen in young pigs as affected by dietary cation-anion difference and supplementation of xylanase.

An experiment was conducted to test the effect of dietary cation-anion difference (CAD, Na(+) + K(+)-Cl(-), mEq/kg diet) and xylanase addition on feed consumption, digestibility of nutrients, plasma electrolyte balance and growth performance in young pigs. A 2 x 3 factorial arrangement with three dietary CAD levels (-100, 200, and 500 mEq/kg) and two levels of xylanase supplementation (0 and 0.1% xylanase derived from Trichoderma longibrachiatum) was used. Thirty-six individually housed, castrated pigs (5 weeks old) with an initial body weight of 9.34 +/- 0.28 kg (mean +/- SEM) were randomly assigned to the six treatments. Diets were provided to pigs as cold pellets. Pigs had ad libitum access to feed and water. Venous plasma Cl(-) concentration was higher (p < 0.0001) in dietary CAD of - 100 mEq/kg group compared with the other two CAD groups. Dietary CAD did not affect Na(+) and K(+) concentrations in the venous plasma. Growth rates were higher (p < 0.05) in pigs receiving dietary CAD of 200 mEq/kg (657 g/pig.day) and dietary CAD of 500 mEq/kg (603 g/pig.day) than in pigs receiving dietary CAD of -100 mEq/kg (484 g/pig.day). Faecal dry matter and nitrogen decreased with increasing dietary CAD. Faecal apparent digestibility of dry matter and nitrogen was higher (p < 0.05) in the dietary CAD of 500 mEq/kg compared to the two lower level CAD groups. Supplementation of xylanase did not affect the performance of pigs. Xylanase addition in the diet significantly increased apparent faecal digestibility of dry matter and tended to increase apparent digestibility of nitrogen. No interaction between dietary CAD and xylanase was found. In conclusion, dietary CAD influenced the performance and digestibility of nutrients of pigs. Xylanase supplementation improved digestibility of dry matter.

Animal Feed↗
PubMed2004

Effect of different fibre types on the digestibility of nutrients in cats.

In this study the effect of different fibre types was investigated on the acceptance of foods (in a short-term study) and on the nutrients' digestibility by using 10 adult, castrated cats. Peanut hull (PH, source of lignin), dried sugar beet pulp (SBP, source of hemicelluloses and pectin) and alfalfa meal (ALF, source of cellulose) were mixed to a poultry meat based cat food in 10% on dry matter (DM) basis. The average DM intake did only slightly differ according to the type of fibre added. Supplementation of basal food by dried SBP did not influence the digestibility of DM and crude protein (CP) significantly. Using ALF as a fibre source decreased the digestibility of DM (85.8% vs. 78.6%) and CP (93.8% vs. 92.0%) significantly. More severe decline could be observed in the digestibility of DM (85.8% vs. 63.4%) and CP (93.8% vs. 83.7%) when using PH as a fibre source. Fibre sources also influenced the stool DM content significantly. While application of PH increased the DM content of the faeces (45.0% vs. 49.6%), the use of dried sugar beet or ALF reduced the faecal DM content (45.0% vs. 24.1% and 39.0%, respectively). According to these results the less digestible fibre source (PH) increased the DM content of the faeces while by improving the digestibility of the fibre sources the DM content of the faeces decreased. It can be concluded, that not only the absolute fibre content of the food but also the type of fibre must be taken into account when evaluating its possible role as a component of weight loss products.

Animal Feed↗
PubMed1983

Effect of lasalocid sodium on rumen fermentation and digestion in sheep.

Four adult sheep were fed 4 diets successively according to a Latin-square design. They were fitted with a rumen cannula and with simple cannulae at the duodenum and ileum. The basal diet (L0) was composed of highly-pressed ensiled sugar beet pulp (56.2%), cereal (barley and corn: 27.6%), urea (1.5%) and wheat straw (14.1%). Lasalocid sodium was added to obtain the following respective amounts: 21 ppm for diet L1, 43 ppm for diet L2 and 64 ppm for diet L3 (table 1). In the rumen, lasalocid significantly increased the molar proportion of propionic acid in the volatile fatty acids (VFA) mixture at the expense of the acetic and butyric acid proportions. The total VFA concentration decreased, especially with 43 and 64 ppm (table 2). Accordingly, the proportion of methane in rumen gases decreased. The ciliate population was always lower in animals fed experimental diets L1, L2, and particularly L3. The non-food-particle-associated bacterial population also decreased; the differences were significant only with the highest doses of lasalocid (L3). At the same time, bacterial cellulolytic activity increased 10%, indicating that qualitative modifications had taken place in the rumen bacterial population (table 3). Overall digestive utilization of organic matter (OM) decreased when lasalocid was added to the diets. This was due to a considerable reduction in forestomach digestion (12% decrease) (table 4). A greater supply of OM rich in cell-wall carbohydrates in the duodenum would explain the lower digestibility in the small intestine of animals given diet L1 and especially the L2 and L3 diets. No significant shift in digestion was noted in the large intestine. The composition of the non-ammonia nitrogen that entered the duodenum of sheep given lasalocid differed from that noted with the control diet (L0) (table 5). The amount of microbial proteins was significantly lower, whilst the proportion of non-degraded feed proteins was higher. The efficiency of microbial synthesis (bacterial proteins/kg OM truly digested in the rumen) was not significantly modified by lasalocid. All these modifications in digestion observed with these diets, and resulting from changes in the qualitative and quantitative composition of flora and fauna in the rumen, have an effect on nitrogen and energy utilization in the ruminant.

Animals↗
PubMedDate not supplied

Comparative study of forestomach digestion in llamas and sheep.

To compare digestion in the forestomach of llamas and sheep, the animals were fed four different diets: hay alone (H), low in nitrogen; the same hay with soybean meal (HS), with barley (HB) and with both soybean meal and barley (HSB). The sheep intakes were restricted to obtain about the same intake level in the two species. On average, the digestibilities of DM, OM and NDF were significantly higher in llamas: respectively, +2.7, 3.6 and 5.3 for the four diets. Added barley impaired hay digestion in the sheep, but very little in the llamas. The llamas retained nitrogen better than the sheep owing to very low urine losses. For hay alone, the retention time of digesta in the forestomach was higher in the llamas than in the sheep. In contrast, there was no difference between species for the other diets. The pH and ammonia levels were higher in llamas. In contrast, the SCFA levels were lower. In all cases the in-situ rate of digestion was greater in llamas. The low intake of llamas generally observed in the literature does not account for their better digestion. The stability of the two first compartment pH levels and an excellent cellulolytic activity are determining factors in the better digestion efficiency of plant cell walls in the llamas. However, higher NH3 levels were observed in llamas, although the urinary N excretion was lower.

Ammonia↗