Noster research: The Anti-Obesity Potential of Gut Microbes in High-Sugar Diets

KYOTO, Japan, April 22, 2025 /PRNewswire/ -- A collaborative research team from Kyoto University, Noster Inc., and others, has uncovered a key mechanism by which the gut bacterium Streptococcus salivarius helps prevent obesity linked to excessive sugar intake. The study reveals how this human commensal bacterium converts dietary sucrose into beneficial exopolysaccharides (EPS), which are further metabolized by other gut microbes into short-chain fatty acids (SCFAs) that support metabolic health.

Background and Key Findings

Obesity, driven by high sugar consumption, is a global health challenge. This study highlights the unique role of S. salivarius, a naturally occurring gut bacterium, in mitigating the effects of sucrose. Unlike other bacteria, S. salivarius produces large quantities of EPS—complex carbohydrates that the human digestive system cannot break down. These EPS act as prebiotics, feeding beneficial gut microbes that produce SCFAs, compounds known to regulate energy metabolism, reduce fat storage, and improve insulin sensitivity.

The research included several pivotal experiments:

1. Microbial Screening: The team screened gut bacteria from over 470 human donors and identified S. salivarius as a dominant EPS producer in individuals with lower body mass index (BMI). Obese individuals showed significantly reduced levels of this bacterium.
2. Mouse Models: In high-fat diet (HFD)-induced obese mice, supplementation with S. salivarius-produced EPS significantly reduced weight gain, fat accumulation, and blood glucose levels compared to control mice. This demonstrated the S. Salivarius-derived EPS protective effect against obesity.
3. SCFA Production: The study found that S. salivarius-derived EPS are fermented by gut microbes like Bacteroides into SCFAs, including acetate and propionate. These SCFAs interact with host receptors to regulate metabolism and energy balance.
4. Genomic Analysis: Using advanced sequencing techniques, researchers pinpointed the specific genes in S. salivarius responsible for EPS production, such as glycosyltransferases and levansucrases, which are enzymes crucial for building polysaccharides.

Implications for Health

This research positions S. salivarius as a potential biomarker for metabolic health and obesity resistance. The bacterium's ability to transform sucrose into health-promoting compounds provides an opportunity to develop probiotic supplements and functional foods that enhance gut health and metabolic balance.

"By leveraging the unique properties of S. salivarius and its ability to produce beneficial metabolites, we can open new doors for addressing obesity and related metabolic disorders," said Ikuo Kimura, leader of the research from Kyoto University.

Glossary

- Exopolysaccharides (EPS): Complex sugar molecules produced by bacteria that serve as prebiotics, feeding beneficial microbes in the gut.
- Short-Chain Fatty Acids (SCFAs): Beneficial compounds like acetate and propionate, produced during the fermentation of dietary fiber by gut bacteria, which influence host energy regulation and inflammation.
- Glycosyltransferases and Levansucrases: Enzymes used by bacteria to assemble polysaccharides from simple sugars like sucrose.
- Prebiotics: Indigestible food components that stimulate the growth of beneficial gut bacteria.

Reference

Shimizu, H., Miyamoto, J., Hisa, K. et al. Sucrose-preferring gut microbes prevent host obesity by producing exopolysaccharides. Nat Commun 16, 1145 (2025).

https://doi.org/10.1038/s41467-025-56470-0

Company Overview

Name: Noster Inc.
CEO: Kohey Kitao
Head Office & Research Center: 35-3 Minamibiraki, Kamiueno-cho, Muko, Kyoto 617-0006, Japan
Business: Research, development, and sales of biopharmaceuticals and functional foods
Website: https://www.noster.inc/jp/

Contact Information
Public Relations: Nanami Akatsuka (Ms)
Tel: +81-75-921-5303 / Fax: +81-75-924-2702
Email: contact@noster.inc