Serum Amino Acid Levels Research Articles

Melatonin alleviates weanling stress in mice: Involvement of intestinal microbiota.

Melatonin influences intestinal microbiota and the pathogenesis of various diseases. This study was conducted to explore whether melatonin alleviates weanling stress through intestinal microbiota in a weanling mouse model. Melatonin supplementation in weanling mice (provided in the drinking water at a dosage of 0.2mg/mL for 2weeks) significantly improved body weight gain (1.4±0.03g/day in melatonin group vs 1.2±0.06g/day in control group) and intestinal morphology (ie, villus length, crypt depth, and villus to crypt ratio), but had little effect on the proliferation or apoptosis of intestinal cells, the numbers of Paneth cells and goblet cells, as well as the expression of makers related to enterocytes (sucrase) and endocrine cells (chromogranin A and peptide YY) in the ileum. Melatonin supplementation had little effect on serum levels of amino acids or stress-related parameters (eg, SOD, TNF-α, and angiotensin I). 16S rRNA sequencing suggested that melatonin supplementation increased the richness indices of intestinal microbiota (observed species, Chao 1, and ACE) and shaped the composition of intestinal microbiota (eg, increase in the abundance of Lactobacillus [19±3% in melatonin group vs 6±2% in control group]), which was demonstrated using an ex vivo proliferation assay and colonic loop proliferation assay. Melatonin supplementation also significantly influenced the metabolism of intestinal microbiota, such as amino acid metabolism and drug metabolism. More importantly, in antibiotic-treated weanling mice and germ-free weanling mice, melatonin failed to affect body weight gain or intestinal morphology. Melatonin significantly reduced (by about 60%) the bacterial load in enterotoxigenic Escherichia coli (ETEC)-infected weanling mice, but had little effect on ETEC load in antibiotic-pretreated animals. In conclusion, melatonin affects body weight gain, intestinal morphology, and intestinal ETEC infection through intestinal microbiota in weanling mice. The findings highlight the importance of intestinal microbiota in mediating the various physiological functions of melatonin in the host.

Integrated hepatic transcriptional and serum metabolic studies on circulating nutrient metabolism in diurnal laying hens.

The aim of the study was to see the diurnal variation of nutrients metabolism and their regulation under the management of large-scaled production. The hepatic transcriptional and serum metabolic studies on circulating nutrient metabolism were investigated in diurnal laying hens. Liver and blood were collected from 36 hens that were slaughtered at 3:30, 7:30, 11:30, 15:30, 19:30, and 23:30 (n = 6), respectively. The serum amino acid, fatty acid and glucose levels, as well as the hepatic transcriptome were analyzed. The results revealed that the circadian clock genes such as Bmal1, Clock, Per1, and Cry2 displayed circadian rhythms in hen livers. The genes related to circulating nutrient transportation, lipogenesis, lipid catabolism, sterol metabolism, and oxidative/anti-oxidative systems also oscillated. However, the nadir of glucose was observed at 7:30 and peaked at 11:30 in the day. Amino acid levels peaked mainly at night, and most amino acids exhibited circadian rhythms based on CircWave analysis. With the exception of undecanoic acid (C11:0), myristoleic acid (C14:1), cis-11, 14-eicosenoic acid (C20:2), and (cis-4, 7, 10, 13, 16, 19-docosahexaenoic acid) C20:3N6 fatty acids, others peaked at 7:30 and 15:30. The results indicated that the hens required more glucose in the early morning. More proteins should be ingested late in the day, since protein catabolism occurred mostly at night. To remove the redundant fats and lipids, fewer should be ingested, especially during the night. All these results would help to design a more accurate nutrition schedule for improving the performance of laying hens in the future.

Composition of gut microbiota in obese and normal-weight Mexican school-age children and its association with metabolic traits.

Childhood obesity is a serious public health problem in Mexico. Adult gut microbiota composition has been linked to obesity, but few studies have addressed the role of gut microbiota in childhood obesity. The aim of this study is to compare gut microbiota composition in obese and normal-weight children and to associate gut microbiota profiles with amino acid serum levels and obesity-related metabolic traits. Microbial taxa relative abundance was determined by 16S rRNA sequencing in 67 normal-weight and 71 obese children aged 6-12years. Serum amino acid levels were measured by mass spectrometry. Associations between microbiota composition, metabolic parameters and amino acid serum levels were tested. No significant differences in phyla abundances or Firmicutes/Bacteroidetes ratios were observed between normal-weight and obese children. However, Bacteroides eggerthii abundance was significantly higher in obese children and correlated positively with body fat percentage and negatively with insoluble fibre intake. Additionally, Bacteroides plebeius and unclassified Christensenellaceae abundances were significantly higher in normal-weight children. Abundance of both these species correlated negatively with phenylalanine serum levels, a metabolite also found to be associated with obesity in Mexican children. The study identified bacterial species associated with obesity, metabolic complications and amino acid serum levels in Mexican children.

Comparative effects of multiple sources of rumen-protected methionine on milk production and serum amino acid levels in mid-lactation dairy cows

ABSTRACT The dairy industry demand for rumen-protected methionine (RP-Met) supplements has been competitive because of the constant emergence of new products. To evaluate performances, our study was designed to characterize the production response of 3 RP-Met supplements in mid-lactation dairy cows. Twelve multiparous Holstein cows were used in a replicated 4 × 4 Latin square design with 21-d treatment period. Treatments included control [(basal) diet based on corn silage and alfalfa haylage, supplemented with 0.025% of ration DM of lysine (Lys; Ajipro)] or 1 of 3 RP-Met supplements [Smartamine M (SMM), Mepron M85 (MM85), or Novimet (NVM)]. For RP-Met groups, Met and Lys were supplemented to the basal diet at 0.03 and 0.20% of ration DM, respectively. Treatments had no effect on DMI or milk yield. Treatment did not modify milk fat or lactose concentration; however, milk protein content was elevated with SMM, relative to control or NVM (3.30% vs. 3.24 or 3.24%, respectively; P

Effects of glucocorticoids on serum amino acid levels during cardiac surgery in children

Children undergoing cardiac surgery with cardio pulmonary bypass often receive glucocorticoids to reduce the systemic inflammatory response. Glucocorticoids stimulate protein breakdown and increase amino acid availability. We studied whether glucocorticoid treatment influences the availability of amino acids, specifically those involved in the nitric oxide pathway. We prospectively studied 49 children with congenital heart disease undergoing cardiac surgery. Serum cortisol and amino acid levels were measured in arterial blood sampled before surgery (t=-5min), directly after surgery (t=0h) and at t=12h and t=24h after surgery. Serum cortisol and amino acid levels were compared between children who had received glucocorticoids (G+) and children who had not (G-). Of 49 patients included ((49% male, age 1.7 (0.5-8.7) y)), 33 (67%) received glucocorticoids. Baseline characteristics were not different between groups, except a higher weighted inotropic score in the G+ group. At t=0h, serum cortisol levels in the G+ group were significantly higher than in the G- group (7218 vs. 660nmol/L; (p<0.05)), but not different at the other time points. The levels of plasma amino acids had dropped after surgery. Compared to the G- group, in the G+ group the total amount of amino acids was significantly higher at t=12 and t=24; citrulline levels were higher at t=12 and t=24; and glutamine and arginine levels were higher at t=12. Glucocorticoid treatment during cardiac surgery in children preserves serum amino acid levels post-surgery. The preservation of glutamine, citrulline and arginine levels might have a beneficial effect on the related NO metabolism.

Melatonin alters amino acid metabolism and inflammatory responses in colitis mice.

Inflammatory bowel disease is a chronic inflammatory dysfunction of the gastrointestinal tract. This study explored the hypothesis that melatonin has beneficial functions in the mouse model of colitis induced by dextran sodium sulfate (DSS), with a specific focus on the expression of intestinal inflammatory cytokines and the serum levels of amino acids. The results revealed that mice with melatonin supplementation had a reduction in weight loss and disease index induced by DSS treatment. Melatonin stifled the expression of colonic IL-17 in mice with DSS-induced colitis. Melatonin also lowered the serum levels of Asp, Ser, Met, and Leu (p<0.05), but increased those of Glu and Cys (p<0.05). Thus, melatonin treatment is promising and may function as a potential adjuvant therapy to alleviate the clinical symptoms of patients with inflammatory bowel disease.

The construction of a panel of serum amino acids for the identification of early chronic kidney disease patients.

Serum creatinine, urea, and cystatin-c are standardly used for the evaluation of renal function in the clinic. However, some patients have chronic kidney disease but still retain kidney function; a conventional serum index in these patients can be completely normal. Serum amino acid levels can reflect subtle changes in metabolism and are closely related to renal function. Here, we investigated how amino acids change as renal impairment increases. Subjects were divided into three groups by renal function glomerular filtration rate: healthy controls, patients with chronic kidney disease with normal kidney function, and patients with chronic kidney disease with decreased kidney function group. We identified 11 amino acids of interest using LC-MS/MS on MRM (+) mode. Statistical analysis indicated that alanine (ALA), valine (VAL), and tyrosine (TYR) decrease with renal function impairment, whereas phenylalanine (PHE) and citrulline (CIT) increase. We tried to construct a diagnostic model utilizing a combination of amino acids capable of identifying early chronic kidney disease patients. The accuracy, specificity, and sensitivity of the combining predictors were 86.9%, 84.6%, and 90.9%, respectively, which is superior to the reported values for serum creatinine, urea, and cystatin-c. Our data suggest that serum amino acid levels may supply important information for the early detection of chronic kidney disease. We are the first to establish a diagnostic model utilizing serum levels of multiple amino acids for the diagnosis of patients with early-stage chronic kidney disease.

Serum Amino Acid Profiles in Normal Subjects and in Patients with or at Risk of Alzheimer Dementia

Background/Aims: Abnormalities in the plasma amino acid profile have been reported in Alzheimer disease (AD), but no data exist for the prodromal phase characterized by subjective memory complaint (SMC). It was our aim to understand if serum amino acid levels change along the continuum from normal to AD, and to identify possible diagnostic biomarkers. Methods: Serum levels of 15 amino acids and 2 organic acids were determined in 4 groups of participants – 29 with probable AD, 18 with mild cognitive impairment (MCI), 24 with SMC, and 46 cognitively healthy subjects (HS) – by electrospray tandem mass spectrometry. Results: Glutamate, aspartate, and phenylalanine progressively decreased, while citrulline, argi­ninosuccinate, and homocitrulline progressively increased, from HS over SMC and MCI to AD. The panel including these 6 amino acids and 4 ratios (glutamate/citrulline, citrulline/phenylalanine, leucine plus isoleucine/phenylalanine, and arginine/phenylalanine) discriminated AD from HS with about 96% accuracy. Other panels including 20 biomarkers discriminated SMC or MCI from AD or HS with an accuracy ranging from 88 to 75%. Conclusion: Amino acids contribute to a characteristic metabotype during the progression of AD along the continuum from health to frank dementia, and their monitoring in elderly individuals might help to detect at-risk subjects.

Abstract 384: Low Carbohydrate High Protein (LCHP) Diets are Atherogenic by Supplying Excess Amino Acids to Alter the Macrophage mTORC1-Autophagy Signaling Axis

Low carbohydrate high protein (LCHP) diets are commonly used in weight loss programs. However, the overall health benefits of such regimens are controversial with recent studies even suggesting an increased cardiovascular risk in certain populations. A few reports in animal models corroborate these concerns demonstrating increased LCHP-induced atherosclerosis. Interestingly, the downstream sequelae of such diets on tissues and cellular signaling are largely inferred with relevant mechanisms undefined. We first confirmed in the ApoE-null mouse model that LCHP diets are indeed atherogenic with the development of complex lesions. Using mass spectrometry, we find high protein feeding not only increases serum amino acid levels but increases amino acid load to tissues including the spleen and aorta with resultant activation of the mTORC1 signaling pathway particularly in macrophages. The involvement of mTORC1 is clearly causal as the atherogenic effect of LCHP-feeding is abrogated in macrophage-specific Raptor-null mice. Further mechanistic evaluation of the effects of amino acids on macrophages reveals dichotomous roles on a predominant mTORC1 target, autophagy. Certain amino acids such as Leucine potently activate mTORC1 via recruitment to lysosome and in turn suppress autophagy via ULK1 phosphorylation, whereas others such as glutamine act indirectly by downregulating the transcription of autophagy chaperones including p62/SQSTM1. This combined suppressive effect on autophagy leads to macrophage inflammasome activation and IL-1β release, accumulation of deleterious protein aggregates, and increased cell death. The in vivo relevance of this LCHP-amino acid-mTORC1-autophagy axis is supported by 1) the absence of increased atherosclerosis in macrophage autophagy-deficient (ATG5-/-) mice fed a LCHP diet, and 2) the absence of reduced atherosclerosis in mice dually deficient in macrophage mTORC1 and autophagy (Raptor/ATG5-/-). Our data provide the first mechanistic details of the deleterious effects of high protein diets on macrophages and the development of atherosclerosis. Incorporation of these concepts in clinical studies will be important to define the vascular effects of dietary protein.

The predictive and prognostic values of serum amino acid levels for clear cell renal cell carcinoma

ObjectivesTo investigate the predictive and prognostic values of the logistic regression model based on the serum amino acid levels. Materials and methodsThe study enrolled 42 patients with clear cell renal cell carcinoma (ccRCC) and 66 matched healthy people admitted to PLA General Hospital from April 2015 to June 2015. Serum samples from the 2 groups were analyzed by isobaric tags for relative and absolute quantitation-liquid chromatography-tandem mass spectrometry (iTRAQ-LC-MS/MS) method. Variables of the 2 groups were compared by Student’s t-test or chi-square test. The prediction model was constructed by logistic regression analysis. Oncological outcomes were evaluated by Kaplan-Meier survival analysis and Cox regression analysis. ResultsPathological diagnosis confirmed that all patients had ccRCC. No significant differences were found in the distribution of age, sex, or body mass index between patients with ccRCC and matched healthy people. A total of 32 amino acids were quantitatively analyzed, and serum levels of 23 amino acids were significantly different between the 2 groups. A predictive logistic regression model containing histidine, glutamine, 1-methyl histidine, and norvaline was constructed. Receiver operating characteristic (ROC) curves for all patients with ccRCC and controls, patients with T1 ccRCC and controls, patients with Fuhrman grade 1 to 2 ccRCC and controls, patients with T2 ccRCC and controls, and patients with Fuhrman grade 3 ccRCC and controls were drawn based on the model. The area under the curve values of the 5 receiver operating characteristic curves were 0.878, 0.885, 0.890, 0.830, and 0.788, respectively. Patients with higher model scores (>2) had significantly poorer progression-free survival (PFS) than patients with lower model scores (≤2). Multivariable Cox regression analysis showed that logistic regression model score was an independent predictor of PFS. ConclusionSerum amino acid levels are a potential predictive biomarker for distinguishing patients with ccRCC, especially early T-stage and low Fuhrman grade patients, from healthy people. Serum amino acid levels can also be used in the prognostic evaluation of patients with ccRCC.

Whole genome sequence analysis of serum amino acid levels.

BackgroundBlood levels of amino acids are important biomarkers of disease and are influenced by synthesis, protein degradation, and gene–environment interactions. Whole genome sequence analysis of amino acid levels may establish a paradigm for analyzing quantitative risk factors.ResultsIn a discovery cohort of 1872 African Americans and a replication cohort of 1552 European Americans we sequenced exons and whole genomes and measured serum levels of 70 amino acids. Rare and low-frequency variants (minor allele frequency ≤5%) were analyzed by three types of aggregating motifs defined by gene exons, regulatory regions, or genome-wide sliding windows. Common variants (minor allele frequency >5%) were analyzed individually. Over all four analysis strategies, 14 gene–amino acid associations were identified and replicated. The 14 loci accounted for an average of 1.8% of the variance in amino acid levels, which ranged from 0.4 to 9.7%. Among the identified locus–amino acid pairs, four are novel and six have been reported to underlie known Mendelian conditions. These results suggest that there may be substantial genetic effects on amino acid levels in the general population that may underlie inborn errors of metabolism. We also identify a predicted promoter variant in AGA (the gene that encodes aspartylglucosaminidase) that is significantly associated with asparagine levels, with an effect that is independent of any observed coding variants.ConclusionsThese data provide insights into genetic influences on circulating amino acid levels by integrating -omic technologies in a multi-ethnic population. The results also help establish a paradigm for whole genome sequence analysis of quantitative traits.Electronic supplementary materialThe online version of this article (doi:10.1186/s13059-016-1106-x) contains supplementary material, which is available to authorized users.

1594 Comparative effects of multiple sources of rumen-protected methionine on milk production and serum amino acid levels in midlactation dairy cows

1594 Comparative effects of multiple sources of rumen-protected methionine on milk production and serum amino acid levels in midlactation dairy cows

Increased CSF levels of aromatic amino acids in hip fracture patients with delirium suggests higher monoaminergic activity

BackgroundTo examine whether delirium in hip fracture patients was associated with changes in the levels of amino acids and/or monoamine metabolites in cerebrospinal fluid (CSF) and serum.MethodsIn this prospective cohort study, 77 patients admitted with an acute hip fracture to Oslo University Hospital, Norway, were studied. The concentrations of amino acids in CSF and serum were determined by high performance liquid chromatography. The patients were assessed daily for delirium by the Confusion Assessment Method (pre-operatively and post-operative day 1–5 (all) or until discharge (delirious patients)). Pre-fracture dementia status was decided by an expert panel. Serum was collected pre-operatively and CSF immediately before spinal anesthesia.ResultsFifty-three (71 %) hip fracture patients developed delirium. In hip fracture patients without dementia (n = 39), those with delirium had significantly higher CSF levels of tryptophan (40 % higher), tyrosine (60 % higher), phenylalanine (59 % higher) and the monoamine metabolite 5-hydroxyindoleacetate (23 % higher) compared to those without delirium. The same amino acids were also higher in CSF in delirious patients with dementia (n = 38). The correlations between serum and CSF amino acid levels were poor.ConclusionHigher CSF levels of monoamine precursors in hip fracture patients with delirium suggest a higher monoaminergic activity in the central nervous system during delirium in this patient group.

Low Circulating Amino Acids and Protein Quality: An Interesting Piece in the Puzzle of Early Childhood Stunting

Low Circulating Amino Acids and Protein Quality: An Interesting Piece in the Puzzle of Early Childhood Stunting

Association between adverse perinatal outcomes and amino acid levels measured with nutrient questionnaire in adolescent pregnancies

BackgroundTo evaluate the maternal serum amino acid levels in first trimester adolescent pregnancies by using a new developed dietary questionnaire. MethodsA group of 169 pregnant women in the first trimester of their pregnancy were asked to complete the dietary questionnaire. Among all the women, 39 were adolescent pregnancies. The results of the questionnaire were evaluated by a nutrient database program (BeBiS software program) designed to evaluate Turkish traditional foods and commercial processed foods. ResultsThere was no statistically significant difference between the groups in terms of body mass index and educational and socio-economic status. The mean age and gravidity was statistically significantly lower in adolescent pregnancies. The mean isoleucine, leucine, lysine, methionine, phenylalanine, tyrosine, threonine, valine, arginine, and proline levels were statistically significantly lower in adolescent pregnancies. Receiver operating characteristic (ROC) curve analysis showed the cut-off values of these amino acids. Of these amino acids; lower values of histidine, serine, and alanine were associated with lower birth weight, and lower values of histidine and alanine were associated with preterm delivery. ConclusionTo the best of our knowledge, this is the first study evaluating the amino acid levels in adolescent pregnancies. According to this study, some amino acid levels were lower in adolescent pregnancies and associated with adverse perinatal outcomes. Further studies with maternal and perinatal outcomes are needed to demonstrate the effects of these amino acids in such pregnancies.

Possible relationship between amino acids, aggression and psychopathy

Objective: Aggressive behaviour is associated with reduced serotonin metabolism in the brain, but there is not enough knowledge on potential changes of the serotonin precursor levels among violent offenders. In this study, we aimed to evaluate the relationships among the tendency of psychopathy, anger and the basic amino acids. Methods: Fifty-two young adult male patients with antisocial personality disorder (APD) and 30 healthy men included the study. Serum amino acid levels were measured by HPLC method. Aggression questionnaire and Hare Psychopathology Scale were used for all participants. Results: Blood levels of phosphoserine, aspartic acid, glutamic acid, aminoadipic acid and 1-methylhistidine in group of patients with APD were significantly higher than the control group. Blood levels of TRP, asparagine, citrulline, cystine, isoleucine, tyrosine, histidine, hydroxylysine, lysine, ethanolamine and arginine in the group of patients were found lower than the control group. A significant positive correlation between anger scores and histidine, methionine and GABA was found. GABA and methionine showed a significant correlation with the indirect aggression score. Conclusion: Our study showed a relationship between serum amino acid levels and the scores of aggression and psychopathy. We think that this is a productive research area for understanding the relationship among biochemical factors, aggression and psychopathy.

Quantifying Diet-Induced Metabolic Changes of the Human Gut Microbiome

The human gut microbiome is known to be associated with various human disorders, but a major challenge is to go beyond association studies and elucidate causalities. Mathematical modeling of the human gut microbiome at a genome scale is a useful tool to decipher microbe-microbe, diet-microbe and microbe-host interactions. Here, we describe the CASINO (Community And Systems-level INteractive Optimization) toolbox, a comprehensive computational platform for analysis of microbial communities through metabolic modeling. We first validated the toolbox by simulating and testing the performance of single bacteria and whole communities in vitro. Focusing on metabolic interactions between the diet, gut microbiota, and host metabolism, we demonstrated the predictive power of the toolbox in a diet-intervention study of 45 obese and overweight individuals and validated our predictions by fecal and blood metabolomics data. Thus, modeling could quantitatively describe altered fecal and serum amino acid levels in response to diet intervention.

The role of branched chain amino acid and tryptophan metabolism in rat’s behavioral diversity: Intertwined peripheral and brain effects

Previously, we showed that a transient early-in-life interference with the expression of multiple genes by mithramycin (MTR) followed by later-in-life exposure to chronic stress, leads to a “daring” and novelty seeking behavior in rats. In this study we searched for molecular changes that contribute to this behavioral alteration. We applied a non-hypothesis driven strategy using whole genome cDNA array analysis (WGA) followed by Genome Scale Metabolic modeling analysis (GSMM). Gene expression validation was performed by qRT-PCR and immunoblotting. Brain and serum amino acids levels were measured by HPLC. WGA data directed us towards metabolic pathways and GSMM pointed at branched chain amino acids (BCAA) pathway. Out of 21 amino acids analyzed in the prefrontal cortex of MTR+Stress rats only tryptophan, whose brain levels depend on serum BCAA levels, showed a significant decrease. No change was observed in serotonin or kynurenine levels. However, a significant reduction in mRNA and protein levels of the large neutral amino acid transporter (LAT1), which transports BCAA and tryptophan into the brain, as well as in serum levels of tryptophan/BCAA ratio were observed. The latter may be attributed to the failure to increase serum insulin, following stress, in rats pre-exposed to mithramycin. Finally, significant correlations were observed between the anxiety index and tryptophan and between T-maze errors and LAT1. This study shows a specific behavioral pattern, which is linked to modulations in fluxes of amino acids both peripheral and central, which converge and reciprocally interact, and may thus be equally important targets for therapeutic intervention.

Serum and cerebrospinal fluid excitatory amino acid, nitric oxide and cerebrospinal fluid malondialdehyde levels in West syndrome

West syndrome (WS) is an epileptic syndrome of early childhood. There have been a limited numbers of studies of cerebrospinal fluid (CSF) excitatory amino acid (EAA), nitric oxide (NO), and malondialdehyde (MDA) levels, as well as plasma levels of EAA, and NO, in WS. In this article, CSF EAA, NO, and MDA levels and plasma EAA, NO status, and a determination of the effects of antiepileptic drug therapy on these values were investigated in children with WS. Evaluation of CSF and serum EAA, NO, and MDA levels and of serum EAA and NO levels after 3 mo of antiepileptic drug therapy revealed a statistically significant decrease in CSF aspartate, glutamate, NO and MDA levels. In conclusion, the decrease in CSF MDA levels in this study is the result of both the decrease in glutamate activity and neuronal damage after controlling seizures with antiepileptic drugs.

PTH-200 Amino acid profiles in patient with intestinal failure: preliminary data on biochemical insights

<h3>Introduction</h3> Amino acid profiles have become increasingly important in intestinal failure (IF), ever since citrulline has been used as an IF marker. The purpose of the present study is to investigate levels in patients with IF needing parenteral nutrition (PN) and to examine their use as markers of IF severity to guide clinical decisions. <h3>Method</h3> Serum amino acids levels were measured prospectively within the cohort of patients managed by the IF Unit at our hospital using Ion Exchange Chromatography. Statistical analysis was performed by R and SPSS 21.0 using Pearson’s Correlation coefficient, t-tests and ANOVA. The traditional classification of IF¹was taken as a proxy of IF severity where Type 1 IF was coded as 1 and type 3 IF was coded as 3. <h3>Results</h3> Our study included 35 patients (11 Males, mean age 45, range 16–87), non IF controls (n = 10), Type 1 IF (n = 3), Type 2 IF (n = 3), Type 3 IF (n = 19); all IF patients were on PN. Causes of IF were short bowel syndrome, enterocutaneous fistula, high stoma output, pseudo-obstruction and radiation enteropathy. Citrulline was significantly lower in patients with Type 3 IF (p = 0.033) and receiving PN (p = 0.031) compared to other groups. Valine was significantly lower in patients with Type 3 and 2 IF compared to other controls and type 1 (p = 0.053); a trend was observed for lower homocysteine in patients receiving PN (p = 0.082). The other amino acids didn’t display differences with respects to groups. Figure 1 shows the correlation matrix between amino acids levels and severity of IF. Lower levels of citrulline, valine, alanine, total homocysteine, methionine, histidine, ornithine, and isoleucine were associated with more severe IF (range of correlation coefficients –0.432 to –0.174) whilst glutamate levels had a positive association (0.215) with less severe IF. Strong positive associations were found between amino acids valine, histidine, threonine, methionine, ornithine, alanine, leucine and isoleucine (correlation coefficient range 0.41–0.73), suggesting involvement in common biochemical pathways. <h3>Conclusion</h3> The present study confirmed the usefulness of citrulline as a marker of enterocytes mass in IF It provided new evidence that lower levels of valine, total homocysteine, methionine, histidine, ornithine, and isoleucine were associated with more severe IF. Larger studies are needed to validate those data. <h3>Disclosure of interest</h3> None Declared. <h3>Reference</h3> ESPEN endorsed recommendations. Definition and classification of intestinal failure in adults. <i>Clin Nutr</i>. 2014. doi: 10.1016/j.clnu.2014.08.017