Effect of protein source in calf milk replacers on morphology and absorptive ability of small intestine

Holstein calves were fed milk or one of four milk replacers with one-third of the total protein supplied by casein, soy protein concentrate, soy flour, or fish protein concentrate. The remainder of the protein in each replacer was from milk sources. Milk and milk replacers (13% solids) were fed at 10% of body weight daily. No dry feed or bedding was provided. Absorptive ability of small intestine was evaluated by xylose absorption test at 2-wk intervals. With calves under general anesthesia, a biopsy of small intestine was taken after each xylose test to examine morphological changes in mucosa by scanning electron microscopy. Villi were long, tapering, and uniform in calves fed milk. Calves fed casein had greater variation in size and conformation of villi. Gradual deterioration in villous integrity was seen in calves fed soy proteins. Calves fed fish protein concentrate performed poorly and had abnormal villi. Diets were changed to milk to test for reversal of effects after marked alterations in intestinal structure had been observed. Atrophy was reversed as villi returned toward normal size and shape within 2 wk after milk feeding began. The surgical procedure apparently did not cause harmful effects of villi. Absorption of xylose and daily gain were greater, and feces firmer, in calves fed milk than in those fed milk replacers.     

The absorption function of the small intestine and the effect on it of diet therapy in food allergy in children]

Small intestine absorption function was studied in 46 children with food allergy basing on the results of D-xylose test and estimating protein absorption by blood serum ovalbumin assay in circulating immune complexes. Decreased carbohydrate and increased protein absorption was recorded in the small intestine of the patients and the normalizing effect of the elimination diet on these changes was shown.     

Scanning electron microscopy of microbes and their mechanism of attachment to human small intestinal mucosa

In connection with the electron-microscopy of bioptic material from the upper small intestine of children with intestinal diseases and diarrhea (10 months to 8 years) we found some cases of fungus infection (26%) besides many cases of bacterial attachment to the intestinal epithelium (72%). On the intestinal wall normal yeasts, pseudomycelium and common mycelium are visible. Partly the epithelium was entirely covered with mycelium. In some cases the hyphae invaded in the intestinal wall. The epithelium and the villi are not or only slightly altered. This gives the reason to believe that the fungi participate in inducing diarrhea. After medicamentous treatment with nystatine-preparations in some cases the health state of these children was improved.     

Morphometry characteristic of the gut mucous membranes condition in growing rats with different selenium provision

The purpose of the given work was to research an influence of polysynthetic diet with various levels of selenium on a condition of distal small intestine mucous membranes in rats. Mucous membranes of distal small intestine were studied by common morphological and morphometrical methods. The histological estimation of influence of quantity of consumed selenium has shown that adverse changes in a mucous membrane of intestines of the rats receiving low selenium diet are most expressed, and least--at the animals receiving a diet as much as possible enriched organic form of selenium.     

Effect of rations with a varying content of polyunsaturated fatty acids and vitamins on the state of the small intestine in respect of age]

Groups of young sexually mature and old albino rats were kept for three months on 4 isocaloric rations, viz. balanced, with reduced proportion of essential fatty acids or group 'B' vitamins and with simultaneous curtailment of fatty acids and vitamins. With vitamin deficiency there was a certain derangement in the structure and function of the small intestine, especially in older animals. A shortage of essential fatty acids impaired the condition of the small intestine only in old animals. In cases of concurrent deficiency of vitamins and essential fatty acids maximal changes in both young and old animals were in evidence.     

Pathogenesis of food poisoning due to enterococci

The enteropathogenic properties of enterococci having proteolytic characteristics were studied in experiments on isolated loops of the rat and rabbit small intestine. It was shown that Str. faecalis v. liguefaciens (4 strains) and Str. faecalis zymogenes (1 strain) possess enteropathogenic properties. However, the degree of pathogenicity varied, which was confirmed by characteristic macro- and microscopic changes seen in the ligated loops of the small intestine of the experimental animals.     

The synthesis and absorption of pantothenic acid in the gastrointestinal tract of the adult sheep

A microbiological assay using Lactobacillus plantarum was used to determine the levels of pantothenic acid (PA) in food and digesta samples from sheep fitted with duodenal and ileal re-entrant cannulas, given a variety of diets. ACP-bound PA was not measured. With most of the diets studied there was an increase in ‘total’ PA and CoA-bound PA before the small intestine. Both the increase in CoA-bound PA prior to the duodenum and the ‘total’ PA reaching the duodenum were positively and significantly related to the microbial dry matter synthesised in the rumen. Free PA at the duodenum was significantly related to the dietary intake of free PA. The apparrent absorption of total PA within the small intestine was significantly related to the quantity entering the small intestine suggesting a passive absorption mechanism. It is suggested that CoA-bound PA entering the small intestine is hydrolysed to release free PA which is then available for absorption.     

可溶性大豆多糖改善左旋肉碱诱导的小鼠小肠首过代谢

目的：研究大豆可溶性多糖（soybean soluble polysaccharides,SSPS）对左旋肉碱喂养小鼠的小肠代谢、氧化应激和炎症相关蛋白表达的影响。方法：24 只雄性昆明小鼠随机分成正常组、左旋肉碱组、SSPS组3 个实验组。连续饲喂56 d后处死小鼠,测定小鼠小肠内P-糖蛋白（P-glycoprotein,P-gp）、多药耐药性蛋白（multidrug resistanceproteins,MRP）1、MRP3、白细胞介素（interleukin,IL）-1、IL-6、肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）质量浓度和尿苷二磷酸葡萄糖醛酸基转移酶（uridine diphosphate glucuronosyltransferase,UGT）活力、硫酸基转移酶（sulfotransferase,SULT）活力、丙二醛（malondialdehyde,MDA）浓度等的变化。结果：与正常组相比,左旋肉碱组小鼠小肠具有更高的P-gp和MRP3质量浓度（P＜0.05）;而SSPS可使左旋肉碱喂养小鼠小肠内P-gp质量浓度显著降低（P＜0.05）,且使MRP3质量浓度轻微下降,表明SSPS可有效抑制左旋肉碱诱导的首过代谢。此外,SSPS与左旋肉碱联合处理可有效避免小鼠小肠组织MDA浓度的增加、超氧化物歧化酶活力的下降和·OH清除能力的减弱,预示SSPS可抑制长期摄入左旋肉碱诱导的氧化应激。然而,所有小鼠小肠组织的SULT和UGT活力以及IL-1、IL-6、TNF-α质量浓度没有显著变化（P＞0.05）,表明过量左旋肉碱和SSPS处理不会影响II相代谢,也不会导致炎症反应。此外,代谢组学分析表明,SSPS可抑制长期过量摄入左旋肉碱导致的能量代谢及脂质代谢紊乱。结论：SSPS可以通过调控氧化应激和代谢紊乱而有效预防左旋肉碱诱导的小鼠小肠首过代谢。     

Regulatory role of phosphoproteins in the development of bovine small intestine during early life

The small intestine is the primary site of nutrient digestion and absorption, which plays a key role in the survival of neonatal calves. A comprehensive assessment of the phosphoproteomic changes in the small intestine of neonatal calves is unavailable; therefore, we used phosphopeptide enrichment coupled with liquid chromatography-tandem mass spectrometry to investigate the changes in the phosphoproteome profile in the bovine small intestine during the first 36 h of life. Twelve neonatal male calves were assigned to one of the following groups: (1) calves not fed colostrum and slaughtered approximately 2 h postpartum (n = 3), (2) calves fed colostrum at 1 to 2 h and slaughtered 8 h postpartum (n = 3), (3) calves fed 2 colostrum meals (at 1–2 and 10–12 h) and slaughtered 24 h postpartum (n = 3), (4) calves fed 3 colostrum meals (at 1–2, 10–12, and 22–24 h) and slaughtered 36 h postpartum (n = 3). Mid-duodenal, jejunal, and ileal samples of the calves were collected after slaughter. We identified 1,678 phosphoproteins with approximately 3,080 phosphosites, which were mainly Ser (89.9%), Thr (9.8%), and Tyr (0.3%) residues; they belonged to the prodirected (52.9%), basic (20.4%), acidic (16.6%), and Tyr-directed (1.7%) motif categories. The regional differentially expressed phosphoproteins included zonula occludens 2, sorting nexin 12, and protein kinase C, which are mainly associated with developmental processes, intracellular transport, vesicle-mediated transport, and immune system process. They are enriched in the endocytosis, tight junction, insulin signaling, and focal adhesion pathways. The temporal differentially expressed phosphoproteins included occludin, epsin 1, and bridging integrator 1, which were mainly associated with macromolecule metabolic process, cell adhesion, and growth. They were enriched in the spliceosomes, adherens junctions, and tight junctions. The observed changes in the phosphoproteins in the tissues of small intestine suggest the protein phosphorylation plays an important role in nutrient transport and immune response of calves during early life, which needs to be confirmed in a larger study.     

抗性淀粉体外消化模拟的研究

采用体外消化模拟方法,研究了抗性淀粉在人工胃肠液和大肠液中的消化吸收情况,并用原淀粉作为对照组。结果表明,抗性淀粉和原淀粉在生理盐水中均没有被分解,生理盐水对抗性淀粉的消化毫无影响。与对照组原淀粉相比,抗性淀粉在人工胃液(pH3、pH4、pH5)和人工肠液(pH6.8)中变化很小,人工胃液和人工肠液对抗性淀粉不起消化作用。抗性淀粉在大肠液中有明显的失重,说明大肠液对抗性淀粉有影响,抗性淀粉能够被大肠中的微生物发酵或部分发酵。从而说明抗性淀粉不能在胃和小肠中消化吸收。     

Short communication: Comparison of the newly developed DVE/OEB (2010) system and the National Research Council (2001) model in modeling metabolic characteristics of proteins in dairy cattle

The truly absorbed protein in the small intestine/degraded protein balance (DVE/OEB)₂₀₁₀ system is a recently developed protein evaluation system for ruminants. The objective of this study was to compare the DVE/OEB₂₀₁₀ system with the National Research Council (2001) model in determining the metabolic characteristics of proteins in dairy cattle. The metabolic characteristics of proteins in bioethanol feedstock and their co-products were compared in terms of (1) truly absorbed rumen synthesized microbial protein in the small intestine; (2) truly absorbed rumen undegraded feed protein in the small intestine; (3) endogenous protein in the digestive tract; (4) total truly absorbed protein in the small intestine; and (5) protein degraded balance. The DVE/OEB₂₀₁₀ system predicted 30% more truly absorbed rumen synthesized microbial protein in the small intestine, 4% more truly absorbed rumen undegraded feed protein in the small intestine, 64% more endogenous protein, 9% more total truly absorbed protein in the small intestine, but 27% less degraded protein balance.     

Microbial protein synthesis and flows of nitrogen fractions to the duodenum of dairy cows.

Attempts have been made to increase nutrient availability for milk production by increasing feed intake, optimizing ruminal fermentation, and supplementing nutrients to the diet that will escape ruminal degradation. Energy and N are the nutritional factors that most often limit microbial growth and milk production. Ruminal fermentation and flow of microbial and dietary protein to the small intestine are affected by feed intake and by the amount and source of energy and protein in the diet. Feeding protein and carbohydrate that are not degraded in the rumen increases the quantity of dietary protein that passes to the small intestine but may decrease the quantity of microbial protein that is synthesized in the rumen. This often results in only small differences in the total NAN that passes to the small intestine. Because microbial protein supplies a large quantity of total AA that passes to the small intestine, differences in passage of individual AA often are only slight. Additional research with cows consuming large amounts of feed are needed to identify combinations of feed ingredients that synchronize availabilities of energy and N for optimizing ruminal digestion, microbial protein synthesis, nutrient flow to the small intestine, and milk production and composition.     

Effects of the oral administration of the products derived from milk fermentation by kefir microflora on immune stimulation

Nutritional status has a major impact on the immune system. Probiotic effects ascribed to fermented dairy products arise not only from whole microorganisms but also from metabolites (peptides, exopolysaccharides) produced during the fermentation. We recently demonstrated the immunomodulating capacity of kefir in a murine model. We now aimed at studying the immunomodulating capacity in vivo of the products derived from milk fermentation by kefir microflora (PMFKM) on the gut. BALB/c mice received the PMFKM for 2, 5 or 7 consecutive days. IgA+ and IgG+ cells were determined on histological slices of the small and large intestine. IL-4, IL-6, IL-10, IL-12, IFNgamma and TNFalpha were determined in the gut, intestinal fluid and blood serum. IL-6 was also determined in the supernatant of a primary culture of small intestine epithelial cells challenged with PMFKM. PMFKM up-regulated IL-6 secretion, necessary for B-cell terminal differentiation to IgA secreting cells in the gut lamina propria. There was an increase in the number of IgA+ cells in the small and large intestine. The increase in the number of IgA+ cells was accompanied by an increase in the number of IL-4+, IL-10+ and IL-6+ cells in the small intestine. Effects of PMFKM in the large intestine were less widely apparent than the ones observed at the small intestine lamina propria. All cytokines that increased in the small intestine lamina propria, also did so in blood serum, reflecting here the immunostimulation achieved in the gut mucosa. We observed that the PMFKM induced a mucosal response and it was able to up and down regulate it for protective immunity, maintaining the intestinal homeostasis, enhancing the IgA production at both the small and large intestine level. The opportunity exists then to manipulate the constituents of the lumen of the intestine through dietary means, thereby enhancing the health status of the host.     

The effect of dietary fibre on bacterial densities in the rat intestine

When non-absorbable food polysaccharides were included in the diet of rats, changes in the distribution of bacteria in intestinal contents were seen. Male Wistar rats were fed a starch-containing fibre-free diet, or a similar diet in which guar gum (40 g kg⁻¹) or cellulose (100 g kg⁻¹) were substituted for an equivalent portion of starch. A fourth group received a commercial pelleted feed. After a 4-week feeding period, the densities (viable count per g contents) of aerobic and anaerobic bacteria in the lumen of the small intestine and caecum were estimated and the concentration of short chain fatty acids (SCFA) in the caecal contents measured.The proximal small intestine from the pellet-fed and the guar-fed rats contained a significantly higher density of anaerobic bacteria than the fibre-free group or the rats fed cellulose. In the caecum, the guar-fed rats had a higher density of anaerobic bacteria than the fibre-free controls, whilst the cellulose-fed group had a lower density. SCFA concentrations in the caecal contents of these three groups were similar. However, although the concentration of SCFA in the caecal contents of the pellet-fed animals was higher than any other group, the density of bacteria was significantly lower than in either the guar-fed or fibre-free animals.It was concluded that dietary fibre influences the distribution of anaerobic bacteria in the small intestine of the rat and alters both the numbers of bacteria and the level of SCFA in the caecum.     

Structural and functional findings in experimental blind loop syndrome

Proximal and distal the blindsack a villus and crypt prolongation connected with a decreasing absorption of octanoate could be pointed out. The structural changes are very likely a hyperplasia of the mucosa. Within the blindsack a hyperplasia in connection with an accelerated proliferation of cells and an almost three and a halffold enlargement of the surface of the villi could be found. Simultaneously, the mucosa was damaged. An artificial bile duct as well as a neomycin therapy caused a decrease of the structural and functional changes but did not prevent the mucosal hyperplasia. These results are explained with adaptive processes of the small intestinal mucosa in a sense of hyperregeneration alterations of sprue typus.     

Nutritional toxicity of raw kidney beans in pigs. Immunocytochemical and cytopathological studies on the gut and the pancreas

The inclusion of raw kidney beans (Phaseolus vulgaris cv. Processor) in diets of growing pigs resulted in loss of appetite, growth depression and intermittent scouring. Immunocytochemical and morphological investigations showed extensive disruption of intestinal microvilli in those areas of the small intestine where dietary bean lectins were bound to the mucosal surfaces. Degenerative changes were also present in pancreatic acinar cells of pigs fed on kidney beans. These changes were not a direct effect of the bean lectins but may have been related to the disturbances in the gut.     

海地瓜岩藻聚糖硫酸酯对环磷酰胺损伤小鼠小肠粘膜的保护作用

目的探讨海地瓜岩藻聚糖硫酸酯,包括原糖及其不同分子量酶解产物(50、100、500kD)对环磷酰胺造成的小鼠小肠粘膜损伤的改善作用,幵对其机制进行探究。方法 60只Balb/c小鼠随机分成6组:空白对照组,环磷酰胺模型组,环磷酰胺损伤小鼠分别干预原糖及50、100、500kD酶解产物组,每组10只。实验周期为14 d,干预组分别ig给予50 mg/(kg·bw)海地瓜岩藻聚糖硫酸酯,第12和13 d给除空白对照组以外小鼠连续ip给予50 mg/(kg·bw)环磷酰胺。测定小鼠体重变化,器官指数变化;采用苏木精-伊红染色法检测小肠组织形态学变化;采用实时荧光定量PCR技术检测溶菌酶、黏蛋白(mucin2,Muc2)、干细胞标志物(leucine-rich repeat-containing G-protein coupled receptor5,Lgr5)mRNA表达水平,幵通过Toll样受体(toll-like receptors, TLRs)和髓样分化因子(myeloid differentiation factor88, MyD88)基因表达的变化探究其作用机制。结果 100 kD和50 kD组枀显著(P0.01)改善环磷酰胺造成的小鼠体重下降; 50 kD组显著(P0.05)提高绒毛长度和隐窝深度比值,改善小鼠小肠形态破坏; 100 kD组和50 kD组小肠溶菌酶、Muc2基因表达量显著高于Cy组,不同分子量的酶解产物均能显著提高Lgr5以及小肠TLRs (TLR-4, TLR-5, TLR-9)和MyD88的基因表达量,且50kD组的改善作用最好。结论酶解片段对化疗型小鼠小肠粘膜损伤的保护效果优于原糖,且50 kD效果最好,作用机制可能与对TLRs/MyD88信号通路的调节有关。     

Effect of dietary sub-lethal doses of lima bean lectin on relative organ weights, pancreatic and intestinal trypsin (EC 3.4.21.4) and chymotrypsin (EC 3.4.21.1) in the rat

The dietary implications of feeding sub-lethal doses of extracted and purified lectin from lima bean were assessed in weanling rats using changes in relative organ weights, pancreatic and intestinal trypsin and chymotrypsin activities as the response indices. Liver weights decreased significantly (p less than 0.05) while the heart showed a slight but non-significant increase in response to dietary lectin levels. The kidneys, pancreas and spleen were not significantly affected by dietary lectin. Although the activities of the pancreatic enzymes tended, for the most part, to decrease with increasing dietary lectin, such decreases were not significant when compared with the control. Intestinal trypsin and chymotrypsin activities were significantly (p less than 0.05) decreased in the small intestine while the activity values in both the large intestine and caecum were relatively unaffected. Activities of both enzymes showed significant (p less than 0.05) negative quadratic relationship with dietary lectin levels in the small intestine as judged by the magnitude of the R2, coefficients of multiple determination, of 0.77 and 0.76 for trypsin and chymotrypsin respectively.     

Effect of supplementation with Cu and Zn on antioxidant enzyme activity in the rat tissues

The activities of antioxidant enzymes—copper, zinc- and manganese-superoxide dismutase (CuZnSOD and MnSOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and glutathione reductase (GR)—were examined in the liver, heart, small intestine and brain, after supplementation with chelated forms of Cu and Zn. In the supplemented animals increased activity of CuZnSOD were found in the liver and heart. Activity of MnSOD and GSH-Px in the heart and GSH-Px in small intestine was decreased. After 43 days of Cu and Zn supplementation no changes in enzymes activity in the rats brain were found. The increased CuZnSOD activity in liver and heart after supplementation may be due to increased levels of the accumulation of excess Cu and Zn in these tissues. Decreased activity of other antioxidant enzymes could be the consequence of establishing a new antioxidant homeostasis, as Zn and Cu may act as antioxidants.     

Zinc absorption from the small intestine in young calves.

Zinc-65 was injected directly into various sites throughout the small intestine of Holstein calves fed a low zinc diet. Zinc absorption was determined by comparing zinc-65 content of blood, liver, kidney, lung, heart, pancreas, rib, muscle, and other tissues. Tissue zinc-65 was plotted against site of injection expressed as percentage of intestinal length from proximal to distal ends. Zinc absorption occurred throughout the small intestine with the amount absorbed per centimeter of length about equal throughout the small intestine. This is in contrast to conclusions from studies of rats indicating more absorption in the proximal part of the small intestine. The difference appears to have been due to artifacts in the procedures with rats. However, species and dietary differences may have affected relative findings between this and earlier work.