Influence of Probiotics on Dietary Protein Digestion and Utilization in the Gastrointestinal Tract

ABSTRACT Background Dietary protein ingestion stimulates muscle protein synthesis by providing amino acids to the muscle. The magnitude and duration of the postprandial increase in muscle protein synthesis rates are largely determined by dietary protein digestion and amino acid absorption kinetics. Objective We assessed the impact of protein type, protein dose, and age on dietary protein digestion and amino acid absorption kinetics in vivo in humans. Methods We included data from 18 randomized controlled trials with a total of 602 participants [age: 53 ± 23 y; BMI (kg/m2): 24.8 ± 3.3] who consumed various quantities of intrinsically l-[1-13C]-phenylalanine–labeled whey (n = 137), casein (n = 393), or milk (n = 72) protein and received intravenous infusions of l-[ring-2H5]-phenylalanine, which allowed us to assess protein digestion and phenylalanine absorption kinetics and the postprandial release of dietary protein–derived phenylalanine into the circulation. The effect of aging on these processes was assessed in a subset of 82 young (aged 22 ± 3 y) and 83 older (aged 71 ± 5 y) individuals. Results A total of 50% ± 14% of dietary protein–derived phenylalanine appeared in the circulation over a 5-h postprandial period. Casein ingestion resulted in a smaller (45% ± 11%), whey protein ingestion in an intermediate (57% ± 10%), and milk protein ingestion in a greater (65% ± 13%) fraction of dietary protein–derived phenylalanine appearing in the circulation (P < 0.001). The postprandial availability of dietary protein–derived phenylalanine in the circulation increased with the ingestion of greater protein doses (P < 0.05). Protein digestion and phenylalanine absorption kinetics were attenuated in older when compared with young individuals, with 45% ± 10% vs. 51% ± 14% of dietary protein–derived phenylalanine appearing in the circulation, respectively (P = 0.001). Conclusions Protein type, protein dose, and age modulate dietary protein digestion and amino acid absorption kinetics and subsequent postprandial plasma amino acid availability in vivo in humans. These trials were registered at clinicaltrials.gov as NCT00557388, NCT00936039, NCT00991523, NCT01317511, NCT01473576, NCT01576848, NCT01578590, NCT01615276, NCT01680146, NCT01820975, NCT01986842, and NCT02596542, and at http://www.trialregister.nl as NTR3638, NTR3885, NTR4060, NTR4429, and NTR4492.

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The impact of Hayward green kiwifruit on dietary protein digestion and protein metabolism

European Journal of Nutrition ◽

10.1007/s00394-020-02363-5 ◽

2020 ◽

Cited By ~ 3

Author(s):

Sanghee Park ◽

David D. Church ◽

Carlene Starck ◽

Scott E. Schutzler ◽

Gohar Azhar ◽

...

Keyword(s):

Amino Acids ◽

Dietary Protein ◽

Protein Metabolism ◽

Plasma Concentrations ◽

Whole Body ◽

Protein Digestion ◽

Body Protein ◽

Before And After ◽

The Impact ◽

Green Kiwifruit

Abstract Purpose The purpose of the study was to determine if an actinidin protease aids gastric digestion and the protein anabolic response to dietary protein. Methods Hayward green kiwifruit (containing an actinidin protease) and Hort 16A gold kiwifruit (devoid of actinidin protease) were given in conjunction with a beef meal to healthy older subjects. Twelve healthy older males (N = 6) and females (N = 6) were studied with a randomized, double-blinded, crossover design to assess muscle and whole-body protein metabolism before and after ingestion of kiwifruit and 100 g of ground beef. Subjects consumed 2 of each variety of kiwifruit daily for 14 d prior to each metabolic study, and again during each study with beef intake. Results Hayward green kiwifruit consumption with beef resulted in a more rapid increase in peripheral plasma essential amino acid concentrations. There were significant time by kiwifruit intake interactions for plasma concentrations of EAAs, branched chain amino acids (BCAAs), and leucine (P < 0.01). However, there was no difference in the total amount of EAAs absorbed. As a result, there were no differences between kiwifruit in any of the measured parameters of protein kinetics. Conclusion Consumption of Hayward green kiwifruit, with a beef meal facilitates protein digestion and absorption of the constituent amino acids as compared to Hort 16A gold kiwifruit. Clinical trial NCT04356573, April 21, 2020 “retrospectively registered”.

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Protein Digestion in Weanling Pigs: Effect of Dietary Protein Source

Journal of Nutrition ◽

10.1093/jn/119.8.1093 ◽

1989 ◽

Vol 119 (8) ◽

pp. 1093-1099 ◽

Cited By ~ 11

Author(s):

Gary L. Asche ◽

Austin J. Lewis ◽

Ernest R. Peo,

Keyword(s):

Dietary Protein ◽

Protein Source ◽

Protein Digestion ◽

Weanling Pigs ◽

Dietary Protein Source

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OBSERVATIONS ON PROTEIN DIGESTION IN VIVO: II. DIETARY FACTORS AFFECTING THE RATE OF DISAPPEARANCE OF CASEIN FROM THE GASTROINTESTINAL TRACT

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o59-167 ◽

1959 ◽

Vol 37 (12) ◽

pp. 1475-1491 ◽

Cited By ~ 14

Author(s):

Carl Peraino ◽

Quinton R. Rogers ◽

Minoru Yoshida ◽

Mou-Liang Chen ◽

Alfred E. Harper

Keyword(s):

Gastrointestinal Tract ◽

Food Intake ◽

Dietary Factors ◽

Protein Digestion ◽

Dietary Carbohydrate ◽

Factors Affecting ◽

Single Meal ◽

Protein Free Diet ◽

Stomach Emptying

The effects of various dietary changes on the emptying of solids and nitrogen from the stomach and on the disappearance of nitrogen from the gastrointestinal tract of rats trained to consume a single meal daily are described. When the animals were fed 5 g of food the presence of casein in the diet caused a general deceleration of stomach-emptying and altered the shape of the stomach-emptying curve. The presence of 50% of casein in the diet did not result in an accumulation of nitrogen in the intestine much above the amount found when a protein-free diet was fed. When dextrin was the dietary carbohydrate the diet emptied from the stomach as a homogeneous mixture, whereas when sucrose was the dietary carbohydrate the casein emptied from the stomach more slowly than did the other components of the diet. Raising the dietary level of fat to 50% caused a general deceleration of emptying and abolished the above-mentioned carbohydrate effect. No delay in stomach-emptying due to the presence of casein in the diet was noted when only 1.5 g of diet was fed. As the level of food intake was raised the total quantity of nitrogen emptying from the stomach per unit time increased although a greater percentage of the amount ingested emptied from the stomach when the level of food intake was low.

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Complex Dietary Protein Improves Growth Through a Complex Mechanism of Intestinal Peptide Absorption and Protein Digestion

Journal of Parenteral and Enteral Nutrition ◽

10.1177/0148607113501556 ◽

2013 ◽

Vol 39 (1) ◽

pp. 95-103 ◽

Cited By ~ 3

Author(s):

Stephanie A. Hansen ◽

Aaron Ashley ◽

Brian M. Chung

Keyword(s):

Dietary Protein ◽

Protein Digestion ◽

Complex Mechanism ◽

Peptide Absorption

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Increased protein level of PEPT1 intestinal H+-peptide cotransporter upregulates absorption of glycylsarcosine and ceftibuten in 5/6 nephrectomized rats

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00270.2004 ◽

2005 ◽

Vol 288 (4) ◽

pp. G664-G670 ◽

Cited By ~ 3

Author(s):

Yuriko Shimizu ◽

Satohiro Masuda ◽

Kumiko Nishihara ◽

Lin Ji ◽

Masahiro Okuda ◽

...

Keyword(s):

Renal Failure ◽

Chronic Renal Failure ◽

Dietary Protein ◽

Peptide Transporter ◽

Protein Digestion ◽

Small Peptides ◽

Progression Of Renal Failure ◽

Progression Of Renal Disease ◽

Drug Pharmacokinetics ◽

Pept1 Mrna

In chronic renal failure (CRF), dietary protein is one of the factors that deteriorates residual renal functions. Numerous studies have indicated that the products of protein digestion are mainly absorbed as small peptides. However, how small peptides are absorbed in CRF remains poorly understood. H+-coupled peptide transporter (PEPT1/ SLC15A1) plays an important role in the absorption of small peptides and peptide-like drugs in the small intestine. Because dietary protein intake is one of the risk factors for renal failure, the alteration of intestinal PEPT1 might have implications in the progression of renal disease as well as the pharmacokinetics of peptide-like drugs. In this study, we examined the alteration of intestinal PEPT1 in 5/6 nephrectomized (5/6 NR) rats, extensively used as a model of chronic renal failure. Absorption of [14C]glycylsarcosine and ceftibuten was significantly increased in 5/6 NR rats compared with sham-operated rats, without a change in intestinal protease activity. Western blot analysis indicated that the amount of intestinal PEPT1 protein in 5/6 NR rats was increased mainly at the upper region. On the other hand, the amount of intestinal PEPT1 mRNA was not significantly different from that of sham-operated rats. These findings indicate that the increase in absorption of small peptides and peptide-like drugs, caused by the upregulation of intestinal PEPT1 protein, might contribute to the progression of renal failure as well as the alteration of drug pharmacokinetics.

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