
The Lactobacillus reuteri yogurt we make to boost oxytocin and obtain its unique profile of upper gastrointestinal probiotic benefits is truly one of the most fascinating things we’ve stumbled across in the Wheat Belly and Undoctored worlds. Using the unique fermentation process that I introduced, we develop a wallop of benefits due to exceptionally high bacterial counts of the L. reuteri strains.
But there seems to be continual confusion on the reasons, species/strains, methods, etc. surrounding our unique “yogurt.” I didn’t stumble on all these ideas at once, but gradually evolved my understanding of how and why this thing achieves such extraordinary effects and how to best put it to use, chronicled in at least a dozen Wheat Belly Blog posts. If you read through them chronologically starting with my appreciation for making yogurt with higher fat content and fermenting with prebiotic fibers and using probiotic species, rather than conventional yogurt species, you can chart the line of thinking. Apparently, most people do not do this. So I thought a Frequently Asked Question, FAQ, post would be helpful, as the same questions come up over and over again.
Q: What is so special about Lactobacillus reuteri? And why do you insist on these two strains?
A: The two strains of L. reuteri used, DSM 17938 and ATCC PTA 6475, are the two strains that have been shown to exert the skin, muscle, bone, hormonal, and probiotic benefits in both experimental and human clinical trials. Of the nearly 200 known strains of L. reuteri, these are the only two that have been shown to exert this wide range of effects. Other strains may indeed do so likewise, but this has not yet been documented. (This is among the projects that we are likely going to undertake ourselves.)
But a word about strain specificity and why choice of strain is critical. You have E. coli in your gut; I have E. coli in my gut. But if we are exposed to E. coli from lettuce contaminated by cow manure, you can die of kidney failure and sepsis—same species, different strain. Strain can therefore make a life-death difference. So, until we know better, we stick to the strains that we know are safe, effective, and generate the benefits we desire.
Q: I’ve made yogurt before and this is not how we do it. We use shorter fermentations times, e.g., 6-12 hours, don’t add prebiotic fibers, and ferment at 108-114 degrees F. Why is the L. reuteri yogurt-making process different?
A: It is purposefully different. The longer fermentation time of 36 or so hours is used to cultivate higher bacterial counts for more pronounced oxytocin-boosting and probiotic effects. We add the prebiotic fibers also for greater bacterial counts, since bacteria feed on the fibers, as well as for better texture and mouthfeel. (I find it surprising that all yogurt makers don’t do this, rather than add thickening agents and emulsifiers.) And L. reuteri “prefers” human body temperature, actually starting to die at the temperatures used for conventional yogurt making. This is why some people have experienced repeated failures using yogurt makers or Instant Pot devices that are sometimes set at higher temperatures. (You can figure this out by turning the device on with a thermometer inside and see what the eventual temperature reaches. Unfortunately, unless you have a variable temperature control, you will have to resort to a new device such as a sous vide device or something like the Luvele yogurt maker with adjustable temperature control that you can find in the Wheat Belly Marketplace.)
Q: Can I make the yogurt with commercial store-bought yogurt and still obtain all the benefits?
A: No. The effects have nothing to do with yogurt. In fact, if I were producing it commercially, I couldn’t even call this thing we make “yogurt”—even though it looks like yogurt and tastes like yogurt, it’s not really yogurt. We specifically need Lactobacillus reuteri, one or two of the strains that we know generate these extravagant effects. (There may be other strains that do likewise, but we have no evidence that they do or do not–see above.) But you can make yogurt by combining L. reuteri with the microoganisms from a live-culture commercial yogurt. Doing so yields lower counts of L. reuteri which thereby does not have the potency of our usual L. reuteri yogurt, but is something you could serve to younger people, including menstruating females, who lack L. reuteri. This is how we make our mixed-culture yogurt suitable for younger people.
Q: Early in the L. reuteri experience, you advised menstruating females and people younger than 45 to not consume the yogurt, but then you changed your mind. Why did you change your mind?
A: My initial concern was that, because oxytocin is known to induce uterine contraction (injected intravenously to induce delivery of a term infant), it is uncertain what a menstruating female with menstrual cramps might experience. (Interestingly, however, a number of younger women reported having dramatically less severe menstrual cramps, bleeding, and emotional turbulence, but this is purely anecdotal from a handful of women.) And, of course, a pregnant woman should not make the full-strength yogurt. In addition, oxytocin is already present at higher levels in younger people who have not yet experienced the age-related decline in oxytocin levels and the same benefits likely do not apply when there are higher levels of endogenous oxytocin present.
BUT it also became clear that L. reuteri is meant to be carried by most, if not all, humans, obtained via breast milk as an infant. L. reuteri has also been administered in dozens of clinical trials in hundreds of millions to several billion CFUs to children with no ill-effect, only benefits such as reduced infant colic, regurgitation of milk or formula, and faster recovery from post-antibiotic diarrhea. This is why I devised the simple method of making a mixed-culture yogurt that delivers L. reuteri in lower counts and is suitable for children and younger people, including menstruating females.
But anyone consuming our high-potency yogurt needs to accept that this is a work in progress and that we are learning lessons along the way, in addition to planning limited clinical trials to further explore some of the effects, especially those on hormonal status.
Q: Can I use raw milk?
A: VERY bad idea. While raw milk has its benefits, you cannot chance even a minuscule amount of contamination by pathogenic organisms like Listeria or Staphylococcus aureus because, if present, their numbers will be amplified by the yogurt-making process. This can make the yogurt a potentially fatal product—not good. So NO raw milk or other raw dairy.
Q: Do I have to re-inoculate the yogurt with additional tablets with each batch?
A: No. I am on my 60th or so batch and have never reinoculated yet all the benefits are maintained, as well as the same taste and texture. It doesn’t hurt to re-inoculate, but it does not seem to be necessary to propagate your live cultures.
Q: The BioGaia Gastrus tablets have mango flavoring? Is this the wrong product?
A: No, this is fine. The yogurt will not have any mango flavoring, as it is diluted in the yogurt-making process, then virtually gone with subsequent batches.
Q: I tried making the yogurt and the first batch was lumpy with separation into curds and whey. Why did this happen and is it okay to consume?
A: This is the expected result with everyone’s first batch. Subsequent batches tend to be thicker and more uniform, with separation in to whey only through straining and/or with removal of some of the curds. And, yes, the first batch is safe to consume.
Q: Should I remove the liquid whey?
A: That’s your call. But remember: Whey is the fraction of dairy that provokes insulin and can thereby block weight loss and contribute to insulin resistance. My advice is to at least pour off the whey when it separates and save it to use as starter for your next batch or just discard. Some people also strain their yogurt through cheesecloth to more thoroughly remove the whey and generate the thicker Greek-style yogurt.
Q: Why is the L. reuteri yogurt so tart or sour?
A: The prolonged fermentation time we use—36 hours, compared to the 6-8 hours typically used in commercial yogurt-making, or 6-24 in home yogurt-making–allows maximal fermentation of lactose sugars to lactic acid, the component that confers the tart or sour taste. We do this, of course, to generate higher bacterial counts but also to 1) exhaust lactose to as low a level as possible and 2) reduce the pH of the yogurt to 3.0-3.5, a level that denatures (breaks down) the casein beta A1 protein and reduces its immune-stimulating potential. So the increased tartness or sourness simply reflects the greater lactic acid content from prolonged fermentation time. You can add some berries, a teaspoon of inulin, a squirt of stevia liquid or other safe natural sweetener to conceal the tartness, if you like.
Q: My yogurt developed a greenish/pinkish discoloration on top. What is this?
A: This is fungal contamination. We remove the discolored area and discard.
However, should this happen, take steps to more meticulously clean your utensils (bowls and spoons) with hot soap and water. Also, be sure that your yogurt is not in the path of airflow from your air condition, heater, or other device. The yogurt mixture should also be lightly covered, e.g., plastic wrap, during the fermentation process.
Q: What’s the best device to use to maintain the 100 degree F temperature for fermentation?
A: As discussed above, not all yogurt making devices or Instant Pots get the job done because of temperatures pre-set at temperatures suitable for conventional yogurt-making, not for fermentation of L. reuteri that prefers human body temperature. My choices for devices include sous vide devices (basin and stick) and yogurt makers with adjustable temperature such as the Luvele device. You can find these devices in the Wheat Belly Marketplace. Some people have even devised their own homemade devices, such as an incandescent lightbulb mounted in a covered box, or just turning on the oven light on a closed oven. Don’t make this harder than it should be.
Q: Can I feed the L. reuteri yogurt I make for myself to my children/grandchildren?
A: Occasional consumption by young people is safe. What is not known is whether chronic or repeated consumption is safe, given the potent oxytocin-boosting effect of the yogurt. This is why I devised the mixed-culture yogurt that delivers lower numbers of L. reuteri because it is combined with several other yogurt-fermenting bacterial species. Whenever I’ve made the mixed-culture yogurt, I found it to be surprisingly tasty, certainly far tastier than anything you buy in the store.
Q: How long with the yogurt keep in the refrigerator?
A: The shelf-life of yogurt is longer than non-fermented dairy and is generally up to 4 weeks.
Q: What if I have repeated failures in my yogurt-making efforts?
A: See this Wheat Belly Blog post on troubleshooting the yogurt-making process. Identify the problem—contaminated utensils, too high fermenting temperature, etc.—and you can join the ranks of people obtaining the extravagant health benefits of the L. reuteri yogurt. But, if you go through all the issues and are still having trouble, then consider taking the new BioGaia Osfortis product with 5 billion CFUs (per capsule) of one L. reuteri strain, available as a probiotic capsule without needing to ferment to yogurt to generate higher counts. What is unclear is what dose to take to mimic the effects of the yogurt. Anecdotally, it required two capsules per day or 10 billion CFUs for me to re-experience the anorexigenic and deep sleep-cultivating effects, though not as potently as that provided by the yogurt. You can find the Osfortis product in the Wheat Belly Marketplace.
Q: My experience with consuming the L. reuteri yogurt is somewhat different than you describe. For instance, I obtain the appetite-suppressing effect and greater skin moisture, but not the skin thickening/wrinkle-smoothing effects. Why is this?
A: This is likely due to such factors as variation in oxytocin receptors. So individual experiences can vary. Also, factor in time: some effects will require a longer time period in some people. There may be other factors that influence response, and I hope that these will become clearer as our understanding of this phenomenal thing progresses.
Q: If consuming one-half cup yields effects, will consuming an entire cup yield more effect?
A: We have no formally quantified this response, i.e., performed bacterial counts on the yogurt, then observed such factors as blood oxytocin levels on consuming increasing quantities of yogurt. Anecdotally, however, some people have indeed reported a better response to greater quantities. Interestingly, these same people have reported no rise in blood sugar with the somewhat greater carb exposure of greater yogurt portions.


Hello, I am attempting to make Dr. Davis is yogurt with the following strains: The BioGaia Gastrus, B. coagulans, L. gasseri BNR-17. The L. gasseri will not be here for a month so I decided to combine the first two for yogurt. I am making it my Instapot ultra at 104°. First batch came out whey and curds, but I took 3 tablespoons and added it to more cream and Inulin for another round. My question: the whey and curds from the first round tastes awful (not tart, more like bucolic acid🙁), no black growths though…is this normal?
Kellie Harnar wrote: «The BioGaia Gastrus, B. coagulans, L. gasseri BNR-17. The L. gasseri will not be here for a month so I decided to combine the first two for yogurt.»
I’m not sure anyone has tried that (I haven’t), so no one may have any experiences to share.
re: «I am making it my Instapot ultra at 104°.»
The optimal temp for B.coagulans is 115-122°F. I suspect this is why the suggested temp for the SIBO yogurt is the bargain temp of 106°F, which is higher than optimal for L.reuteri (but not too high, nor too low for coagulans).
re: «First batch came out whey and curds, but I took 3 tablespoons and added it to more cream and Inulin for another round.»
I’ve also never done that, so can’t guess as to what’s going on. When I started making the SIBO yogurt, I followed my usual personal practice of making a small batch (one ice cube tray’s worth) each of the component yogurts, each at its ideal temp. One each of the slowly-thawed ice cubes are then used to make a consumption batch of the SIBO yogurt, at 106°F. I have not tried using the finished SIBO yogurt as starter. And indeed, the recipe on the Inner Circle site says:
“While the recipe is written as if started with raw probiotic product, you can also use 1-2 tablespoons of a yogurt made with each individual species.”
Because you don’t have all three of the probiotics needed (and even when you do), another approach is to make each yogurt separately, then serve the final ½ cup portions as a hand-stirred mix of ~11 tsp. of each.
More tips on these yogurts generally.
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Hi, i hab a problem mixing the 10 crushed tablets and the inulin powder when I added the cold milk to it!
Immediately I was very clumpy didn’t resolve at all, whats the problem? Was it the cold milk?
Thanks for your help!
Tom73 wrote: «…a problem mixing the 10 crushed tablets and the inulin powder when I added the cold milk to it! Immediately I was very clumpy didn’t resolve at all, whats the problem? Was it the cold milk?»
I’m not clear on what was clumpy; the inulin and/or the crushed Gastrus® tablets?
If the tablets, how are you crushing them?
If the inulin, you could experiment with warmed milk (and no Gastrus).
In my personal process, when I need to start over from tablets, I don’t use the pre-mix step, so have no experience with it.
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My slurry was also clumpy but I continued nonetheless. Will the yogurt still have the beneficial effects?
C2Rower wrote: «My slurry was also clumpy but I continued nonetheless. Will the yogurt still have the beneficial effects?»
Very likely, but moreso in subsequent batches made from saved yogurt as starter.
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I forgot to take my yogurt out last night. Yikes! I made it in an instant pot for 36 hours and looks & smells great! But, now it is 10 hours passed the 36 hours. Is it still good? I was going to use this batch as “starter” for future batches. Is that OK? Or, do I need to throw it out? Ugh…..
appreciate your response, Bob.
I used saved yogurt from first batch as a starter
I used organic heavy cream . Checked ingredients just now on package: Grade A organic cream, gellun gum. Suppose the gellun gum is a bad idea as it is a polysaccaride.
I’ll discard the starter that I put in freezer, and I’ll begin the next batch from yogurt and Bio Gaia tabs.
It’s good that you don’t get contamination. I don’t want to take the time to repasturize. Will get/make half and half for next batch. if contamination continues, I might opt for Osfortis, the easy way.
Suzanne Kryder wrote: «Checked ingredients just now on package: Grade A organic cream, gellun gum. Suppose the gellun gum is a bad idea as it is a polysaccaride.»
Gellan gum is not endorsed at present, as far as I know. Natural emulsifiers and gums are getting careful consideration, and sometimes get a green light (here’s guar).
But in the case of cream, or H&H, there’s simply no case for using these agents at all. Find a brand that’s delivering a traditional product, even a cream-top.
re: «I don’t want to take the time to repasturize.»
It adds about 20 minutes to my process, which is pretty rote at this point. 20 minutes isn’t a big deal when I make a gallon at a time, that lasts weeks. And I’m doing other stuff during the prep, like answering blog questions.☺
re: «… I might opt for Osfortis, the easy way.»
That’s only a single strain, and vastly lower CFUs than a portion of yogurt, but I do use the Osfortis when traveling.
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I just made my second batch. Store only had heavy cream, so used that instead of half and half. fermented for 36 hours. top had about 5 different very tiny black specks much smaller than a piece of black pepper, even smaller than the thickness of a piece of hair. I took out an inch around each speck then stirred and ate a couple spoons. tastes really good. Is it ok to eat this after removing specks or do I need to discard the whole batch? thanks, Suzanne
Suzanne Kryder wrote: «I just made my second batch.»
Using what for starter?
(i.e. tablets or saved yogurt)
re: «Store only had heavy cream, so used that instead of half and half.»
You can make your own H&H by mixing cream & milk, and I do when H&H isn’t handy. Retail cream, esp. heavy whipping cream, needs more careful inspection of the Ingredients list than H&H and milk, as creams are commonly contaminated with carrageenan, if not polysorbate 80.
re: «…top had about 5 different very tiny black specks much smaller than a piece of black pepper, even smaller than the thickness of a piece of hair.»
When I get these, I remove them as you did, and consume the yogurt anyway … but I don’t save any to use as starter.
And I never get this sort of surface contamination any more, perhaps due to my practice of [re]pasteurizing every batch with the prebiotic fiber stirred in, then water-bath cooling it to just above ferment temp before adding starter (my incubator can’t cold-start).
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I’ve had great success with the L. Reuteri fermented youghurt. My SIBO has abated. My Dr wants me to track my carbs, protein and fat. I’m wanting to know what the Macro count would be for 1/4 cup?
Janis St Louis wrote: «…L. Reuteri fermented youghurt. … what the Macro count would be for 1/4 cup?…»
Here’s my estimate from earlier this year.
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Thanks for all the replies. I have an “instant pot” (Cuisinart version) which I have yet to even turn on. I have a Sous Vide stick which, again, I haven’t used. the stick might be useable as I have a large stainless steel pot that might work. I’ll give that a go … and thanks again.
My question is about the 36 hour fermentation cycle. My current yogurt maker won’t work as I cannot change the temp. and it heats the milk to 110°. I’m looking at a Luvele yogurt maker that does allow the temp change but only goes a total of 12 hours. So I’m assuming that at the end of each 12 hour cycle I’ll need to restart the cycle over again. Sorry for appearing dense but I just want to make sure of this before I plop down $80 for a new one. Thank you.
You may want to consider the Instant Pot Ultra. I use it even though the temp can not be set lower than 104 but time can be set to 36 hours. At 104, some of the bacteria may be compromised but not enough to negate the benefits.
I would get a Sous Vide. Its bullet proof. Use 32 or 64 oz Ball Mason Jars in a large steel pot. Very easy to scale if others want your yogurt.
DarleenMB wrote: «I’m looking at a Luvele yogurt maker that does allow the temp change but only goes a total of 12 hours. So I’m assuming that at the end of each 12 hour cycle I’ll need to restart the cycle over again.»
That would work, but why settle for such a short-sighted widget? The suggestions here on sous vide devices might be helpful, and the blog Marketplace feature links to some.
We also made the mistake of buying a device that had very provincial views on how to make yogurt. It either ran too hot (110-115°F), or too short (4 hours), and caused me to invent my own solution.
If someone already had a 12-hour device, it might suffice, as it at least allows you to get some sleep, and head off to work. Set a phone alarm as a reminder to reboot it.
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Test Post. Does my Nickname display or my email address?
dan####s@mailserver.dom wrote: «Test Post. Does my Nickname display or my email address?»
I’m not a member admin here,
but I’m seeing a user name that matches an email address (which I’ve obfuscated here). I have no access to user account details, but I could arrange to have the comment deleted if you desire.Update: The comment metadata has been corrected.
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I emailed supoport from Contact link. For some reason after I signed up for a paid account my comments showed with my email address. The default should not be that. It should be fixed for subsequent post by me….
What works for me after the first batch with 10 tabs:
Per 32 Oz
1) 3 Tbsp of Starter
2) 2 Tbsp Inulin
3) 32 Half & Half (all organic)
Dump Starter into clean Pyrex cup. Add a bit of H&H and whisk to liquid consistency. Next add Inulin and whisk until Inulin is dissolved. Next add more H&H and whisk; repeat until all H&H added. Set Sous Vide to 97 F and 36 hours. Pour mixture into Bell Jar leaving tin cap to cover but allow gas to escape. Put jar into pot and press Start on Sous Vide. 36 hours later always perfect yogurt. I lost 30 stubborn pounds especially midsection in 3 months of eating this yogurt.
Woo Hoo! I almost wish I had a video running. At 23 hours, it was a little thicker, like runny Kefir. At 26 hours, the whey has separated out and I have what appears to be very thick yogurt underneath. Will be taking it out tomorrow morning.
It is interesting that there seemed to be such a defining moment vs. just slowly thickening.
Bob,
I got my Osfortis capsules yesterday (10 billion CFU each). 2 quarts milk (whole), scalded to 185 (like how I do regular yogurt) then cooled to 100. Made a slurry of 3 tbsp of potato starch and 4 capsules. Have had it all sitting in a sous vide setup at 100F. It is now 13 hours later and I am seeing absolutely zero thickening so far. I added another tablet for the heck of it.
I actually called up the company (Everidis) in St. Louis to explain my concern about transport and what if they get to too high a temperature. They said with 1 day delivery to the Chicago area it would not be an issue.
Anyway, I will certainly let this go to 36 hours, but as of yet there’s no signs that this is going well.
I’ve never heated the dairy prior to making the yogurt and I use organic half-n-half as opposed to milk. In addition, for the first batch, I used l reuteri which is the Bio Gaia, not the Osfortis. I believe Dr Davis recommends the Bio Gaia l reuteri for the yogurt and Osfortis if you are consuming the tablets alone.
I’ve used an Instant Pot Ultra set to 104
(lowest setting it will go) and fermented in 1/2 cup lidded jars in a water bath for 36 hours. Thick, beautiful yogurt every time. Is it possible that beneficial l reuteri is killed off at this temp?
Lisa Muzic wrote: «…Instant Pot Ultra set to 104 (lowest setting it will go) and fermented in 1/2 cup lidded jars in a water bath for 36 hours. Thick, beautiful yogurt every time. Is it possible that beneficial l reuteri is killed off at this temp?»
Nope. At 104°F, the reproduction rate is only mildly slowed, compare to the rate at the peak, which is reportedly 97°F.
As I understand it, you have to go above 110°F before fermentation is materially affected; above 115 for pronounced effect, and above 122 for mass die-off. There’s a different set of considerations for temps below 97, but 95-105 appears to be fine.
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Thank you!!!!
I do want to order the BioGaia prouduct but looked at the reviews. Some people have had bad luck in that perhaps the shipping/storage of the product before it arrived to the consumer, killed the bacteria. Is there a way to tell if it is effective or if you have a batch that is not effective?
Karen wrote: «Some people have had bad luck in that perhaps the shipping/storage of the product before it arrived to the consumer, killed the bacteria.»
See remarks on this a couple of days ago. I have yet to hear from everidis on distribution.
If I needed either Gastrus® or Osfortis® for starter, and couldn’t find a regional retailer, or a mail-order source offering cold pack, I might just mind the long-range forecast and wait for cooler weather.
As I also put it in a general probiotic discussion on the subscription forum: The main problem with mail-order is the last mile — the final delivery in a postal jeep, or uninsulated parcel van. Using a PO Box or PMB might improve the odds, and upgrading the shipping to next-day would as well.
re: «Is there a way to tell if it is effective or if you have a batch that is not effective?»
You’d have to bet US$5 of ingredients to find out. If the quart of dairy+inulin has the same soupy consistency at 36 hours as it had at the start, chances are the L.reuts were kaput on arrival.
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Thank you Bob, thanks help. I may do both. Wait for cooler wx and ship overnight.