The study, published in the Journal of Dairy Science, suggests that dietary cheese whey protein could reduce symptoms and markers of inflammatory bowel disease (IBD), after it was found to reduce gene expression of inflammation markers and diminish the clinical symptoms of IBD such as diarrhea and fecal blood loss in an animal model.
“To our knowledge, this is the first study showing that dietary cheese whey protein may be beneficial in colitis by being a rich source of the amino acids threonine and cysteine,” said the researchers, led by Corinne Sprong, from NIZO Food Research, in the Netherlands.
Chronic inflammatory bowel disease (IBD) is a multi factorial disease with an unknown cause.
The prevalence of IBD rapidly increased in Europe and North America in the second half of the twentieth century, and is becoming more common in the rest of the world as countries adopt a Western lifestyle.
The researchers suggest that the link between IBD and a Western lifestyle indicates a role for lifestyle and diet in the development of the disease. Therefore, knowledge of food and supplements that can modulate inflammatory bowel disease is essential, they said.
“Whey protein contains bioactive proteins and peptides, such as lactoferrin and, in the case of whey protein obtained from the cheese-making process, glycomacropeptide that can be beneficial in preventing colitis [chronic inflammation of the large intestine],” said the researchers.
Whey protein is also a rich source of threonine, cysteine, serine, and to a lesser extent proline
Recent research has shown that supplementation of cysteine, threonine, proline, and serine increases mucin synthesis and improves histological changes in dextran sulfate sodium (DSS)-induced colitis in rats.
The new study aimed to test if cheese whey protein, being a rich source of threonine and cysteine, protects against colitis compared with casein (which has a low content of threonine and cysteine).
The cheese whey protein was reported to diminish inflammatory gene expression, and protected against diarrhea induced by DSS colitis.
Sprong and colleagues observed that this protection coincided with increased mucin secretion and fecal counts of bifidobacteria and lactobacilli. In addition, they said that fecal counts of bifidobacteria and lactobacilli were increased in rats fed casein diets supplemented with threonine and cysteine, but not in those fed with casein.
Moreover, they said the cheese whey protein increased fecal mucin secretion without affecting gene expression of MUC2, thus suggesting enhanced production of mucin.
The authors said beneficial effects observed in the rats can most likely be explained by the cheese whey proteins threonine and cysteine content. They added that the protection can be the result of both the stimulation of intestinal mucin synthesis and modification of microflora composition.
They added that further research is needed in order to determine whether dietary whey protein protects humans against colitis.
Source: Journal of Dairy Science
Volume 93, Pages 1364–1371, doi: 10.3168/jds.2009-2397
“Dietary cheese whey protein protects rats against mild dextran sulfate sodium–induced colitis: Role of mucin and microbiota”
Authors: R. C. Sprong , A. J. Schonewille , R. van der Meer