Which foods are actually healthy for your individual gut microbiome? Several companies are offering personalized dietary guidance based on your test results, but their answers in one experiment turned up with some conflicting advice.
I recently got on the scale to weigh myself, thinking I've got to eat better. With so many trendy diets today claiming to improve health, from Keto to Paleo to Whole30, it can be confusing to figure out what we should and shouldn't eat for optimal nutrition.
A number of companies are now selling the concept of "personalized" nutrition based on the genetic makeup of your individual gut bugs.
My next thought was: I've got to lose a few pounds.
Consider a weird factoid: In addition to my fat, skin, bone and muscle, I'm carrying around two or three pounds of straight-up bacteria. Like you, I am the host to trillions of micro-organisms that live in my gut and are collectively known as my microbiome. An explosion of research has occurred in the last decade to try to understand exactly how these microbial populations, which are unique to each of us, may influence our overall health and potentially even our brains and behavior.
Lots of mysteries still remain, but it is established that these "bugs" are crucial to keeping our body running smoothly, performing functions like stimulating the immune system, synthesizing important vitamins, and aiding digestion. The field of microbiome science is evolving rapidly, and a number of companies are now selling the concept of "personalized" nutrition based on the genetic makeup of your individual gut bugs. The two leading players are Viome and DayTwo, but the landscape includes the newly launched startup Onegevity Health and others like Thryve, which offers customized probiotic supplements in addition to dietary recommendations.
The idea has immediate appeal – if science could tell you exactly what to make for lunch and what to avoid, you could forget about the fad diets and go with your own bespoke food pyramid. Wondering if the promise might be too good to be true, I decided to perform my own experiment.
Last fall, I sent the identical fecal sample to both Viome (I paid $425, but the price has since dropped to $299) and DayTwo ($349). A couple of months later, both reports finally arrived, and I eagerly opened each app to compare their recommendations.
First, I examined my results from Viome, which was founded in 2016 in Cupertino, Calif., and declares without irony on its website that "conflicting food advice is now obsolete."
I learned I have "average" metabolic fitness and "average" inflammatory activity in my gut, which are scores that the company defines based on a proprietary algorithm. But I have "low" microbial richness, with only 62 active species of bacteria identified in my sample, compared with the mean of 157 in their test population. I also received a list of the specific species in my gut, with names like Lactococcus and Romboutsia.
But none of it meant anything to me without actionable food advice, so I clicked through to the Recommendations page and found a list of My Superfoods (cranberry, garlic, kale, salmon, turmeric, watermelon, and bone broth) and My Foods to Avoid (chickpeas, kombucha, lentils, and rice noodles). There was also a searchable database of many foods that had been categorized for me, like "bell pepper; minimize" and "beef; enjoy."
"I just don't think sufficient data is yet available to make reliable personalized dietary recommendations based on one's microbiome."
Next, I looked at my results from DayTwo, which was founded in 2015 from research out of the Weizmann Institute of Science in Israel, and whose pitch to consumers is, "Blood sugar made easy. The algorithm diet personalized to you."
This app had some notable differences. There was no result about my metabolic fitness, microbial richness, or list of the species in my sample. There was also no list of superfoods or foods to avoid. Instead, the app encouraged me to build a meal by searching for foods in their database and combining them in beneficial ways for my blood sugar. Two slices of whole wheat bread received a score of 2.7 out of 10 ("Avoid"), but if combined with one cup of large curd cottage cheese, the score improved to 6.8 ("Limit"), and if I added two hard-boiled eggs, the score went up to 7.5 ("Good").
Perusing my list of foods with "Excellent" scores, I noticed some troubling conflicts with the other app. Lentils, which had been a no-no according to Viome, received high marks from DayTwo. Ditto for Kombucha. My purported superfood of cranberry received low marks. Almonds got an almost perfect score (9.7) while Viome told me to minimize them. I found similarly contradictory advice for foods I regularly eat, including navel oranges, peanuts, pork, and beets.
Contradictory dietary guidance that Kira Peikoff received from Viome (left) and DayTwo from an identical sample.
To be sure, there was some overlap. Both apps agreed on rice noodles (bad), chickpeas (bad), honey (bad), carrots (good), and avocado (good), among other foods.
But still, I was left scratching my head. Which set of recommendations should I trust, if either? And what did my results mean for the accuracy of this nascent field?
I called a couple of experts to find out.
"I have worked on the microbiome and nutrition for the last 20 years and I would be absolutely incapable of finding you evidence in the scientific literature that lentils have a detrimental effect based on the microbiome," said Dr. Jens Walter, an Associate Professor and chair for Nutrition, Microbes, and Gastrointestinal Health at the University of Alberta. "I just don't think sufficient data is yet available to make reliable personalized dietary recommendations based on one's microbiome. And even if they would have proprietary algorithms, at least one of them is not doing it right."
There is definite potential for personalized nutrition based on the microbiome, he said, but first, predictive models must be built and standardized, then linked to clinical endpoints, and tested in a large sample of healthy volunteers in order to enable extrapolations for the general population.
"It is mindboggling what you would need to do to make this work," he observed. "There are probably hundreds of relevant dietary compounds, then the microbiome has at least a hundred relevant species with a hundred or more relevant genes each, then you'd have to put all this together with relevant clinical outcomes. And there's a hundred-fold variation in that information between individuals."
However, Walter did acknowledge that the companies might be basing their algorithms on proprietary data that could potentially connect all the dots. I reached out to them to find out.
Amir Golan, the Chief Commercial Officer of DayTwo, told me, "It's important to emphasize this is a prediction, as the microbiome field is in a very early stage of research." But he added, "I believe we are the only company that has very solid science published in top journals and we can bring very actionable evidence and benefit to our uses."
He was referring to pioneering work out of the Weizmann Institute that was published in 2015 in the journal Cell, which logged the glycemic responses of 800 people in response to nearly 50,000 meals; adding information about the subjects' microbiomes enabled more accurate glycemic response predictions. Since then, Golan said, additional trials have been conducted, most recently with the Mayo Clinic, to duplicate the results, and other studies are ongoing whose results have not yet been published.
He also pointed out that the microbiome was merely one component that goes into building a client's profile, in addition to medical records, including blood glucose levels. (I provided my HbA1c levels, a measure of average blood sugar over the previous several months.)
"We are not saying we want to improve your gut microbiome. We provide a dynamic tool to help guide what you should eat to control your blood sugar and think about combinations," he said. "If you eat one thing, or with another, it will affect you in a different way."
Viome acknowledged that the two companies are taking very different approaches.
"DayTwo is primarily focused on the glycemic response," Naveen Jain, the CEO, told me. "If you can only eat butter for rest of your life, you will have no glycemic response but will probably die of a heart attack." He laughed. "Whereas we came from very different angle – what is happening inside the gut at a microbial level? When you eat food like spinach, how will that be metabolized in the gut? Will it produce the nutrients you need or cause inflammation?"
He said his team studied 1000 people who were on continuous glucose monitoring and fed them 45,000 meals, then built a proprietary data prediction model, looking at which microbes existed and how they actively broke down the food.
Jain pointed out that DayTwo sequences the DNA of the microbes, while Viome sequences the RNA – the active expression of DNA. That difference, in his opinion, is key to making accurate predictions.
"DNA is extremely stable, so when you eat any food and measure the DNA [in a fecal sample], you get all these false positives--you get DNA from plant food and meat, and you have no idea if those organisms are dead and simply transient, or actually exist. With RNA, you see what is actually alive in the gut."
More contradictory food advice from Viome (left) and DayTwo.
Note that controversy exists over how it is possible with a fecal sample to effectively measure RNA, which degrades within minutes, though Jain said that his company has the technology to keep RNA stable for fourteen days.
Viome's approach, Jain maintains, is 90 percent accurate, based on as-yet unpublished data; a patent was filed just last week. DayTwo's approach is 66 percent accurate according to the latest published research.
Natasha Haskey, a registered dietician and doctoral student conducting research in the field of microbiome science and nutrition, is skeptical of both companies. "We can make broad statements, like eat more fruits and vegetables and fiber, but when it comes to specific foods, the science is just not there yet," she said. "I think there is a future, and we will be doing that someday, but not yet. Maybe we will be closer in ten years."
Professor Walter wholeheartedly agrees with Haskey, and suggested that if people want to eat a gut-healthy diet, they should focus on beneficial oils, fruits and vegetables, fish, a variety of whole grains, poultry and beans, and limit red meat and cheese, as well as avoid processed meats.
"These services are far over the tips of their science skis," Arthur Caplan, the founding head of New York University's Division of Medical Ethics, said in an email. "We simply don't know enough about the gut microbiome, its fluctuations and variability from person to person to support general [direct-to-consumer] testing. This is simply premature. We need standards for accuracy, specificity, and sensitivity, plus mandatory competent counseling for all such testing. They don't exist. Neither should DTC testing—yet."
Meanwhile, it's time for lunch. I close out my Viome and DayTwo apps and head to the kitchen to prepare a peanut butter sandwich. My gut tells me I'll be just fine.
Q. We are sitting here in the so-called pop-up network state Zuzalu temporarily realized in the village of Lusticia Bay by the beautiful Mediterranean Sea. To me this is an entirely new concept: What is a network state?
A. A network state is a highly aligned online community that has a level of in-person civility; it crowd-funds territory, and it eventually seeks diplomatic recognition. In a way it's about starting a new country. The term was coined by the crypto influencer and former CTO of Coinbase Balaji Srinivasan in a book by the same title last year [2022]. What many people don't know is that it is a more recent addition or innovation in a space called competitive governance. The idea is that you have multiple jurisdictions competing to provide you services as a customer. When you have competition among governments or government service providers, these entities are forced to provide you with a better service instead of the often worse service at higher prices or higher taxes that we're currently getting. The idea went from seasteading, which was hardly feasible because of costs, to charter cities getting public/private partnerships with existing governments and a level of legal autonomy, to special economic zones, to now network states.
Q. How do network states compare to charter cities and similar jurisdictions?
A. Charter cities and special economic zones were legal forks from other existing states. Dubai, Shenzhen in China, to some degree Hong Kong, to some degree Singapore are some examples. There's a host of other charter cities, one of which I'm based in myself, which is Prospera located in Honduras on the island Roatán. Charter cities provide the full stack of governance; they provide new laws and regulations, business registration, tax codes and governance services, Estonia style: you log on to the government platform and you get services as a citizen.
When conceptualizing network states, Balagi Srinivasan turns the idea of a charter city a bit on its head: he doesn't want to start with this full stack because it's still very hard to get these kinds of partnerships with government. It's very expensive and requires lots of experience and lots of social capital. He is saying that network states could instead start as an online community. They could have a level of alignment where they trade with each other; they have their own economy; they meet in person in regular gatherings like we're doing here in Zuzulu for two months, and then they negotiate with existing governments or host cities to get a certain degree of legal autonomy that is centered around a moral innovation. So, his idea is: don't focus on building a completely new country or city; focus on a moral innovation.
Q. What would be an example of such a moral innovation?
A. An example would be longevity—life is good; death is bad—let's see what we can do to foster progress around that moral innovation and see how we can get legal forks from the existing system that allow us to accelerate progress in that area. There is an increasing realization in the science that there are hallmarks of aging and that aging is a cause of other diseases like cancer, ALS or Alzheimer's. But aging is not recognized as a disease by the FDA in the United States and in most countries around the world, so it's very hard to get scientific funding for biotechnology that would attack the hallmarks of aging and allow us potentially to reverse aging and extend life. This is a significant shortcoming of existing government systems that groups such as the ones that have come together here in Montenegro are now seeking alternatives too. Charter cities and now network states are such alternatives.
Q. Would it not be better to work within the current systems, and try to improve them, rather than abandon them for new experimental jurisdictions?
A. There are numerous failures of public policies. These failures are hard, if not impossible, to reverse, because as soon as you have these policies, you have entrenched interests who benefit from the regulations. The only way to disrupt incumbent industries is with start-ups, but the way the system is set up makes it excessively hard for such start-ups to become big companies. In fact, larger companies are weaponizing the legal system against small companies, because they can afford the lawyers and the fixed cost of compliance.
I don't believe that our institutions in many developed countries are beyond hope. I just think it's easier to change them if you could point at successful examples. ‘Hey, this country or this zone is already doing it very successfully’; if they can extend people’s lifespan by 10 years, if they can reduce maternal mortality, and if they have a massive medical tourism where people come back healthier, then that is just very embarrassing for the FDA.
Q. Perhaps a comparison here would be the relationship between Hong Kong and China?
A. Correct, so having Hong Kong right in front of your door … ‘Hey, this capitalism thing seems to work, why don't we try it here?’ It was due to the very bold leadership by Deng Xiaoping that they experimented with it in the development zone of Shenzhen. It worked really well and then they expanded with more special economic zones that also worked.
Próspera is a private city and special economic zone on the island of Roatán in the Central American state of Honduras.
Q. Tell us about Prospera, the charter city in Honduras, that you are intimately connected with.
A. Honduras is a very poor country. It has a lot of crime, never had a single VC investment, and has a GDP per capita of 2,000 per year. Honduras has suffered tremendously. The goal of these special economic zones is to bring in economic development. That's their sole purpose. It's a homegrown innovation from Honduras that started in 2009 with a very forward-thinking statesman, Octavio Sanchez, who was the chief of staff to the president of Honduras, and then president. He had his own ideas about making Honduras a more decentralized system, where more of the power lies in the municipalities.
Inspired by the ideas of Nobel laureate economist Paul Romer, who gave a famous Ted Talk in 2009 about charter cities, Sanchez initiated a process that lasted for years and eventually led to the creation of a special economic zone legal regime that’s anchored in the Hunduran constitution that provides the highest legal autonomy in the world to these zones. There are today three special economic zones approved by the Honduran government: Prospera, Ciudad Morazan and Orchidea.
Q. How did you become interested and then involved in Prospera?
A. I read about it first in an article by Scott Alexander, a famous rationalist blogger, who wrote a very long article about Prospera, and I thought, this is amazing! Then I came to Prospera and I found it to be one of the most if not the most exciting project in the world going on right now and that it also opened my heart to the country and its people. Most of my friends there are Honduran, they have been working on this for 10 or more years. They want to remake Honduras and put it on the map as the place in the world where this legal and governance innovation started.
Q. To what extent is Prospera autonomous relative to the Honduran government?
A. What's interesting about the Honduran model is that it's anchored within the Honduran constitution, and it has a very clear framework for what's possible and what's not possible, and what's possible ensures the highest degree of legal autonomy anywhere seen in the world. Prospera has really pushed the model furthest in creating a common law-based polycentric legal system. The idea is that you don't have a legislature, instead you have common law and it's based on the best practice common law principles that a legal scholar named Tom W. Bell created.
One of the core ideas is that as a business you're not obligated to follow one regulatory monopoly like the FDA. You have regulatory flexibility so you can choose what you're regulated under. So, you can say: ‘if I do a medical clinic, I do it under Norwegian law here’. And you even have the possibility to amend it a bit. You're still required to have liability insurance, and have to agree to binding arbitration in case there's a legal dispute. And your insurance has to approve you. So, under that model the insurance becomes the regulator and they regulate through prices. The limiting factor is criminal law; Honduran criminal law fully applies. So does immigration law. And we pay taxes.
Q. Is there also an idea of creating a kind of healthy living there, and encourage medical tourism?
A. Yes, we specifically look for legal advantages in autonomy around creating new drugs, doing clinical trials, doing self-medication and experimentation. There is a stem cell clinic here and they're doing clinical trials. The island of Roatán is very easily accessible for American tourists. It's a beautiful island, and it's for regulatory reasons hard to do stem cell therapies in the United States, so they're flying in patients from the United States. Most of them are very savvy and often have PhDs in biotech and are able to assess the risk for themselves of taking drugs and doing clinical trials. We're also going to get a wellness center, and there have been ideas around establishing a peptide clinic and a compound pharmacy and things like that. We are developing a healthcare ecosystem.
Q. This kind of experimental tourism raises some ethical issues. What happens if patients are harmed? And what are the moral implications for society of these new treatments?
A. As a moral principle we believe in medical freedom: people have rights over their bodies, even at the (informed) risk of harm to themselves if no unconsenting third-parties are harmed; this is a fundamental right currently not protected effectively.
What we do differently is not changing ethical norms around safety and efficacy, we’re just changing the institutional setup. Instead of one centralized bureaucracy, like the FDA, we have regulatory pluralism that allows different providers of safety and efficacy to compete under market rules. Like under any legal system, common law in Prospera punishes malpractice, fraud, murder etc. This system will still produce safe and effective drugs, and it will still work with common sense legal notions like informed consent and liability for harm. There are regulations for medical practice, there is liability insurance and things like that. It will just do so more efficiently than the current way of doing things (unless it won’t, in which case it will change and evolve – or fail).
A direct moral benefit ´to what we do is that we increase accessibility. Typical gene therapies on the market cost $1 million dollars in the US. The gene therapy developed in Prospera costs $25,000. As to concern about whether such treatments are problematic, we do not share this perspective. We are for advancing science responsibly and we believe that both individuals and society stand to gain from improving the resiliency of the human body through advanced biotechnology.
Q. How does Prospera relate to the local Honduran population?
A. I think it's very important that our projects deliver local benefits and that they're well anchored in local communities. Because when you go to a new place, you're seen as a foreigner, and you're seen as potentially a danger or a threat. The most important thing for Prospera and Ciudad Morazan is to show we're creating jobs; we're creating employment; we're improving people's lives on the ground. Prospera is directly and indirectly employing 1,100 people. More than 2/3 of the people who are working for Prospera are Honduran. It has a lot of local service workers from the island, and it has educated Hondurans from the mainland for whom it's an alternative to going to the United States.
Q. What makes a good Prosperian citizen?
A. People in Prospera are very entrepreneurial. They're opening companies on a small scale. For example, Vehinia, who is the cook in the kitchen at Prospera, she's from the neighboring village and she started an NGO that is now funding a school where children from the local village can go to instead of a school that's 45 minutes away. There's very much a spirit of ‘let's exchange and trade with each other’. Some people might see that as a bit too commercial, but that's something about the culture that people accept and that people see as a good thing.
Q. Five years from now, if everything goes well, what do we see in Prospera?
A. I think Prospera will have at least 10,000 residents and I think Honduras hopefully will have more zones. There could be zones with a thriving industrial sector and sort of a labor-intensive economy and some that are very strong in pharmaceuticals, there could also be other zones for synthetic biology, and other zones focused on agriculture. The zones of Prospera, Ciudad Morazan and Orchidea are already showing the results we want to see, the results that we will eventually be measured by, and I'm tremendously excited about Honduras.
Through her research and companies, Dr. Picard has developed wearable sensors, algorithms and systems for sensing, recognizing and responding to information about human emotion. Her products are focused on using fitness trackers to advance clinical quality treatments for a range of conditions.
Meanwhile, in just the past few years, numerous fitness tracking companies have released products with their own stress sensors and systems. You may have heard about Fitbit’s Stress Management Score, or Whoop’s Stress Monitor – these features and apps measure things like your heart rhythm and a certain type of invisible sweat to identify stress. They’re designed to raise awareness about forms of stress such as anxieties and anger, and suggest strategies like meditation to relax in real time when stress occurs.
But how well do these off-the-shelf gadgets work? There’s no one more knowledgeable and experienced than Rosalind Picard to explain the science behind these stress features, what they do exactly, how they might be able to help us, and their current shortcomings.
Dr. Picard is a member of the National Academy of Engineering and a Fellow of the National Academy of Inventors, and a popular speaker who’s given over a hundred invited keynote talks and a TED talk with over 2 million views. She holds a Bachelors in Electrical Engineering from Georgia Tech, and Masters and Doctorate degrees in Electrical Engineering and Computer Science from MIT. She lives in Newton, Massachusetts with her husband, where they’ve raised three sons.
In our conversation, we discuss stress scores on fitness trackers to improve well-being. She describes the difference between commercial products that might help people become more mindful of their health and products that are FDA approved and really capable of advancing the science. We also talk about several fascinating findings and concepts discovered in Dr. Picard’s lab including the multiple arousal theory, a phenomenon you’ll want to hear about. And we explore the complexity of stress, one reason it’s so tough to measure. For example, many forms of stress are actually good for us. Can fitness trackers tell the difference between stress that’s healthy and unhealthy?
Show links:
- Dr. Picard’s book, Affective Computing
- Dr. Picard’s bio
- Dr. Picard on Twitter
- Dr. Picard’s company, Empatica - https://www.empatica.com/ - The FDA-cleared Empatica Health Monitoring Platform provides accurate, continuous health insights for researchers and clinicians, collected in the real world
- Empatica Twitter
- Dr. Picard and her team have published hundreds of peer-reviewed articles across AI, Machine Learning, Affective Computing, Digital Health, and Human-computer interaction.
- Dr. Picard’s TED talk
Rosalind Picard