Maintenance Notice

Due to necessary scheduled maintenance, the JMIR Publications website will be unavailable from Wednesday, July 01, 2020 at 8:00 PM to 10:00 PM EST. We apologize in advance for any inconvenience this may cause you.

Who will be affected?

Currently submitted to: JMIR Formative Research

Date Submitted: Apr 16, 2026
Open Peer Review Period: Apr 17, 2026 - Jun 12, 2026
(closed for review but you can still tweet)

NOTE: This is an unreviewed Preprint

Warning: This is a unreviewed preprint (What is a preprint?). Readers are warned that the document has not been peer-reviewed by expert/patient reviewers or an academic editor, may contain misleading claims, and is likely to undergo changes before final publication, if accepted, or may have been rejected/withdrawn (a note "no longer under consideration" will appear above).

Peer review me: Readers with interest and expertise are encouraged to sign up as peer-reviewer, if the paper is within an open peer-review period (in this case, a "Peer Review Me" button to sign up as reviewer is displayed above). All preprints currently open for review are listed here. Outside of the formal open peer-review period we encourage you to tweet about the preprint.

Citation: Please cite this preprint only for review purposes or for grant applications and CVs (if you are the author).

Final version: If our system detects a final peer-reviewed "version of record" (VoR) published in any journal, a link to that VoR will appear below. Readers are then encourage to cite the VoR instead of this preprint.

Settings: If you are the author, you can login and change the preprint display settings, but the preprint URL/DOI is supposed to be stable and citable, so it should not be removed once posted.

Submit: To post your own preprint, simply submit to any JMIR journal, and choose the appropriate settings to expose your submitted version as preprint.

Warning: This is an author submission that is not peer-reviewed or edited. Preprints - unless they show as "accepted" - should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.

Toilet-Mounted System for Non-invasive Gut Microbiota Estimation from Fecal Odor: A Proof-of-Concept Study

  • Shingo Teranishi; 
  • Daisuke Ueyama; 
  • Hirotaka Koike; 
  • Rintaro Fujikawa; 
  • Tomohisa Tanaka; 
  • Kazuya Sano; 
  • Hiromichi Sadamoto; 
  • Yoshinobu Nakamura; 
  • Hiroshi Katta; 
  • Shinichi Abe

ABSTRACT

Background:

A novel, toilet-mounted system was developed to transform the restroom into a seamless health monitoring platform. This system non-invasively estimates the gut microbiota by analyzing fecal odor.

Objective:

The objective was to develop an end-to-end system for this purpose and to conduct a proof-of-concept study to evaluate its effectiveness as a healthcare service in a real-world setting.

Methods:

The system architecture comprises a self-developed gas sensor device for unobtrusive measurement, a two-stage machine learning framework to estimate fecal gas concentrations and predict the relative abundance of the gut microbiota, and a smartphone application for delivering personalized health insights. Its effectiveness was assessed through a survey evaluating the impact on users’ health awareness, behavioral changes, and perceived health outcomes.

Results:

The results demonstrated strong user acceptance. 90% of the participants indicated that the service was effective. The system was highly successful in increasing users' health awareness (88% agreed) and interest in gut flora (100% agreed).

Conclusions:

This study confirms the feasibility of using the toilet-mounted system for daily and effortless health monitoring. It establishes a foundational methodology for a novel approach to personalized and preventive healthcare.


 Citation

Please cite as:

Teranishi S, Ueyama D, Koike H, Fujikawa R, Tanaka T, Sano K, Sadamoto H, Nakamura Y, Katta H, Abe S

Toilet-Mounted System for Non-invasive Gut Microbiota Estimation from Fecal Odor: A Proof-of-Concept Study

JMIR Preprints. 16/04/2026:94550

DOI: 10.2196/preprints.94550

URL: https://preprints.jmir.org/preprint/94550

Download PDF


Request queued. Please wait while the file is being generated. It may take some time.

© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.