In Vivo Digestibility of Carbohydrate Rich in Isomaltomegalosaccharide Produced from Starch by Dextrin Dextranase.

Slowly digestible carbohydrates are needed for nutritional support in diabetic patients with malnutrition. They are a good source of energy and have the advantage that their consumption produces a low postprandial peak in blood glucose levels because they are slowly and completely digested in the small intestine. A high-amount isomaltomegalosaccharide containing carbohydrate (H-IMS), made from starch by dextrin dextranase, is a mixture of glucose polymers which has a continuous linear structure of α-1,6-glucosidic bonds and a small number of α-1,4-glucosidic bonds at the reducing ends. It has a broad degree of polymerization (DP) distribution with glucans of DP 10－30 as the major component. In our previous study, H-IMS has been shown to exhibit slow digestibility in vitro and not to raise postprandial blood glucose to such levels as that raised by dextrin in vivo. This marks it out as a potentially useful slowly digestible carbohydrate, and this study aimed to evaluate its in vivo digestibility. The amount of breath hydrogen emitted following oral administration of H-IMS was measured to determine whether any indigestible fraction passed through to and was fermented in the large intestine. Total carbohydrate in the feces was also measured. H-IMS, like glucose and dextrin, did not result in breath hydrogen excretion. Carbohydrate excretion with dietary H-IMS was no different from that of glucose or water. These results show that the H-IMS is completely digested and absorbed in the small intestine, indicating its potential as a slowly digestible carbohydrate in the diet of diabetic patients.

An Evaluation of the Protein Requirements of Japanese Young Men by Consuming Two Types of Dairy Proteins Using the Indicator Amino Acid Oxidation Method.

The indicator amino acid oxidation method is a relatively new method for determining protein requirements. Our hypothesis was that the protein requirement of the casein-whey protein mixture (70% casein and 30% whey protein) was lower than the protein requirement of plain casein, because casein and whey proteins compensate for the lack of the first-limiting amino acids. The optimal mixing ratio was determined based on the amino acid scoring pattern which is used to calculate the digestible indispensable amino acid score. In this study, digestibility was not considered to determine the optimal mixing ratio because dairy protein is a good source of digestible protein. This study aimed to evaluate the protein requirements of Japanese young men by consuming casein and casein-whey protein mixture. Ten healthy young men (22±0.2 y old) participated in 12 experiments according to a graded protein intake (0.5, 0.7, 0.9, 1.0, 1.2, 1.4 g/kg/d) of casein and casein-whey protein mixture. The mean protein requirement was calculated as the breakpoint of breath 13CO2 enrichment using change-point regression models. The mean protein requirements of Japanese young men by consuming casein and casein-whey protein mixture were estimated to be 1.00 g/kg/d and 0.90 g/kg/d, respectively. These estimated requirements were consistent with the protein quality expected from the amount of the first-limiting amino acids. The indicator amino acid oxidation method may be useful to evaluate protein quality.

Evaluation of Protein Requirements Using the Indicator Amino Acid Oxidation Method.

The indicator amino acid oxidation (IAAO) method is a novel method for determining protein requirements. Recently, the protein requirement of healthy young men was reevaluated using this method, and the currently recommended protein requirement based on nitrogen balance study was found to be deficient. Similarly, with respect to experimental animals, the protein concentration used widely in the experimental diets was assumed to be deficient. However, only a few studies have tested the IAAO method in experimental animals. In particular, there are no studies on the protein requirement of adult rats measured using this method. Therefore, we applied the IAAO method to adult rats, to determine their casein protein requirement. Male Wistar/ST rats (15-18 wk old, housed in lighting (lights on from 23:00 to 11:00) conditions) were provided with the test diet including graded casein (5, 7, 9, 13, 17, 21 and 25%) every 2 h from 11:00 to 17:00. Tracer administration of 13C-phenylalanine was performed hourly from 14:00 to 17:00. Breath 13CO2 was measured every 30 min after the first tracer administration. There were significant differences between the 13CO2 concentration of the 5% and 17% casein groups at 17:00 and 18:00 (p<0.05). The mean casein protein requirement and recommended dietary allowance (RDA) were estimated to be 5.2 g/kg BW/d and 7.0 g/kg BW/d using the mixed-effect change point regression model, respectively. Our results indicated that the recommended casein value may be slightly deficient to satisfy the protein metabolic demand of some adult rats.

Effects of a Novel Nutritional Formula Enriched With Eicosapentaenoic Acid and Docosahexaenoic Acid Specially Developed for Tube-Fed Hemodialysis Patients.

OBJECTIVE: To evaluate the effects of a nutritional formula enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in tube-fed bedridden hemodialysis patients. DESIGN: A prospective, multicenter, single-arm study. SETTING: Koyukai Memorial Hospital, Orimoto Hospital, and Chofu Hospital, Japan. SUBJECTS: Eleven tube-fed bedridden hemodialysis patients. INTERVENTION: Patients were fed a nutritional formula enriched with EPA and DHA for 12 weeks. MAIN OUTCOME MEASURES: Body weight; body mass index (BMI); serum levels of total protein, albumin, prealbumin, total cholesterol, triglyceride, and C-reactive protein (CRP); serum fatty acid composition. RESULTS: Body weight; BMI; and serum levels of total protein, albumin, total cholesterol, triglyceride, and CRP at 12 weeks were not significantly different from baseline levels. Serum prealbumin, EPA, and DHA levels significantly increased after 12 weeks of treatment. CONCLUSIONS: A nutritional formula enriched with EPA and DHA may be beneficial for nutritional management in tube-fed bedridden hemodialysis patients.