Walmart’s New bettergoods Soda Has the Exact Postbiotic Dose From the Trials. Here’s What They Found

The can is white, with two cartoon bottle caps tumbling down the front and a word most sodas have never needed: postbiotic. It is bettergoods Prebiotic & Postbiotic Soda, the newest drink from Walmart’s store brand, in a flavor called Dr. Fizz. We read its label images front, back and side, down to three lines of small print at the edge of the Nutrition Facts panel, half cut off by the curve of the can. The first of those lines holds the most interesting number on it.

It reads “2.5 B cells,” and the cells are heat-treated Bifidobacterium longum CECT 7347. That is, to the cell, the daily dose in the published digestive trials of this ingredient, which were funded wholly or partly by ADM, the company that licenses the strain. In adults with diarrhea-predominant IBS, that dose came with a large drop in symptoms compared with placebo. In healthy adults with mild digestive complaints, symptoms barely changed. The rest of the can is 40 calories, 5 grams of soluble corn fiber, 4 grams of sugar, and two different percentages for the same 5 grams.

The label: What the Dr. Fizz can says

Walmart’s Dr. Fizz listing carries eight images, including a standalone Nutrition Facts panel and ingredient list. Per 12-ounce can: 40 calories, no fat or sodium, 13 grams of carbohydrate, 5 grams of fiber at 18 percent of the Daily Value, and 4 grams of sugar, all of it added. Vitamin C comes in at 25 percent, B6 and B12 at 15 each. Soluble corn fiber is the second ingredient, after carbonated water, and the sweeteners are organic agave syrup and stevia leaf extract. That agave is a syrup, a sweetener, not the agave inulin fiber that Poppi uses.

The postbiotic: Bacteria that have been switched off, then counted

A postbiotic, in the definition published in 2021 by an expert panel of the International Scientific Association for Probiotics and Prebiotics, is a “preparation of inanimate microorganisms and/or their components that confers a health benefit on the host.” Inanimate means the cells are no longer alive. Unlike the live cultures in a probiotic, these have been heat-treated so they cannot grow, which is part of why they can sit in a shelf-stable can. The definition also builds in the benefit, so whether an ingredient earns the name depends on the evidence for that ingredient.

This one is a single strain, which ADM uses under license from CSIC, Spain’s national research council. ADM sells the heat-treated form, HT-ES1, to brands, and one of its executives has named sparkling waters among the formats. The bettergoods label names no supplier, but it does print a count, more than Culture Pop did for its live probiotic when we read that can. A milligram figure follows in parentheses, cut off in the photo. The count is what matters: in ADM’s trials, 2.5 billion cells equaled 50 milligrams of their powder, a weight that depends on how concentrated a batch is.

The trials: Same dose, two very different results

Both digestive trials gave 2.5 billion cells a day, as two capsules. The larger one, published in Gut Microbes in 2024, randomized 200 adults in India with diarrhea-predominant IBS to the live strain, the heat-treated strain or a placebo for 12 weeks. On the IBS symptom severity scale, which runs from 0 to 500, the heat-treated group’s score fell by about 178 points on average and the placebo group’s by about 60, a result the authors called clinically meaningful. ADM funded the trial and helped design it and write the paper, three authors work for ADM, an Indian research company, Vedic Lifesciences, conducted it, and the paper sized it using guidance for pilot studies.

The second, a 2024 pilot study in Madrid, gave the same dose or a placebo for eight weeks to 60 healthy adults with mild to moderate digestive symptoms, a group closer to the average soda drinker. Its main measure, a digestive symptom score, showed no significant difference from placebo. The authors reported “minimal changes” in symptoms, noted that no formal sample-size calculation was done, and described shifts in some gut bacteria and a fall in cholesterol as secondary findings. ADM paid for part of it, and ten of its twelve authors work for the company.

Neither trial tested a soda. The capsules were taken daily for eight to twelve weeks, and no published study has measured what these cells do after months in a carbonated drink, or what an occasional can does. For anyone managing IBS, the trial is worth raising with a clinician; a soda is not the form it was tested in.

The fiber: Five grams of soluble corn fiber

Soluble corn fiber is, in the words of the FDA’s 2018 science review, one of the “common names used to identify resistant maltodextrin,” the same family as the Fibersol in Vita Pop. The FDA lets it count as dietary fiber, and the benefit it accepted in doing so was calcium absorption and retention. The label does not say whose it is. In a 2016 University of Reading study funded by Tate & Lyle, which sells one as Promitor, groups of eight healthy adults took 6, 12 or 18 grams of its fiber a day for two weeks, and bifidobacteria rose most at 6 grams, a little more than a can holds.

For comfort, 5 grams is a small dose of this fiber. In a French tolerance study of Tate & Lyle’s ingredient, run at Biofortis in Nantes, 40 grams in one sitting was the highest dose that still met the study’s tolerance criteria, “twice the amount tolerated for inulin,” the authors wrote, and 65 grams spread across a day passed too. A University of Minnesota trial supported by an NIH grant gave 12 grams a day of four fibers, soluble corn fiber among them, and found them “well tolerated, with mild to moderate GI symptoms.” Fermentable soluble fibers can cause some gas, especially for someone new to them, but a can holds a fraction of the doses tested.

The fine print: Sixteen percent or eighteen?

The top of the can carries a three-part strip: 4g total sugars, 5g fiber, B&C vitamins. Under “5g fiber per serving,” the main image on the listing and the size-guide image both say 18% DV, as do the Nutrition Facts panel and Walmart’s product description. Two styled photographs on the same listing, one with a glass of soda and fresh cherries, show the front of the can reading 16% DV. One of them sets the can beside a graphic that says 18.

Five grams of the 28-gram Daily Value is 17.9 percent, which rounds to 18. Both numbers can still describe the same can. The FDA’s rule for the Nutrition Facts panel says fiber is declared “to the nearest gram,” and that the percent may be calculated from “either the amount declared on the label” or “the actual amount of each nutrient (i.e., before rounding).” A can measured at about 4.5 grams would be labeled 5 grams, and 4.5 divided by 28 rounds to 16 percent. The listing does not say which version of the can is headed for shelves, and Walmart has not explained the difference publicly.

The aisle: Where it lands, and when you can buy it

On fiber, 5 grams sits above Poppi’s 3 and below both Olipop lines, 6 grams shelf-stable and 9 refrigerated, level with Vita Pop. What it adds is the postbiotic. It is also cheap. The same day, Walmart.com listed a four-pack of Poppi’s Doc Pop at $6.97 and a single refrigerated Olipop Crisp Apple at $2.28, which by our arithmetic works out to about 32 cents per gram of fiber for bettergoods, 58 for Poppi and 25 for Olipop. Our prebiotic soda tracker has the rest of the aisle.

As for when: Sporked reported on September 23, a day after the Instagram account @candyhunting first posted the line, that four flavors, Crisp Apple, Cherry Limeade, Strawberry Guava and Dr. Fizz, were “heading to Walmart stores soon.” On October 1, the Dr. Fizz listing showed the can out of stock for shipping, pickup and delivery, with no release date, and we found no Walmart.com listing for the other three flavors.

The short version: a light, low-sugar store-brand soda with a middling dose of a well-tolerated fiber, plus a postbiotic printed at exactly the daily count ADM’s capsule trials used, a count that went with big improvements in IBS-D and little change in healthy adults. Walmart and ADM had no involvement in this article. It is educational, describes what the cited labels, listings, regulations and studies say, and is not medical advice.