Recent research uncovers an unexpected connection between advantageous and detrimental gut bacteria that could facilitate tailored strategies for enhancing intestinal health.

The human gastrointestinal tract harbours trillions of bacteria that are crucial for digesting, immunological control, and overall health. An imbalance in the composition or variety of these microbes, referred to as gut microbiota dysbiosis, has been associated with numerous digestive problems and diseases.

Nevertheless, scientists have not yet comprehensively elucidated the mechanisms by which these bacteria interact to preserve or disturb this microbial equilibrium.

Investigating Microbial Interactions

A research team headed by Associate Professor Koji Hosomi from Osaka Metropolitan University’s Graduate School of Veterinary Science examined the interaction between two principal bacterial species:

• Fusobacterium varium (F. varium) – a bacterium found in the oral cavity and intestines linked to inflammation and colorectal carcinoma
• Faecalibacterium prausnitzii (F. prausnitzii) is a gut bacterium recognised for its production of butyrate, a short-chain fatty acid that enhances gastrointestinal health.

The researchers examined stool samples from 236 subjects employing next-generation sequencing (NGS) and mass spectrometry to investigate the interdependence of bacterial growth.

The study found an uneven relationship: F. prausnitzii suppresses F. varium through increased acidity and β-hydroxybutyric acid, while F. varium boosts F. prausnitzii growth, likely through direct contact.

Implications for Gut Health

These discoveries offer fresh perspectives on the self-regulation of microbial communities and may inform innovative treatments for intestinal disorders.

“Going forward, further clarification of the relationships between these bacteria could provide new insights into medical and health methods for improving the intestinal environment and find new methods for preventing or improving intestinal disorders and diseases. Further understanding these bacteria could pioneer the development of foods and supplements that enhance the power of bacteria to support gut health.” stated Professor Hosomi.

About Osaka Metropolitan University

Osaka Metropolitan University (OMU) is among the largest public institutions in Japan. It is committed to enhancing societal progress through multidisciplinary collaboration and exemplary research, guided by the vision: “Convergence of Knowledge.”

Key Takeaways of the Research

• The gut bacterium F. prausnitzii suppresses the detrimental F. varium, whereas F. varium facilitates the proliferation of F. prausnitzii.
• The interaction probably transpires via direct bacterial contact and acidic metabolic byproducts.
• Results may result in novel treatments for gut health, encompassing food supplements or probiotic therapy.
• The study underscores the significance of microbial interactions in preserving gut equilibrium and averting illness.

Original Publication
Authors: Koji Hosomi, Satoko Maruyama, Tsubasa Matsuoka, Mari Furuta, Yoko Tojima, Keita Uchiyama, Makiko Morita, Hitoshi Kawashima, Toshiki Kobayashi and Jun Kunisawa.
Journal: Microbiome
DOI: 10.1186/s40168-025-02168-w
Method of Research: Experimental study
Subject of Research: People
Article Title: Metabolite-mediated interactions and direct contact between Fusobacterium varium and Faecalibacterium prausnitzii
Article Publication Date: 28-Jul-2025
COI Statement: The authors have the following potential conflicts of interest: S. Maruyama, T. Matsuoka, and T. Kobayashi are employees of Hakubaku Co., Ltd. (Yamanashi, Japan). Other authors declare no competing interests.

Original Source: https://www.omu.ac.jp/en/