Nutritional and Physiological Constraints Contributing to Limitations in Small Intestinal Starch Digestion and Glucose Absorption in Ruminants

Increased efficiency of nutrient utilization can potentially be gained with increased starch digestion in the small intestine in ruminants. However, ruminants have quantitative limits in the extent of starch disappearance in the small intestine. The objective is to explore the nutritional and physiological constraints that contribute to limitations of carbohydrate assimilation in the ruminant small intestine. Altered digesta composition and passage rate in the small intestine, insufficient pancreatic α-amylase and/or small intestinal carbohydrase activity, and reduced glucose absorption could all be potentially limiting factors of intestinal starch assimilation. The absence of intestinal sucrase activity in ruminants may be related to quantitative limits in small intestinal starch hydrolysis. Multiple sequence alignment of the sucrase-isomaltase complex gives insight into potential molecular mechanisms that may be associated with the absence of intestinal sucrase activity, reduced capacity for intestinal starch digestion, and limitations in the efficiency of feed utilization in cattle and sheep. Future research efforts in these areas will aid in our understanding of small intestinal starch digestion and glucose absorption to optimize feeding strategies for increased meat and milk production efficiency.

Corrigendum: Inhibitory Effect of Codeine on Sucrase Activity

A typographical error appeared in the author’s name of the article entitled “Inhibitory Effect of Codeine on Sucrase Activity“ by Dariush Minai-Tehrani, Saeed Minoui, Marzie Sepehre, Zohre Sharif-Khodai, Tooka Aavani, Drug Metabolism Letters, 2009; 3(1): 58-60. [1]. Details of the error and a correction are provided here. The fourth author#039;s name in this article was misspelled. Hence it should be read as "Zohreh Sharifkhodaei" as per the request of the author. We regret the error and apologize to readers. The original article can be found online at: https://www.eurekaselect.com/93132/article Original: Zohre Sharif-Khodai Corrected: Zohreh Sharifkhodaei

Birth Weight and Nutrient Restriction Affect Jejunal Enzyme Activity and Gene Markers for Nutrient Transport and Intestinal Function in Piglets

Significant variation in the birth weight of piglets has arisen due to increased sow prolificacy. Intestinal development and function may be affected by birth weight. Low birth weight (LBW) pigs may also have reduced feed intake, leading to further impairment of intestinal development. The objective of this study was to examine the intestinal development pattern of LBW and normal birth weight (NBW) piglets with normal nutrition (NN) or restricted nutrition (RN) in the pre-weaning period. Jejunal intestinal samples were analyzed for target gene expression and enzyme activity at d 28 (weaning) and d 56 (post-weaning). At d 28, excitatory amino acid transporter (EAAC1) and sodium-dependent neutral amino acid transporter (B0AT1) were downregulated in LBW compared to NBW pigs (p < 0.05). On d 56, B0AT1 and ASCT2 (glutamine transporter) were downregulated in RN compared to NN pigs (p < 0.05), regardless of birth weight. Peptide transporter 1 (PepT1) expression was downregulated in LBW compared to NBW pigs at 28 d (p < 0.05), with no effects of treatments at 56 d. Sodium-glucose transporter-1 (SGLT1) was upregulated in NBW-NN compared to LBW-NN pigs (p < 0.05) at 28 d. Alkaline phosphatase (ALP) was upregulated in LBW-RN at d 28. At d 56, claudin-3 (CLDN-3) and Zonular occludin-1 (ZO-1) were upregulated in NN compared to RN pigs (p < 0.05). There were no treatment effects on ALP, maltase, or sucrase activity at 28 d. However, at 56 d, ALP was upregulated in NBW-NN pigs while sucrase activity was upregulated in NN pigs (p < 0.05). The results demonstrate differences in jejunal gene expression associated with birth weight, with reduced gene expression of amino acid transporters (PepT1, EAAC1, B0AT1) in LBW compared to NBW pigs (p < 0.05). While neonatal nutrient restriction had minimal effects at 28 d and d 56 for tight junction protein transcript abundance, neutral amino acid transporter abundance was upregulated in NN pigs compared to RN piglets (p < 0.05).

Birth weight and nutrient restriction affect jejunal enzyme activity and gene markers for nutrient transport and intestinal function in piglets

Background Significant variations in live birth weight of piglets have arisen due to increased sow prolificacy. Intestinal development and function may be affected by birth weight. Low birth weight (LBW) pigs may also have reduced feed intake, leading to further impairment of intestinal development. The objective of this study was to examine the intestinal development pattern of low and normal birth weight (NBW) piglets with normal (NN) or restricted (RN) neonatal feed intake. Results Jejunal intestinal samples were analyzed for target gene expression and enzyme activity at d 28 (weaning) 56 post-birth (post-weaning). At d 28, EAAC1 and B0AT1 were downregulated in LBW compared to NBW pigs (P < 0.05). On d 56, B0AT1 and ASCT2 were downregulated in RN compared to NN pigs (P < 0.05), regardless of birth weight. PepT1 expression was downregulated in LBW compared to NBW pigs at 28 d (P < 0.05), with no effects of treatments at 56 d. SGLT1 was upregulated in NBW-NN compared to LBW-NN pigs (P < 0.05) at 28 d. Alkaline phosphatase (ALP) was upregulated in LBW-RN at d 28. At d 56, CLDN-3 and ZO-1 were upregulated in NN compared to RN pigs (P < 0.05). There were no treatment effects on ALP, maltase, or sucrase activity at 28 d. However, at 56 d, ALP was upregulated in NBW-NN pigs while sucrase activity was upregulated in NN pigs. Conclusion The results demonstrate differences in jejunal gene expression associated with birth weight, with reduced expression of protein/amino acid transporters (PepT1, EAAC1, B0AT1) in LBW compared to NBW pigs. While neonatal nutrient restriction had minimal effects at 28 d, intestinal barrier function (Claudin-3 and ZO-1) and neutral amino acid transport (B0AT1 and ASCT2) were improved in pigs under normal compared to restricted feeding pre-weaning at d 56.

Optimisation, validation and field applicability of a 13C-sucrose breath test to assess intestinal function in environmental enteropathy among children in resource poor settings: study protocol for a prospective study in Bangladesh, India, Kenya, Jamaica, Peru and Zambia

IntroductionEnvironmental enteropathy (EE) is suspected to be a cause of growth faltering in children with sustained exposure to enteric pathogens, typically in resource-limited settings. A major hindrance to EE research is the lack of sensitive, non-invasive biomarkers. Current biomarkers measure intestinal permeability and inflammation, but not the functional capacity of the gut. Australian researchers have demonstrated proof of concept for an EE breath test based on using naturally 13C-enriched sucrose, derived from maize, to assay intestinal sucrase activity, a digestive enzyme that is impaired in villus blunting. Here, we describe a coordinated research project to optimise, validate and evaluate the usability of a breath test protocol based on highly enriched 13C-sucrose to quantify physiological dysfunction in EE in relevant target populations.Methods and analysisWe use the 13C-sucrose breath test (13C-SBT) to evaluate intestinal sucrase activity in two phases. First, an optimisation and validation phase will (1) confirm that a 13C-SBT using highly enriched sucrose tracers reports similar information to the naturally enriched 13C-SBT; (2) examine the dose–response relationship of the test to an intestinal sucrase inhibitor; (3) validate the 13C-SBT in paediatric coeliac disease (4) validate the highly enriched 13C-SBT against EE defined by biopsy in adults and (5) validate the 13C-SBT against EE defined by the urinary lactulose:rhamnose ratio (LR) among children in Peru. Second, a cross-sectional study will be conducted in six resource-limited countries (Bangladesh, India, Jamaica, Kenya, Peru and Zambia) to test the usability of the optimised 13C-SBT to assess EE among 600 children aged 12–15 months old.Ethics and disseminationEthical approval will be obtained from each participating study site. By working as a consortium, the test, if shown to be informative of EE, will demonstrate strong evidence for utility across diverse, low-income and middle-income country paediatric populations.Trial registration numberNCT04109352; Pre-results.

Aversive responses to L-arabinose in caterpillars of Helicoverpa armigera (Hübner)

ABSTRACTBackgroundOne of the naturally non-nutritive artificial sweeteners, L-arabinose, is widely used in the modern human food industry to combat obesity and diabetes because of its inhibition effect on the intestinal sucrase activity in mammals. However, whether it shows impact on herbivorous insects remains largely unknown. In the present study, we investigated the effects of L-arabinose on the feeding behaviors, gustation, development and intestinal sucrase activity of an herbivorous insect species, the cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae).ResultsThe results show that both the feeding preferences of H. armigera caterpillars for host plants and for phagostimulants were inhibited by L-arabinose in a dose-dependent manner. Gustatory receptor neurons (GRNs) sensitive to L-arabinose were not found in the peripheral gustatory sensilla, but the sensitivities of GRNs sensitive to other plant metabolites were suppressed by L-arabinose. Exposure of dietary L-arabinose to caterpillars resulted in prolonged larval developmental duration, suppressed activity of intestinal sucrase and reduced glucose level in midguts. In vitro, L-arabinose inhibits activity of intestinal sucrase of H. armigera caterpillars in an uncompetitive manner.ConclusionTaken together, these findings demonstrate that L-arabinose is a feeding and physiological inhibitor to caterpillars of H. armigera caterpillars. To our knowledge, this is the first report of a non-nutritive sweetener perceived by an animal as an inhibitor from both peripheral taste coding and feeding decisions, which should provide a physiological and behavioral basis for the future possible application of L-arabinose in controlling the herbivores pests.

Duodenal Infusions of Starch with Casein or Glutamic Acid Influence Pancreatic and Small Intestinal Carbohydrase Activities in Cattle

ABSTRACT Background Small intestinal starch digestion in ruminants is potentially limited by inadequate production of carbohydrases. Previous research has demonstrated that small intestinal starch digestion can be improved by postruminal supply of casein or glutamic acid. However, the mechanisms by which casein and glutamic acid increase starch digestion are not well understood. Objectives The objective of this experiment was to evaluate the effects of duodenal infusions of starch with casein or glutamic acid on postruminal carbohydrase activities in cattle. Methods Twenty-two steers [mean body weight (BW) = 179 ± 4.23 kg] were surgically fitted with duodenal and ileal cannulas and limit-fed a soybean hull–based diet containing small amounts of starch. Raw cornstarch (1.61 ± 0.0869 kg/d) was infused into the duodenum alone (control), or with 118 ± 7.21 g glutamic acid/d, or 428 ± 19.4 g casein/d. Treatments were infused continuously for 58 d and then steers were killed for tissue collection. Activities of pancreatic (α-amylase) and intestinal (maltase, isomaltase, glucoamylase, sucrase) carbohydrases were determined. Data were analyzed as a randomized complete block (replicate group) design using the GLM procedure of SAS to determine effects of infusion treatment. Results Duodenal casein infusion increased (P &lt; 0.05) pancreatic α-amylase activity by 290%. Duodenal glutamic acid infusion increased (P &lt; 0.03) duodenal maltase activity by 233%. Duodenal casein infusion increased jejunal maltase (P = 0.02) and glucoamylase (P = 0.03) activity per gram protein by 62.9% and 97.4%, respectively. Duodenal casein infusion tended to increase (P = 0.10) isomaltase activity per gram jejunum by 38.5% in the jejunum. Sucrase activity was not detected in any segment of the small intestine. Conclusions These results suggest that small intestinal starch digestion can be improved in cattle with increased small intestinal flow of casein through increases in postruminal carbohydrase activities.

PSIV-1 Effects of nutrient restriction and realimentation of gestating ewes on fetal carbohydrase activities in the small intestine

The small intestine plays an important role in post-ruminal carbohydrate digestion and there is limited information on its function in response to nutritional adaptation. To examine the effects of nutrient restriction and realimentation on fetal small intestinal carbohydrase activities during mid- to late-gestation, 41 singleton ewes (48.3±0.6 kg BW) were randomly assigned to dietary treatments: 100% (control; CON; n = 20) or 60% of nutrient requirements (restricted; RES; n = 21) from day 50–90 (mid-gestation) of gestation. At day 90, 14 ewes (CON, n = 7; RES, n = 7) were slaughtered. The remaining ewes were subjected to treatments of nutrient restriction or remained under a control diet from day 90–130 (late-gestation): CON-CON (n = 6), CON-RES (n = 7), RES-CON (n = 7), and RES-RES (n = 7) and were slaughtered at day 130. The fetal small intestine was weighed, subsampled, and assayed for carbohydrase (maltase, isomaltase, glucoamylase, lactase, and sucrase) activity. Enzyme activity was expressed as U/g and U/g protein. Protein concentration was expressed as mg/g intestine. Differences between means were determined using contrasts in the MIXED procedure of SAS. Small intestinal mass increased (P &lt; 0.001) with day of gestation. Sucrase activity was undetected in the small intestine. Day of gestation did not affect carbohydrase development in the fetal small intestine. Nutrient restriction did not affect glucoamylase, maltase, or isomaltase activities. There was a significant mid-gestation treatment × late-gestation treatment interaction for lactase activity (P &lt; 0.05). Realimentation during late-gestation after nutrient restriction during mid-gestation increased lactase activity in the fetal small intestine. These data demonstrate that fetal mucosal carbohydrases are imprinted early in gestation and brush border α-glycohydrolases involved in starch digestion (maltase, isomaltase, glucoamylase) do not respond to maternal nutrient restriction in sheep. Nutrient restriction of ewes during mid-gestation followed by realimentation during late-gestation may be a programming strategy to increase fetal lactase activity.

Effect of the flavonoid hesperidin on glucose and fructose transport, sucrase activity and glycaemic response to orange juice in a crossover trial on healthy volunteers

Although polyphenols inhibit glucose absorption and transportin vitro, it is uncertain whether this activity is sufficient to attenuate glycaemic responsein vivo. We examined this using orange juice, which contains high levels of hesperidin. We first used a combination ofin vitroassays to evaluate the potential effect of hesperidin and other orange juice components on intestinal sugar absorption and then tested whether this translated to an effect in healthy volunteers. Hesperidin attenuated transfer of14C-labelled glucose across differentiated Caco-2/TC7 cell monolayers. The involvement of the sugar transporter GLUT2 was demonstrated by experiments carried out in the absence of Na to exclude the contribution of sodium-glucose linked transporter 1 and further explored by the use ofXenopus laevisoocytes expressing human GLUT2 or GLUT5. Fructose transport was also affected by hesperidin partly by inhibition of GLUT5, while hesperidin, even at high concentration, did not inhibit rat intestinal sucrase activity. We conducted three separate crossover interventions, each on ten healthy volunteers using orange juice with different amounts of added hesperidin and water. The biggest difference in postprandial blood glucose between orange juice and control, containing equivalent amounts of glucose, fructose, sucrose, citric acid and ascorbate, was when the juice was diluted (ΔCmax=–0·5 mm,P=0·0146). The effect was less pronounced when the juice was given at regular strength. Our data indicate that hesperidin can modulate postprandial glycaemic response of orange juice by partial inhibition of intestinal GLUT, but this depends on sugar and hesperidin concentrations.