In the Wheat Belly lifestyle, we generally avoid juices, as they are packed with huge quantities of sugar. An 8-ounce glass of orange juice that many regard as healthy, for instance, contains 25.5 grams net carbs or the equivalent of 6 teaspoons of sugar—more than enough to cause weight gain, send blood sugar sky-high, disrupt bowel flora, and contribute to all the awful consequences of insulin resistance. Likewise, an 8-ounce glass of cranberry juice contains 31 grams net carbs or the equivalent of over 7 teaspoons of sugar. Even a teensy-teensy serving size of 2 ounces of cranberry juice, or 1/4-cup, yields around 8 grams net carbs. Despite healthy components such as vitamin C and flavonoids/polyphenols in juices, the carb/sugar challenge is just too high and consuming more than the smallest amount is inviting health trouble.
But bacterial fermentation can come to the rescue. While excessive sugar and carbs have awful consequences for us, bacteria love sugar and can consume them and proliferate, yielding metabolites beneficial to humans, such as butyrate and propionate. This is why, for example, you may feed your kombucha 1/2 cup of sugar per week, but the final end-product after, say, 10 days of fermentation is no longer sweet: most of the sugar has been metabolized by bacteria and fungi.
I’ve lately been discussing how obtaining high counts of Lactobacillus casei Shirota of 40-100 billion CFUs per day augments the immune response and can reduce the likelihood of respiratory viruses by 50% or more, abbreviate the duration of illness should you develop a respiratory viral illness by 50% or more, and improves both inflammatory markers and insulin resistance, both of which further improve immune protection.
But in case you are tired of consuming “yogurts” as our means of increasing bacterial counts to super-duper high levels (far, far higher than the insignificant counts obtained in commercial yogurts fermented for around 4 hours), here is how you can use fruit juices filled with sugar to ferment a probiotic species, in this case L. casei Shirota. I used Trader Joe’s organic Mango Nectar juice blend of mango and white grapes, but any sugary juice will do. Because there is a generous quantity of sugar already present, there is no need to add any additional sugar or prebiotic fiber (as we do to ferment our “yogurts.”) You will also, just as with yogurt fermentation, require some means of maintaining the mixture around 100 degrees F (though this species will survive and ferment in the range of 95-109 degrees F, so some non-adjustable yogurt makers and Instant Pots that typically are too hot for L. reuteri may be fine for L. casei.
The end-result will be low in sugar and be rich in probiotic L. casei with its immune-promoting effects, including at least partial protection from respiratory viruses.
In my test batch, it required 48 hours of fermentation for the juice to no longer be sweet, meaning all or most of the sugar had been fermented out. In your own efforts, taste your result; if it remains sweet, ferment a bit longer, e.g., another 6-8 hours. (I have not performed a formal nutritional analysis of the fermented juice; until we do, go lightly and consume no more than 1/2 cup per serving. Likewise, we have not performed a formal bacterial count. Should this practice prove popular, we shall do so in future.)
I used the whey of L. casei yogurt to get started, but you could instead use a tablespoon of Yakult off the shelf.
Makes 4 cups or 8 servings
Pour 4 cups of juice into a large jar. Add one tablespoon of L. casei whey or Yakult. Stir gently.
Cover lightly (e.g., plastic wrap, cheesecloth fastened with rubber band) and maintain at specified temperature for 48 hours.
Refrigerate when done.