Amount and fate of egg protein escaping assimilation in the small intestine of humans
Abstract
Studies attempting to evaluate protein assimilation in humans have hitherto relied on either ileostomy subjects or intubation techniques. The availability of stable isotope-labeled protein allowed us to determine the amount and fate of dietary protein escaping digestion and absorption in the small intestine of healthy volunteers using noninvasive tracer techniques. Ten healthy volunteers were studied once after ingestion of a cooked test meal, consisting of 25 g of13C-,15N-, and2H-labeled egg protein, and once after ingestion of the same but raw meal. Amounts of 5.73% and 35.10% (P < 0.005) of cooked and raw test meal, respectively, escaped digestion and absorption in the small intestine. A significantly higher percentage of the malabsorbed raw egg protein was recovered in urine as fermentation metabolites. These results 1) confirm that substantial amounts of even easily digestible proteins may escape assimilation in healthy volunteers and 2) further support the hypothesis that the metabolic fate of protein in the colon is affected by the amount of protein made available.
REFERENCES
- 1 Amino acid degradation by anaerobic bacteria.Annu. Rev. Biochem.5019812340
Crossref | PubMed | ISIGoogle Scholar - 2 Resistant starch lowers fecal concentrations of ammonia and phenols in humans.Am. J. Clin. Nutr.631996766772
Crossref | PubMed | ISIGoogle Scholar - 3 The production of urinary phenols by gut bacteria and their possible role in the causation of large bowel cancer.Am. J. Clin. Nutr.29197614481454
Crossref | PubMed | ISIGoogle Scholar - 4 Nitrogen losses in the human small bowel: obligatory losses and the effect of physical form of food.Gut291988809815
Crossref | PubMed | ISIGoogle Scholar - 5 Colonic protein fermentation and promotion of colon carcinogenesis and thermolyzed casein.Nutr. Cancer231995271281
Crossref | PubMed | ISIGoogle Scholar - 6 Dietary fibre, fermentation and large bowel cancer.Cancer Surv.61987601621
PubMedGoogle Scholar - 7 The effect of meat protein and dietary fiber on colonic function and metabolism.Am. J. Clin. Nutr.32197920942101
Crossref | PubMed | ISIGoogle Scholar - 8 Digestibility of cooked and raw egg protein, assessed by stable isotope techniques.J. Nutr.128199817161722
Crossref | PubMed | ISIGoogle Scholar - 9 The production of egg proteins, enriched with l-leucine-13C1, for the study of protein assimilation in humans by means of breath test technique.J. Nutr.1271997327331
Crossref | PubMed | ISIGoogle Scholar - 10 A role for sulfate reducing bacteria in ulcerative colitis (Abstract).Gastroenterology981990A170
Google Scholar - 11 Amino acid losses in ileostomy fluid on a protein-free diet.Am. J. Clin. Nutr.5919947073
Crossref | PubMed | ISIGoogle Scholar - 12 The influence of dietary protein supplements on bacterial colonic metabolism.Gut4119977076
Crossref | PubMed | ISIGoogle Scholar - 13 Geypens, B., D. Claus, N. Gorris, P. Evenepoel, P. Rutgeerts, and Y. Ghoos. Determination of total multi-2H labeled phenol andp-cresol in urine to demonstrate protein fermentation in man (Abstract). Proc. Int. Symposium on Capillary Chromatography XX, Riva del Garda, Italy, 1998.
Google Scholar - 14 Geypens, B., D. Claus, N. Gorris, A. Luypaerts, P. Evenepoel, P. Rutgeerts, and Y. Ghoos. Determination of deuterated phenylalanine and tyrosine in egg protein by GCQ (Abstract). Proc. Int. Symposium on Capillary Chromatography XX, Riva del Garda, Italy, 1998.
Google Scholar - 15 Breath tests in gastric emptying and transit studies: technical aspects of 13CO2-breath tests.Progress in Understanding and Management of Gastrointestinal Motility Disorders, Janssens J.1993169180KU LeuvenLeuven, Belgium
Google Scholar - 16 Protein absorption and ammonia production: the effects of dietary protein and removal of the colon.Br. J. Nutr.3519766165
Crossref | PubMed | ISIGoogle Scholar - 17 Evidence of colonic absorption of protein nitrogen in infants.Acta Paediatr. Scand.761987741744
Crossref | PubMed | ISIGoogle Scholar - 18 Salvage of urea-nitrogen and protein requirements.Proc. Nutr. Soc.541995535547
Crossref | PubMed | ISIGoogle Scholar - 19 Factors influencing the development of sigmoid colon cancer.Cancer77199617011706
Crossref | PubMed | ISIGoogle Scholar - 20 Protein absorption and energy digestibility at high altitude.J. Appl. Physiol.73199224252431
Link | ISIGoogle Scholar - 21 Nutritional adaptation of Papua New Guinea highlanders.Eur. J. Clin. Nutr.441990853885
ISIGoogle Scholar - 22 Ileal recovery of nutrients and mucin in humans fed total enteral formulas supplemented with soy fiber.Am. J. Clin. Nutr.631996584595
Crossref | PubMed | ISIGoogle Scholar - 23 The colonic flora, fermentation, and large bowel digestive function.The Large Intestine: Physiology, Pathophysiology, and Disease, Phillips S. F., Pemberton H., Shorter R. G.19915192RavenNew York
Google Scholar - 24 Gastroileal nitrogen and electrolyte movements after bovine milk ingestion in humans.Am. J. Clin. Nutr.561992410416
Crossref | PubMed | ISIGoogle Scholar - 25 Colonic carcinogenesis: the microbial feast or famine mechanism.Nutr. Cancer1019872328
Crossref | PubMedGoogle Scholar - 26 15N-urea metabolism in the functioning human colon: luminal hydrolysis and mucosal permeability.Gut311990454457
Crossref | PubMed | ISIGoogle Scholar - 27 Hydrogen sulfide: a bacterial toxin in ulcerative colitis?Gut39199614
Crossref | PubMed | ISIGoogle Scholar - 28 Analgesic ingestion and other factors preceding relapse in ulcerative colitis.Gut241983187189
Crossref | PubMed | ISIGoogle Scholar - 29 Colonic microflora: nutrition and health.Nutr. Rev.531995127130
Crossref | PubMed | ISIGoogle Scholar - 30 Reducing sulfur compounds of the colon impair colonocyte nutrition: implications for ulcerative colitis.Gastroenterology1041993802809
Crossref | PubMed | ISIGoogle Scholar - 31 Clinical significance of colonic fermentation.Am. J. Gastroenterol.85199013071312
PubMed | ISIGoogle Scholar - 32 Experimental model for in vivo determination of dietary fibre and its effects on the absorption of nutrients in the small intestine.Br. J. Nutr.451981283294
Crossref | PubMed | ISIGoogle Scholar - 33 Effects of short chain fatty acids on gut morphology and function.Gut1, Suppl.1994S35S38
Crossref | ISIGoogle Scholar - 34 Does digestibility of meat protein help explain large bowel cancer risk?Nutr. Cancer241995279288
Crossref | PubMed | ISIGoogle Scholar - 35 The human intestinal microflora.Dig. Dis. Sci.311986147S162S
Crossref | PubMed | ISIGoogle Scholar - 36 The microbial contribution to human fecal mass.J. Med. Microbiol.1319804556
Crossref | PubMed | ISIGoogle Scholar - 37 Mechanism of action of dietary fibre in the human colon.Nature2841980283284
Crossref | PubMed | ISIGoogle Scholar - 38 Effect of changing transit time on colonic microbial metabolism.Gut281987601609
Crossref | PubMed | ISIGoogle Scholar - 39 Diet and cell growth modulation by ammonia.Am. J. Clin. Nutr.311978S216S220
Crossref | PubMed | ISIGoogle Scholar - 40 Excretion of 15N and incorporation into plasma proteins after high-dosage pulse labeling with various tracer substances in infants.Clin. Nutr. (Phila.)411987431439
Google Scholar

