Pancreatic-like enzymes of microbial origin restore growth and normalize lipid absorption in a pig model with exocrine pancreatic insufficiency.

INTRODUCTION: The standard therapy for exocrine pancreatic insufficiency (EPI) is porcine-derived pancreatic enzyme replacement therapy (PERT). In the present study we tested a new approach with a mixture of pancreatic-like enzymes of microbial origin (PLEM) in a 1-week efficacy study in EPI pigs. In addition to the conventionally used coefficient of fat and nitrogen absorption (CFA and CNA), parameters that more accurately reflect the nutritional and health status, such as changes in the lipemic index (LI), plasma triglyceride (TG) and non-esterified fatty acid (NEFA) levels, and somatic growth, were determined. MATERIAL AND METHODS: A PLEM dose containing 120 000 active lipase units, 80 000 active protease units and 12 000 active amylase units (all from Sigma, St. Louis, MO) was given as a powder, twice daily with a meal (40 g fat/meal) to 8 EPI pigs for 7 days. Ten healthy pigs were used as a comparator. RESULTS: The PLEM enhanced fat and protein digestion, and reversed growth impairment in EPI pigs. With treatment, CFA and CNA increased by 59% and 43% (p < 0.05), respectively. Although fat and protein absorption were lower than in the comparator, the postprandial blood lipid profile was normal as in healthy pigs. The mucosal thickness significantly increased by 27%, 50% and 26%, in the proximal, middle, and distal jejunum (p < 0.05) with treatment and resembled that of healthy animals. CONCLUSIONS: Pancreatic-like enzymes of microbial origin supported somatic growth and normalized the postprandial lipid profile. As a measure of efficacy, postprandial LI, TG and NEFA are viable endpoints to be explored in human trials.

Immune suppression by cyclosporin A inhibits phytohemagglutinin-induced precocious gut maturation in suckling rats.

OBJECTIVES: Enteral exposure to the lectin phytohemagglutinin (PHA) provokes precocious gut maturation in suckling rats coinciding with an early expansion of intestinal mucosal T and B lymphocytes. Here, the role of the immune system in neonatal gut growth and maturation was further studied. MATERIALS AND METHODS: The effects of immunosuppression by cyclosporine A (CyA), 7.5 microg/g of body weight, injected 12 hours before and then daily after the intragastric gavage of PHA, 100 microg/g body weight, to 14-day-old suckling rats were studied after 4 and 12 hours and later after 72 hours. RESULTS: At 4 hours after PHA feeding, an early rapid increase in the intestinal levels of the proinflammatory cytokines interleukin-6, interleukin-1beta, and tumor necrosis factor was obtained, and the CyA treatment did not prevent the temporary PHA-induced intestinal disturbance seen at 12 hours. Later, at 72 hours after PHA gavage the CyA treatment significantly counteracted the PHA-induced gut changes with a decrease in small intestinal growth, a delay in the appearance of adult-phenotype enterocytes in the distal small intestinal, and total inhibition of the PHA-induced pancreas development. Additionally, the increase in plasma level of the acute phase protein, haptoglobin, after PHA feeding was dampened by CyA. CONCLUSIONS: The results indicate that proinflammatory cytokines are involved in the early recruitment of lymphocytes to the gut after PHA challenge, and that the ensuing precocious gut maturation is dependent on activation of the immune system, presumably T cells, in suckling rats.

The effect of long-term lactobacilli (lactic acid bacteria) enteral treatment on the central nervous system of growing rats.

The aim of this study was to explore the relationship between consumption of large doses of lactic acid bacteria (LAB) and the behaviour and brain morphobiochemistry of normal growing rats. Four groups of rats were treated with LAB cultures twice daily for 6 months. The control group received 1 ml of saline per treatment, while two experimental groups received 1 ml of living bacteria (Lactobacillus plantarum and Lactobacillus fermentum, respectively) and the remaining group received a heat-treated (inactivated) L. fermentum culture. After 2 and 6 months of treatment, respectively, eight animals from each group were sacrificed, and specimens were taken for further analyses. The behaviour of the rats was evaluated five times in an open-field test at monthly intervals throughout the study. Lactobacilli treatment for 2 months induced changes in the motoric behaviour of the rats. The concentration of the astrocytesoluble and filament glial fibrillary acidic protein (GFAP) decreased in the posterior part of the hemispheres, including the thalamus, hippocampus and cortex of the rats treated with L. fermentum. A greater decrease in filament GFAP (up to 50%) was shown in the group receiving the live form of L. fermentum. In contrast, the GFAP in the live L. plantarum-treated group increased, showing elevated levels of the soluble and filament forms of GFAP in the posterior part of the hemispheres. A 60-66% decrease in the amount of the astrocyte-specific Ca-binding protein S-100b was shown in the posterior parts of the hemispheres and in the hindbrain of rats given LAB for 2 months. Prolonged feeding with LAB for 4 months up to full adulthood led to a further decrease in astrocyte reaction, reflected as an additional decrease in the amount of soluble GFAP and locomotor activity in all experimental groups. The changes in filament GFAP and S-100b appeared to disappear after prolonged feeding (total of 6 months) with LAB. In summary, LAB dietary treatment affected the ontogenetic development of the astrocytes, with the highest intensity observed in the early stages of rat development. It can be postulated that LAB treatment may play a preventive role in neurological diseases by decreasing astrocyte reaction and, consequently, lowering locomotor activity.

Precocious gut maturation and immune cell expansion by single dose feeding the lectin phytohaemagglutinin to suckling rats.

The dietary lectin phytohaemagglutinin (PHA) induces gut growth and precocious maturation in suckling rats after mucosal binding. The present study investigated the dose range in which PHA provokes gut maturation and if it coincided with immune activation. Suckling rats, aged 14 d, were orogastrically fed a single increasing dose of PHA: 0 (control), 2, 10, 50 or 250 microg/g body weight (BW) in saline. The effect on gut, lymphoid organs and appearance of CD3+ (T-lymphocyte) and CD19+ (B-lymphocyte) cells in the small-intestinal mucosa was studied at 12 h (acute) and 3 d (late phase) after treatment. The low PHA doses (2 and 10 microg/g BW) induced intestinal hyperplasia without mucosal disarrangement but did not provoke gut maturation. Only the high PHA doses (50 and 250 microg/g BW) temporarily disturbed the intestinal mucosa with villi shortening and decrease in disaccharidase activities, and later after 3 d provoked precocious maturation, resulting in an increase in maltase and sucrase activities and decrease in lactase activity and disappearance of the fetal vacuolated enterocytes in the distal small intestine. Exposure to the high, but not to the low, PHA doses increased the number of mucosal CD19+ and CD3+ cells in the small intestine after 12 h, a finding also observed in untreated weaned rats aged 21-28 d. In conclusion, there was a dose-related effect of PHA on gastrointestinal growth and precocious maturation that coincided with a rapid expansion of mucosal B- and T-lymphocytes, indicating a possible involvement of the immune system in this process.

Binding and the effect of the red kidney bean lectin, phytohaemagglutinin, in the gastrointestinal tract of suckling rats.

Enteral exposure of suckling rats to phytohaemagglutinin (PHA) has been shown to induce growth and precocious functional maturation of the gastrointestinal tract. The aim of the present study was to explore the mechanism of this action. Suckling rats, 14 d old, were fed a single dose of PHA (0.05 mg/g body weight) or saline. The binding of PHA to the gut epithelium and its effect on the morphology and functional properties of the gut and pancreas were studied up to 3 d after treatment. Initially, at 1-24 h, the PHA bound along the gut mucosal lining, resulting in disturbed gut morphology with villi shortening and rapid decreases in disaccharidase activities and macromolecular absorption capacity. During a later phase, between 1 and 3 d, the PHA binding had declined, and an uptake by enterocytes was observed. An increase in crypt cell proliferation and gut growth became evident during this period, together with a functional maturation, as indicated by increases in disaccharidase (maltase and sucrase) activities and the low macromolecular absorption capacity. Pancreas growth also increased, as did its content of digestive enzymes. We conclude that enteral exposure to PHA in suckling rats temporarily causes mucosal disarrangement and functional impediment of the gut, which may be explained by binding to and disruption of the gut mucosa and a two-fold increase in the plasma corticosterone concentration. These findings may lead to a better understanding of the role of diet in gastrointestinal maturation and may constitute a basis for the treatment of mammals having an immature gut.

Enterally but not parenterally administered Phaseolus vulgaris lectin induces growth and precocious maturation of the gut in suckling rats.

BACKGROUND: The lectin, phytohemagglutinin (PHA) has been shown to induce growth and functional maturation of the gastrointestinal (GI) tract in suckling rats. OBJECTIVES: To investigate the effect of the administration route, and whether enteral exposure to PHA was necessary to induce functional maturation. METHODS: Fourteen-day-old rats were daily administered PHA via orogastric feeding (0.05 mg PHA/g BW) or via subcutaneous injection (0.05 or 0.005 mg PHA/g BW) for 3 days, while the controls received saline orogastrically. At 17 days of age, organ weight, intestinal and pancreatic function, and plasma corticosterone levels were analyzed. Moreover, 14-days old pups receiving a single dose of PHA, enterally or parenterally, were sacrificed after 12 h and examined for organ PHA binding using immunohistochemistry. RESULTS: Enteral PHA exposure resulted in PHA binding in the epithelial lining of the small intestine, increased gastrointestinal growth, reduced intestinal macromolecular absorption, altered the disaccharidase expression towards an adult-like pattern, and increased the pancreatic protein and trypsin contents. In contrast, parenteral PHA exposure (high dose) resulted in PHA-binding in extra-intestinal organs, increased liver and spleen weight, and decreased thymus weight. Moreover, the intestinal maltase activity increased moderately, and the transfer of BSA to blood plasma was partially reduced. Both PHA treatments led to elevated plasma corticosterone levels. CONCLUSION: These results demonstrated that enteral exposure to PHA was necessary to induce the precocious maturation of the GI tract and the pancreas, while parenteral administration affects the extra-intestinal organs. Furthermore, the enteral effects were probably not mediated via a corticosteroid dependent pathway.