Low-protein Group Research Articles

Meals Containing Equivalent Total Protein from Foods Providing Complete, Complementary, or Incomplete Essential Amino Acid Profiles do not Differentially Affect 24-h Skeletal Muscle Protein Synthesis in Healthy, Middle-Aged Women

BackgroundDietary protein quality can be assessed by skeletal muscle protein synthesis (MPS) stimulation. Limited knowledge exists on how consuming isonitrogenous meals with varied protein qualities affects postprandial and 24-h MPS. ObjectivesWe assessed the effects of protein quality and complementary proteins on MPS. We hypothesized that meals containing a moderate amount of high-quality, complete protein would stimulate postprandial and 24-h MPS. Meals containing 2 complementary, plant-based incomplete proteins would stimulate MPS less, and meals containing plant-based incomplete proteins at each meal, but complementary over 24 h would not stimulate MPS. Methods: This quasi-experimental study included a randomized, crossover design to assess protein quality and a nonrandomized low-protein control. We measured postprandial and 24-h MPS responses of healthy middle-aged women (n = 9, age 56 ± 4 y), to 3 dietary conditions: isonitrogenous meals containing 23 g protein/meal from 1) complete protein (lean beef), 2) 2 incomplete, but complementary protein sources (navy/black beans and whole wheat bread), and 3) single incomplete protein sources (black beans or whole wheat bread at 1 meal), but providing a complete amino acid profile over 24 h. In the low-protein group women (n = 8, 54 y) consumed a single breakfast meal containing 5 g of protein. Venous blood and vastus lateralis samples were obtained during primed, constant infusions of L-[ring-13C6]phenylalanine to measure mixed muscle fractional synthetic rates (FSR). ResultsMeals containing complete, complementary, or incomplete proteins did not differentially influence FSR responses after breakfast (P = 0.90) or 24 h (P = 0.38). At breakfast, the complete (P = 0.030) and complementary (P = 0.031) protein meals, but not the incomplete protein meal (P = 0.38), had greater FSR responses compared with the low-protein control meal. ConclusionsIsonitrogenous meals containing a moderate serving of total protein from foods providing complete, complementary, or incomplete essential amino acid profiles do not differentially stimulate muscle protein synthesis after a meal and daily. Trial registration numberThis clinical trial was registered at clinicaltrials.gov as NCT03816579. URLhttps://www.clinicaltrials.gov/ct2/show/NCT03816579?term=NCT03816579&draw=2&rank=1.

Influence of Maternal Dietary Protein during Late Gestation on Performance of Black Bengal Does and Their Kids.

The present study aimed to elucidate the effect of different levels of dietary protein during late pregnancy on the performance of Black Bengal does and their kids. Twelve does were divided into three groups, with four in each, and three diets, i.e., high protein (18% CP), medium protein (14% CP), and low protein (10% CP) were supplied for 50 days, commencing from 100 days post-coitum to parturition. During the first 100 days of pregnancy, uniform rations with similar ingredients were provided to fulfill the nutrient requirements depending on the live weight of does. All three diets were isocaloric (10.0 MJ/kg DM). Data were subjected to one-way ANOVA, and the significance of the difference among means was determined by Duncan's Multiple Range Test (DMRT). The main effects of diet and sex, as well as their interaction, were analyzed by two-way ANOVA by using the GLM procedure. The relative expression values of qPCR were calculated by using the 2-ΔΔCt analysis method. Live weight gain was significantly (p < 0.05) higher in high-protein-fed dams than other groups during the experimental period. The milk yield of does was significantly (p < 0.05) higher in high-protein-fed goats than in the low-protein group. The lactation length of does was significantly (p < 0.05) higher in the high- and medium-protein-fed does than in the low-protein-fed does. The duration of post-partum anestrus of does was significantly (p < 0.05) higher in the low-protein-fed dams than in the high-protein group. The birth weight of kids tended to be higher in the high-protein group but did not differ significantly among the treatment groups. In male kids, weaning weight, final weight, live weight gain, and average daily gain were significantly (p < 0.05) higher than in female kids. Weaning weight was higher (p < 0.05) in kids of the high-protein-fed does than the low-protein group. Final weight and live weight gain were significantly (p < 0.05) higher in kids of the high-protein-fed does than in the low-protein-fed group. On the other hand, average daily gain was significantly (p < 0.05) higher in kids of the high- and medium-protein-fed does than the low-protein group. The average body length and wither height of kids at the 32nd week was significantly (p < 0.05) higher in kids of high-protein-fed does than those of the low-protein-fed group. The average heart girth of kids at the 32nd week was significantly (p < 0.05) higher in kids of high-protein-fed does than the medium- and low-protein groups. The survival rate of kids was higher in the medium- and high-protein-fed does than in low-protein group. Hot carcass weight and ether extract content of meat were significantly (p < 0.05) higher in the high-protein group than in the other groups. The dressing percentage was significantly (p < 0.05) higher in the kids of high-protein-fed does than low-protein-fed goats. The expression of the H-FABP gene was significantly (p < 0.05) higher in kids of high-protein-fed does than those of the medium- and low-protein groups. In conclusion, maternal dietary protein levels positively influences the production performance of Black Bengal does and their kids.

The role of bile acid in regulating head-kidney, spleen and skin immune function of on-growing grass carp (Ctenopharyngodon idella)

Bile acids (BA) are receiving a great deal of attention and interest as critical regulators of the immune system of immune organs. Nevertheless, there are few researches on the effect of BA on immunity of aquatic animals. Hence, the objective of this research was to evaluated the effects of BA supplementation on immune function and the mechanisms in immune organs [head-kidney (HK), spleen (SP) and skin (SK)] of grass carp (Ctenopharyngodon idella). A total of 540 fish (the average body weight was 179.85 ± 1.34 g) were randomly assigned to a normal diet group (NPNL: 29 % protein and 5 % lipid) and five low protein and high lipid diet groups (LPHL: 26 % protein and 6 % lipid) with graded levels of 0 (no supplement), 80, 160, 240 and 320 mg/kg BA for 50 days. Grass carp were subjected to a 14-day challenge with Aeromonas hydrophila after growth experiment. Results indicated that: (1) LPHL group (without BA supplementation) increased SK lesion morbidity compared to NPNL group, and LPHL+160 mg/kg BA supplementation improved the disease resistance; (2) LPHL group (without BA supplementation) decreased the levels of antimicrobial compounds and the gene expressions of antimicrobial peptides in immune organs compared to NPNL group, and LPHL+(160–240) mg/kg BA supplementation significantly increased (P < 0.05) lysozyme (LZ) and acid phosphatase (ACP) activities, complement (C3, C4) and immunoglobulin M (IgM) contents, as well as the gene expressions of hepcidin, antimicrobial peptide 2 A (Leap-2 A), Leap-2B, Mucin2, βdefensin-1 in immune organs of fish; (3) LPHL group (without BA supplementation) aggravated inflammatory response by upregulated pro-inflammatory factors and downregulated anti-inflammatory factors gene expressions compared to NPNL group, and LPHL+240 mg/kg BA supplementation significantly increased transforming growth factor (TGF)-β1, interleukin 11 (IL-11), −4/13 A, TOR, eIF4E-binding proteins (4E-BP)1, S6K1, but markedly reduced (P < 0.05) the gene expressions of tumor, necrosis factor α (TNF-α), interferon γ2 (IFN-γ2), IL-1β, IL-6, IL-8, IL-15, IL-17D, IL-12p35, nuclear factor kappa B p65 (NF-κB p65), c-Rel, inhibitor of κBα (IκBα), IκB kinase β (IKKβ), IKKγ in immune organs of fish. In conclusion, LPHL diet (without BA supplementation) increased SK lesion morbidity and impaired the immunity of immune organs. In addition, LPHL+(160–240) mg/kg BA supplementation enhanced the disease resistance and immunity of grass carp by inhibiting NF-κB signaling molecule and activating TOR signaling molecule.

Mandible development under gestational protein restriction: cellular and molecular mechanisms.

Insufficient evidence regarding how maternal undernutrition affects craniofacial bone development persists. With its unique focus on the impact of gestational protein restriction on calvaria and mandible osteogenesis, this study aims to fill, at least in part, this gap. Female mice were mated and randomized into NP (normal protein) or LP (low protein) groups. On the 18th gestational day (GD), male embryos were collected and submitted to microtomography (µCT), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), PCR, and autophagy dynamic analyses. The study shows that the LP offspring exhibited lower body mass than the NP group, with µCT analysis revealing no volumetric differences in fetus's head. EDS analysis showed lower calcium and higher phosphorus percentages in mandibles and calvaria. SEM assessment evidenced higher hydroxyapatite crystal-like (HC) deposition on the calvaria surface in LP fetus. Conversely, lower HC deposition was observed on the mandible surface, suggesting delayed matrix mineralization in LP fetuses with a higher percentage of collagen fibers in the mandible bone. The autophagy process was reduced in the mesenchyme of LP fetuses. PCR array analysis of 84 genes revealed 27 genes with differential expression in the LP progeny-moreover, increased mRNA levels of Akt1, Mtor, Nfkb, and Smad1 in the LP offspring. In conclusion, the results suggest that gestational protein restriction anticipated bone differentiation in utero, before 18GD, where this process is reduced compared to the control, leading to the reduction in bone area at 15 postnatal day previously observed. These findings provide insights into the molecular and cellular mechanisms of mandible development and suggest potential implications for the Developmental Origins of Health and Disease (DOHaD).

Reduced protein levels in latex gloves may play an alternative approach to lowering latex sensitization risks among health workers; a cross-sectional analytical study

BackgroundLatex gloves are essential for protecting healthcare workers from biological hazards but pose a risk of latex allergy, particularly due to powdered, protein, and allergen content. Recent advancements in latex glove manufacturing have led to reduced levels of extractable proteins, a known factor triggering allergenic reaction. This study aimed to compare latex sensitization between nursing staff using low-protein and high-protein latex gloves at a tertiary university hospital in Thailand.MethodsA cross-sectional analytical study categorized participants into two groups based on glove exposure: the low extractable protein group (only exposed to non-powdered latex gloves with extractable protein levels below 50 µg/g) and the high extractable protein group (exposed to powdered latex gloves with levels above 50 µg/g). The sample size comprised 163 individuals in the low protein group and 318 in the high protein group (1:2). Latex allergy symptoms and sensitization were assessed using a self-administered questionnaire and latex-specific IgE measurement (ImmunoCAP), respectively. Data analysis involved descriptive and inferential statistics, including odds ratios and 95%CI.ResultsDemographic data was mostly similar in both exposure groups except for age. No significant differences in latex sensitization between the low and high protein groups were found via latex-specific IgE measurement (crude OR 1.90, 95%CI: 0.5, 7.18), potentially attributed to lower extractable protein levels in powdered latex gloves compared to previous studies. In contrast, the low protein group exhibited significantly fewer current latex allergy symptoms in both bivariate (crude OR 0.24, 95%CI: 0.06, 0.74) and multiple variable analysis (adjusted OR 0.18, 95%CI: 0.04, 0.86). Moreover, there was a significant reduction in latex allergy symptoms among the low protein group, decreasing from 9.8% who reported experiencing symptoms (when powdered latex gloves were used) to 1.2% who still reported current symptoms (OR 0.11, 95%CI: 0.02, 0.44).ConclusionsThis study underscores the importance of using non-powdered and low-protein latex gloves to reduce latex allergy symptoms while emphasizing the need for further investigation into the relationship between extractable protein levels in addition to the attempt of the major allergen removal and latex sensitization amid evolving glove manufacturing practices.

Impact of increased protein intake in older adults: a 12-week double-blind randomised controlled trial.

Emerging evidence suggests health-promoting properties of increased protein intake. There is increased interest in plant protein but a dearth of information in relation to its impact on muscle function. The objective of the present work was to examine the impact of intake of different types of proteins on muscle functional parameters including handgrip strength, biomarkers of metabolic health, sleep quality and quality of life in a group of older adults. Healthy men and women aged 50years and older entered a double-blinded, randomised, controlled nutritional intervention study with three parallel arms: high plant protein, high dairy protein and low protein. Participants consumed once daily a ready-to-mix shake (containing 20g of protein in high protein groups) for 12weeks. Changes in handgrip and leg strength, body composition, metabolic health, quality of life and sleep quality were analysed by linear mixed models in an intention-to-treat approach. Eligible participants (n= 171) were randomly assigned to the groups (plant: n= 60, dairy: n= 56, low protein: n= 55) and 141 completed the study. Handgrip strength increased after the intervention (Ptime= 0.038), with no significant difference between the groups. There was no significant difference between groups for any other health outcomes. In a population of older adults, increasing protein intake by 20g daily for 12weeks (whether plant-based or dairy-based) did not result in significant differences in muscle function, body composition, metabolic health, sleep quality or quality of life, compared with the low protein group.

Low-Protein Diets Differentially Regulate Energy Balance during Thermoneutral and Heat Stress in Cobb Broiler Chicken (Gallus domesticus).

The objective was to assess whether low-protein (LP) diets regulate food intake (FI) and thermogenesis differently during thermoneutral (TN) and heat stress (HS) conditions. Two-hundred-day-old male broiler chicks were weight-matched and assigned to 36 pens with 5-6 chicks/pen. After 2 weeks of acclimation, birds were subjected into four groups (9 pens/group) including (1) a normal-protein diet under TN (ambient temperature), (2) an LP diet under TN, (3) a normal-protein diet under HS (35 °C for 7 h/day), and (4) an LP diet under HS, for 4 weeks. During HS, but not TN, LP tended to decrease FI, which might be associated with a lower mRNA abundance of duodenal ghrelin and higher GIP during HS. The LP group had a higher thermal radiation than NP under TN, but during HS, the LP group had a lower thermal radiation than NP. This was linked with higher a transcript of muscle β1AR and AMPKα1 during TN, but not HS. Further, LP increased the gene expression of COX IV during TN but reduced COX IV and the sirtuin 1 abundance during HS. The dietary protein content differentially impacted plasma metabolome during TN and HS with divergent changes in amino acids such as tyrosine and tryptophan. Compared to NP, LP had increased abundances of p_Tenericutes, c_Mollicutes, c_Mollicutes_RF9, and f_tachnospiraceae under HS. Overall, LP diets may mitigate the negative outcome of heat stress on the survivability of birds by reducing FI and heat production. The differential effect of an LP diet on energy balance during TN and HS is likely regulated by gut and skeletal muscle and alterations in plasma metabolites and cecal microbiota.

The impact of guideline recommended protein intake on mortality and length of intensive care unit and hospital stay in critically ill adults: A systematic review

International guidelines recommend a target protein intake of ≥1.2 g/kg/day to all critically ill patients for optimal outcomes. There are however various conflicting data related to this recommendation. The primary objective of this review was to compare a protein intake group (≥1.2 g/kg/day) with a lower protein intake group (<1.2 g/kg/day) in critically ill adult patients on mortality, length of intensive care unit (ICU) and hospital stay. Secondly, the effect of protein intake on length of mechanical ventilation, adverse nutrition-related events and muscle mass and strength parameters were investigated. Sixteen randomised controlled trials (RCTs) of adult patients admitted to an intensive or high care unit and receiving nutrition support in the form of enteral- and/or parenteral nutrition were selected against prespecified eligibility criteria. Two independent reviewers extracted relevant data and assessed the risk of bias of the included studies. Review Manager 5.4.1 was used to analyse data and GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) was used to evaluate the certainty of the evidence. The higher protein group, when compared to the lower protein group, probably results in little to no difference in mortality (risk ratio [RR] 1.01; 95% confidence interval [CI]: 0.89 to 1.14; moderate-certainty evidence); with a probable slight increase in length of ICU stay (mean difference [MD] 0.33; 95% CI -0.57 to 1.23; moderate-certainty) and length of hospital stay (MD 1.72; 95% CI -0.58 to 4.01; moderate-certainty evidence), on average. For secondary outcomes, it was found that the higher protein group probably does not reduce the length of mechanical ventilation (MD 0.08; 95% CI -0.38 to 0.53; moderate-certainty evidence). Higher protein group probably reduces the occurrence of diarrhoea and high gastric residual volume and may reduce the occurrence of constipation. It may also increase nitrogen balance (MD 3.66; 95% CI 1.81 to 5.51; low-certainty evidence). Importantly, there does not seem to be harm associated with the higher protein group, though it should be mentioned that for many of the adverse events in this study, the certainty of evidence was low or very low.

Effects of essential amino acids supplementation in a low-protein diet on growth performance, intestinal health and microbiota of juvenile blotched snakehead (Channa maculata)

Developing a low-protein feed is important for the sustainable advancement of aquaculture. The aim of this study was to investigate the effects of essential amino acid (EAA) supplementation in a low-protein diet on the growth, intestinal health, and microbiota of the juvenile blotched snakehead, Channa maculata in an 8-week trial conducted in a recirculating aquaculture system. Three isoenergetic diets were formulated to include a control group (48.66 % crude protein (CP), HP), a low protein group (42.54 % CP, LP), and a low protein supplementation EAA group (44.44 % CP, LP-AA). The results showed that significantly lower weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), and feed efficiency ratio (FER) were observed in fish that were fed LP than in the HP and LP-AA groups (P < 0.05). The HP and LP-AA groups exhibited a significant increase in intestinal villus length, villus width, and muscular thickness compared to the LP group (P < 0.05). Additionally, the HP and LP-AA groups demonstrated significantly higher levels of intestinal total antioxidant capacity (T-AOC), catalase (CAT), and superoxide dismutase (SOD) and lower levels of malondialdehyde (MDA) compared to the LP group (P < 0.05). The apoptosis rate of intestinal cells in the LP group was significantly higher than those in the LP and HP groups (P < 0.05). The mRNA expression levels of superoxide dismutase (sod), nuclear factor kappa B p65 subunit (nfκb-p65), heat shock protein 70 (hsp70), and inhibitor of NF-κBα (iκba) in the intestine were significantly higher in the LP group than those in the HP and LP-AA groups (P < 0.05). The 16s RNA analysis indicated that EAA supplementation significantly increased the growth of Desulfovibrio and altered the intestinal microflora. The relative abundances of Firmicutes and Cyanobacteria were positively correlated with antioxidant parameters (CAT and T-AOC), whereas Desulfobacterota was negatively correlated with sod and T-AOC. The genera Bacillus, Bacteroides, and Rothia were associated with the favorable maintenance of gut health. In conclusion, dietary supplementation with EAAs to achieve a balanced amino acid profile could potentially reduce the dietary protein levels from 48.66 % to 44.44 % without adversely affecting the growth and intestinal health of juvenile blotched snakeheads.

Effects of low protein diets on acid-base balance, electrolyte balance, intestinal structure, and amino acid transport in piglets.

Reducing the dietary crude protein (CP) could effectively reduce pressure on protein ingredient supplies. However, few data have been reported about the extent to which CP can be reduced and whether limiting the use of soybean meal leads to electrolyte imbalance. In this experiment, using the low protein (LP) diet [2% lower than NRC (2012)], seventy-two piglets (35 days old) were randomly divided into 2 groups with 6 replicates of 6 piglets each: CON group (CP = 18.5%) and LP group (CP = 16.5%), to investigate the effect of the LP diet on electrolyte balance, acid-base balance, intestinal structure and amino acid transport in piglets. The results revealed that the LP diet decreased the average daily gain and dietary CP digestibility, and damaged the villi structure of the small intestine. Compared with the CON diet, the potassium content decreased and the chlorine content increased in the LP diet, and similar trends were shown in piglet serum. The arterial pH, pCO2, HCO3 -, and base excess of piglets in the LP group were lower than those in the CON group, while pO2 was higher than those in the CON group. Interestingly, the LP diet significantly increased the lysine content in piglet serum and significantly decreased the levels of arginine, leucine, and glutamic acid. Furthermore, the LP diet significantly affected the expression of some amino acid transport vectors (B0AT1, EAAC1, and y+LAT1). In summary, these findings suggested that the LP diet leads to acid-base imbalance, amino acid transport disorder and amino acids imbalance in piglets, and the dietary electrolyte may be a key factor in the impact of the LP diet on piglet growth performance and intestinal health.

Maternal malnutrition associated with postnatal sugar consumption increases inflammatory response and prostate disorders in rat offspring

Maternal malnutrition can alter developmental biology, programming health and disease in offspring. The increase in sugar consumption during the peripubertal period, a worldwide concern, also affects health through adulthood. Studies have shown that maternal exposure to a low protein diet (LPD) is associated with an increase in prostate disease with aging. However, the combined effects of maternal LPD and early postnatal sugar consumption on offspring prostate disorders were not investigated. The effects on aging were evaluated using a maternal gestational model with lactational LPD (6% protein) and sugar consumption (10%) from postnatal day (PND) 21–90, associating the consequences on ventral prostate (VP) rats morphophysiology on PND540. An increase was shown in mast cells and in the VP of the CTR + SUG and Gestational and Lactational Low Protein (GLLP) groups. In GLLP + SUG, a significant increase was shown in TGF-β1 expression in both the systemic and intra-prostatic forms, and SMAD2/3p had increased. The study identified maternal LPD and sugar consumption as risk factors for prostatic homeostasis in senility, activating the TGFβ1-SMAD2/3 pathway, a signaling pathway with potential markers for prostatic disorders.

Effects of Individual Essential Amino Acids on Growth Rates of Young Rats Fed a Low-Protein Diet.

To investigate the effects of individual essential amino acids (EAA) on growth and the underlying mechanisms, EAA individually supplemented a low-protein (LP) diet fed to young rats in the present study. Treatments were an LP diet that contained 6% crude protein (CP), a high-protein (HP) diet that contained 18% CP, and 10 LP diets supplemented with individual EAA to achieve an EAA supply equal to that of the HP diet. The CP concentration of the LP diet was ascertained from the results of the first experiment, which examined the effects of dietary CP concentrations on growth rates, with CP ranging from 2% to 26%. Weight gain was increased with the supplementation of His, Ile, Lys, Thr, or Trp as compared to the LP diet (p < 0.05). Feed intake was greater for the His-, Lys-, and Thr-supplemented treatments as compared to the LP group (p < 0.05). Protein utilization efficiency was lower for the HP group than other groups (p < 0.01). The supplementation of Leu, Lys, and Val led to reduced protein utilization efficiency (p < 0.05), but the supplementation of Thr and Trp led to greater efficiency than the LP group (p < 0.05). Compared to the LP group, plasma urea concentrations were elevated with individual EAA supplementation, with the exception of the Thr addition. The added EAA resulted in increased concentrations of the corresponding EAA in plasma, except for Arg and Phe supplementation. The supplementation of Arg, His, Leu, Lys, and Met individually stimulated mTORC1 pathway activity (p < 0.05), and all EAA resulted in the decreased expression of ATF4 (p < 0.05). In summary, the supplementation of His, Ile, Lys, Thr, or Trp to an LP diet improved the growth performance of young rats. Responses to His and Lys additions were related to the activated mTORC1 pathway and feed intake increases. The improved growth performance resulting from the addition of a single EAA is not solely attributed to the increased plasma availability of EAA. Rather, it may be the consequence of a confluence of factors encompassing signaling pathways, the availability of amino acids, and other associated elements. The additivity of these factors results in independent responses to several EAA with no order of limitation, as is universally encoded in growth models for all production animal species.

Effect of Low Protein Diet on Bone Structure of Young Wistar Mice.

&lt;b&gt;Background and Objective:&lt;/b&gt; Malnutrition and stunting are major unresolved problems in Indonesia. Protein deficiency can cause stunted growth, as well as make physical and cognitive abilities cannot reach their maximum potential. During childhood the need for protein must be fulfilled so that the peak of bone formation during adolescence can be perfect. In malnourished children, a low protein diet will lead to thinning of the bone cortex. Due to the high rate of stunting and malnutrition in children due to protein deficiency, a study was conducted on the effects of feeding low protein diet on rat bones. &lt;b&gt;Materials and Methods:&lt;/b&gt; Male Wistar rats (n = 10) at 6-8 weeks old (body weight around 250 g), control groups were fed a normal chow diet and low protein diet groups were given low protein chow diet (protein 5%) for 18 weeks, then the rats were sacrificed and the femoral bones were isolated. Body weight, femur weight, femur length were checked and bone density was examined using X-ray. &lt;b&gt;Results:&lt;/b&gt; The body proportions of the low protein group rats were smaller and thinner than those of the control group. This difference is supported by the significant weight loss starting from the sixth week after low protein feeding. There are significant differences in body weight and femur weight between the control and low protein diet groups. Bone density decreases significantly in low protein diet group. Macroscopically, the femur length of the low protein group was shorter than the control group, however the femur length did not show significant differences statistically between the two groups. &lt;b&gt;Conclusion:&lt;/b&gt; A low protein diet decreased the body weight of the rats, also causing impaired bone growth characterized by decreasing femur weight. The low protein diet also caused osteoporosis in the bones.

A maternal low-protein diet impaired glucose metabolism and altered the lncRNA profiles of islets in adult offspring

A maternal low-protein diet during pregnancy can increase children's susceptibility to diabetes mellitus in adulthood. However, whether long noncoding RNAs (lncRNAs) in islets participate in the development of diabetes in adult offspring following maternal protein restriction is not fully understood. Female mice were fed a low-protein (LP) diet or control diet throughout gestation and lactation. The male offspring were then randomly divided into two groups according to maternal diet: offspring from control diet group dams (Ctrl group) and offspring from LP group dams (LP group). We observed the glucose metabolism of adult offspring. A lncRNA microarray was constructed for the islets from the LP group and Ctrl group to explore the differently expressed lncRNAs. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes analyses were subsequently used to predict the functions of the differently expressed lncRNAs. The body weight from birth to 12 weeks of age was significantly lower in the LP offspring. Adult LP offspring exhibited impaired glucose tolerance and decreased insulin secretion, consistent with the reduction in β-cell proliferation. According to the lncRNA microarray, four lncRNAs, three upregulated lncRNAs, and one downregulated lncRNA were differently expressed in LP offspring islets compared with Ctrl offspring. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that these differentially expressed lncRNAs were mostly associated with the hypoxia-inducible factor-1α signaling pathway. Additionally, we validated the expression of these four differentially expressed lncRNAs via quantitative real-time polymerase chain reaction. Our findings demonstrated the expression patterns of lncRNAs in islets from adult offspring of mothers who consumed a maternal low-protein diet.

Ruminal microbiota and muscle metabolome characteristics of Tibetan plateau yaks fed different dietary protein levels.

The dietary protein level plays a crucial role in maintaining the equilibrium of rumen microbiota in yaks. To explore the association between dietary protein levels, rumen microbiota, and muscle metabolites, we examined the rumen microbiome and muscle metabolome characteristics in yaks subjected to varying dietary protein levels. In this study, 36 yaks were randomly assigned to three groups (n = 12 per group): low dietary protein group (LP, 12% protein concentration), medium dietary protein group (MP, 14% protein concentration), and high dietary protein group (HP, 16% protein concentration). 16S rDNA sequencing revealed that the HP group exhibited the highest Chao1 and Observed_species indices, while the LP group demonstrated the lowest. Shannon and Simpson indices were significantly elevated in the MP group relative to the LP group (P < 0.05). At the genus level, the relative abundance of Christensenellaceae_R-7_group in the HP group was notably greater than that in the LP and MP groups (P < 0.05). Conversely, the relative abundance of Rikenellaceae_RC9_gut_group displayed an increasing tendency with escalating feed protein levels. Muscle metabolism analysis revealed that the content of the metabolite Uric acid was significantly higher in the LP group compared to the MP group (P < 0.05). The content of the metabolite L-(+)-Arabinose was significantly increased in the MP group compared to the HP group (P < 0.05), while the content of D-(-)-Glutamine and L-arginine was significantly reduced in the LP group (P < 0.05). The levels of metabolites 13-HPODE, Decanoylcarnitine, Lauric acid, L-(+)-Arabinose, and Uric acid were significantly elevated in the LP group relative to the HP group (P < 0.05). Furthermore, our observations disclosed correlations between rumen microbes and muscle metabolites. The relative abundance of NK4A214_group was negatively correlated with Orlistat concentration; the relative abundance of Christensenellaceae_R-7_group was positively correlated with D-(-)-Glutamine and L-arginine concentrations. Our findings offer a foundation for comprehending the rumen microbiome of yaks subjected to different dietary protein levels and the intimately associated metabolic pathways of the yak muscle metabolome. Elucidating the rumen microbiome and muscle metabolome of yaks may facilitate the determination of dietary protein levels.

The association of prealbumin, transferrin, and albumin with immunosenescence among elderly males

Objective As people get older, the innate and acquired immunity of the elderly are affected, resulting in immunosenescence. Prealbumin (PAB), transferrin (TRF), and albumin (ALB) are commonly used markers to monitor protein energy malnutrition (PEM). However, their relationship with the immune system has not been fully explored. Methods In our study, a total of 93 subjects (≥65 years) were recruited from Tongji Hospital between January 2015 and February 2017. According to the serum levels of these proteins (PAB, TRF, and ALB), we divided the patients into the high serum protein group and the low serum protein group. Then, we compared the percent expression of lymphocyte subsets between two groups. Results All the low serum protein groups (PAB, TRF, and ALB) had significant decreases in the percentage of CD4+ cells, CD3+CD28+ cells, CD4+CD28+ cells and significant increases in the percentage of CD8+ cells, CD8+CD28− cells. PAB, TRF, and ALB levels revealed positive correlations with CD4/CD8 ratio, proportions of CD4+ cells, CD3+CD28+ cells, CD4+CD28+ cells, and negative correlation with proportions of CD8+ cells, CD8+CD28− cells. Conclusions This study suggested PAB, TRF, and ALB could be used as immunosenescence indicators. PEM might accelerate the process of immunosenescence in elderly males.

Low Selenium and Low Protein Exacerbate Myocardial Damage in Keshan Disease by Affecting the PINK1/Parkin-mediated Mitochondrial Autophagy Pathway.

Keshan disease (KD) is a myocardial mitochondrial disease closely related to insufficient selenium (Se) and protein intake. PTEN induced putative kinase 1 (PINK1)/Parkin mediated mitochondrial autophagy regulates various physiological and pathological processes in the body. This study aimed to elucidate the relationship between PINK1/Parkin-regulated mitochondrial autophagy and KD-related myocardial injury. A low Se and low protein animal model was established. One hundred Wistar rats were randomly divided into 5 groups (control group, low Se group, low protein group, low Se + low protein group, and corn from KD area group). The JC-1 method was used to detect the mitochondrial membrane potential (MMP). ELISA was used to detect serum creatine kinase MB (CK-MB), cardiac troponin I (cTnI), and mitochondrial-glutamicoxalacetic transaminase (M-GOT) levels. RT-PCR and Western blot analysis were used to detect the expression of PINK1, Parkin, sequestome 1 (P62), and microtubule-associated proteins1A/1B light chain 3B (MAP1LC3B). The MMP was significantly decreased and the activity of CK-MB, cTnI, and M-GOT significantly increased in each experimental group (low Se group, low protein group, low Se + low protein group and corn from KD area group) compared with the control group (P<0.05 for all). The mRNA and protein expression levels of PINK1, Parkin and MAP1LC3B were profoundly increased, and those of P62 markedly decreased in the experimental groups compared with the control group (P<0.05 for all). Low Se and low protein levels exacerbate myocardial damage in KD by affecting the PINK1/Parkin-mediated mitochondrial autophagy pathway.

Effects of Amino Acid Supplementation to a Low-Protein Diet on the Growth Performance and Protein Metabolism-related Factors in Broiler Chicks.

A low-protein (LP) diet may alleviate the environmental impact of chicken meat production by reducing nitrogen excretion and ammonia emissions. Thus, this study investigated the effect of a 15% reduced protein diet with or without amino acid (AA) supplementation on the growth performance of broiler chicks from 10 to 35 days of age and the underlying mechanism for loss of skeletal muscle mass. Thirty-six male broiler chicks were allocated to three experimental groups based on body weight: control, LP, and essential AA-supplemented LP (LP+AA). The body weight gain, feed conversion ratio, and weight of breast muscles and legs significantly decreased only in the LP group at the end of the feeding period. Plasma uric acid levels were significantly lower in the LP+AA group than those of the other groups. In the LP group, mRNA levels of microtubule-associated protein 1 light chain 3 isoform B were significantly higher in the pectoralis major, whereas those of atrogin-1, muscle RING-finger protein-1, and myoblast determination protein 1 were significantly higher in the biceps femoris compared to those in the control group. There were no significant differences in insulin-like growth factor 1 mRNA levels in the liver or skeletal muscle between groups. These findings suggested that supplementation with essential AAs ameliorated the impaired effects of an LP diet on growth performance in broiler chicks, and that the transcriptional changes in proteolytic genes in skeletal muscles might be related to the impaired effects of the LP diet.

Effects of dietary microbial protease on growth performance, nutrient apparent digestibility, hepatic antioxidant capacity, protease activities and intestinal microflora in juvenile genetically improved farmed tilapia, Oreochromis niloticus

The study was to evaluate the effects of four types of microbial protease on growth performance, nutritional composition, apparent digestibility coefficients (ADC), physiological parameters and microbiota of genetically improved farmed tilapia (GIFT, Oreochromis niloticus). Six diets were prepared, including a positive control diet (protein 300 g/kg, high protein group, HP) and one negative control diet (protein 280 g/kg, low protein group, LP) and four proteases were added to the low protein diets, included HuPro protease (LPH), acid protease (LPAC), neutral protease (LPN) and alkaline protease (LPAK). Compared with the fish fed LP diet, the weight gain rate (WGR), specific growth rate (SGR), feed conversion rate (FCR), protein efficiency ratio (PER) and feed intake ratio (FIR) were improved in fish fed LPH diet. The ADC of dry matter in LPH diet was improved. The serum total protein (TP) in LPH diet was higher than the LP diets. The activities of total antioxidant capacity (T-AOC) and catalase (CAT) in LPH group was higher than the LP and HP group, respectively. The protease activities of stomach and gut in fish fed LPH diet was higher than LP group. Shannon and Simpson indices in LPH group were higher than the LP group. The abundance of Fusobacteria in the six groups reached more than 70 % at the phylum level, and the largest difference in the relative abundance at the genus level was Cetobacterium. In conclusion, this study demonstrates the positive effects of HuPro protease on tilapias and selection of HuPro protease to the low protein diet is suitable.

Transcriptomics and metabolomics reveal the regulation of reproductive performance and egg quality of blotched snakehead Channa maculata broodstock induced by a high protein diet

To evaluate the effects of dietary protein on reproductive performance, egg quality and larval health of the blotched snakehead Channa maculata, three groups were designed: a high protein group (HP) with 48% protein content, a low protein group (LP) with 44% protein content, and a control group (C) fed with commercial feed containing 40% protein. The results demonstrated that the HP diet significantly enhanced maternal absolute fecundity, egg size and offspring health; however, it had no impact on fertilization rate and hatching rate. The maternal plasma levels of 11-ketotestosterone, 17β-estradiol, and vitellogenin in the HP group were found to be significantly higher compared to those in the C group. Plasma SOD activity and T-AOC capacity in the HP group were significantly higher than those in the C group, while MDA content showed an opposite trend. The trend of T-AOC in 7 days post-hatching larvae exhibited a consistent pattern with that observed in the maternal. Metabolomics and transcriptomics results indirectly indicated that the differences in reproductive and egg quality of the broodstock were associated with the regulation of arachidonic acid metabolism, steroid hormone biosynthesis, cholesterol metabolism, glycerophospholipid metabolism, and glycerolipid metabolism. The expression levels of star, zp3, foxo3, tgf-β, ghr, igf, cyp17a1, and cyp19a1 genes associated with reproduction and were significantly upregulated in the HP group. By depleting the abundance of metabolites in key pathway such as the pentose phosphate pathway, glycolysis/gluconeogenesis, nicotinate and nicotinamide metabolism, vitamin B6 metabolism within the ovary, there is an elevation in arachidonic acid metabolite abundance, thereby facilitating ovarian maturation and regulating egg quality. In conclusion, the high protein diet may affect the reproductive process and egg quality by inducing an upregulation of TGF-beta signaling pathway and ovarian steroidogenesis and arachidonic acid metabolism, leading to increased plasma cholesterol levels and enhanced steroid hormone synthesis.