Protein Sources Impact Gut Microbiome, Study Finds

updated June 10, ⁣2025
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The source of protein in ⁢an animal’s diet can⁢ dramatically reshape the population and function of gut‌ microorganisms, according to new research from North Carolina State University. These changes in the​ gut microbiome can ‌influence various aspects of health, perhaps leading to new strategies for preventing and treating gastrointestinal diseases.

Alfredo Blakeley-Ruiz, an ⁣NC State postdoctoral researcher, noted​ the increasing concern about modern diets. The study aimed to‍ understand how different diets affect the gut’s microbial composition and their functional responses.

The study focused on how protein sources like milk, eggs, and plants (pea or soy) affect the gut microbiomes of mice. For one week ⁢at a time, mice consumed diets featuring a single protein source, ⁢including egg‌ whites, brown rice, ​soy, and yeast.

Researchers used metagenomics and metaproteomics with⁣ high-resolution mass spectrometry to analyze the gut‌ microbiomes.They observed notable shifts in⁣ the microbiome’s composition, with some protein ⁢sources causing extreme⁣ effects on​ gut health and⁣ function.

Blakeley-Ruiz said the gut microbiome’s composition‌ changed significantly with each⁤ protein source. Brown rice, yeast, ‍and egg whites had the most substantial‍ functional effects⁣ on the gut microbiome.

The ‌study revealed that dietary protein primarily ⁤affected amino acid metabolism and complex sugar degradation within the⁢ gut microbiome. Researchers found that brown rice and egg white diets increased amino⁢ acid degradation, suggesting the microbes were ​breaking down proteins rather of synthesizing amino acids.

Blakeley-Ruiz explained that while this makes sense given proteins are made of amino acids, further inquiry is needed due to potential health implications. Some ⁣amino acids can degrade into toxins or affect the gut-brain axis.

The research also highlighted the role of glycans, or long chains⁤ of sugars attached⁣ to dietary proteins. Various protein sources, including soy, rice, yeast, and egg ​white, prompted changes in the production of glycan-degrading enzymes by gut microbes.

Blakeley-Ruiz noted the potential health implications, particularly with the⁢ egg white diet.​ One bacterium dominated and activated glycan-degrading ‌enzymes. When grown in the lab,this bacterium produced similar enzymes ⁢in media containing ⁣egg white protein and mucin.

Mucin ‌protects the digestive system by lining the​ gut.If bacteria ​produce enzymes that degrade⁣ mucin, it could damage the intestinal lining and negatively impact gut health.

“I’m excited​ to explore this potential connection between the expression of glycan degrading enzymes in the ‌egg white diet and the breakdown of mucin by the gut‌ microbiome in future studies,” said Blakeley-Ruiz.

Manuel Kleiner, ‌an NC State associate professor, said the study provides ‌a foundation for future research on how protein sources affect the gut ‍microbiome.

Kleiner acknowledged​ the artificial nature of​ the diets as a limitation that could amplify⁢ results. However, the study clearly demonstrates the extreme effects of egg whites on the microbiome. Future research will focus​ on understanding the mechanism of this effect in mixed ⁤protein diets in mice.

“Our study​ shows not only which bacterial species are in the gut microbiome and their abundance,⁣ but ‌also what they are actually doing. Here, they are specifically digesting the glycans.The result is a very extensive picture of what really​ matters in ​the gut in terms of diet and function,” Kleiner said.

What’s next

Future studies will‍ investigate the specific mechanisms by⁢ which different ‍protein sources,especially egg whites,impact the gut microbiome in⁢ more complex,mixed-protein diets. This research aims to provide a more nuanced understanding of⁣ how dietary choices affect gut health ‍and overall well-being.