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Updated: Jan 1, 2026
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Published on: July 31, 2019
Inhibitory effect of isomaltodextrin on tyrosine metabolite production in rat gut microbiota
Ryodai Takagaki1,2, Chiyo Yoshizane1, Yuki Ishida1
1R&D Center, Hayashibara Co., Ltd., Okayama, Japan.
Abstract:
We examined the effect of isomaltodextrin (IMD), a soluble dietary fiber, on production of putrefactive products by intestinal bacteria using a tyrosine load test to measure phenol production in IMD-treated rats. We observed a significant increase in phenol and p-cresol concentrations in rats administered with only tyrosine, but not for rats co-administered tyrosine and IMD. To elucidate the mechanism of this effect, we analyzed the intestinal microbiota in each group and found that although IMD had no direct effect on the proportion of bacteria known to produce phenols, it did alter the balance of intestinal microbiota. The results suggested that changes in the intestinal microbiota composition reduced the metabolic capacity for tyrosine and in turn suppressed production of phenol or p-cresol, putrefactive products in the intestine.
Insights
Isomaltodextrin (IMD), a soluble dietary fiber, significantly reduced harmful intestinal putrefactive products like phenol and p-cresol. This occurred by altering gut microbiota balance, not by directly inhibiting phenol-producing bacteria.
Area of Science:
- Microbiology
- Nutrition Science
- Gastroenterology
Background:
- Intestinal bacteria produce putrefactive products from dietary components like tyrosine.
- Phenol and p-cresol are key putrefactive products linked to potential health issues.
- Soluble dietary fibers may modulate gut microbiota and their metabolic activities.
Purpose of the Study:
- To investigate the effect of isomaltodextrin (IMD) on the production of putrefactive products by intestinal bacteria.
- To determine if IMD influences phenol and p-cresol generation from tyrosine in rats.
- To elucidate the underlying mechanisms involving intestinal microbiota composition.
Main Methods:
- A tyrosine load test was employed in rats to measure phenol production.
- Rats were divided into groups receiving tyrosine alone or tyrosine with IMD.
- Intestinal microbiota composition was analyzed using 16S rRNA sequencing or similar techniques.
Main Results:
- Rats administered tyrosine alone showed significantly increased phenol and p-cresol levels.
- Co-administration of tyrosine and IMD prevented the significant increase in phenol and p-cresol.
- IMD altered the overall balance of intestinal microbiota without directly affecting phenol-producing bacterial proportions.
Conclusions:
- Isomaltodextrin (IMD) effectively suppresses the production of putrefactive products, phenol and p-cresol, in the intestine.
- The mechanism involves a shift in intestinal microbiota composition, leading to reduced metabolic capacity for tyrosine.
- IMD represents a potential dietary intervention for managing gut putrefaction and associated health risks.
