Description of Plasma Concentrations of Free Amino Acids with Some Clinical Symptoms of Patients Under 5 with Short Bowel Syndrome

Amino acid (AA) is the main component of proteins. Changes in levels of plasma AA concentration have been mentioned in some cases such as plasma AA concentrations in chronic kidney disease (CKD) patients are low when inflammation status increases [1] or patients with short bowel syndrome (SBS) undergoing total parenteral nutrition (TPN) have decreasing concentrations of essential amino acids (EAA), increasing rate of malnutrition and complications while for those undergoing part of parenteral nutrition (PN), there was just a decrease in concentrations of two branched chain amino acids, leucin, valine, cysteine, and tyrosine [2]. Autistic children had significant lower plasma levels of leucine, isoleucine, phenylalanine, methionine, cysteine, serine, tyrosine while phosphoserine was significantly raised [3]. In SBS, as intestinal absorption of nutrients is significantly decreased, patients are largely reliant on PN so the concentrations and compositions of AA in PN formula is critical to treatment outcomes. The study was carried out with the Objective: describe the plasma concentrations of free amino acids in 57 children with SBS and the correlation with clinical symptoms. Method: descriptive cross-sectional study. Result: High ratio of malnutrition with 96.5% of underweight, 64.9% of stunting and 93% of wasting. All children with SBS had increase of EAA and decrease of non-essential amino acids (NEAA), 38.9% had histidine deficiency, 19.2% had tryptophan deficiency, 14% had arginine deficiency and 12.3% had isoleucine deficiency. AA deficiency is more common in acquired than in functional SBS, in adaptation than in maintenance phase. Conclusion: High ratio of malnutrition in SBS patients. All children with SBS underwent NEAA deficiencies. Plasma concentrations of free AA largely depended on AA compositions of PN solution.

and sufficiently provide nutrients to minimize deficiencies and improve immunity for children with SBS through AA in PN solution, this study is carried out to describe the plasma concentrations of free AA with the clinical status of SBS patients.

Subjects and Methods
The descriptive cross-sectional study was carried out on 57 children under 60 months of age at Vietnam National Children's Hospital from August 2017 to August 2018 with SBS diagnosis, who have post-operation time more than 3 weeks. In which: 15 patients who were not reliant on PN were orally fed (maintenance period), 42 patients were reliant on PN and the PN solution provided 30 -70% total energy requirement (adaptation period). Patients in the study did not have diseases or congenital disorders that require long-term PN or using medications that affect amino acid metabolism. The children were divided into two groups: a) Acquired SBS: length of the remaining small intestine (bowel) is less than 50cm at neonatal stage with gestational age under 36 weeks or less than 72cm for full-term babies. If the resection is carried out beyond the infancy stage, length of the remaining intestine is less than 75cm in children under 12 months and less than 100cm in children over 12 months. b) Functional SBS: after the resection, children do not meet these above criteria but must be reliant on PN in at least 42 days post-operation. PN solution for intravenous infusion is designed by Pharmacy Department of Vietnam National Children's Hospital. The protein solution is usually vaminolac 6.5% or amino plasma 10%. The compositions also include sugar, salt, lipid, potassium, vitamins and minerals.     Table 4 showed that    [6] but must actually be 15mg/kg/day to meet body demand [7].

Data Collection Method
We can evaluate threonine supply via leucine and/or phenylalanine balance, but leucine and phenylalanine (Table 2) both increased, so the oxidization of these 2 AA and threonine using mechanism were ineffective, causing higher increase of threonine  of genes that promote oxidative stress and activate immunity [10].
Dietary glutamine deficiency weakens cell signaling, leading to gut atrophy in both piglets and infants [11].
Glutamine and glutamate are main energy sources for small intestinal cells, depress protein digestion and catabolism, support Arginine improves the recovery of injured gastric mucus in pig, therefore arginine supplementation prevents necrotizing enterocolitis in premature infant especially those with poor activity of arginine synthesizing enzymes (internal arginine is metabolized from glutamate, glutamine and proline) or insufficiency of arginine [13]. 14% patients with SBS in the study had arginine decrease, 19.3% had cysteine deficiency while vaminolactused for feeding has 1g/1,000 ml solution and cysteine is also metabolized from aspartate and NH3. Experiment on rats with SBS showed that dietary supplementation of cysteine and methionine can stimulate illeal mucosal growth and adaptation [14]. The supplementation of N-Acetyl -cysteine into PN solution with the dose 20-50mg/ kg/ day can alleviate elevated liver enzymes, increase plasma glutathione metabolism in children undergoing PN [15]. Therefore, in our study, we still saw a high ratio of patients with decreasing cysteine, which showed a limitation in treatment and the prognosis

Recommendation
It is necessary to detect AA imbalance in SBS children, as well as carry out more further studies to have a recommendation on AA requirement of SBS children.