Serum lipid mediator profiles in COVID-19 patients and lung disease severity: a pilot study.

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection is highly heterogeneous, ranging from asymptomatic to severe and fatal cases. COVID-19 has been characterized by an increase of serum pro-inflammatory cytokine levels which seems to be associated with fatal cases. By contrast, the role of pro-resolving lipid mediators (SPMs), involved in the attenuation of inflammatory responses, has been scarcely investigated, so further studies are needed to understand SPMs metabolism in COVID-19 and other infectious diseases. Our aim was to analyse the lipid mediator metabolome, quantifying pro- and anti-inflammatory serum bioactive lipids by LC-MS/MS in 7 non-infected subjects and 24 COVID-19 patients divided into mild, moderate, and severe groups according to the pulmonary involvement, to better understand the disease outcome and the severity of the pulmonary manifestations. Statistical analysis was performed with the R programming language (R Foundation for Statistical Computing, Vienna, Austria). All COVID-19 patients had increased levels of Prostaglandin E2. Severe patients showed a significant increase versus controls, mild- and moderate-affected patients, expressed as median (interquartile range), in resolvin E1 [112.6 (502.7) vs 0.0 (0.0) pg/ml in the other groups], as well as in maresin 2 [14.5 (7.0) vs 8.1 (4.2), 5.5 (4.3), and 3.0 (4.0) pg/ml, respectively]. Moreover, 14-hydroxy docosahexaenoic acid (14-HDHA) levels were also increased in severe vs control and mild-affected patients [24.7 (38.2) vs 2.4 (2.2) and 3.7 (6.4) ng/mL, respectively]. Resolvin D5 was also significantly elevated in both moderate [15.0 (22.4) pg/ml] and severe patients [24.0 (24.1) pg/ml] versus controls [0.0 (0.0) pg/ml]. These results were confirmed by sparse partial least squares discriminant analysis which highlighted the contribution of these mediators to the separation between each of the groups. In conclusion, the potent inflammatory response to SARS-CoV-2 infection involves not only pro- but also anti-inflammatory lipid mediators that can be quantified in easily accessible serum samples, suggesting the need to perform future research on their generation pathways that will help us to discover new therapeutic targets.

Concentration and solubility of flavanones in orange beverages affect their bioavailability in humans.

Orange juice is a very rich source of dietary flavanones. The effect of flavanone concentration and solubility of orange beverages on their bioavailability has been studied in a crossover study with 10 healthy volunteers. Five different beverages with different flavanone concentrations were evaluated. Commercial orange juices (29.2-70.3 mg of flavanones/100 mL) were compared with experimental orange beverages in which the flavanone concentration was enhanced (110.2 mg/100 mL). Hesperetin and naringenin glucuronides and sulfates were detected and quantified in plasma and urine. The study shows that the solubility of the flavanones, and particularly that of hesperidin, in the juice is a key factor for the bioavailability as flavanone excretion and the C(max) in plasma correlate well with the soluble flavanone concentration in the juice, whereas it has no correlation with the total flavanone intake. In addition, a large interindividual variation was observed, this being consistent for each individual after the intake of the different beverages, suggesting that flavanone bioavailability is also dependent on the occurrence of specific microbiota that is able to remove the rutinosides from the juice glycosides, which results in aglycones that are then absorbed from the gut.

Micronutrient bioavailability research priorities.

A micronutrient bioavailability workshop, which involved international experts and members of the scientific community and the food industry, with interactive breakout sessions based on synectics principles, was organized by the International Life Sciences Institute Europe Addition of Nutrients to Food Task Force and the European Commission Network of Excellence European Micronutrient Recommendations Aligned. After presentations by experts, a series of "challenge statements" was discussed. The aim was to address topical issues, in particular those that linked bioavailability with the derivation of micronutrient requirements and dietary recommendations, to identify gaps in knowledge and to consider research priorities. Several generic research priorities were identified, including improving the quality of dietary surveys/food composition tables, the need for more metabolic studies that use stable isotopes and high-quality longer-term interventions, and the development of multifactorial mathematical models. Among the common recurrent factors identified as important were polymorphisms/genotype, consideration of the whole diet, chemical form of the micronutrient, and the determination of physiologic requirements. The involvement of all participants in the structured discussions ensured a broad overview of current knowledge, state-of-the-art research, and consideration of priorities for future research.

Intestinal and immunological effects of daily oral administration of Lactobacillus salivarius CECT5713 to healthy adults.

There is an increasing interest in the intestinal and immunological effects of probiotics. The aim of the present study is to evaluate the tolerance and beneficial effects in healthy adults of the strain, Lactobacillus salivarius CECT5713 isolated from breast milk. A phase II, randomized, double-blinded, placebo-controlled human clinical trial was carried out in 40 healthy adults. The Probiotic group received a daily dose of 2 x 10(8) CFU of L. salivarius CECT5713 in capsules during 4 weeks while volunteers of the control received only a placebo. Gastrointestinal and immunological parameters were analyzed. Results showed that L. salivarius CECT5713 was well tolerated and no adverse effects were detected. Consumption of the probiotic strain increased fecal lactobacilli counts (7.9+/-0.1 vs. 7.05+/-0.2 CFU/g feces, P=0.001). Also, an improvement in the frequency of defecation (P=0.04) was observed. Probiotic treatment induced significantly the percentage of NK cells and monocytes, as well as the plasmatic levels of immunoglobulins M, A and G, and the regulatory cytokine IL-10 (72.3+/-11.7 in probiotic group vs. 27.3+/-6.4 pg/mL in control group, P<0.01). Thus, it can be concluded that daily administration of L. salivarius CECT5713 to healthy adults is safe and improve gut microbiota and different parameters related to immune response.

Safety and tolerance of the human milk probiotic strain Lactobacillus salivarius CECT5713 in 6-month-old children.

OBJECTIVE: Intestinal microbiota plays an important role in the prevention of certain diseases during the pediatric years. Thus, there is an increasing interest in the addition of probiotics to infant formulas. The aim of this study was to evaluate the safety of a follow-on formula with Lactobacillus salivarius CECT5713 in 6-mo-old children. METHODS: The antibiotic susceptibility of L. salivarius CECT5713 was analyzed by a dilution method. A double-blinded, randomized, placebo controlled study was performed. Children (n = 80) were distributed in two groups and consumed the formula supplemented or not with probiotics (2 × 10(6) colony-forming units [cfu]/g) during 6 mo. Fecal samples were collected at enrollment, at 3 mo, and at the end of trial. Clinical and anthropometric evaluations were performed. Depending on the variable, one-way or two-way repeated measures analysis of variance were used for the statistical analysis. RESULTS: The antibiotic susceptibility profile of the strain resulted as safe. No adverse effects associated with the consumption of the probiotic formula were reported. In addition, clinical parameters did not differ between groups. Consumption of the probiotic supplemented formula led to an increase in the fecal lactobacilli content (7.6 ± 0.2 versus 7.9 ± 0.1 log cfu/g, P < 0.05). Lactobacillus salivarius CECT5713 was detected in the feces of volunteers from the probiotic group. Probiotic consumption induced a significant increase in the fecal concentration of butyric acid at 6 mo. CONCLUSION: Thus, a follow-on formula with L. salivarius CECT5713 is safe and well tolerated in 6-mo-old infants.

A probiotic dairy product containing L. gasseri CECT5714 and L. coryniformis CECT5711 induces immunological changes in children suffering from allergy.

The increase in the prevalence of allergic diseases in children has been attributed to an unbalanced immune response probably due to environmental factors. The immunoregulatory properties of probiotic bacteria could balance the disequilibrium in the immune response causing the allergic response. The aim of this study was to evaluate the immunological effects of the consumption of a dairy product containing two probiotic strains in children suffering from allergy. A double-blinded, randomized, control comparative study was performed with 44 allergic children. Children were randomly distributed in two groups, a control Yogurt and a Probiotic group. Both groups daily consumed 200 ml of a dairy fermented product for 3 months. The Yogurt group consumed a conventional yogurt, whereas the Probiotic group consumed a similar dairy product where Lactobacillus bulgaricus was substituted by a mixture of Lactobacillus gasseri CECT5714 and Lactobacillus coryniformis CECT5711 (at least 10(6) cfu/g each strain). Intestinal and immunological parameters were measured in fecal and blood samples. The consumption of the probiotic product induced a significant decrease in the level of IgE in plasma (p = 0.03) and an increase in CD4(+)/CD25(+) T regulatory cells (p = 0.01). The decrease in IgE was accompanied by a significant increase in mucosal IgA (p = 0.01). However, changes in other effector cells potentially involved in allergic reactions such as eosinophiles, basophiles or other IgE+ cells were not detected. The consumption of the probiotic product also induced significant changes in innate response as a significant increase in natural killer cells was detected (p = 0.03). The daily consumption of a probiotic product containing L. gasseri CECT5714 and L. coryniformis CECT5711 for 3 months induces, in allergic children, beneficial effects on immune parameters involved in the allergic response such as a reduction of IgE in plasma and an increase in regulatory T cells. The probiotic product also enhanced innate and specific immune parameters that may improve the general health status of children.

Milk enriched with "healthy fatty acids" improves cardiovascular risk markers and nutritional status in human volunteers.

OBJECTIVE: The main goal of the present study was to evaluate the effect of a commercially available milk containing small amounts of eicosapentaenoic acid and docosahexaenoic acid, oleic acid, and vitamins A, B6, D, E, and folic acid compared with semi-skimmed and skimmed milk in volunteers with moderate cardiovascular risk. METHODS: Two hundred ninety-seven subjects 25 to 65 y of age with moderate cardiovascular risk were randomly allocated into three groups. In addition to their diets, one group consumed 500 mL/d of the enriched milk, another group consumed 500 mL/d of skimmed milk, and a control group consumed 500 mL/d of semi-skimmed milk. All groups consumed the dairy drinks for 1 y and blood samples were taken at 0 and 12 mo. RESULTS: Consumption of enriched milk for 1 y produced significant (P < 0.05) increases in serum folate (58%) and high-density lipoprotein cholesterol (4%). Plasma triacylglycerols (10%), total cholesterol (4%), and low-density lipoprotein cholesterol (6%) were reduced significantly only in the supplemented group. Serum glucose, homocysteine, and C-reactive protein remained unchanged. In the skimmed milk and semi-skimmed milk groups, the only significant decreases were in serum folate (17% and 11%, respectively). CONCLUSION: Daily intake of a milk enriched with fish oil, oleic acid, and vitamins improved the nutritional status and cardiovascular risk markers of volunteers, whereas skimmed milk and semi-skimmed milk did not.

Beneficial effects of probiotic bacteria isolated from breast milk.

Breast milk is the best food for the neonate because it provides a unique combination of proteins, carbohydrates, lipids, minerals and vitamins that ensures the correct growth and development of the infant. In addition, it also contains bioactive compounds responsible for a wide range of beneficial effects such as the promotion of immune system maturation and the protection against infections. Among these bioactive agents, probiotic bacteria have been recently isolated from human milk. The present work reviews the beneficial effects of these bacteria both in animal models and in clinical trials. The promotion of immune system maturation and defence against infections as well as the anti-inflammatory properties are among the main healthy effects of these bacteria. The isolation of probiotic bacteria with beneficial effects for the host provides scientific support for the supplementation of infant formula with these bacteria, in order to advance the pursuit of the main goal of formula: to mimic breast milk and its functional effects as closely as possible.

Intake of fish oil, oleic acid, folic acid, and vitamins B-6 and E for 1 year decreases plasma C-reactive protein and reduces coronary heart disease risk factors in male patients in a cardiac rehabilitation program.

Certain nutrients have been shown to be effective in preventing coronary heart disease. We hypothesized that a daily intake of low amounts of a number of these nutrients would exert beneficial effects on risk factors and clinical variables in patients that suffered from myocardial infarction (MI) and were following a cardiac rehabilitation program. Forty male MI patients were randomly allocated into 2 groups. The supplemented group consumed 500 mL/d of a fortified dairy product containing eicosapentaenoic acid, docosahexaenoic acid, oleic acid, folic acid, and vitamins A, B-6, D, and E. The control group consumed 500 mL/d of semi-skimmed milk with added vitamins A and D. The patients received supervised exercise training, lifestyle and dietary recommendations, and they were instructed to consume the products in addition to their regular diet. Blood extractions and clinical examinations were performed after 0, 3, 6, 9, and 12 mo. Plasma concentrations of eicosapentaenoic acid, docosahexaenoic acid, oleic acid, folic acid, vitamin B-6, and vitamin E increased after supplementation (P<0.05). Plasma total and LDL-cholesterol, apolipoprotein B, and high-sensitivity C-reactive protein concentrations decreased in the supplemented group (P<0.05), and plasma total homocysteine decreased in both groups. There were no changes in heart rate, blood pressure, or cardiac electrocardiographic parameters in either group. Therapeutic lifestyle changes, effected through a CR program comprising regular exercise and the intake of a combination of dietary nutrients, reduced a variety of risk factors in MI patients, which supports the rationale for nutritional programs in the secondary prevention of coronary heart disease.

Goat milk oligosaccharides are anti-inflammatory in rats with hapten-induced colitis.

Oligosaccharides are included among the anti-inflammatory components of milk because of their prebiotic properties and their capacity to act as receptors of microorganisms. Here the intestinal anti-inflammatory effect of goat milk oligosaccharides (O) was assessed in trinitrobenzenesulfonic (T) acid-induced colitis in rats. Rats were randomly assigned to three different groups. Two groups (T and OS) of colitic rats and a control group (C) were studied. Group OS received 500 mg/(kg.d) of goat milk oligosaccharides orally, starting 2 d before the colitis induction until d 6, and groups T and C received the vehicle. When compared with the T group, the OS group showed decreased anorexia and body weight loss; reduced bowel wall thickening and longitudinal extension of necrotic lesions; downregulated colonic expression of interleukin 1beta, inducible nitric oxide synthase, cyclooxygenase 2, and mucin 3; and increased trefoil factor 3. Thus, goat milk oligosaccharides have anti-inflammatory effects in rats with experimental colitis and may be useful in the management of inflammatory bowel disease.

Absorption of calcium from milks enriched with fructo-oligosaccharides, caseinophosphopeptides, tricalcium phosphate, and milk solids.

BACKGROUND: Adequate intakes of calcium are required for optimal bone health and protection against chronic disease. Dairy products are an excellent source of calcium. OBJECTIVE: The absorption of calcium from a range of fortified milks was measured in humans with the use of stable isotopes. DESIGN: Fifteen volunteers participated in a randomized, controlled, double-blind crossover study. Five types of semi-skimmed (1.9% fat) milk drinks were administered with a light breakfast: standard milk (control milk); milk enriched with calcium from milk solids and tricalcium phosphate [(TCP) MSS milk]; milk enriched with calcium from concentrated milk (CON milk); milk with added fructo-oligosaccharides [(FOSs) FOS milk]; and milk with added caseinophosphopeptides [(CPPs) CPP milk]. All the milks were labeled with 42Ca as CaCl2. The MSS milk was also labeled with 44Ca as TCP. The quantity of calcium in each drink was kept the same by varying the volume given. RESULTS: Calcium absorption did not differ significantly between the control milk and the calcium-fortified milks (MSS and CON milk) or the FOS and CPP milks. However, calcium absorption from the TCP added to the MSS milk was significantly higher than that from the control milk (27.5 +/- 7.6% and 24.5 +/- 7.3%, respectively; P = 0.003). CONCLUSIONS: Calcium-enriched milks are a valuable source of well-absorbed calcium. Absorption of added calcium as TCP was higher than that of calcium from the control milk, but the addition of FOSs or CPPs did not significantly increase calcium absorption. Further research is needed to ascertain the cost-effectiveness and public health benefits of consuming fortified milks.

Oligosaccharides isolated from goat milk reduce intestinal inflammation in a rat model of dextran sodium sulfate-induced colitis.

BACKGROUND AND AIMS: There is increased interest in the study of manipulation of the flora with pro- and prebiotics regarding inflammatory bowel disease. The aim of this work was to evaluate the effect of oligosaccharides from goat milk in a rat model of dextran sodium sulfate- (DSS-) induced colitis. METHODS: Twenty rats were fed the same diet but with different sources of fiber (5% of the diet): cellulose or a mixture of goat's milk oligosaccharides (GMO) and cellulose. DSS treatment was used to induce a colonic inflammation. Several clinical and inflammatory parameters, as well as intestinal micorbiota and gene expression by DNA microarray technology, were evaluated. RESULTS: DSS induced a decrease in body weight which was not observed in rats fed the GMO (decrease of 21+/-11% in control rats vs increase of 5.2+/-8.6 in GMO rats, P<0.05). DSS also caused an acute colonic inflammatory process which was weaker in rats fed the GMO, as shown by colon myeloperoxidase activity (0.53+/-0.16 vs 0.14+/-0.07U/mg of protein, P<0.05), as well as clinical symptoms measured by a scoring system (1.25+/-1.14 vs 0.4+/-0.07, P<0.05). GMO rats also showed less severe colonic lesions and a more favorable intestinal microbiota. The expression of genes involved in intestinal function, such as mucine-3, was down-regulated in DSS-control rats but returned to normal values in GMO rats. CONCLUSION: GMO reduce intestinal inflammation and contribute to the recovery of damaged colonic mucosa.

Increased immune response in mice consuming rice bran oil.

BACKGROUND: Polyunsaturated fatty acids play a key role in a number of biological functions. Rice bran oil (RBO) is rich in linoleic acid, an essential n-6 fatty acid. n-6 fatty acids are said to have proinflammatory effects as a result of an increase in n-6 fatty acid-derived eicosanoids. RBO is also rich in gamma-oryzanol, a compound from the unsaponifiable fraction, with antioxidant properties. OBJECTIVE: The aim of this work is to examine the effect of RBO-and/or gamma-oryzanol-enriched diets on the regulation of the immune response. METHODS: 4 week-old Balb/C mice were fed diets enriched with either RBO or high oleic-sunflower oil (HOSO), for one month. Serum samples, bone marrow-derived macrophages and lymphocytes from the spleen were collected. RESULTS: Compared to HOSO, our results show that RBO modulates the immune system by enhancing B-lymphocyte proliferation (6842 +/- 2959 vs 10073 +/- 4186 cpm; HOSO vs RBO; n = 10 per group) and TH1-type cytokines such as IL-2 (55.85 +/- 18.2 vs 101.7 +/- 21.6 pg/ml) or TNF-alpha (49.12 +/- 18.6 vs 184.9 +/- 46.2 pg/ml; HOSO vs RBO) in a significant way (n = 10 per group). Moreover, the reduction found in the TH2 cytokine IL-4 (7.59 +/- 2.3 vs 4.48 +/- 1.6 pg/ml) and IgE (56.9 +/- 39.2 vs 42.4 +/- 35.2 ng/ ml; HOSO vs RBO, n = 10 per group) levels suggests RBO may have antiallergenic properties. To elucidate the role of gamma-oryzanol, a similar study was also carried out including diets enriched with refined RBO or HOSO containing gamma-oryzanol (2 %). Our results suggest that although gamma-oryzanol may modulate the immune system, it is not responsible for the overall immunostimulation effect seen for RBO. CONCLUSIONS: RBO-enriched diets could be useful in situations where a potentiation of the immune response was required. The fatty acids composition, more than the unsaponifiable fraction, might be responsible for this effect.

Goat milk is less immunogenic than cow milk in a murine model of atopy.

OBJECTIVES: Cow milk protein allergy occurs in 2% to 6% of infants population. Goat milk has been used as an alternative to cow milk, but there is probably some cross-reactivity between the milks. Little is known about the allergenicity of goat milk per se. The aim of this study is to compare cow and goat milk allergenicity in a mouse atopy model. METHODS: Balb/C mice were intragastrically sensitized to cow or goat milk by five doses administrated weekly. Six weeks after the first dose mice were killed, sera were collected and spleens removed for analysis. RESULTS: The number of mice with diarrhea was significantly higher in the cow milk-sensitized group than in the goat milk-sensitized group. Serum cow milk-specific immunoglobulin G1 and histamine levels were also significantly higher in cow milk-sensitized mice. Cytokine production by spleen derived T cells showed a Th2 response with high levels of interleukin-4 production and low levels of interferon-gamma in cow milk-sensitized mice. In addition, goat milk induced a lower lymphocyte sensitization as a result of a significant decrease in the specific proliferation ratio of these cells. CONCLUSION: Goat milk, when used as the first source of protein after a breast-feeding period, is less allergenic than cow milk in mice. Further studies are needed to clarify if goat milk is suitable as an alternative to cow milk in milk based formulas for infant nutrition.

The administration of a multivitamin/mineral fortified dairy product improves folate status and reduces plasma homocysteine concentration in women of reproductive age.

BACKGROUND AND OBJECTIVES: Folate deficiency during the periconceptional period is related to the occurrence and recurrence of neural tube defects. The aim of the study was to assess whether the administration of folic acid and other vitamins and minerals as a fortified dairy product (400 microg per day of folic acid) improves the folate status in women of reproductive age. DESIGN AND METHODS: Plasma and red blood cell folate, plasma vitamin E, B12, total plasma homocysteine, plasma lipid profile, and serum ferritin and transferrin levels were investigated in 31 healthy nonpregnant women receiving 500 mL/day of the fortified dairy product for eight weeks. RESULTS: The women showed a significant increase in plasma levels of folate and vitamin B12 concentrations after four and eight weeks of supplementation. Moreover, we observed an increase in red blood cell folate concentration during the period of the study. Simultaneously, total plasma homocysteine levels decreased significantly during the intervention period. CONCLUSIONS: The regular consumption of a folic acid and other vitamins (mainly vitamins B6 and B12) and minerals in a fortified dairy product improves folate status and reduces total plasma homocysteine concentration in healthy women of childbearing age.

Cardiovascular effects of milk enriched with omega-3 polyunsaturated fatty acids, oleic acid, folic acid, and vitamins E and B6 in volunteers with mild hyperlipidemia.

OBJECTIVE: Results from epidemiologic studies and clinical trials have indicated that consumption of omega-3 fatty acids, oleic acid, and folic acid have beneficial effects on health, including decreased risk of cardiovascular disease. We evaluated the combined effects of these nutrients through the consumption of milk enriched with omega-3 polyunsaturated fatty acids, oleic acid, vitamins E and B6, and folic acid on risk factors for cardiovascular disease in volunteers with mild hyperlipidemia. METHODS: Thirty subjects ages 45 to 65 y (51.3 +/- 5.3 y) were given 500 mL/d of semi-skimmed milk for 4 wk and then 500 mL/d of the enriched milk for 8 wk. Plasma and low-density lipoproteins were obtained at the beginning of the study and at 4, 8, and 12 wk. RESULTS: Consumption of enriched milk for 8 wk increased plasma concentrations of docosahexaenoic acid and eicosapentaenoic acid and significantly (P < 0.05) decreased plasma concentrations of triacylglycerol (24%), total cholesterol (9%), and low-density lipoprotein cholesterol (13%). Plasma and low-density lipoprotein oxidation and vitamin E concentration remained unchanged throughout the study. Significant decreases in plasma concentrations of vascular cell adhesion molecule-1 (9%) and homocysteine (17%) were found, accompanied by a 98% increase in plasma concentration of folic acid. CONCLUSIONS: Dairy supplementation strategies with omega-3 polyunsaturated fatty acids, oleic acid, and vitamins may be useful for decreasing risk factors for cardiovascular disease.

Short-term dietary conjugated linoleic acid supplementation does not enhance the recovery of immunodepleted dexamethasone-treated rats.

BACKGROUND: Conjugated linoleic acid (CLA) has been reported to decrease fat deposition, and increase lean body mass. This has been broadly inferred to mean that CLA alters protein turnover. However, data to test the effects of CLA on protein turnover are lacking. An enhancement in immune responses by CLA has also been demonstrated. AIM OF THE STUDY: The objective of this study was to determine the potential for dietary CLA and protein intervention to improve nutritional and functional recovery in an animal model of catabolic stress and immunodepletion. METHODS: Diets varying in their protein levels in the presence or absence of CLA were tested for their effects on the recovery of glucocorticoid (intraperitoneal injection of dexamethasone, 120 mg/kg) treated rats. Following steroid injection, rats were fed 4 dietary treatments for 4 d. The diets contained 10 or 20 g/100 g protein with or without 0.5 g/100 g CLA. RESULTS: Dexamethasone treatment resulted in a decreased food intake and loss of weight, independent of dietary treatment. A higher number of blood monocytes occurred in rats fed the high CLA diets. The protein fractional synthesis rate in spleens of rats fed the diets containing either high proteins or CLA were higher compared to those fed diets with low protein content or without CLA, respectively. CLA, consumed post-dexamethasone treatment, did not improve protein turnover in the other tissues studied, including gut mucosa, liver, muscle and thymus. CONCLUSIONS: The present study was performed to determine the effect of CLA in acute conditions, as opposed to a preventive approach, on the recovery from a catabolic stress with immunodepletion. Overall, no effect of short-term feeding CLA on the recovery from dexamethasone-mediated immunodepletion was observed.

Development of a rapid and convenient method to purify mucins and determine their in vivo synthesis rate in rats.

The intestinal mucoprotein synthesis rate was measured in vivo for the first time. For this, a rapid, reproducible, and convenient method to purify mucoproteins from large numbers of intestinal samples at the same time was developed. The method takes advantage of both the high mucin resistance to protease activities due to their extensive glycosylations and the high mucin molecular size. Intestinal homogenates were partially digested with Flavourzyme. Nonprotected proteins partially degraded were easily separated from mucoproteins by small gel filtration chromatography using Sepharose CL-4B. Electrophoretically pure mucins were obtained. Their amino acid composition was typical of purified intestinal epithelial mucins. The mucoprotein synthesis rate was determined in vivo in rats using the flooding dose method with the stable isotope L-[1-13C]valine. Free L-[1-13C]valine enrichments in the intracellular pool were determined by GC-MS. L-[1-13C]valine enrichments into purified mucoproteins or intestinal mucosal proteins were measured by gas chromatography-combustion-isotope ratio mass spectrometry. In rats, we found that the gut mucosa protein synthesis rate (%/day) decreased regularly from duodenum (122%/day) to colon (43%/day). In contrast, mucoprotein fractional synthesis rates were in the same range along the digestive tract, between 112%/day (colon) and 138%/day (ileum).