The Future of Everything covers the innovation and technology transforming the way we live, work and play, with monthly issues on education, money, cities and more. This month is Health, online starting Sept. 3 and in the paper on Sept. 10.

The next frontier of at-home health tracking is flush with data: the toilet.

Researchers and companies are developing high-tech toilets that go beyond adding smart speakers or a heated seat. These smart facilities are designed to look out for signs of gastrointestinal disease, monitor blood pressure or tell you that you need to eat more fish, all from the comfort of your personal throne.

“All of the things that have come with smartwatches and phones, you can imagine that on another scale,” says Joshua Coon, a bioanalytical chemist at the University of Wisconsin-Madison and Morgridge Institute for Research, who published a 2019 study exploring the potential of continuously monitoring a person’s health by looking at molecules in their urine samples. “You could really start to understand disease risk.”

Doctors have long used fecal and urine samples for clues to people’s health, but there has been a renewed interest in recent years as scientists have begun to better understand how the microbes in our gut influence our well-being. In the Covid-19 pandemic, more communities launched wastewater surveillance initiatives, enabling health officials to hunt for early signs of the virus in cities and neighborhoods and track its spread.

Some researchers want to harness that wealth of information on the individual level and have come up with models to peer into the toilet bowl remotely. Some smart toilets are geared toward helping doctors monitor patients with chronic conditions or heightened risk for certain diseases, whereas other companies aim to sell the toilets—with price tags in the hundreds or thousands of dollars—directly to consumers as a tool to track or improve their own health and wellness.

Researchers at Stanford School of Medicine have outfitted a toilet bowl with cameras and trained a machine-learning algorithm to analyze the waste against a diagnostic chart. The toilet can also track the flow, color and volume of urine. It is equipped with a urine test-strip similar to a pregnancy test that detects specific molecules that can provide insight into a person’s health. To tell users apart, the toilet has both a fingerprint scan when a person flushes and a scan of their anus’s characteristics, or an anal print.

The Stanford team has signed an agreement with Izen, a Korean toilet maker, to manufacture the toilet. They hope to have working prototypes that can be used in clinical trials by the end of this year, says Seung-min Park, who leads the project, which was started by Sanjiv Gambhir, the former chair of radiology at Stanford, who died in 2020.

Another prototype smart toilet developed at Duke University also deploys cameras and machine learning to analyze waste after it has been flushed. It uses other sensors to capture consistency, presence of blood and specific proteins, and extracts a small vial of stool that can be shipped off to a lab for further analysis. The smart toilet, along with others in development, is designed to connect with an app on a person’s phone.

“[You could] get personalized alerts for having more fiber or avoiding certain foods to avoid flare-ups,” says Sonia Grego, founder of the Duke Smart Toilet Lab and Coprata Inc., a startup that she and two other team members launched in 2021 to commercialize the technology.

A remote smart toilet could help doctors monitor patients with chronic conditions such as irritable bowel syndrome or spot early signs of disease, says Dr. Grego. Another plus is that it could allow for frequent measurements that can be tracked over time, which could be a more effective, noninvasive way to track certain metrics and quickly identify and flag changes than sporadic readings during doctor’s visits.

“What your blood pressure is at 2 p.m. on a Tuesday doesn’t matter. To get that information with real trends behind it is super valuable,” says Austin McChord, the chief executive of Casana, a home-health monitoring startup working on a toilet seat that can measure vital signs including blood pressure, blood-oxygen levels or heart rate.

SHARE YOUR THOUGHTS

Would you ever use a high-tech toilet? Join the conversation below.

The company said in February that it had raised $14 million in Series A funding and is working toward getting clearance from the Food and Drug Administration for the seat to measure a handful of vital signs, Mr. McChord says.

Some diagnostics experts argue that the value in a smart toilet would come from being able to analyze the molecular substances in patient samples and that other devices, including smartwatches, can easily monitor blood pressure and heart rate. Mr. McChord and others working on smart-toilet technology say that advantages to using a toilet seat over another wearable device are adherence and ease-of-use.

“If you want someone to use something, it has to be incredibly simple,” says Chad Adams, president and chief executive of the company Medic.Life, which is working to get FDA clearance for its Medic.Lav smart toilet. “Everybody has to go to the bathroom.”

Medic.Life first plans to sell its toilet to assisted living facilities, where it could help track residents’ vital signs, body weight or even the sugar or sodium levels in their urine, among other metrics, before expanding to general consumers. A future version for assisted living facilities, pharmacies and healthcare providers would diagnose certain infections, such as urinary-tract infections or Covid-19.

Google LLC also has a patent for a toilet seat that doubles as a cardiovascular monitor, filed in 2015, although it isn’t clear whether the company is pursuing the project. Google Health declined to comment. Toilet maker Toto is designing a toilet that could analyze people’s waste and provide recommendations to improve wellness, such as drinking more water or adding something to their diets. The company anticipates launching the toilet in the next several years.

Toilet makers say that their products can provide medical-grade results for some vital signs and urine tests, but a smart toilet that can analyze the broader chemical makeup of waste is likely further off. Developers will have to work out how to prepare samples for analysis and refill the chemicals needed to run the reaction, as well as make the toilet cost-effective, biochemists and diagnostic experts say.

Another key barrier is privacy. A 300-person survey conducted by the Stanford team found that one third of respondents were uncomfortable with the concept of a smart toilet that collects health data, with many citing privacy as a chief concern. Respondents were especially uncomfortable with the camera-based approach. More than half, however, were at least somewhat comfortable with a smart toilet.

“I have now heard every toilet pun or joke you can imagine,” Casana’s Mr. McChord says. “A toilet seat is something that everyone is going to giggle about, but you have that moment to explain what it really does, and people really do see the value there.”

Write to Brianna Abbott at brianna.abbott@wsj.com