You’ve likely noticed that commercial probiotics can be expensive, especially if you’d like to obtain meaningful bacterial counts (tens to hundreds of billions), and if you’d like to address multiple species and strains.

I’ve discussed a number of ways to economize on probiotics in my Super Gut book, such as fermenting probiotics into yogurt, a way to reduce the need to repeatedly buy the probiotic. Here’s an even less expensive way to obtain some microbes: ferment from low-cost foods. Among them:

VitaLife Organic Kombucha—such as the Ginger Lemon version shown above. This product, available at Aldi’s for around $2 per 16 ounce bottle, is a source of Bacillus subtilis. This microbe has been shown to be protective over probiotic Lactobacillus species by helping form a biofilm. It also helps suppress fecal microbial species, such as E. coli, Pseudomonas, Klebsiella, and Staphylococcus aureus, and fungi such as Candida albicans,  (although I would not use this alone to manage SIBO or SIFO). B. subtilis also decreases the absorption of toxic heavy metals, cadmium and arsenic. This microbe is adaptable to a wide range of temperatures and can be fermented at room temperature or human body temperature. The easiest way to cultivate B. coagulans is to just empty 1-2 tablespoons of VitaLife kombucha into any juice, provided no preservatives (e.g., potassium sorbate, sodium benzoate) are listed on the ingredients, then allow to sit on your kitchen counter with the cap loose for about 48 or more hours, just as we do with our Saccharomyces boulardii sparkling juices. Taste after 48 hours—if still sweet, ferment another 12-24 hours or until no longer sweet. (Some strains of B. subtilis produce vitamin K2, but we have no evidence that the strain used for this kombucha is capable of this. However, you can also ferment B. subtilis subspecies natto that does produce K2.)

GT’s Kombucha—This popular kombucha is a source of Saccharomyces boulardii, Bacillus coagulans GBI-30,6086, and unspecified Lactobacillus species. Getting S. boulardii is among the most powerful strategies you can adopt to protect your microbiome during a course of antibiotics. B. coagulans reduces muscle injury during strenuous exercise or work, thereby accelerating recovery. As with the VitaLife Kombucha, just take 1-2 tablespoons and add to a juice that contains no preservatives and allow to ferment at room temperature for a minimum of 48 hours.

Good Belly—The Good Belly line of products is available as juices, probiotic shots, or probiotic capsules and is a source for Lactobacillus plantarum 299v. This is the most studied strain of L. plantarum that has been shown to reduce the symptoms of irritable bowel syndrome, increase absorption of non-heme iron significantly, and strengthen the intestinal mucus barrier. The most economical way to ferment this product is by purchasing one of the juices (one quart cartons) or the shots, add to a non-preservative containing juice, and ferment at room temperature for a minimum of 48 hours and test for sweetness, as described above. You can find this product in most major supermarkets.

Yakult—This product, available in little 2-ounce plastic jars, is a source for Lactobacillus casei Shirota. Because the product is made with skim milk and sugar, we don’t drink the product but use it as a starter for making yogurt or other ferments. This is a human body temperature-fermenting microbe, so ferment just as you would L. reuteri. L. casei Shirota has been shown, in several human clinical studies, to significantly reduce the incidence of upper respiratory viral infections. It is also a magnificent microbe to improve sleep. (As a chronic insomniac, my sleep improved dramatically with L. reuteri: sleeping straight through the night with almost no awakenings. When I added L. casei, I was sleeping 12+ hours per night—I had to stop it. Most people don’t experience the extreme effect that I had, but be aware that such a profound sleep augmentation is possible.) You can find this product in the dairy refrigerator at Meijer, Walmart, and Asian food stores, usually as a six-pack.

You get the idea. You can also combine products as starters to cut down on the number of foods you ferment. Adding some Good Belly juice to GT Kombucha would be a terrific combination, for example.