Brush Border Enzyme Activities Research Articles

Comparative study of different doses of oral zinc supplementation in children with acute diarrhea

Background There are several mechanisms of action of zinc on acute diarrhea as zinc restores mucosal barrier integrity and enterocyte brush border enzyme activity, it promotes the production of antibodies and circulating lymphocytes against intestinal pathogens. Aim To evaluate the effect of oral zinc supplementation in different doses on the reduction of duration and severity of acute diarrhea in infants and children. Patients and methods This randomized controlled clinical trial was carried out on 80 infants and children aged less than 5 years old, both sexes, with acute diarrhea. Patients were divided into four equal groups: group 1: received oral zinc supplementation in a dose of 20 mg/day for 14 days, group 2: received oral zinc supplementation in a dose of 40 mg/day for 14 days, group 3: received oral zinc supplementation in a dose of 60 mg/day for 14 days and group 4: did not receive. Results Diarrhea frequency and duration of diarrhea were significantly decreased in group 3 more than group 2 more than group 1, while group 4 showed a significantly higher frequency of diarrhea after 14 days and a longer duration of diarrhea compared with all other groups. Zinc levels were significantly higher after treatment compared with before treatment in all groups (P <0.001). Low Zinc supplementation, long duration of fever, long duration of diarrhea before treatment, and smaller rise in zinc levels were independent risk factors associated with persistent diarrhea more than 7 days after treatment. Conclusions Oral zinc supplementation reduces diarrhea’s duration and severity in all doses. The higher doses of zinc supplemented, the earlier the recovery from diarrheal episodes, with no serious adverse effects.

Xylooligosaccharides alleviate the carbohydrate-enriched diet-induced intestinal barrier dysfunction in carp Megalobrama amblycephala by promoting intestinal development, immunity and gut microbiota

To date, although the high-carbohydrate (HC) feed has been extensively adopted in the aquaculture industry, its effects on the intestinal function and development of aquatic animals still remain unclear. In addition, the corresponding nutritional intervention is still barely reported. This study aimed to evaluate the influence of xylooligosaccharides (XOS) on the intestinal health of Megalobrama amblycephala subjected to a HC feeding. Fish (average weight: 44.55 ± 0.15 g) were randomly offered 3 diets, including a control one (29 % carbohydrate), a HC one (41 % carbohydrate), and a XOS supplemented one (HC + 1.0 % XOS, HCX) respectively for 12 weeks. The HC feeding caused morphological abnormalities of intestine, an increased intestinal permeability, and the intestinal immunosuppression, all of which were markedly reversed by XOS administration. In addition, compared with the HC group, HCX feeding remarkably promoted the intestinal activities of digestive and brush border enzymes, and the expressions of cell proliferation-related proteins (Wnt10b and Cyclin D1). The 16s rDNA sequencing also revealed that XOS administration increased the abundance of beneficial bacteria, and decreased that of pathogenic ones. In conclusion, dietary supplementation of XOS improved the intestinal histomorphology, barrier function, cell proliferation and bacterial communities of carbohydrate-overloaded fish Megalobrama amblycephala.

Effect of supplemental milk replacer and liquid starter diet for 4 and 11 days postweaning on intestinal parameters of weaned piglets and growth to slaughter

Reduced piglet feed intake immediately postweaning (pw) leads to disruption of small intestine structure and function and reduced growth. Our objective was to evaluate the effect of providing supplemental milk or liquid starter diet for either 4 or 11 days pw, on intestinal parameters of newly weaned piglets and growth to slaughter. At weaning (28 ± 0.6 days old), five hundred and eighty−seven piglets ((Large White × Landrace) × Duroc) were divided into 59 pen groups, each containing 9–10 same sex (entire male or female) piglets. The pen groups were blocked by sex and weaning weight and provided with ad-libitum access to one of five dietary treatments: (1) Dry pelleted starter diet (control; CON); (2) CON+liquid milk replacer for 4 days pw (M4); (3) CON+liquid milk replacer for 11 days pw (M11); (4) CON+liquid starter diet for 4 days pw (S4) and (5) CON+liquid starter diet for 11 days pw (S11). Pen groups were weighed at weaning, days 11, 20, 28, and 47 pw and at target sale weight. Feed disappearance (on a DM basis) was recorded on each weighing day. On day 7 pw, 10 piglets per treatment were euthanised to collect small intestine tissue samples for determination of villus height (VH), crypt depth and brush-border membrane enzyme activity. Data were analysed using SAS-version 9.4. Between days 0 and 11 pw, M11 increased average daily feed intake by 48% and average daily gain (ADG) by 57% compared to CON (P < 0.05), and increased ADG by 54% (P < 0.05) compared to S4. Piglets on M11 also had improved feed conversion efficiency compared with CON piglets between days 0 and 11 pw. Treatment did not affect growth performance after day 28 pw, or carcass parameters at slaughter. At day 7 pw, M11 piglets had 37% higher jejunal VH than CON piglets (P < 0.05) and S11 piglets had 28% higher ileal VH than S4 piglets (P < 0.05). M11 piglets had up to 150% higher ileal sucrase activity than M4, S4 and S11 piglets (P < 0.05) and 180% higher ileal maltase activity than S4 piglets (P < 0.05). In conclusion, M11 reduced the immediate negative effects of weaning, as it was associated with increased feed intake, growth, brush-border membrane enzyme activity and improved intestinal structure early pw. However, there were no carryover effects of any of the liquid supplements on growth or feed efficiency or carcass weight at slaughter.

Enteral plasma feeding improves gut function and immunity in piglets after birth asphyxia.

Birth asphyxia may negatively affect gut function and immunity in newborns. Conversely, immunomodulatory milk diets may protect the gut and immune system against damage caused by asphyxia. Using caesarean-derived pigs as models, we hypothesised that enteral feeding with plasma improves gut and immune functions in asphyxiated newborns. Near-term pig fetuses (98% gestation,) were delivered by caesarean section after 8 min umbilical cord occlusion, leading to transient birth asphyxia (ASP, n = 75) and compared with non-occluded controls (CON, n = 69). Piglets were further randomised to supplementation with/without porcine plasma (plasma, PLA/vehicle, VEH), into bovine colostrum (first 24 h) or formula (until 72 h). Compared with CON, ASP piglets took longer to achieve stable respiration and showed reduced blood pH, weight gain and survival. Independent of asphyxia, plasma supplementation reduced gut haemorrhagic lesions, permeability and inflammatory cytokines together with improved villous morphology and brush-border enzyme activities. Asphyxia reduced blood cytokine responses to ex vivo bacterial stimulation, whereas plasma supplementation ameliorated this effect. Dietary plasma supplementation improves survival, gut functions and immunity in both normal and asphyxiated newborns. The components in plasma that mediate gut-protective effects in piglets remain to be identified, but may benefit also birth-compromised newborn infants. Complicated deliveries leading to birth asphyxia, may negatively affect gut, liver and immune adaptation in the first days after birth. Using a model of birth asphyxia in caesarean-derived piglets, we show that enteral feeding with maternal plasma exerts gut maturational and immunomodulatory effects in both control and asphyxiated animals in the first days of life. The mechanisms behind the gut-protective effects of plasma are unknown, but plasma components hold potential for new oral therapies for compromised newborn infants as well as piglets.

Role of sodium octanoate in regulating survival, growth, intestinal development, digestive and absorptive capacities, antioxidant capacity and innate immunity of large yellow croaker (Larimichthys crocea) larvae

The present study was conducted to investigate the effects of dietary sodium octanoate (So) on the survival, growth, intestinal development, digestive and absorptive capacities, antioxidant capacity and innate immunity of Larimichthys crocea larvae. Larvae (initial body weight: 7.44 ± 0.53 mg) were fed with either a control diet or diets with different levels (0.1%, 0.2%, 0.4%, and 0.8%) of So for 30 days. The results showed that larvae fed diets with 0.1%–0.4% So had significantly increased survival compared to the control. Compared to the control, larvae fed the diet with 0.4% So showed dramatically improved growth performance, although there were no significant differences between other diets. Notably, larvae fed diets with 0.2%–0.4% So displayed significantly higher fold height of intestine compared to the control group. Increased levels of selected intestinal cell proliferation and differentiation gene markers (pcna and odc) and increased activity of intestinal brush border enzymes (alkaline phosphatase and leucine aminopeptidase) further affirmed the promotional effect of So on intestinal development. Moreover, for genes related to the intestinal apical junction complex, larvae fed diets with 0.1%–0.8% So showed significantly higher mRNA expression levels of occludin and cateninα1 than the control group. Meanwhile, compared to the control, the expression of claudin1, afadin and cadherin2 significantly increased in larvae fed diets with 0.1%–0.4% So. Also, larvae fed diets with 0.1%–0.8% So showed significantly higher activity of lipase than the control group, whereas the activity of trypsin was significantly higher only in larvae fed the diet with 0.4% So. Furthermore, absorption capacity, as reflected by the activity of brush border enzymes (Na+-K+-Adenosinetriphosphatase and creatine kinase), significantly increased in larvae fed diets with 0.2%–0.4% So compared to the control. Furthermore, larvae fed the diet with 0.4% So exhibited improved antioxidant enzyme activity (catalase and total antioxidant capacity), upregulated antioxidant related gene expression (sod2, sod3, cat, and nrf2), increased antioxidant substance levels (reduced glutathione), and decreased malondialdehyde content compared to the control group. Moreover, larvae fed the diet with 0.4% So showed the highest activity of innate immune-related enzymes (lysozyme, acid phosphatase, inducible nitric oxide synthase and total nitric oxide synthase) and the highest mRNA expression of anti-inflammatory cytokines (il4/13 and arg1). In summary, the diet supplemented with 0.4% So may optimally improve larval survival and growth probably by enhancing intestinal development, digestion and absorption, antioxidant capacity, and innate immunity.

Effect of fermented rapeseed meal on growth performance, nutrient digestibility, and intestinal health in growing pigs

To explore the effects of fermented rapeseed meal (FRSM) on growth performance and intestinal health, a total of 30 growing pigs were randomly allotted to three treatments consisting of corn-soybean meal diet (CSD), rapeseed meal diet (RSD), and fermented rapeseed meal diet (FRSD). Results showed that compared with RSD, FRSD feeding increased the average daily gain and final body weight in pigs (P < 0.01). Compared with RSD feeding, FRSD feeding elevated the apparent digestibility of crude protein, acid detergent fiber, and ether extract in pigs (P < 0.01). Moreover, the FRSD group exhibited greater apparent ileal digestibility of His, Thr, Lys, and Ser than the RSD group (P < 0.01). The digestible energy, metabolic energy, and nitrogen utilization were higher in the FRSD and CSD groups than in the RSD group (P < 0.01). As compared to the RSD, FRSD feeding decreased the serum concentration of leptin but significantly increased the concentrations of immunoglobulin (Ig) A, IgG, ghrelin, and enzyme activities of amylase, lipase, and trypsin in the pancreas (P < 0.05). Interestingly, the villus height, the ratio of villus height to crypt depth, and the activities of brush border enzymes (e.g., maltase and sucrase) in the small intestine were higher in the CSD and FRSD groups than in the RSD group (P < 0.05). As compared to the RSD, the FRSD feeding not only increased the expression level of the occludin in the small intestinal epithelium (P < 0.05) but also elevated the expression levels of claudin-1, MUC1, and PepT1 genes in the duodenum, and elevated the expression levels of SGLT1 and CAT1 genes in the jejunum (P < 0.05). Importantly, FRSD feeding significantly decreased the abundance of Escherichia coli, but increased the abundance of Lactobacillus and the content of butyrate in the cecum and colon (P < 0.05). These results indicated that compared with rapeseed meal, fermented rapeseed meal exhibited a positive effect on improving the growth performance and intestinal health in growing pigs, and the results may also help develop novel protein sources for animal nutrition and the feed industry.

Effects of defatted yellow mealworm (Tenebrio molitor) on growth performance, intestine, and liver health of turbot (Scophthalmus maximus)

Yellow mealworm Tenebrio molitor is an emerging feed ingredient with several key advantages. However, research on the T. molitor as a fishmeal substitute reported discrepancies in feasibility in different fish species, with a particular need for T. molitor products to be widely evaluated. In this research, an eight-week feeding trial was conducted to evaluate the effect of T. molitor on turbot Scophthalmus maximus mainly from the perspective of growth performance and health status of the intestine and liver. Turbot with an initial weight of approximately 150 g were randomly assigned six isonitrogenous and isolipidic diets, including fishmeal-based control diet or diets with gradually increasing level of defatted T. molitor meal (TM) to replace 15 % (TM15), 30 %, 45 %, 60 % and 75 % of fishmeal compared to the control diet. Weight gain of turbot increased significantly at the 30 % replacement level (P < 0.05). However, TM in 45 %, 60 % and 75 % of fishmeal replacement level impaired overall growth performance. There was no obvious impairment in the assayed levels of TM towards the intestine from the view of structure, activities of brush border enzymes, antioxidant conditions, or immunity of proximal, middle and distal segments. However, the amount of goblet cells was significantly decreased by TM (P < 0.05). Similarly, TM in the assayed levels did not induce any negative effects on the antioxidant and immune status of the liver. But TM45, TM60 and TM75 diets induced weight loss in the liver and smaller hepatocytes, accompanied by a decrease of liver lipid content as well as decreases in levels of triglyceride and cholesterol in plasma. In conclusion, the optimal dietary level of TM for turbot was 24.5 %, corresponding to a 30 % substitution of fishmeal from the control group. Dietary TM can improve the antioxidant and immune function of the intestine and liver, but excess TM will disturb lipid metabolisms.

Application of enzymatically treated Artemisia annua L. on adult grass carp (Ctenopharyngodon idella): Improved growth performance, intestinal antioxidant capacity and apical junctional complex

The present study evaluated the effects of enzymatically treated Artemisia annua L. (EA) on the growth performance, intestinal antioxidant capacity, and apical junctional complex (AJC) of adult grass carp. In this experiment, 375 healthy grass carp (initial body weight 673.96 ± 1.24 g) were selected and randomly divided into 5 treatments, and fish in each group were fed diets with different levels of EA (0, 400, 800, 1200, and 1600 mg/kg) 9 weeks. The results showed that compared with the control group (0 mg/kg EA diet), the EA supplementation in the diet increased the percentage of weight gain (PWG), specific growth rate (SGR), and feed intake (FI) (P < 0.05), indicating that dietary EA supplementation improved the growth performance of adult grass carp. The dietary EA supplementation also enhanced the digestion and absorption ability of adult grass carp, which might be reflected by improving the activities of hepatopancreas digestive enzymes (trypsin, chymotrypsin, lipase, and amylase) and intestinal brush border enzymes (alkaline phosphatase, Na+/K+-ATPase, and γ-glutamyl transpeptidase), but EA did not affect the creatine kinase enzyme activity. Meanwhile, we explored the effect of dietary EA addition on the structural integrity of the grass carp intestine. We observed that dietary EA supplementation improved the antioxidant capacity of the intestine which be reflected by increasing the activities levels of superoxide dismutase (SOD) and catalase (CAT), which might be related to the binding protein Keap1a (not Keap1b)/ NF-E2-related factor-2 (Nrf2) signaling pathway. In addition, dietary EA supplementation enhanced the integrity of AJC by increasing the mRNA levels of intestinal tight junction proteins (TJs) (except claudin 11, claudin 12, claudin 15a) and adhere junction proteins (AJs) (E-cadherin, α-catenin, β-catenin, nectin, and afadin), which might be related to the Rho family GTPases (RhoA)/ Rho-associated protein kinase (ROCK)/ myosin light chain kinase (MLCK) signaling pathway. Collectively, dietary EA supplementation improved growth performance, digestion and absorption ability, and intestinal structural integrity in grass carp, which were associated with the activation of related signaling pathways and regulatory factors. Finally, by the growth indicator percent weight gain (PWG) and intestinal oxidative damage index protein carbonyl (PC), the optimum amounts of EA supplementation of adult grass carp (673–1726 g) were assessed to be 808.09 and 730.38 mg/kg diet, respectively.

Hypothyroidism impairs development of the gastrointestinal tract in the ovine fetus.

Growth and maturation of the fetal gastrointestinal tract near term prepares the offspring for the onset of enteral nutrition at birth. Structural and functional changes are regulated by the prepartum rise in cortisol in the fetal circulation, although the role of the coincident rise in plasma tri-iodothyronine (T3) is unknown. This study examined the effect of hypothyroidism on the structural development of the gastrointestinal tract and the activity of brush-border digestive enzymes in the ovine fetus near term. In intact fetuses studied between 100 and 144days of gestation (dGA; term ∼145days), plasma concentrations of T3, cortisol and gastrin; the mucosal thickness in the abomasum, duodenum, jejunum and ileum; and intestinal villus height and crypt depth increased with gestational age. Removal of the fetal thyroid gland at 105-110 dGA suppressed plasma thyroxine (T4) and T3 concentrations to the limit of assay detection in fetuses studied at 130 and 144 dGA, and decreased plasma cortisol and gastrin near term, compared to age-matched intact fetuses. Hypothyroidism was associated with reductions in the relative weights of the stomach compartments and small intestines, the outer perimeter of the intestines, the thickness of the gastric and intestinal mucosa, villus height and width, and crypt depth. The thickness of the mucosal epithelial cell layer and muscularis propria in the small intestines were not affected by gestational age or treatment. Activities of the brush border enzymes varied with gestational age in a manner that depended on the enzyme and region of the small intestines studied. In the ileum, maltase and dipeptidyl peptidase IV (DPPIV) activities were lower, and aminopeptidase N (ApN) were higher, in the hypothyroid compared to intact fetuses near term. These findings highlight the importance of thyroid hormones in the structural and functional development of the gastrointestinal tract near term, and indicate how hypothyroidism in utero may impair the transition to enteral nutrition and increase the risk of gastrointestinal disorders in the neonate.

A comparison of post-ruminal provision of Ca-gluconate and Ca-butyrate on growth performance, gastrointestinal barrier function, short-chain fatty acid absorption, intestinal histology, and brush-border enzyme activity in beef heifers.

The objective of this study was to compare the effects of post-ruminal provision of Ca-butyrate (CaB) when delivered via abomasal dosing, and Ca-gluconate (CaG) when provided ruminally using a rumen protected form or using an unprotected form via abomasal dosing on short-chain fatty acid (SCFA) concentration throughout the GIT, nutrient digestibility, GIT barrier function, ruminal SCFA absorption, ruminal morphometrics, intestinal brush border enzyme activity, and blood parameters for beef heifers. Thirty-two beef heifers fitted with ruminal cannulas were used in a randomized complete block design and assigned to one of four treatments: 1) negative control (ruminal infusion of double-distilled water; CON); 2) abomasal infusion of CaB (AB; 0.0029% of BW); 3) abomasal infusion of CaG (AG; 0.0077% of BW); and 4) ruminal infusion of a hydrogenated fat-embedded CaG (RG; 0.0192% of BW) to provide ruminal protection. Excluding CON, treatments were designed to deliver the same amount of butyrate in the small intestine. Heifers were housed in individual pens and DMI was limited to 95% of voluntary intake to minimize a potential confounding effect of DMI on treatment responses. Total GIT barrier function was assessed on day 17 and SCFA disappearance was evaluated on day 21 using the temporarily isolated and washed reticulo-rumen technique. On day 28, heifers were slaughtered, and ruminal and colonic digesta were collected to assess SCFA concentration. Additionally, ruminal, jejunal, and colonic tissues were collected to assess SCFA fluxes and regional barrier function ex vivo using the Ussing chamber technique. For colonic digesta, both AB and CaG treatments reduced the proportion of acetate (P < 0.05) and increased the proportion on propionate (P < 0.05) compared to CON. Relative to CON, AB but not CaG treatments increased in vivo ruminal disappearance of total SCFA (P = 0.01), acetate (P = 0.03), propionate (P = 0.01), and butyrate (P > 0.01). Treatments did not affect (P ≥ 0.10) acetate and butyrate fluxes in the ruminal and colonic tissues when measured ex vivo; however, when compared with CON, AB tended to decrease (P = 0.09) mannitol flux across ruminal tissue. In addition, mannitol flux was affected (P < 0.01) by region, with greater mannitol flux across the jejunum than rumen and colon. We conclude that while both abomasal infusion of CaB and CaG affect the molar proportion of acetate and propionate in the colon, only abomasal CaB stimulated ruminal SCFA absorption for growing beef heifers.

Bioengineered intestinal tubules as a tool to test intestinal biological efficacy of lettuce species

Lettuce (Lactuca sativa) is one of the most consumed and cultivated vegetables globally. Its breeding is focused on the improvement of yield and disease resistance. However, potential detrimental or beneficial health effects for the consumer are often not targeted in the breeding programs. Here, a bioengineered intestinal tubule was used to assess the intestinal efficacy of extracts from five plant accessions belonging to four Lactuca species. These four species include the domesticated L. sativa, closely related wild species L. serriola, and phylogenetically more distant wild relatives L. saligna and L. virosa. We assessed the epithelial barrier integrity, cell viability, cell attachment, brush border enzyme activity, and immune markers. Extracts from L. sativa cv. Salinas decreased cell attachment and brush border enzyme activity. However, extracts from the non-edible wild species L. saligna and L. virosa reduced the epithelial barrier functions, cell attachment, cell viability, and brush border enzyme activity. Since wild species represent a valuable germplasm pool, the bioengineered intestinal tubules could open ways to evaluate the safety and nutritional properties of the lettuce breeding material originating from crosses with wild Lactuca species.

Clinical outcome and gut development after insulin-like growth factor-1 supplementation to preterm pigs.

BackgroundElevation of circulating insulin-like growth factor-1 (IGF-1) within normal physiological levels may alleviate several morbidities in preterm infants but safety and efficacy remain unclear. We hypothesized that IGF-1 supplementation during the first 1–2 weeks after preterm birth improves clinical outcomes and gut development, using preterm pigs as a model for infants.MethodsPreterm pigs were given vehicle or recombinant human IGF-1/binding protein-3 (rhIGF-1, 2.25 mg/kg/d) by subcutaneous injections for 8 days (Experiment 1, n = 34), or by systemic infusion for 4 days (Experiment 2, n = 19), before collection of blood and organs for analyses.ResultsIn both experiments, rhIGF-1 treatment increased plasma IGF-1 levels 3-4 fold, reaching the values reported for term suckling piglets. In Experiment 1, rhIGF-1 treatment increased spleen and intestinal weights without affecting clinical outcomes like growth, blood biochemistry (except increased sodium and gamma-glutamyltransferase levels), hematology (e.g., red and white blood cell populations), glucose homeostasis (e.g., basal and glucose-stimulated insulin and glucose levels) or systemic immunity variables (e.g., T cell subsets, neutrophil phagocytosis, LPS stimulation, bacterial translocation to bone marrow). The rhIGF-1 treatment increased gut protein synthesis (+11%, p < 0.05) and reduced the combined incidence of all-cause mortality and severe necrotizing enterocolitis (NEC, p < 0.05), but had limited effects on intestinal morphology, cell proliferation, cell apoptosis, brush-border enzyme activities, permeability and levels of cytokines (IL-1β, IL-6, IL-8). In Experiment 2, rhIGF-1 treated pigs had reduced blood creatine kinase, creatinine, potassium and aspartate aminotransferase levels, with no effects on organ weights (except increased spleen weight), blood chemistry values, clinical variables or NEC.ConclusionPhysiological elevation of systemic IGF-1 levels for 8 days after preterm birth increased intestinal weight and protein synthesis, spleen weight and potential overall viability of pigs, without any apparent negative effects on recorded clinical parameters. The results add further preclinical support for safety and efficacy of supplemental IGF-1 to hospitalized very preterm infants.

Condensed tannins increased intestinal permeability of Chinese seabass (Lateolabrax maculatus) based on microbiome-metabolomics analysis

Condensed tannins (CT) have been reported to induce intestinal injury of fish, whereas the injury mechanism is unclear. This study evaluated the effects of dietary grape seed CT on growth, intestinal permeability, tight junction structure, intestinal digestive and brush border enzyme activity, bacterial community and intestinal metabolites of Chinese seabass (Lateolabrax maculatus). A total of 640 fish were randomly distributed into 16 tanks with 4 tanks per group and 40 fish per tank. Four diets were formulated to contain 0 (CT0), 1 (CT1), 2 (CT2), and 2 g/kg of CT plus 4 g/kg of polyethylene glycol (PEG) (CT2 + PEG). PEG specifically binds with CT to neutralize CT activity. The experiment was arranged as complete randomized design. Fish were hand-fed to apparent satiation twice daily and the feeding trial lasted for 63 days. Fish fed CT2 had lower (P < 0.05) final body weight, weight gain rate, specific growth rate and feed intake, but higher (P < 0.05) serum diamine oxidase activity and endotoxin level than other diets. Tight junction structures in CT1 and CT2 showed varying degrees of ambiguity and damage. The trypsin activity ranked as CT0 > CT1 > CT2 (P < 0.05). Fish fed CT2 had lower (P < 0.05) activities of lipase, amylase and creatine kinase than other diets. Na+, K+-ATPase activity was lower (P < 0.05) in CT1 and CT2 than in CT0. All parameters were similar (P > 0.05) between CT0 and CT2 + PEG. Intestinal microbiota analysis showed that the abundances of Bacillus, Acinetobacter and Pseudomonas were decreased (P < 0.05) but Clostridium was increased (P < 0.05) as dietary CT increasing. Fish fed CT2 + PEG had higher (P < 0.05) abundances of Bacillus, Acinetobacter and Pseudomonas but lower (P < 0.05) Clostridium than those of fish fed CT2. Bacterial diversity measurements were not affected (P > 0.05) by dietary treatments. Metabolomics analysis indicated that CT altered the intestinal metabolomics profile of L. maculatus. The valeric acid was decreased (P < 0.05), but phenylacetic acid was increased (P < 0.05) as dietary CT increasing. Compared to CT0, CT2 had lower (P < 0.05) isobutyric acid but higher (P < 0.05) butyric acid and isovaleric acid. In conclusion, this study suggests association between reduced growth and increased intestinal permeability and varying intestinal bacterial microbiota and metabolites of L. maculatus. This study warns that dietary CT at 2 g/kg could induce intestinal injury, microecological imbalance and metabolic disorder of fish, and the resulting adverse effects may neutralize by applying polyethylene glycol in fish diets.

Growth and Welfare of Rainbow Trout (Oncorhynchus mykiss) in Response to Graded Levels of Insect and Poultry By-Product Meals in Fishmeal-Free Diets.

Simple SummaryProcessed animal proteins, such as poultry by-product meal (PBM) and insect meal from black soldier fly (BSFM), are receiving growing interest as alternative or complementary protein sources for carnivorous farmed fish diets, due to their high nutritional value and low environmental footprint. The present study aimed to evaluate the effects of PBM and BSFM as partial substitutes for vegetable protein in fishmeal-free diets on growth, whole-body composition, nutrient-energy mass balance and retention, digestive functions, stress, metabolic status, innate immunity, and liver health in rainbow trout (Oncorhynchus mykiss). The overall results showed that fishmeal-free diets, including high levels of both PBM and BSFM, either singly or in combination, improved growth, dietary nutrient and energy utilization, and gut function relative to a plant-protein control diet or a fishmeal-based one, with no detrimental effects on fish welfare.This study compared the nutrient-energy retention, digestive function, growth performance, and welfare of rainbow trout (ibw 54 g) fed isoproteic (42%), isolipidic (24%), fishmeal-free diets (CV) over 13 weeks. The diets consisted of plant-protein replacement with graded levels (10, 30, 60%) of protein from poultry by-product (PBM) and black soldier fly H. illucens pupae (BSFM) meals, either singly or in combination. A fishmeal-based diet was also tested (CF). Nitrogen retention improved with moderate or high levels of dietary PBM and BSFM relative to CV (p < 0.05). Gut brush border enzyme activity was poorly affected by the diets. Gastric chitinase was up-regulated after high BSFM feeding (p < 0.05). The gut peptide and amino acid transport genes were differently regulated by protein source and level. Serum cortisol was unaffected, and the changes in metabolites stayed within the physiological range. High PBM and high BSFM lowered the leukocyte respiratory burst activity and increased the lysozyme activity compared to CV (p < 0.05). The BSFM and PBM both significantly changed the relative percentage of lymphocytes and monocytes (p < 0.05). In conclusion, moderate to high PBM and BSFM inclusions in fishmeal-free diets, either singly or in combination, improved gut function and nutrient retention, resulting in better growth performance and the good welfare of the rainbow trout.

Effect of feeding calcium gluconate embedded in a hydrogenated fat matrix on feed intake, gastrointestinal fermentation and morphology, intestinal brush border enzyme activity and blood metabolites in growing lambs.

Gluconate salts have been identified as a butyrate precursor when fed to non-ruminant species and may increase the butyrate concentration in the large intestine supporting gastrointestinal health and development. The objective of this study was to evaluate the dose response of hydrogenated fat-embedded calcium gluconate (HFCG) on performance and gastrointestinal tract (GIT) development in growing lambs. Thirty-two wether lambs were used in a randomized complete block design and assigned to 1 of 4 treatments differing in the inclusion of HFCG: 0.0% (CON), 0.075% (LOW), 0.30% (MED), and 0.60% of the diet (HIGH). Lambs were allocated into individual pens and fed ad libitum with feed delivered twice daily. Feed intake was recorded daily, and body weight (BW) was assessed at the beginning and the end of the 29-d period. Blood was sampled on day 21, prior to feeding and 6 h post-feeding to evaluate changes in β-hydroxybutyrate, glucose, and insulin concentrations. Total fecal collection was conducted during days 25 to 28 to assess apparent total tract digestibility. On day 29, lambs were slaughtered, and the entire GIT was separated by region to enable sampling of tissue and digesta. Data were analyzed to assess linear, quadratic, and cubic effects of HFCG dose. Final BW, average daily gain, and dry matter intake decreased linearly (P ≤ 0.02) with increasing HFCG. Increasing inclusion of HFCG linearly decreased (P = 0.01) the thickness of the stratum corneum in ruminal papillae but did not affect other strata (P ≥ 0.34). Omasal digesta weight linearly decreased (P = 0.01) as the concentration of HFCG increased and abomasal digesta weight was cubically affected (P = 0.03) the increasing dose of HFCG. Short-chain fatty acid concentration in the cecum was cubically affected (P < 0.01) with increasing dose of HFCG where low dose had the greatest concentration. Moreover, increasing the dietary supply of HFCG linearly increased the proportion of acetate (P = 0.04) in the cecum and linearly decreased the proportion of propionate in the digesta of both the cecum (P < 0.01) and colon (P = 0.01). Colon crypt depth was quadratically (P = 0.03) affected with the increasing dose of HFCG, where lambs fed MED had greatest crypt depth. We conclude that feeding HFCG to growing lambs did not increase butyrate concentration in the large intestine and consequently does not increase the absorptive surface area of the whole tract, the size of the GIT, or the functionality of the intestine.

An emerging role of vitamin D3 in amino acid absorption in different intestinal segments of on-growing grass carp (Ctenopharyngodon idella).

Vitamin D3 (VD3), an essential nutrient for animals, has been demonstrated to stimulate the uptake of certain amino acids. However, the role of VD3 in the intestine, the primary site for digestion and absorption of nutrients, remains poorly characterized. Here, the grass carp (Ctenopharyngodon idella) was studied to assess the influence of different doses of VD3 (15.2, 364.3, 782.5, 1,167.9, 1,573.8, and 1,980.1 IU/kg) on growth performance, intestinal morphology, digestive absorption, amino acid transport, and potential signaling molecule levels in a feeding experiment. As a result, dietary VD3 improved growth performance, intestinal structure, and digestive and brush border enzyme activities. Additionally, most intestinal free amino acids and their transporters were upregulated after VD3 intake, except for Ala, Lys, Asp, Leu, solute carrier (SLC) 7A7, SLC1A5, and SLC1A3 mRNA in different segments, Leu and SLC6A14 mRNA in the proximal intestine, and SLC7A5 mRNA in the mid and distal intestine. In the crucial target of rapamycin (TOR) signal pathway of amino acid transport, the gene and protein expression of TOR, S6 kinase 1, and activating transcription factor 4 were elevated, whereas 4E-binding protein 1 was decreased, further suggesting an advanced amino acid absorption capacity in the fish due to VD3 supplementation. Based on percentage weight gain, feed efficiency, and trypsin activity, the VD3 requirements of on-growing grass carp were estimated to be 968.33, 1,005.00, and 1,166.67 IU/kg, respectively. Our findings provide novel recommendations for VD3 supplementation to promote digestion and absorption capacities of fish, contributing to the overall productivity of aquaculture.

Lactose Glycation of the Maillard-Type Impairs the Benefits of Caseinate Digest to the Weaned Rats for Intestinal Morphology and Serum Biochemistry.

The Maillard reaction between the lactose and milk proteins unavoidably occurs during the thermal treatment of milk. Although the impact of this reaction on protein nutrition and safety has been well-studied, whether a lactose glycation of milk proteins of the Maillard-type might affect the rats in their growth and intestinal morphology needs an investigation. In this study, caseinate and lactose-glycated caseinate were digested using pepsin and trypsin. Afterward, the resultant caseinate digest and glycated caseinate digest (lactose content of 13.5 g/kg of protein) at 100, 200, and 400 mg/kg body weight (BW)/d were assessed for their effects on the female weaned Wistar rats in terms of daily body weight gain, intestinal morphology, digestive and brush-border enzyme activities, as well as serum chemical indices. The results showed that glycated caseinate digest always showed a weaker effect on rat than caseinate digest either at the 0–7 or 0–28 d feeding stage, and more importantly, at the highest dose of 400 mg/kg BW/d, it caused obvious adverse effect on the rats, reflected by lower values of these indices. Compared with caseinate digest, glycated caseinate digest in the rats caused 0.9–15.4% and 10.6–49.7% decreases in average daily gain of BW and small intestinal length, 1.1–21.5% and 2.3–33.3% decreases in villus height and the ratio of villus height to crypt depth of the small intestine, or 0.3–57.6% and 0.2–55.7% decreases in digestive and critical brush-border enzyme activities, respectively. In addition, when the rats were fed with glycated caseinate digest, some serum indices related to oxidative stress status were enhanced dose-dependently. Lactose glycation of the Maillard-type is thus considered as a negative event of the Maillard reaction on milk proteins because this reaction might impair protein benefits to the body.

Maternal High-Fat Diet Exposure During Gestation and Lactation Affects Intestinal Development in Suckling Rats.

Maternal health and diet influence metabolic status and play a crucial role in the development of metabolic function in offspring and their susceptibility to metabolic diseases in adulthood. The pathogenesis of various metabolic disorders is often associated with impairment in intestinal structure and function. Thus, the aim of the current study was to determine the effects of maternal exposure to a high fat diet (HFD), during gestation and lactation, on small intestinal growth and maturation in rat pups at 21 days old. Female, Wistar Han rats were fed either a breeding diet (BD) or high fat diet (HFD), from mating until the 21st day of lactation. Maternal HFD exposure increased body weight, BMI and adiposity. Compared to the maternal BD, HFD exposure influenced small intestine histomorphometry in a segment-dependent manner, changed the activity of brush border enzymes and had an impact on intestinal contractility via changes in cholinergic signaling. Moreover, offspring from the maternal HFD group had upregulated mRNA expression of cyclooxygenase (COX)-2, which plays a role in the inflammatory process. These results suggest that maternal HFD exposure, during gestation and lactation, programs the intestinal development of the offspring in a direction toward obesity as observed changes are also commonly reported in models of diet-induced obesity. The results also highlight the importance of maternal diet preferences in the process of developmental programming of metabolic diseases.

Stages of Gut Development as a Useful Tool to Prevent Gut Alterations in Piglets.

Simple SummaryIntensive growth and development of the piglet’s small intestine is a process that is faster than growth of the whole organism; moreover, it begins early in the prenatal period, accelerating soon after birth and continuing into the post-weaning phase. In fact, during gestation, the gut experiences important morpho-functional changes facilitated by hormones, growth factors, and luminal products. All of these changes are essential to ensure a correct gut function in order to protect animal health and welfare, to ensure optimal productive and reproductive performance, and reduce antimicrobial use.During the prenatal, neonatal, and weaning periods, the porcine gastrointestinal tract undergoes several morpho-functional, changes together with substantial modification of the microbial ecosystem. Modifications of the overall structure of the small intestine also occur, as well as a rapid increase of the volume, mainly in the last period of gestation: intestinal villi, starting from jejunum, appears shortly before the sixth week of gestation, and towards the end of the third month, epithelial cells diversify into enterocytes, goblet cells, endocrine, and Paneth cells. Moreover, in the neonatal period, colostrum induces an increase in intestinal weight, absorptive area, and brush border enzyme activities: intestine doubles its weight and increases the length by 30% within three days of birth. During weaning, intestinal environment modifies drastically due to a replacement of highly digestible sow milk by solid feed: profound changes in histological parameters and enzymatic activity are associated with the weaning period, such as the atrophy of the villi and consequent restorative hypertrophy of the crypts. All these modifications are the result of a delicate and precise balance between the proliferation and the death of the cells that form the intestinal mucosa (i.e., mitosis and apoptosis) and the health conditions of the piglet. An in-depth knowledge of these phenomena and of how they can interfere with the correct intestinal function can represent a valid support to predict strategies to improve gut health in the long-term and to prevent weaning gut alterations; thus, reducing antimicrobial use.

Effect of a Phytogenic Feed Additive on Growth Performance, Nutrient Digestion, and Immune Response in Broiler-Fed Diets with Two Different Levels of Crude Protein.

Simple SummaryThe rising concerns on antibiotics resistance from using antibiotics in animal production has resulted in an increase in researches on antibiotic alternatives. A phytogenic feed additive from a blend of extracts of oregano, cinnamon, citrus peel, and fructooligosaccharides was evaluated in the present study. The objective of the present study is not only to evaluate the effect of phytogenic feed additive on broiler performance, but also to explore the potential mode of actions through immune response, digestive enzyme activities, nutrient transporter gene expressions and nutrient digestibility. Supplementation of phytogenic feed additives improved broiler FCR through stimulating ileum immunity.The aim of this experiment was to evaluate the effect of a phytogenic feed additive (PFA) on growth performance and nutrient digestibility of broilers fed corn and soybean meal-based diets containing two different levels of crude protein. A 2 × 2 completely randomized factorial arrangement (eight replicates/treatment, 30 birds/replicate) was conducted with a positive control (PC) and negative control (NC) containing crude protein at standard or reduced by 1.5% (equivalent to a reduction of 15 g/kg), respectively, and supplementation of PFA at 0 or 125 ppm of diet. There were no significant interactions found between PFA and CP levels in the current study. Main effect analysis showed that during 0–42 d of age NC diets decreased body weight gain (p < 0.05), but increased feed intake (p < 0.05) and feed conversion ratio (FCR, p < 0.01), whereas supplementation of PFA resulted in a lower FCR (p < 0.01). The ileal nutrient digestibility was reduced (p < 0.05) in the broilers fed a reduced protein diet at 21 d compared to the standard protein level group, but there were no effects for PFA levels. Similarly, supplementing PFAs showed no effects on digestive enzyme (Alkaline phosphatase, amylase, and lipase) activity in jejunal digesta and jejunal brush border enzyme (maltase, sucrase, and aminopeptidase) activity. Supplementation of PFA downregulated (p < 0.05) the mRNA expressions of cytochrome P450 1A and interleukin 6 in the ileum but had no effects on nutrient transporter genes in the jejunum. In conclusion, supplementation of PFA reduced broiler FCR during the whole grow-out period and positively regulated the immune responses in the ileum.