What’s the best-tasting prebiotic or probiotic soda? It’s rough out there.

In recent years, drink cases at grocery stores and delis have been transformed into rainbow-colored seas. Cans of fizzy drinks — with Gen-Z-bait graphic design and bright hues — touting healthier-than-regular-soda properties are muscling up to the standard fare of bottled waters and juices.

Many of these elixirs aren’t just promising to take the place of traditional sodas, only with lower sugar and fewer calories — they also claim to offer health benefits, including the holy grail of buzzy wellness: “gut health.”

This bubbling trend got its ticket officially punched earlier this year when Pepsi purchased prebiotic soda brand Poppi, and Coca-Cola launched its own prebiotic lineup, Simply Pop. The global probiotic and prebiotic soda market was valued at $443 million in 2023 and is expected to grow to $766.14 million by 2030, according to a report by Grand View Research.

Some scientists are skeptical of the purported benefits conferred by fruity drinks, and a false-advertising lawsuit against Poppi last year claimed that a can doesn’t contain enough of the prebiotic fiber it claims will make one’s gut “happy.” Still, the appeal remains as new products continue to enter the fray, so we gathered the top-selling brands, as identified by Grand View Research, to see which can would rise to the top of the fizzy heap.

While many offer quirky flavors and combinations, all have a lemon-lime or similar citrus version, so we stuck with that in the interest of direct comparison. I invited six colleagues from the Food team to a blind taste test, meaning they didn’t know which brands they were tasting. Each sample was awarded a score from 1-10 (although one of the panel broke the rules and gave our loser a zero), meaning each had a potential high score of 60.

Alas, none came anywhere close. In general, our verdict (spoiler alert!) was … bad. The scores overall were lower than in any other taste test I recall. Bottom line: We couldn’t find the “fun” in these functional sodas.

But if you’re committed to finding a can, here’s what to avoid and what to seek out.

7. Poppi (Lemon Lime)

Score: 9

“Bad medicine” and “bathroom cleaner” were some of the similes this overwhelmingly detested sample evoked among our tasters, with several adding “vinegar” to that list. Our panel agreed that it fell flat — literally. And one found the viscosity that stevia imparted reminiscent of the stuff your doctor might prescribe to prepare for a certain procedure: “this entire experience makes me wonder whether I forgot I have a colonoscopy scheduled in the morning.”

Per serving: Calories: 25; Carbohydrates: 6 g; Sodium: 0 mg; Protein: 0 g; Dietary Fiber: 2 g; Sugar: 3 g.

6. Humm Probiotic Soda (Lemon Lime)

Score: 18

A couple tasters liked this one better than many (“cleaner and brighter-tasting than the rest,” according to one). But most found it cloying, which might be explained by the fact that allulose syrup — a nearly zero-calorie, plant-derived sweetener — is the second ingredient behind water. “Like a really bad powdered lemonade mix, but with even less nuance,” complained one person. “Fake sugar alert,” said another. “I can taste that stuff from across the street.”

Per serving: Calories: 0; Carbohydrates: 10 g; Sodium: 0 mg; Protein: 0 g; Sugar: 0 g.

5. Olipop (Lemon Lime)

Score: 19

This popular brand was confusing to some — they were supposed to be tasting lemon-lime sodas, right? One found “no citrus notes,” while another lamented that “I do not get lemon-lime at all.” A creative colleague imagined an explanation: We had an impostor on our hands! “She’s MEAD!” he determined. “This is honey in seltzer.” Despite the apparent misnomer, several people liked that it seemed to be the fizziest of the bunch.

Per serving: Calories: 50; Carbohydrates: 16 g; Sodium: 25 mg; Protein: 0 g; Dietary Fiber: 9 g; Sugar: 4 g.

3. (Tie) Culture Pop Soda (Lemon Lime)

Score: 21

Culture Pop, which touts the fact that its sweetness comes only from fruit juice (a rarity in this swamp of sweeteners) might have been the least sugary-tasting of the bunch. And even though our tasters complained that the others were too sweet, it still didn’t hit that perfect Goldilocks mark. One found it “fairly pleasant and tart.” Another said it “needs to be sweeter,” and several described it as merely “sour.” At least it came across as more natural than its competition: “Not too bad on the fake-sugar count,” was a tepid compliment.

Per serving: Calories: 45; Carbohydrates: 10 g; Sodium: 50 mg; Protein: 0 g; Sugar: 10 g.

3. (Tie) SunSip (Lemon Lime)

Score: 21

This was one taster’s favorite of the bunch (“tastes like a French limonade”) while another offered that she would drink it if there weren’t other options (hey, that’s what passes for high praise in this unpopular crowd). But its score was dragged down by several who sniffed out some decidedly unpleasant notes — dishwashing soap, anyone? “Smells like a pool?” one wondered. “No bueno.”

Per serving: Calories: 30; Total Fat: 0 g; Carbohydrates: 7 g; Sodium: 0 mg; Protein: 0 g; Dietary Fiber: 2 g; Sugar: 5 g.

2. Live Soda (Citrus Rush)

Score: 22

I suppose that when the flavors people do pick up on are generally disliked, being described as faintly flavored isn’t such a bad thing. Which was the case for this wan soda. “Another drink that tells me it’s lemony, but it’s not,” someone said. “I feel like I’m being gaslit.” “Fake ginger ale,” a taster dubbed it. But one of our panel had an idea for what to do with the bland bubbles: “Probably better as a cocktail mixer than a straight soda.”

Per serving: Calories: 10; Total Fat: 0 g; Saturated Fat: 0 g; Carbohydrates: 7 g; Sodium: 0 mg; Cholesterol: 0 mg; Protein: 0 g; Dietary Fiber: 4 g; Sugar: 3 g.

1. Simply Pop (Lime)

Score: 24

The most ardent stevia hater among us was pleasantly surprised by this sample, which incorporates monkfruit for sweetness in addition to fruit juice. “Refreshingly clean-tasting,” he enthused. “Closest approximation to a lemon-lime soda,” declared another sorta-fan. Still, not everyone was on board, and even the winner of this dubious derby got dinged. “Tastes like a watered down, fizzy Gatorade,” lamented one. “This lands at the midpoint between ginger ale and lemon Pledge.”

Per serving: Calories: 60; Total Fat: 0 g; Carbohydrates: 18 g; Sodium: 25 mg; Protein: 0 g; Dietary Fiber: 6 g; Sugar: 10 g.

After we were finished with the lemon-lime varieties, we also tasted the traditional cola flavors from brands where they were available. Since we try to make our test as apples-to-apples (not apples-to-limes!) as possible, we ranked them separately.

Here’s how the colas stacked up.

4. Live Soda (Fountain Cola)

Score: 14

Another fizzy beverage that did not live up to its billing. The pale yellow color and lack of the classic, deeper flavors (or, really, any at all) confused the panel. “Not a cola,” said one. “Don’t understand this as a cola at all” agreed another.

Per serving: Calories: 10; Total Fat: 0 g; Saturated Fat: 0 g; Carbohydrates: 7 g; Sodium: 0 mg; Cholesterol: 0 mg; Protein: 0 g; Dietary Fiber: 4 g; Sugar: 3 g.

3. SunSip (Cherry Cola)

Score: 17

A couple of tasters appreciated a discernible fruit flavor (“hello, cherry!), but several likened it to cough syrup.

Per serving: Calories: 30; Total Fat: 0 g; Carbohydrates: 8 g; Sodium: 0 mg; Protein: 0 g; Dietary Fiber: 2 g; Sugar: 5 g.

2. Poppi (Classic Cola)

Score: 23

Flat and full of off notes (such as “cinnamon death,” “maple-y”), some thought it might appeal to Dr Pepper fans. “Not terrible,” was as effusive as anyone could muster.

Per serving: Calories: 25; Total Fat: 0 g; Carbohydrates: 8 g; Sodium: 0 mg; Protein: 0 g; Dietary Fiber: 3 g; Sugar: 5 g.

1. Olipop (Vintage Cola)

Score: 28

The panel was unanimous in finding this to be the darkest and richest of the bunch — making it the closest thing to a dupe for traditional cola. “Tastes most like conventional soda to me,” one panelist declared.

Per serving: Calories: 35; Total Fat: 0 g; Carbohydrates: 16 g; Sodium: 25 mg; Protein: 0 g; Dietary Fiber: 9 g; Sugar: 2 g.