• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.511-518
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• 2023

The use of dietary protein products has increased with interests in health promotion, and demand for sports supplements. Among various protein sources, milk protein is one of the most widely employed, given its economic and nutritional advantages. However, recent studies have revealed that milk protein undergoes fecal excretion without complete hydrolysis in the intestines. To increase protein digestibility, heating and drying were implemented; however, these methods reduce protein quality by causing denaturation, aggregation, and chemical modification of amino acids. In the present study, we observed that Lacticaseibacillus rhamnosus IDCC 3201 actively secretes proteases that hydrolyze milk proteins. Furthermore, we showed that co-administration of milk proteins and L. rhamnosus IDCC 3201 increased the digestibility and plasma concentrations of amino acids in a high-protein diet mouse model. Thus, food supplementation of L. rhamnosus IDCC 3201 can be an alternative strategy to increase the digestibility of proteins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.176-180
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• 2005

This study was conducted to examine effect dietary protein and calcium levels on calcium metabolism of the rat. Weaned 6-week old male rats were divided into 4 groups and were fed experimental diets for six weeks. Experimental groups were HPNC group-high protein normal calcium (protein: 400 g/kg diet, calcium: 0.5%), HPLC group-high protein low calcium (protein: 400 g/kg diet, calcium: 0.1%), NPNC group-normal protein normal calcium (protein: 200 g/diet, calcium: 0.5%), NPLC group-normal protein low calcium (protein: 200 g/diet, calcium: 0.1%). The calcium excretion in urine was higher in high protein group than in normal protein group, and it was highest in HPLC group. The activation of alkaline phophatase had a tendency to low in normal calcium group, and the concentration of parathyroid hormone (PTH) was the lowest in HPLC group. The deoxypyridinoline (DPD) concentration of urine was investigated as the highest in HPLC group and it was significantly lower in HPNC group that consumed normal calcium. The bone density of the femur was the highest in NPNC group and the lowest in NPLC group. As the results of this study, calcium excretion in urine and DPD density were the highest and the bone density was the lowest in HPLC group. It may suggest that the deficiency of calcium causes adversely effect in calcium metabolism upon consuming high protein diet. Therefore, it should be emphasized to consume enough calcium to prevent the hindrance of skeletal metabolism caused by deficiency of calcium upon consuming high protein diet.

• Nutritional Sciences
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• v.8 no.1
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• pp.28-34
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• 2005

To examine the combined effects of a high-protein diet and aerobic exercise on body weight and composition and blood lipid profiles in overweight women, 30 young women were recruited and placed into three groups: The high-protein diet and exercise group (HPE), the exercise-only group (EXO) and the control group (CON) (30$\pm$3%, 27$\pm$2%, and 29$\pm$3% body fat, respectively) for an 8-week experimental period. Daily diet included 25% isolated soybean protein (>90% protein, approximately 400 kcal) combined with each subject s usual diet for the HPE group. The exercise program consisted of aerobic-type exercises undertaken >3 times/wk and for>30 min/session at 50-60% of maximal capacity. Physical fitness, body composition, serum total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), triglycerides (TG) and glucose were measured before and after the experiment. Maximal aerobic capacity increased by the end of experiment in both the HPE (from 27.2$\pm$3.5 to 35.l$\pm$5.9 ml/kg/min, p<0.01) and EXO (from 30.3$\pm$5.4 to 33.8$\pm$3.8 mㅣ/kg/min, p<0.05) groups. Percent body fat decreased by 3.3% (p<0.01) in the HPE group and by 1.5% (p<0.05) in the EXO group by the end of the experiment, but not in the CON group. Lower back strength and agility increased only in the HPE group. In the HPE group, TC decreased from 168$\pm$20 to 155$\pm$18 mg/dL and HDL-C increased from 57$\pm$l0 to 61$\pm$9 mg/dL in HPE (p<0.01). But TC and HDL-C did not change in the EXO and CON groups. TG and glucose did not vary among the groups. Although the EXO group showed a similar outcome to that of the HPE group, a favorable change in body composition and blood lipids as well as an improvement in aerobic capacity was more marginal in the latter group.

• Journal of Nutrition and Health
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• v.6 no.1
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• pp.15-29
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• 1973

Albio rats right after weaning, weighing $50{\sim}55g$, were divided into the control, high-carbohydrate-, high-lipid-, and high-protein-fed groups. and were fed for 12 weeks with the respective diets to observe the increase in body weights as well as changes in the chemical constituentes and enzyme activities in the liver tissue, with the following results. (1) There was little difference in the rate of increase in the body weights among the groups, showing normal growth, except the high-protein-fed group which showed decrease in rate of body weight increase from the 7th week after feeding. (2) The liver weight was either increased after 12 weeks of feeding with the high-carbohydrate and high-Lipid diets, or showed no difference with the high-protein diet, as compared to the control weight. (3) The liver cytosol protein content was increased when fed with the high-protein diet, but decreased when fed with the high-carbohydrate and high lipid diets, as compared to the control content. (4) The triglyceride and cholesterol contents in the liver were decreased in the high-protein-fed group, but increased markedly in the high-carbohydrate- and high-lipid-fed groups as compared to the control values. (5) The hepatic glucokinase, G6PD, LDH, and fatty acid synthetase activities were increased in the high-carbohydrate and high-lipid-fed groups, and GOT and CPT activities were increased in the high-protein-fed group. From the above results. it was known that the high-carbohydrate and high-lipid diets stimulated the hepatic lipid metabolism, giving rise to lipogenesis, but the high- protein diet could prevent the lipogeuesis leading to the body weight increase.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.383-389
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• 2015

The purpose of this study was to investigate the anti-apoptosis-related protein expression in skeletal muscle of rats with different amount of mountain ginseng (MG) added high-fat diet fed. Twenty-four Sprague Dawley male rats were divided into the high-fat diet control group (CON), 0.5% of MG added diet group (MG1), and 1.0% of MG added diet group (MG2) with eight rats each. The P53, anti-apoptotic protein, was significantly lower in MG2 than CON and MG1. The bcl-2 and bcl-xl, however, were not significantly different from MG1 but from CON. The caspase-9 and -3, were significantly lower in MG groups than CON. In addition, it was dramatically lower in MG2. These results suggested that MG addition to the high-fat diet suppressed p53 protein expression and enhanced anti-apoptototic protein expression. MG may be a positive effects on health as a medicinal plant.

• Journal of Nutrition and Health
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• v.28 no.4
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• pp.298-308
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• 1995

To investigate the effect of estrogen and dietary protein level on Ca metabolism, female rats were undergone ovariectomy or sham-operation. Ovariectomized rate were divided into either estrogen-or vehicle-treated groups. Each treatment group was again divided into 40%-casein(H) or 10%-casein(L) diet groups. All experimental diets contained 0.2% Ca, 0.4% P and fed to rats for 8 weeks. Apparant Ca absorption and Ca balance were not affected by dietary protein level and ovariectomy, however they were increased by estrogen injection and this effect was even higher in low protein groups. Urinary Ca excretion were higher in high protein groups. GFR was not affected by dietary protein level, ovariectomy, or by estrogen injection. Urinary protein excretion was higher in high protein groups, which implies that the kidney funtion was deteriorated by high protein diet, and this may account partly for the higher urinary Ca in high protein groups. Ovariectomy or estrogen treatment had no effect on urinary protein excretion. Urinary hydroxyproline was higher in ovariectomized rats and increased in high protein grous. Elevated value of ovarictomized rats was lowered by estrogen injection, especially in low protein group. Alkaline phosphatase tended to increase in ovariectomized groups and lowered with estrogen treatment, but this difference was not statistically significant. Serum PTH was not affected by ovariectomy and dietary protein level. Therefore the increased hydroxproline excretion does not seem to be attributed to PTH. Dietary protein level, ovariectomy and estrogen treatment did not affect the weights and components of femur, scapular, and 4th vertebra. Ash/wt ratio of femur was, however, lower in ovariectomized rats and increased with estrogen treatment. Therefore, among the bones studied, femur seemed to be the most vulnerable. The results of this study shows that estrogen treatment may alleviate or reduce bone loss in postmenopausal women somewhat, especially for those people with low protein diet.

• Journal of Nutrition and Health
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• v.20 no.2
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• pp.122-134
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• 1987

In order to investigate the effect of dietary protein and fat levels on the growth and the utilization of nitrogen and energy and body composition in rats, Sprague\ulcornerDawley 48 male rats of 8 weeks old weighing approxijIlately 215-220g were subjected to feeding trials for 8 weeks and then subsequently to metabolic trials for 2 weeks. Four dietary protein levels (4, 8, 16, 32%) and each protein level contained two fat levels(3.9, 11.7%=1O,3J% of 3600kcal ME/kg) by addition of an appropriate amount of carbo\ulcornerhydrate and the following results were obtained. The body weight gain and food efficiency ratio of the rats to which a diet of 16% protein and 3.9% fat was fed were significantly higher than in either case of 8% pro\ulcornertein diet or of 32% protein diet. The digestibility of protein in the experimental diets was 73.3 -93.4%. The digesti\ulcornerbility of energy ( energy absorption) in the experimental diets was 83.2 -91.5%. The utilization of protein and the metabolic energy efficiency in the experimental diets was highest at the diet of 8% protein and 3.9% fat. The analysis of the body composition after feeding trials for 8 weeks has shown that the content of body water and protein were not affected by protein and fat levels in diet. The content of body fat in the rats to which 3.9% fat diet was fed was high\ulcornerer than that in those to which 11.7% fat diet was fed. From the above experimental results it may be suggested that the best formula of diet for the 8 weeks old rats may be composed of the 8% protein and 3.9% fat.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.8
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• pp.1181-1188
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• 2014

The aim of this study was to evaluate protein expression patterns of liver in response to subacute ruminal acidosis (SARA) induced by high-concentrate diet. Sixteen healthy mid-lactating goats were randomly divided into 2 groups and fed either a high-forage (HF) diet or a high-concentrate (HC) diet. The HC diet was expected to induce SARA. After ensuring the occurrence of SARA, liver samples were collected. Proteome analysis with differential in gel electrophoresis technology revealed that, 15 proteins were significantly modulated in liver in a comparison between HF and HC-fed goats. These proteins were found mainly associated with metabolism and energy transfer after identified by matrix-assisted laser desorption ionization/time of flight. The results indicated that glucose, lipid and protein catabolism could be enhanced when SARA occurred. It prompted that glucose, lipid and amine acid in the liver mainly participated in oxidation and energy supply when SARA occurred, which possibly consumed more precursors involved in milk protein and milk fat synthesis. These results suggest new candidate proteins that may contribute to a better understanding of the mechanisms that mediate liver adaptation to SARA.

• Journal of Nutrition and Health
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• v.19 no.1
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• pp.16-22
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• 1986

This study was designed to investigate the nutritional effect of mugowrt powder supple mentation to rice diets with different protein levels. Thirty female albino rats weighing 39-43g were adopted for the feeding trial for 4 weeks. The different 5 kind of experimental diets were performed . Control diet was commercially available forage for rats, experimental diet (I-C) highly milled rice, (Ⅰ) highly milled rice 95% and mugwort powder 5%, (Ⅱ-C)highly milled rice 95% and milk casein 5%, and (Ⅱ) highly milled rice 90%, milk casein 5 % and mugwort powder 5%. Growth rate was remarkably high in the dietary group fed on highly milled rice supplemented with 5% mugwort powder (protein 8%) (P<0.05), but it showed the tendency to be rather low in the group fed on highly milled rice supplemented with 5% casein and 5% mugwort powder (protein 12%). Food efficiency as well as protein efficiency appeared similar to the growth rate. Hematodcrit level demonstrated the same tendency as growth rate, but hemoglobin content was observed to increase by diets supplemented with increasing amount of mugwort regardless of protein level. Each nutrient intake was increased by adding mugwort powder to diets after a week's feeding, but it was increased by 8% protein diet, and decreased by 12% protein diet in 3 weeks as well as 4 weeks after feeding . The absorption rate of carbohydrate and protein decreased by feeding mugwort supplemented diets regardless of protein level and feeding period, and that of lipid increased with 12% protein diet.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.146-153
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• 2016

A feeding experiment was conducted to determine the nutritional value of various dietary protein sources without a vitamin premix supplementation in juvenile black rockfish, Sebastes schlegeli. Diets containing similar quantities of lipid and carbohydrate with 50% crude protein from fish meal (FM)/soybean meal (SBM)/corn gluten meal (CGM), FM only, casein/gelatin, high FM/low casein and low FM/high casein were fed to rockfish along with a commercial rockfish diet. The diet containing only 65.6% FM and the commercial rockfish diet produced significantly greater weight gain (WG) and feed efficiency (FE) than all other semipurified diets (SPDs); the economical diet with 52.8% FM, 10% SBM and 5% CGM produced lower WG than the diet containing FM and commercial rockfish diet, but FE and survival were similar both diets. Intermediate responses were observed for rockfish fed the SPD containing 32.8% FM and 27.4% casein, while SPDs containing 10% FM and 41.8% casein and 38.5% casein and 10% gelatin yielded the lowest WG and FE. Some differences in tissue indices and body composition of rockfish were induced by the diets containing various protein sources and levels without the vitamin premix supplementation.