MD Diet Research Articles

Comparison of premenstrual symptoms, psychological well-being, and nutritional status between Palestinian women with and without polycystic ovarian syndrome: a case-control study

BackgroundPolycystic ovarian syndrome (PCOS) is a widely seen reproductive and endocrinological disorder. PCOS can exert substantial effects on many aspects of an individual’s life, including reproductive health and psychological well-being. The objective of this study was to assess the nutritional status, premenstrual syndrome, and mental health of women affected by PCOS in comparison to women without PCOS.MethodologyA case-control observational study in Palestine included 100 PCOS patients and 200 healthy women. The collected data included socio-demographic information, medical history, premenstrual syndrome, mental health, nutritional status, and lifestyle. Anthropometric measurement and the Mediterranean Diet Adherence Screener (MEDAS) were used to evaluate the nutritional status. The General Health Questionnaire (12-GHQ) was used to evaluate the state of mental health. Premenstrual syndrome (PMS) severity was evaluated using a validated Arabic premenstrual syndrome questionnaire.ResultsThe study’s findings indicated that there was a statistically significant increase in the three dimensions of PMS among participants with PCOS, p < 0.05. Similarly, PCOS patients demonstrated elevated ratings across all aspects of mental health, p < 0.05. In terms of the other variables, it has been observed that PCOS patients have a notably greater prevalence of perceived sleep disturbances and decreased adherence to the Mediterranean diet. Regression analysis revealed that PCOS is associated with mental health problems indicated by a higher GHQ score (OR: 1.09; 95% CI: 1.03; 1.16, p < 0.05), lower adherence to the MD diet (OR: 0.86; 95% CI: 0.76; 0.98, p < 0.05), and pre-menstrual syndrome, especially the physical symptoms (OR: 1.06; 95% CI: 1.003; 1.12, p < 0.05) after adjusting for age, smoking, waist-hip ratio, and body mass index (BMI).ConclusionThe study has linked polycystic ovary syndrome to negative mental health outcomes and an increased severity of premenstrual syndrome (PMS). Additional investigation is required in order to establish a causal association between polycystic ovary syndrome (PCOS) and lifestyle behaviors within the Palestinian population. Intervention and instructional studies are necessary to investigate the efficacy of management strategies in alleviating the effects of polycystic ovary syndrome (PCOS) on both physical and mental well-being.

Dietary Pattern or Weight Loss: Which One Is More Important to Reduce Disease Activity Score in Patients with Rheumatoid Arthritis? A Randomized Feeding Trial.

Objectives Herein, disease activity score 28 (DAS 28) was compared between patients with rheumatoid arthritis (RA) receiving the Mediterranean dietary pattern (MD) and low-fat diet. Subjects/Methods. Overweight and obese RA patients aged 15–75 y participated in this randomized feeding trial. Participants were randomized to MD (n = 51) and low-fat high-carbohydrate diet (n = 53) for 12 weeks. The control group followed their regular diet (n = 50). Participants completed the form of tender and swollen joint counts before the study enrollment and after 12 weeks to compute DAS 28. Results Weight loss was not statistically significant between the MD and LF-HC groups. DAS 28 significantly decreased in MD compared to the LF-HC group (p=0.02) and controls (p=0.001). Adjusting for the baseline variables, MD reduced DAS 28 by 76% (95% CI = −0.45, −0.2; p=0.03) after 12 weeks of intervention. The baseline serum ESR level showed 99.8% effect on DAS 28 score at the end (95% CI = 0.014, 0.035; p < 0.001). Conclusions The MD showed beneficial effects on DAS 28 compared to the LF-HC diet in patients with RA, regardless of weight loss. It is a better dietary choice for pain reduction in patients with RA. The trial is registered at Iranian Registry of Clinical Trials (IRCT20200929048876N2).

Comparison of short-term hypocaloric high-protein diets with a hypocaloric Mediterranean diet: Effect on body composition and health-related blood markers in overweight and sedentary young participants

ObjectivesThe aim of the present study was to compare the short-term effects of a hypocaloric Mediterranean diet and two high protein diets, with and without whey protein supplementation, on body composition, lipidemic profile, and inflammation and muscle-damage blood indices in overweight, sedentary, young participants. MethodsThirty-three young, overweight, male and female participants (mean ± SD age: 22.8 ± 4.8 y; body mass: 85.5 ± 10.2 kg; body fat percentage: 34.3% ± 8.1%) were randomly allocated to three different hypocaloric (−700 kcal/d) diets: a Mediterranean diet (MD; n = 10), a high-protein diet (HP; n = 10) diet, and a high-protein diet with whey supplementation (n = 10). The intervention lasted 6 wk. Body composition and biochemical indices were evaluated 1 wk before and after the nutritional interventions. ResultsBody and fat mass were decreased in the MD and HP groups (−3.5% ± 1.1% and −5.9% ± 4.2% for body and fat mass respectively in MD, and −1.7% ± 1.2% and −2.0% ± 1.8% for body and fat mass respectively in HP;P < 0.05), with no significant decline of fat-free mass observed in the MD group. The MD group's diet beneficially altered the lipid profile (P < 0.05), but the HP and HPW groups’ diets did not induce significant changes. Subclinical inflammation and muscle-damage indices significantly increased in the HP and HPW groups (7.4% ± 3.5% and 66.6% ± 40.1% for neutrophils and CRP respectively in HP, and 14.3% ± 6.4% and 266.6% ± 55.1% for neutrophils and CRP respectively in HPW; P < 0.05) but decreased in the MD group (1.8% ± 1.2% and −33.3% ± 10.1% for neutrophils and CRP respectivelyc; P < 0.05). Energy intake of carbohydrates and proteins were significantly related to the changes in body composition and biochemical blood markers (r = −0.389 and −0.889; P < 0.05). ConclusionsAmong the three hypocaloric diets, only the Mediterranean diet induced positive changes in body composition and metabolic profile in overweight, sedentary individuals.

Effects of dietary methionine on growth performance and metabolism through modulating nutrient-related pathways in largemouth bass (Micropterus salmoides)

Methionine (Met) as molecular signaling plays a vital regulatory role in growth-related cellular functions. However, more research in the regulatory mechanism of Met in fish species is needed. Therefore, this study was designed to elucidate the regulatory role of dietary Met on body growth performance and metabolism. Largemouth bass (initial body weight: 4.10 ± 0.01 g) fed with control (CON, Met: 1.21 % of diet) diet and Met deficiency (MD, Met: 0.93 % of diet) diet, respectively for 8 weeks. Results of present study showed that compared with the MD diet (specific growth performance: 3.01 ± 0.03 %/d; weight gain ratio: 438 ± 9.16 %), control diet significantly increased the specific growth performance (3.36 ± 0.02 %/d) and weight gain ratio (557 ± 7.41 %), respectively (P < 0.05). Moreover, the fish fed with control diet also had higher feed efficient ratio and protein efficiency ratio (1.12 ± 0.01; 2.28 ± 0.01) than the fish fed with MD diet (0.88 ± 0.03; 1.83 ± 0.05). Mechanically, present study demonstrated that Met supplementation increased the amino acid (AA) concentrations through improving transport efficiency of AA transporters. Elevated AA concentrations promoted systemic nutrient sensing by activating the growth hormone-insulin-like growth factor (GH-IGF) signaling pathway. Activated GH-IGF signaling then up-regulated the target of rapamycin (TOR) signaling and suppressed the amino acids response (AAR) signaling. Up-regulated TOR and down-regulated AAR caused by Met supplementation acted together to increase the nutrient metabolic level, which further accelerate the growth performance. Our study better explained how fish through nutrient sensing signaling to coordinating growth and metabolism in response to dietary Met availability.

Impaired Performance of Broiler Chickens Fed Diets Naturally Contaminated with Moderate Levels of Deoxynivalenol.

Mycotoxin exposure is common in the poultry industry. Deoxynivalenol (DON) is usually detected at levels below the maximum threshold (5000 ppb), but depending on diet and age, broiler performance can be affected. We evaluated the effects of 900 ppb and 2300 ppb DON on the performance, intestinal morphometry, and lesion scores of broiler chickens. One-day-old male Ross broilers (n = 736) were divided into 4 treatments with 8 replicates each, and a pen containing 23 birds was the experimental unit. The animals were fed diets naturally contaminated with two levels of DON: 900 (Low DON—LD) or 2300 (Moderate DON—MD) ppb, with or without activated charcoal, over 28 days. After this, all birds were fed a marginally DON-contaminated diet without charcoal. During the first 28 days, body weight gain (BWG) and feed conversion ratio (FCR) were significantly impaired when broilers were fed a MD diet without activated charcoal. Even after feeding a marginally contaminated diet from D28–35, birds previously fed the MD diet presented a significantly lower performance. The villus height:crypt depth (VH:CD) ratio was significantly higher in the ileum from 14-day-old broilers fed the MD when compared with the LD diet. At D28, the MD diet caused decreased villus height (VH) and increased crypt depth (CD), affecting VH:CD ratio in both intestinal segments, with higher levels in the jejunum from 28-day-old broilers fed a non-supplemented LD diet. Broiler production was negatively affected by DON, even at moderate levels (2300 ppb).

Effects of methionine as free amino acid and dipeptide on productive efficiency and meat quality of broilers under acute and chronic heat stress

Context Methionine in the form of free amino acid has been widely studied in broilers challenged by heat stress (HS). However, the effects of methionine dipeptide in broilers subjected to HS are not known. Aims To evaluate the effects of methionine as free amino acid and dipeptide on the performance, oxidative status, plasma parameters and meat quality of broilers subjected to acute and chronic HS. Methods Broilers were evaluated at the following three experimental periods: 24 h of evaluation (21–22 days of age); 10 days of evaluation (22–32 days of age); and 20 days of evaluation (22–42 days of age). Broilers were divided into two groups; one group was raised in thermal comfort, and the other group was raised in continuous HS of 30°C. In both groups, animals received a diet without methionine supplementation (MD), with supplementation of methionine as free amino acid (dl-M), and with supplementation of methionine as dipeptide (dl-MM). Key results HS reduced body weight gain after 10 and 20 days of evaluation. Broilers under HS condition fed the MD diet had the highest concentrations of thiobarbituric acid reactive substances (TBARS) at 22 days of age and carbonylated proteins (CP) at 32 days of age. At 42 days of age, broilers fed the MD diet had higher concentrations of TBARS and CP. At 32 days of age, broilers under HS had lower high-density lipoprotein and higher low-density lipoprotein concentrations. In breast meat, broilers in thermal comfort fed the dl-M or dl-MM diets had a lower cooking loss. Broilers in HS fed the dl-M diet had the lowest cooking loss. HS reduced the pH of the meat of legs. Conclusions The acute and chronic HS affect the broiler performance in different ways. Methionine supplementation contributes to reduce the effects of HS. There were no notable differences between the supplementation of dl-M or dl-MM. Implications Productivity and the quality of the chicken meat are the most important attributes of the production. The ambient temperature can influence these parameters. The methionine in its most varied forms, due to its direct and indirect antioxidant function, has been shown to be an effective source of protection for the animal in adverse conditions such as during HS.

Heat stress effect on the intestinal epithelial function of broilers fed methionine supplementation

The objective of this study was to evaluate the effect of DL-methionine supplementation on the expression of genes related to immune function and intestinal integrity in the jejunum and ileum of 21- or 42-day-old broilers subjected to 38 °C for 24 h. Broilers of 1–21 and 22–42 days of age were divided into two treatments related to methionine supplementation: without DL-methionine supplementation (MD) or recommended level of DL-methionine (MS). In addition, the animals were either maintained at a comfort environment or exposed to heat stress (HS) (38 °C for 24 h, starting on day 20 or day 41 for Experiments 1 and 2, respectively). Heat stress increased body temperature and the respiratory rate of the birds in both the experimental periods evaluated (1–21 and 22–42 days of age) (body temperature: P = 0.0010 and P = 0.0005, respectively; respiratory rate: P < 0.0001). Experiment 1 (1–21-day-old broilers): in the jejunum, we observed higher heat shock protein 70 kDA (HSP70) gene expression in HS broilers fed the MD diet (P = 0.0010). Broilers from HS presented higher expression of lipopolysaccharide-induced tumor necrosis factor (TNF)-alpha factor (LITAF) (P = 0.0001), interleukin-1β (IL1B) (P = 0.0003), and claudin 1 (CLDN1) (P = 0.0391). Regarding the diet effect, the highest LITAF (P = 0.0002) and IL1B (P = 0.0067) gene expression was observed in birds fed the MD diet. In the ileum, birds from comfort and fed the MD diet presented the highest IL1B expression (P < 0.0001). Broilers from HS presented higher occludin (OCLN) expression (P = 0.0072).Experiment 2 (22–42-day-old broilers): in the jejunum, broilers from HS presented higher LITAF (P < 0.0001) and OCLN (P < 0.0001) expression gene. Broilers fed the MS diet presented higher LITAF (P = 0.0007) and IL1B (P = 0.0220) gene expression. The highest HSP70 (P < 0.0001) and CLDN1 (P = 0.0349) gene expression was observed in HS broilers fed the MD diet. In the ileum, we observed that broilers submitted to HS presented higher HSP70 (P = 0.0008), LITAF (P = 0.0044), and OCLN (P < 0.0001) gene expression. Broilers fed the MD diet presented lower CLDN1 gene expression (P = 0.0141). Our results suggest that methionine supplementation in adequate amounts may assist the body in combating the deleterious effects of stress by stimulating the expression of genes capable of maintaining intestinal epithelial cell function.

Association between Breast Milk Mineral Content and Maternal Adherence to Healthy Dietary Patterns in Spain: A Transversal Study.

The composition of breast milk is influenced by many factors, some of which dependent on the mother and others on the child. Changes in lactation and other factors depending on the mother’s physiology and anthropometric characteristics, as well as her nutritional status and diet, are of key importance. Breast milk minerals have been extensively studied with highly uneven results. In this work, a comparison will made with data across the world. To understand the factors that might explain the disparity, several minerals (Na, K, Ca, P, Mg, Fe, Se and I) have been analyzed using ICP-MS in a set of human milk samples (n = 75). The samples had an identical geographical origin (Galicia, in northwestern Spain) but different lactation circumstances, including maternal anthropometric data, lactating time, newborn sex and maternal adherence to healthy dietary patterns (Mediterranean Diet, MD, or Atlantic Diet, AD). The required concentrations of essential elements reported in the literature are similar to those found in these Spanish women. A univariate approach revealed that factors such as lactating time, body mass index (BMI) and newborn sex have a significant influence in breastmilk mineral content. According to multivariate linear regression analysis, minerals in milk are particularly associated with lactating time, but also with newborn sex, maternal BMI, age and diet pattern in some cases. More precisely, these results suggest that the iron and selenium concentrations in the milk of Galician donors may be positively influenced by maternal adherence to AD and MD, respectively.

Assessing Validity of Self-Reported Dietary Intake within a Mediterranean Diet Cluster Randomized Controlled Trial among US Firefighters.

Collecting dietary intake data is associated with challenges due to the subjective nature of self–administered instruments. Biomarkers may objectively estimate the consumption of specific dietary items or help assess compliance in dietary intervention studies. Our aim was to use a panel of plasma and urine biomarkers to assess the validity of self-reported dietary intake using a modified Mediterranean Diet Scale (mMDS) among firefighters participating in Feeding America’s Bravest (FAB), an MD cluster-randomized controlled trial. In our nested biomarker pilot study, participants were randomly selected from both the MD intervention group (n = 24) and the control group (n = 24) after 12-months of dietary intervention. At baseline data collection for the pilot study (t = 12-months of FAB), participants in the control group crossed-over to receive the MD intervention (active intervention) for 6-months. Participants in the intervention group continued in a self-sustained continuation phase (SSP) of the intervention. Food frequency questionnaires (FFQ), 13-item-mMDS questionnaires, 40 plasma fatty acids, inflammatory biomarkers and urinary hydroxytyrosol and tyrosol were analyzed at both time points. Spearman’s correlation, t-tests and linear regression coefficients were calculated using SAS software. Overall, the mMDS derived from the FFQ was highly correlated with the specific 13-domain-mMDS (r = 0.74). The concordance between the two questionnaires for low and high adherence to MD was high for all the participants in the parent trial (κ = 0.76). After 6 months of intervention in the pilot study, plasma saturated fatty acid decreased in both groups (active intervention: −1.3 ± 1.7; p = 0.002; SSP: −1.12 ± 1.90; p = 0.014) and oleic acid improved in the SSP (p = 0.013). Intake of olive oil was positively associated with plasma omega-3 (p = 0.004) and negatively with TNF-α (p < 0.001) at baseline. Choosing olive oil as a type of fat was also associated with higher levels of plasma omega-3 (p = 0.019) at baseline and lower TNF-α (p = 0.023) at follow up. Intake of red and processed meats were associated with lower serum omega-3 (p = 0.04) and fish consumption was associated with lower IL-6 at baseline (p = 0.022). The overall mMDS was associated with an increase in plasma omega-3 (p = 0.021). Good correlation was found between nutrient intake from the FFQ and the corresponding plasma biomarkers (omega-3, EPA and DHA). In this MD randomized controlled trial, some key plasma biomarkers were significantly associated with key MD diet components and the overall mMDS supporting the validity of the mMDS questionnaire as well as compliance with the intervention.

Dietary methionine deficiency affects oxidative status, mitochondrial integrity and mitophagy in the liver of rainbow trout (Oncorhynchus mykiss)

The low levels of methionine in vegetable raw materials represent a limit to their use in aquafeed. Methionine is considered as an important factor in the control of oxidative status. However, restriction of dietary methionine has been shown to reduce generation of mitochondrial oxygen radicals and thus oxidative damage in liver. Here, we aim to evaluate the effect of dietary methionine deficiency in hepatic oxidative status in rainbow trout and identify the underlying mechanisms. Fish were fed for 6 weeks diets containing two different methionine concentrations: deficient (MD, Methionine Deficient diet) or adequate (CTL, control diet). At the end of the experiment, fish fed the MD diet showed a significantly lower body weight and feed efficiency compared to fish fed the CTL diet. Growth reduction of the MD group was associated to a general mitochondrial defect and a concomitant decrease of the oxidative status in the liver. The obtained results also revealed a sharp increase of mitochondrial degradation through mitophagy in these conditions and emphasized the involvement of the PINK1/PARKIN axis in this event. Collectively, these results provide a broader understanding of the mechanisms at play in the reduction of oxidant status upon dietary methionine deficiency.

Effects of methionine hydroxy analogue supplementation on the expression of antioxidant-related genes of acute heat stress-exposed broilers

We evaluated the effects of heat stress (HS) and methionine supplementation on biological markers of stress and expression of the genes for superoxide dismutase (SOD), thioredoxin (TRx), thioredoxin reductase 1 (TRxR1) and methionine sulfoxide reductase A (MsrA) in broilers aged 1 to 21 or 22 to 42 days. The broilers were divided into two treatments, one with the recommended level of methionine supplementation (MS, supplementation of dl-2-hydroxy-4-methylthiobutanoic acid (dl-HMTBA)) and one without methionine supplementation (MD). The animals were maintained at a temperature of thermal comfort or one of HS (38°C for 24 h). Mortality was only observed in 42-day-old broilers exposed to HS and fed the MD diet, and the rate was 5%. Starter period: we observed an interaction effect between diet and temperature on the gene expression of TRxR1 and MsrA, and expression of these genes was higher in the HS animals that received the MS diet than that in birds with the MD diet. Grower period: the expression of SOD, TRxR1 and MsrA genes, activities of aspartate aminotransferase (AST) and creatine kinase (CK) and content of creatinine were influenced by both study variables. In the HS animals, the expression of these genes, AST activity and creatinine content increased and CK activity decreased. In the animals on the MD diet, the expression of these genes and AST and creatinine values were higher and the CK activity was lower than those for the birds on the MS diet. Our results indicated that under HS conditions, the supplementation with dl-HMTBA could mitigate major damage caused by stress through the action on some genes related to TRx complex activity.

Seeking Optimal Nutrition for Healthy Body Mass Reduction among Former Athletes.

The aim of the study was to investigate the efficacy of 6 week Mediterranean diet or 30% calorie restriction on the fatty acid profile and eicosanoids (hydroxyoctadecadienoi acids and hydroxyeicosatetraenoic acids) concentration. Furthermore, basic biochemical variables such as insulin, glucose, HOMA-IR, and a lipid profile were estimated. The study enrolled 94 Caucasian former athletes aged 20-42, with body height of 179 ± 16.00 cm and body mass of 89.26 ± 13.25 kg who had not been active for at least 5 years. The subjects were randomly assigned to one of the three intervention groups: CR group – the 30% calorie restriction (n = 32), MD group - the Mediterranean diet (n = 34), and C group - a control group (n = 28). The pattern of nutrition was analysed before and after the experiment using the 72 h food diaries. In order to evaluate the effect of diet intervention, the following variables were measured: anthropometrics, basic biochemical variables (insulin, fasting glucose, HOMA-IR, lipid profile), fatty acids and their blood derivatives profiles. The CR group showed significantly lower levels of several biochemical variables, i.e., BMI, total cholesterol LDL, TG, total lipids, insulin and HOMA – IR (p < 0.05). Subjects consuming the MD diet significantly decreased their BMI and reduced the level of total lipids (p < 0.05). We did not find any significant changes in the C group. The analysis of the fatty acid profile revealed that the CR group had a significantly decreased EPA level (p < 0.05). The MD group showed a significantly increased level of the DHA (p < 0.05) and improvement in the omega - 3 index (p < 0.05). Subjects following the MD also showed significantly lower concentrations of 15 - hydroxyicosatetraenoic acid (15-HETE). We did not observe any significant differences between the CR and C groups. Within short time, calorie restriction helps to improve lipid variables and insulin resistance. The MD diet seems to be more advantageous in the decrease of inflammation, but does not improve basic biochemical variables. We can conclude that calorie restriction can be a good choice for former athletes, although EPA and DHA supplementation is needed.

Raw meat based diet influences faecal microbiome and end products of fermentation in healthy dogs.

BackgroundDietary intervention studies are required to deeper understand the variability of gut microbial ecosystem in healthy dogs under different feeding conditions and to improve diet formulations. The aim of the study was to investigate in dogs the influence of a raw based diet supplemented with vegetable foods on faecal microbiome in comparison with extruded food.MethodsEight healthy adult Boxer dogs were recruited and randomly divided in two experimental blocks of 4 individuals. Dogs were regularly fed a commercial extruded diet (RD) and starting from the beginning of the trial, one group received the raw based diet (MD) and the other group continued to be fed with the RD diet (CD) for a fortnight. After 14 days, the two groups were inverted, the CD group shifted to the MD and the MD shifted to the CD, for the next 14 days. Faeces were collected at the beginning of the study (T0), after 14 days (T14) before the change of diet and at the end of experimental period (T28) for DNA extraction and analysis of metagenome by sequencing 16SrRNA V3 and V4 regions, short chain fatty acids (SCFA), lactate and faecal score.ResultsA decreased proportion of Lactobacillus, Paralactobacillus (P < 0.01) and Prevotella (P < 0.05) genera was observed in the MD group while Shannon biodiversity Index significantly increased (3.31 ± 0.15) in comparison to the RD group (2.92 ± 0.31; P < 0.05). The MD diet significantly (P < 0.05) decreased the Faecal Score and increased the lactic acid concentration in the feces in comparison to the RD treatment (P < 0.01). Faecal acetate was negatively correlated with Escherichia/Shigella and Megamonas (P < 0.01), whilst butyrate was positively correlated with Blautia and Peptococcus (P < 0.05). Positive correlations were found between lactate and Megamonas (P < 0.05), Escherichia/Shigella (P < 0.01) and Lactococcus (P < 0.01).ConclusionThese results suggest that the diet composition modifies faecal microbial composition and end products of fermentation. The administration of MD diet promoted a more balanced growth of bacterial communities and a positive change in the readouts of healthy gut functions in comparison to RD diet.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-017-0981-z) contains supplementary material, which is available to authorized users.

A Methionine Deficient Diet Enhances Adipose Tissue Lipid Metabolism and Alters Anti-Oxidant Pathways in Young Growing Pigs.

Methionine is a rate-limiting amino-acid for protein synthesis but non-proteinogenic roles on lipid metabolism and oxidative stress have been demonstrated. Contrary to rodents where a dietary methionine deficiency led to a lower adiposity, an increased lipid accretion rate has been reported in growing pigs fed a methionine deficient diet. This study aimed to clarify the effects of a dietary methionine deficiency on different aspects of tissue lipid metabolism and anti-oxidant pathways in young pigs. Post-weaned pigs (9.8 kg initial body weight) were restrictively-fed diets providing either an adequate (CTRL) or a deficient methionine supply (MD) during 10 days (n=6 per group). At the end of the feeding trial, pigs fed the MD diet had higher lipid content in subcutaneous adipose tissue. Expression levels of genes involved in glucose uptake, lipogenesis but also lipolysis, and activities of NADPH enzyme suppliers were generally higher in subcutaneous and perirenal adipose tissues of MD pigs, suggesting an increased lipid turnover in those pigs. Activities of the anti-oxidant enzymes superoxide dismutase, catalase and glutathione reductase were increased in adipose tissues and muscle of MD pigs. Expression level and activity of the glutathione peroxidase were also higher in liver of MD pigs, but hepatic contents in the reduced and oxidized forms of glutathione and glutathione reductase activity were lower compared with control pigs. In plasma, superoxide dismutase activity was higher but total anti-oxidant power was lower in MD pigs. These results show that a dietary methionine deficiency resulted in increased levels of lipogenesis and lipolytic indicators in porcine adipose tissues. Decreased glutathione content in the liver and coordinated increase of enzymatic antioxidant activities in adipose tissues altered the cellular redox status of young pigs fed a methionine-deficient diet. These findings illustrate that a rapidly growing animal differently adapts tissue metabolisms when facing an insufficient methionine supply.

Effects of methionine supplementation on the expression of protein deposition-related genes in acute heat stress-exposed broilers.

The objective of this study was to evaluate the effect of heat stress and methionine supplementation on the gene expression of insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), phosphatidylinositol 3-kinase, and regulatory 1 (PI3KR1) in the liver, as well as the expression of the atrogin 1 and cathepsin L2 (CTSL2) genes in the breast muscle of broilers. Broilers from 1–21 and 22–42 days of age were divided into three treatments related to methionine supplementation as follows: without methionine supplementation (MD), recommended level of methionine (DL1), and excess supplementation of methionine (DL2). The animals were either maintained at a thermal comfort temperature or exposed to heat stress (HS) (38°C for 24 hours, starting on day 20 or day 41 for experiments 1 and 2, respectively). The heat stress increased the body temperature at both ages. Starter period: The HS animals presented increased plasma creatinine content (P<0.0001) and the highest CTSL2 gene expression (P<0.0001). The methionine supplementation increased the IGF-I (P = 0.0144) and GHR (P = 0.0011) gene expression and decreased the CTSL2 (P = 0.0004) and atrogin 1 (P = 0.0012) gene expression. Grower period: Significant effects for the interaction between supplementation and environment were observed for GHR (P = 0.0252) and CTSL2 (P = 0.0011) gene expression. The highest GHR expression was observed in animals that remained in thermal comfort on the DL2 diet, and the lowest expression occurred in the HS animals fed the MD diet. For CTSL2, the HS animals fed the MD diet presented the highest CTSL2 gene expression, and the lowest expression was observed in the animals maintained at thermal comfort on DL1 and DL2 diets. Only methionine supplementation had effect on atrogin-1 gene expression (P<0.0001), with higher methionine content in the diet lower atrogin-1 gene expression was observed. Our results suggest that heat stress induces greater protein degradation and that methionine supplementation could induce protein deposition because methionine increased the expression of genes related to protein synthesis and decreased the expression of genes related to protein breakdown.

Effects of methionine supplementation on the redox state of acute heat stress–exposed quails1

The aims of the present study were to evaluate the possible effects of heat stress (HS) on H2O2 production and to evaluate whether methionine supplementation (MS) could mitigate the deleterious effects on cell metabolism and the redox state induced by oxidative stress. Meat quails (Coturnix coturnix coturnix) were fed a diet that either met the nutritional demands for methionine or did not meet this demand (methionine deficient [MD] diet) for 7 d. The animals were either kept at a thermal comfort temperature (25°C) or exposed to HS (38°C for 24 h, starting on the sixth day). Heat stress induced decreased food intake (P = 0.0140), decreased daily weight gain (P < 0.0001), and increased water intake (P = 0.0211). A higher rate of H2O2 production was observed in HS animals (0.0802 vs. 0.0692 nmol of reactive oxygen species [ROS] produced per minute per milligram of protein; P = 0.0042) and in animals fed with the MD diet (0.0808 vs. 0.0686 nmol of ROS produced per minute per milligram of protein; P = 0.0020). We observed effects of the interaction between diet and the environment on the activities of glutathione peroxidase (GP-x) and catalase (P = 0.0392 and P < 0.0001, respectively). Heat stress induced higher levels of GP-x activity in animals on the MS diet and higher catalase activity in animals on the MD diet. Glutathione (GSH) levels were higher in animals on the MS diet (P = 0.0273) and in animals that were kept in thermal comfort (P = 0.0018). The thiobarbituric acid reactive substances level was higher in HS animals fed with the MD diet (P = 0.0386). Significant effects of the interaction between supplementation and environment were observed on uric acid concentration levels, which were higher in HS animals fed the MS diet (P = 0.008), and on creatine kinase activity levels, which were lower in HS animals fed the MD diet (1,620.33 units/L; P = 0.0442). Our results suggest that under HS conditions, in which H2O2 production is increased, MS was able to mitigate ROS-induced damage, possibly by increasing the activities of antioxidant elements such as GSH, GPx activity, and uric acid concentration, which were present in higher levels in animals that were subjected to HS and fed the MS diet.

Acute heat stress and dietary methionine effects on IGF-I, GHR, and UCP mRNA expression in liver and muscle of quails

This study evaluated the expression of insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), and uncoupling protein (UCP) mRNA in muscle and liver of quails that were in thermal comfort or exposed to heat stress and that were fed diets with or without methionine supplementation. Meat quails were fed a diet that either met the nutritional demands for methionine (MS) or did not meet this demand (methionine-deficient diet, MD). The animals were either kept at a thermal comfort temperature (25°C) or exposed to heat stress (38°C for 24 h starting on the 6th day). RNA was extracted from liver and breast muscle, and cDNA was synthesized and amplified using quantitative reverse transcription-polymerase chain reaction. Animals that were fed the MS diet and remained at the thermal comfort temperature exhibited increased IGF-I mRNA expression in the liver (0.56 AU). The GHR mRNA expression in the liver and muscle was influenced by both the study variables. Animals receiving the MS diet showed higher GHR expression, while increased expression was observed in animals at the thermal comfort temperature. The UCP mRNA expression in the muscle was influenced by both methionine supplementation and heat stress. Higher expression was observed in animals that received the MD diet (2.29 vs 3.77 AU) and in animals kept in thermal comfort. Our results suggest that heat stress negatively affects the expression of growth-related genes and that methionine supplementation is necessary to appropriately maintain the levels of IGF-I, GHR, and UCP transcripts for animal metabolism.

Influence of dietary nitrogen sources with different ruminal degradability on growth performance of Comisana ewe lambs

The effect of diets with different ruminal degradability on growth performance of Comisana ewe lambs was studied. Forty-five ewe lambs, with average live weight of 16 ± 0.55 kg (mean ± sem), were allocated randomly to three isocaloric (2.19 Mcal/kg), isonitrogenous (15.5% of crude protein) diets for 18 weeks. Pelleted total mixed rations (PTMR) were formulated in order to provide N sources with different ruminal degradability: (1) urea (46% N) associated to soybean meal (high-degradability diet, HD), (2) soybean meal (medium-degradability diet, MD) and (3) corn gluten meal associated to soybean meal (low-degradability diet, LD). In vivo nutrient apparent digestibility of the three PTMR was determined using Comisana rams (mean LW 68 ± 3.8 kg) and indicated significant ( P < 0.05) differences for protein, ether extract, N-free extract, neutral detergent fiber (NDF) and hemicellulose fractions. The results from the current trial using Comisana ewe lambs showed that average daily gain was unaffected by ruminally degradable protein and ruminally undegradable protein ratio in diets ( P > 0.05). Final body weight in ewe lambs fed the MD diet was significantly greater ( P < 0.05) compared with the HD and LD treatment groups. Feed conversion ratio was lower in MD diet than HD and LD diets ( P < 0.05).

Utilization of different carbohydrates by the European eel ( Anguilla anguilla)

The present study was conducted to compare the utilization of several different carbohydrate sources and to evaluate the effect of two different methods of feed-processing in eel feeding. Five experimental isoenergetic diets were formulated (all containing 28.5% protein, 8% fat and 40% carbohydrate in dry matter), differing in the carbohydrate source: raw wheat starch (RWS diet), corn malto-dextrins (MD diet), manioc ( Manihot dulcis) meal (MAN diet) and pregelatinized corn starch (PCS1 diet). These four diets were manufactured by extrusion in a Clextral BC-45 extruder. A fifth diet was prepared with the same pregelatinized corn starch (PCS2 diet) but by using a customary laboratory procedure: pellets were made in a mincing machine after mixing dry premix with water and thereafter dried under hot-air flow. Each experimental diet was supplied to three lots of European eels. Feed acceptance, growth, feed efficiency, digestibility, dietary protein utilization, and effects on body composition were evaluated. All extruded diets were well utilized and promoted similar growth rates, irrespective of the origin and nature of the carbohydrate source. Diet PCS1 resulted in more tough pellets and was poorly accepted by the eels; besides its digestibility was clearly lower, so growth rate and feed conversion were the poorest. Results confirm the ability of eels to use high dietary carbohydrate levels and demonstrated the importance of selecting an appropriate processing method when these high carbohydrate levels are to be utilized.