Pages Navigation Menu

60-Day Human Food Challenge

Screen Shot 2013-06-16 at 3.24.10 PMShort Summary:
We are looking for 25-30 super motivated people who have joined – or will be joining the American Gut project – that are willing to shift their diet for 60-days, record everything they eat and share the information with the larger group during and after the 60-day challenge. Based on your first American Gut sample (you pay for), we will compare your gut microbiota after 60-days (cost on us) to see if you experience any significant/interesting changes.


Nobody tells a giraffe what to eat, but humans seem to have a hard time figuring it out these days. During the 60-Day Human Food Challenge we are interested in seeing how your gut microbial composition shifts (if at all) when you eat more human food, and less processed food. We also want you to do more human-like things during this 60-Day challenge as well. We don’t need you to become a hunter-gatherer and stop bathing, but we do want you to spend a lot more time outside, keep your home (and office if possible) windows open, spend more time in the dirt (and stay dirty when you can), spend a lot more time with pets (if you don’t have one – go hug the neighbors dog), we want you to visit chickens, horses, cows, hogs and any other species that isn’t human as much as you can, swim in ponds, streams, lakes, and ocean when you can (avoid public pool – kids pee in them anyway), and the list goes on. In short, we want you to “re-wild” your life and body as much as possible, and have you reconnect with the larger microbial metacommunity we have all disconnected with in our modern lives. None of this is hard, but will require some effort on your end.

As for diet, we are very interested in seeing you eat 30+ species of plants a week (the more the better). We will ask that you eat the “whole” whole plant. For example, no more cutting of the fibrous bottom of the asparagus shoots or broccoli. Eat the whole thing! Same goes for every other plant. We will also ask that you lots of onions, leeks, garlic and explore cooking/eating lots of new plants (there is more out there than just leafy greens). We also want you to drop 100% of anything made with a grain of any kind – that includes rice. Beans and lentils OK (sorry Paleo friendos). We will also ask that you not steam, boil, or otherwise cook your vegetables for too long. Cook a little less, so your body works a little harder. Eat all the meat you like – but we ask that you avoid any meat, poultry, fish etc that has been raised on growth hormones or antibiotics as this “may” impact your gut microbiota. We will also ask that you not drink your tap water, as the chlorine (and fluoride where added) “may” be having an impact on your gut microbiota. Rule of Thumb: If you have to ask if it’s human food, then it’s probably not.

NOTE: we are not looking for participants who ALREADY live and eat this way. We are looking for people who are living and eating a totally different way so that when you switch to some of the things discussed above, we can monitor any shifts in the composition of your microbiota after 60 days.

(Please note there is no meal plan to follow, or very rigid rules for that matter. But we do want you to focus on the thrust of what we are trying to do and please minimize the cheating! No worries, booze still allowed but plan your booze cruise to the Bahamas after the 60-day challenge if possible).

At the end of the day, people will respond differently based on their baseline sample (sample #1). But we are very interested in 1) if we can increase the abundance of Actinobacteria, such as Bifidobacterium and Faecalibacterium, reduce Prevotella, and possible increase bacteria associated with fermentation of cellulose and other fibers. Will also be looking to see if we can drop your levels of Proteobacteria, which include many opportunistic pathogens that haunt us. We would also like to see the diversity of your gut bugs increase as well. As with all things ecological, a more diverse ecosystem within is a good thing. Oh yeah, did I mention you will likely be eating between 30-80g of fiber a day from a myriad of sources.

**Note we are very interested in anyone that is currently eating lots of “whole” grains that would like to take the plunge and give them up for 60-days.

There is a lot more information to follow. Please note this is NOT a clinical trial or organized study of ANY kind. Just a group of people sharing information about what they are eating and doing for 60-Days and how that might change/shift their gut microbiota. Your data associated with the sample you will take at 60-Days is private information, that only you – not the group – will see. You will need to share with the group in order for all of us to compare our before and after results.

If you think this is something you might be interested in doing – CLICK HERE and provide your email and we will get back to you in a week or so. If you have any questions, jeff AT humanfoodproject DOT com. We want this to be fun, interesting, and useful to everyone that participates. So please, no whiners, wimps, or crazy people (you know who you are).



  1. How does one apply to participate?

  2. That pretty much describes the food that my husband & I eat, right until you get to the bit about no grain. Would love to take part, but, as farmers who mostly eat what we produce (including vegetables, fruit, mushrooms, eggs, meat, some legumes & corn), I don’t think there’s any way we can meet our energy needs & maintain our personal food ethics (in terms of what we’re willing to buy from the big food system) without supplemental grain. We learned from our one week of food tracking for American Gut that our calorie counts on active days were well in the 3000s. Our potato plants are looking good…but not two-months-without-grains good…

    For the folks taking part in this, I hope there’s a food tracking tool other than the online calorie counter that was advised for American Gut. Trying to track real food, made-from-scratch was very difficult for just the one week that I slogged through. There’s not even a decent nutritional profile for the simplest goat yogurt, made from goat milk & culture. And home-fermented veggies? Good luck entering those.

    Also, for the folks taking part, I think it would be interesting to have data on sources of animal products (meat, dairy, & eggs). I think it was Michael Pollan that said something along the lines of you’re not just what you eat, but what you eat eats, too. Avoiding animal products from critters fed hormones & antibiotics is a start, but it’s not necessarily the same as being GMO free, grain free (in the case of ruminants; chickens never are), pastured, or rotationally pastured on land managed for nutrient-balanced soils with high organic-matter content & microbial activity. I hope that you’ll encourage tracking, at some level, what the sources of animal products are.

    • Hi, I appreciate this as I also found the tracking site recomended tedious, and lacking real foods as well. I also don’t trust the analysis of the fit day that I used. But think it is better than the calorie count site also recomended.

      It’s good to hear about folks like you out there. so thanks

  3. Any interest in folk already living a semi-paleo life?

  4. How much does the initial testing cost?

  5. I believe I’ve been accepted into the 60 day project; however, I’ll be receiving a one-time dose of the antibiotic moxicillin on July 3 (4 tablets, prior to some dental work).
    This, I believe, may “mess up” my normal gut microbiome — but maybe not too badly, as it’s a one-time dose. I have my americangut kit; but perhaps I should wait one week — or even longer — after July 3 for my normal diet to enable my normal gut microbiome to be restored, prior to taking my first sample, and mailing it off. Then I can modify my diet, in the highly interesting way requested by Jeff, eating many “unwashed” raw organic vegetables of many different sorts, mostly bought directly from the farmers in our local public market, and “rolling around with my pet cat”, etc.
    Jeff, does that make sense? Most directly: Should I wait until a week after July 3 — or later or less — prior to taking my first sample?

    — Saul

    • might want to wait 3-4 weeks after antibiotics.
      we have selected ppl for 60-day challeneg yet. stay tuned.

  6. OK. I will or did sign up. I think I applied only and then got a follow up email. So the next step is to contribute and start a food diary, waiting for the kit. And then how do you know I want to be in the study as opposed to being a random customer?

    • i’ll pic the 60-day challenge ppl this week.

  7. This is a great idea, Jeff. Have you thought about also studying the microbiota changes that occur AFTER the 60 days, when subjects return to their previous lifestyles? I wouldn’t be surprised to see the improvements being lost quite rapidly — weeks instead of months.

    • yes. might do that… but likely not. would be even harder to control the gazillion confounders.

  8. Darn! I wanted to sign up for the 60 day challenge, but I realize that I mostly am pretty wild already. Who knew!?

  9. I would consider participating, but it would have to be in the fall. I am planning a 3-4 week backpacking hike this summer. That would probably qualify me for the ‘dirt’ part, but hiking food is, well, not what’s being specified here. LOL

  10. Have you picked the participants yet? If we are not picked, will we get a notification?

    • have not picked yet. will email everyone soon. thanks for your interest.

  11. I’m about to start gluten free diet. Will this matter? Seems like there won’t be gluten anyway.

  12. Jeff, it would be interesting to see how chlorination of public water impacts the gut ecosystem. Are you collecting samples from countries/regions where water is not chlorinated (i.e. still in its natural form)? How about the effect of gut fungi?
    Thanks for the great work!

    • Thanks Jay. great Q. yes, been thinking a lot about public water supplies. no doubt these are having an impact – though nobody has looked yet. would need to be done in a mouse model – too many confounders with humans. and yes, water sources in non western settings will be interesting. i’m off to tanzania in near future – will be collecting lots of water, soil etc samples – along with poo from hunter-gatherers – should b interesting. i hope!!!

  13. Have you picked the 60 challenge people yet? This sounds like a lot of fun. I would be a perfect candidate for this sort of thing. I have been able to stick to all vegan diets on a bet for 6 months. Stuck to a fat, protein only diet for 6 weeks as an experiement to lose a LOT of weight fast. Anyway, I am hoping you have not picked the group yet and I can still get in.

    • haven’t picked yet. just make sure you get on the email list.

      • I just got my kit after 23 days. I started monitoring my calories and food intake on the 1st. Am I the only one who was startled at how much they had been consuming and what? I cannot believe my own logs but they are true. I hope this study begins soon and I am selected. I will send in my sample this week. Has the selection happened yet?

        • I now have my results back when will participants be chosen for this?

          • they’ve been selected. have some other – interesting – projects to consider in the near future.

          • Sounds good. I look forward to reading the results.

  14. I got my kit and am waiting to hear whether I got chosen. Should I start the food diary now or wait to hear back?

    • just move forward on your regular kit – ie, start food log and sample!

  15. My husband and I would like to participate in the general Human Food Project, but how will we understand what you send back to us? In other words, so you tell me I have lots of dumbidumbidum bacteria in my guts, then what? Will you also tell me if that’s good, bad, or indifferent? And if good, how am I achieving this? If bad, what can I do about it? (If really bad, am I going to die from dumbidumbidum disease?) Thank you!

    • sorry, we don’t provide medical advice as per our IRB.

  16. very interested in this project, but am wondering if the results will give me an idea of how diverse my gut bacteria are.compared with others

  17. How does one do a parasite clean out

  18. I just ordered my kit today but I don’t think I can join this experiment because I learned recently that I am sensitive to salicylates and what I can eat is very limited, I am still trying and experimenting. Brussels sprouts, cashews, butternut squash, white rice are safe for me at this point. I also heard that salicylates intolerance is accumulative, so it may be ok to eat food high in salicylates once in a while.

    I am curious to know why you require strictly no grains? Can you explain? I like whole wheat bread, I assume that would forbidden. Why? There is so much confusion about whole wheat grains. I was planning to add more safe grains like millet and barley into my diet. I am a fan of Masanobu Fukuoka and his diet of grains and vegetables. He considers a diet of “brown rice, unpolished barley, millet, buckwheat, together with seasonal plants and semi-wild vegetables” to be “human food” as he describes in The One Straw Revolution. Your idea of “dirtying your food” would have appealed to him, I guess.

    I also like to add a shameless plug for my forum that I am trying to build a discussion forum for healing through nutrition. Please delete the link if this is not appropriate. Thanks for this project, I look forward to learning more about what is living in my gut and if I can find any clues about salicylates intolerance in there.

  19. Hi, Jeff, I just read that the participants have already been selected for this project. I tried to send an email to apply for this project — I have a relatively good diet already, but I want to improve it more, as I have high populations of Aeromonas veronii and Blastocysis hominus that I discovered through fecal testing. I want to avoid antibiotics and improve my gut microbiome to restore balance. I think participating in the study would help. Did you get my email? I don’t know if it went through. I sent it today — April 13, 2014. You mentioned above that you have other projects coming up. Are any ready? Jan Reek

  20. Why no grains but you can eat beans? I have been looking into resistant starch and grains come up as a good supplier of RS. Just wondering why you are electing to eliminate them if you care to share. Cheers, Nan

  21. I wish I could find one of your projects to participate in… I eat a variety of foods, am a Nutritionist at a local hospital, am outside camping and hiking a lot, Vit D insufficient, but seem to have a great immune system, grew up on a farm so had my hands in all sorts of crap, so to speak. Am going to Tanzania, Iringa and Pommern, next summer for 3 weeks with Global Volunteers. Would love to see what the change in my gut will be after eating their diet, but will not be drinking their water for safety reasons. Any ideas? Haven’t bought a kit yet for anything yet.

  22. I eat this way too, but look, this research effort makes a huge mistake in assuming that close exposure to animals is beneficial to human health. History shows the opposite. Once we began agriculture and domesticating animals it meant living closely with them, often in the same structure, and human health suffered. We lived hundreds of thousands of years BEFORE THIS as roaming scavengers so this new switch to agriculture and living with animals is relatively young on evolutionary scale. I suggest anyone who wants to play in the dirt and hug outdoor animals wash their hands. To ignore that risks tape worms and a host of other things.

  23. Tal, I think the point is that we are getting out of our sterile environments and colonizing more often from “wild” or other sources.

  24. I’m a nutritionist who often recommends this way of eating, but never recommends the ‘get dirty’ part. My diet may not change a whole lot through this ‘observation’, but the microbial exposure will be a big shift and may be interesting. Michigan is currently covered in snow but May will be a great time to roll around in mud. I may even host a ‘Meet Your Microbes’ fest.

  25. Is it also possible to participate form Holland? We already eat paleo 80/20 rule. Don’t know if we are interesting for you in that matter?

    • yes. can join via the british gut project

  26. Great idea! Obviously this project is closed. Are there any particulars about what exactly was done and tracked for the 60 days so somebody may do it on their own? Any results posted?

Leave a Reply