Here is a summary on the Lactobacillus reuteri yogurt that I have been talking about over several blog posts, all put together for ease.

I’ve been discussing this idea of making yogurt by starting with a specific strain of Lactobacillus reuteri ATCC PTA 6475, based on the detailed studies conducted at MIT and elsewhere, both experimental animal and human, that have suggested dramatic effects. Those effects include:

  • Complete shut-down of appetite, an “anorexigenic” effect, that can be used to facilitate intermittent fasting or break a weight loss plateau. This, along with an increase in metabolic rate, explain why weight loss results.
  • Dramatic increase in skin thickness and skin collagen, along with acceleration of skin healing, a surrogate for overall youthfulness and health. I’m a big fan of dietary collagen, such as those provided by collagen hydrolysates, bone broths/soups, slow-cooking meats, eating the skin on chicken and fish, etc. This L. reuteri strategy amplifies this effect considerably.
  • Increased oxytocin–A doubling of oxytocin blood levels was observed in mice, the effect responsible for the extravagant skin benefits, reduced insulin resistance, dramatic increases in testosterone in males, increased estrogen in females (magnitude unclear), thicker and more plentiful hair (though the consistency of this effect is not yet clear). Other studies have demonstrated substantial weight loss, especially from visceral fat, increased muscle mass, and increased bone density (protection from osteoporosis/osteopenia).

Put all these effects together—caloric reduction, increased skin health, increased bone density, fat loss, muscle gain, reduced insulin resistance, etc.—and you have one of the most powerful anti-aging, youth-preserving strategies I have ever come across.

Because the most robust data were generated using the ATCC PTA 6475 strain of L. reuteri (and, to a lesser extent, the DSM 17938 strain), I have been confining my efforts to this strain. Other L. reuteri strains may mimic these effects, but we simply don’t know that for certain, as the studies have not been performed. Strain specificity can be a crucial factor. After all, all of us have several strains of E. coli in our intestines that live quietly and don’t bother anyone. But, get exposed to selected strains of E. coli from contaminated produce and you develop life-threatening diarrhea that can be fatal, especially in children. Same species (E. coli), different strains—strain specificity can be a critical factor.

So we start with L. reuteri ATCC PTA 6475 provided by the Swedish company, BioGaia, who has somehow locked this species up with patents (not sure how; I thought biological organisms were non-patentable). Their product is called Gastrus and combines the ATCC PTA 6475 strain with the DSM 17938 strain. (Just Google “BioGaia Gastrus” to find a retailer.) Problem: There are only 100 million CFUs (live organisms) per tablet. I have not observed any substantial health benefits by ingesting the tablets.

So I have been amplifying bacterial counts by making yogurt. The counts are further increased by performing fermentation in the presence of prebiotic fibers. Just as ingesting prebiotic fibers increases bacterial counts in your intestines, so it goes in making yogurt, as well. It also yields a thicker, richer end-product.

The yogurt is thick, delicious, and contains a marked increase in bacterial counts, though I have not yet performed a formal count. Given the extraordinary thickness of the end-product, it is likely that trillions of CFUs are present, sufficient to convert the soupy liquid of your starting milk, half-and-half, cream, coconut milk or other starter to rich, thick yogurt, sometimes thick enough to stand up on a plate. People who consume 1/2 cup per day of this preparation (mixed with blueberries, strawberries, etc.) are reporting the effects listed above. And this yogurt is so much richer and better tasting than products you buy in grocery stores.

There are probably many ways to make this yogurt and yield the bacterial counts you desire. But this is how I did it:

1 quart of organic half-and-half (or cream, whole milk, canned coconut milk, goat’s milk/cream, sheep’s milk/cream)
2 tablespoons inulin (or unmodified potato starch or other prebiotic)
10 tablets of BioGaia Gastrus, crushed

If you use coconut milk, you will need to add sugar, e.g., one tablespoon, to the prebiotic or use more sugar in place of the prebiotic, as there is no lactose to ferment in coconut milk. The probiotic tablets can be crushed using a mortar and pestle or other hard object (clean stone, bottom of a thick drinking glass, rolling pin, etc.). Don’t worry: The end-product should have little remaining sugar, as it is fermented to lactic acid. (If in doubt, just let it ferment a few more hours.) Just as the cucumbers you grow in your garden were fertilized with cow manure but ripe cucumbers contain no cow manure, so the final fermented yogurt product should contain little to no sugar.

In large glass/ceramic bowl, combine 2 tablespoons of liquid with the inulin, sugar or other prebiotic, and the crushed probiotic tablets. (We start by making a slurry, as inulin or potato starch will form hard clumps if added to the entire volume.) Mix thoroughly and make sure the prebiotic and sugar are dissolved. Then add the remaining liquid and stir.

Maintain the mixture at 100 degrees F. This can be accomplished with a yogurt maker, Instant Pot, sous vide device, rice cooker, or any other device that allows maintaining a continual temperature in this range. I use my oven: Turn onto any temperature, e.g., 300 degrees, for about 60-90 seconds, just until a desert-hot temperature is reached. Turn off the oven; repeat every 4-6 hours—not precise, but it works fine when using dairy for fermentation. Fermenting coconut milk is much fussier and a continual precise control over temperature will be required, e.g., one of the other devices. I used a yogurt maker and sous vide with good results.

The first batch tends to be a bit thinner with curdles, but subsequent batches tend to be thicker and smoother. To make subsequent batches, reserve a few tablespoons from the prior batch and use in place of crushed tablets, since your yogurt should contain plentiful microbes.

There are some uncertainties:

  • Is there reduction in bacterial counts or contamination by air organisms as you make yogurt from prior batches? Some people have “re-seeded” their yogurt by adding a few more crushed tablets of probiotic after several rounds of yogurt-making.
  • We’ve arrived at the 1/2-cup “dose” by trial and error, as judged by the anorexigenic effect that results when oxytocin levels increase. But is that the ideal dose? Don’t know yet.
  • Can we improve on taste/texture/bacterial counts by altering fermentation temperature, choice of prebiotic, or other conditions?
  • If your efforts fail to yield thick yogurt, check the temperature of your device. It may be too high, as the organisms die at 115 degrees F and higher.

Despite the uncertainties, I am witnessing some very dramatic changes in the people following this idea. If you give it a try, be sure to come back and report your experience.