Recently, Naveen Jain discovered that he was pre-diabetic. In response, his doctor recommended that he cut down on carbohydrates and starches, such as potatoes, bread, and rice. After several weeks of consuming primarily legumes and lentils, Jain's blood glucose levels were static; as a stool sample analysis later revealed, he actually needed to eat more carbohydrates, not fewer.

Jain received this advice after taking a microbiome test, a service from his new company, Viome, which offers to sequence bacteria in the digestive tract to get a better picture of one's overall health. Based in Bellevue, Washington, Viome combines the results of a simple stool sample with artificial intelligence to make custom suggestions for a user's diet and lifestyle, and potentially flag if the person's at risk for certain illnesses. Indeed, a growing body of research suggests that microorganisms in the human gut may play a critical role in health and disease, and it's a trend that startups are hungrily seizing on.

Earlier this week, Jain's business confirmed that it had raised $15 million in funding, in a round led by the venture capital firm Khosla Ventures, with participation from Bold Capital Partners. In total, Viome has raised $21 million in funding; it generates revenue through the sale of beta tests to thousands of customers, according to Jain. The company operates on a subscription model, charging $595 annually for two tests, or $59 per month. Users send their stool samples to the company's lab, and can also conduct at-home blood and urine tests.

"How we respond to what's happening inside of our gut is the key to understanding aging and health, and the prevention of chronic diseases," Jain tells Inc. in an interview. The company has 45 employees, four of whom are licensed physicians.

Viome is also the first official venture to emerge from BlueDot, the innovation factory that Jain founded back in 2015.

Another moonshot

Ambitious though this latest endeavor may seem, it's nothing new for Jain. The billionaire entrepreneur is best known for having launched InfoSpace, the search behemoth that contributed in part to the dot-com bust of 2000. Jain has since gone on to start companies including Intelius, a public-records database, as well as Moon Express. The latter is the first private venture to win government approval to launch a rocket to the moon. He wants to mine the surface for materials such as iron and manganese, as well as gold and other precious metals. The interim goal, Jain explains, is to win the coveted Google Lunar X Prize for missions in 2017; at present, he says, the startup is on track to launch its lunar rocket by December.

The ultimate goal, though, is even loftier: "I'm thinking about what the best thing is I can do to help humanity," Jain says. "Saving humanity from extinction is the goal for Moon Express, and eliminating chronic diseases is the goal for Viome."

Still, the health care business is an expensive one. Jain notes that Viome's profit margins are incredibly slim, so the startup is generating very little money. Over time, it aims to drive down the cost of tests to as low as $10--or free--at which point he said it would generate sales off of the recommendations it makes, instead.

Gut skepticism

To be sure, many analysts are skeptical of microbiome testing. Viome does not, at present, have FDA approval. Therefore, it's A.I.--however smart--can make recommendations only about diet and exercise, not about medical issues. (Jain insists that the business doesn't need FDA approval for what it's offering at present, though he affirms it will seek this down the line when it begins work to diagnose and cure diseases.) Some scientists doubt that the tests will have the ability to detect illnesses, or make the kinds of recommendations their creators have promised.

"The enthusiasm of their manufacturers simply goes well beyond where the science is right now," noted Rob Knight, the leading microbiome researcher and professor at the University of California, San Diego, in an interview with Technology Review. And Adam Drewnowski, a professor of nutritional sciences in the University of Washington's epidemiology department, says there's little hard science to show that the microbiome in fact influences specific conditions. "It's very new and very controversial," he told Inc. "There are some very interesting links that are currently being established. But to [suggest] at this point that microbiome imbalance causes something like Alzheimer's, I would think, is something of an overstatement."

Tough medicine

Meanwhile, Viome faces competition from other microbiome startups, such as San Francisco-based uBiome, which is either fully or partially covered by most health insurance companies. (Viome does not work with any health insurers.) UBiome makes the Gut Explorer test kit, which costs $89.

What sets Viome apart, Jain says, is the technology it's using to the power the kits. The company pays to license information from the Los Alamos National Laboratory in New Mexico, which analyzes RNA, or ribonucleic acid, to identify species and strains beyond bacteria, including viruses, yeast, mold, and fungi.

Jain is well aware that he's no expert in medicine. "I'm not reinventing the wheel," he explains. "I'm simply making [this technology] available to the consumers that can help and benefit society."

The entrepreneur adds that he spends roughly 60 percent of his time focusing on Viome, and the other 40 percent he splits between operations at Moon Express--preventing human extinction, that is--and at Singularity University, where he is a board member.

Correction: A previous version of this story misstated the name of the test kit made by uBiome. It is Gut Explorer.