Gut-Health Foods in the US and EU (2026): The Prebiotic Soda Market, Kefir and Fibre

The gut-health food boom in the US and EU

Digestive health is now a mainstream purchase driver. In a survey of 1,000 US adults run in March 2022 by the International Food Information Council (IFIC), 24% said digestive health is the most important aspect of their overall health and 32% said they actively try to consume probiotics.^[6]

Brand results point the same way. Olipop told investors its sales roughly doubled to about US$400 million in 2024, from about US$200 million in 2023.^[1][2] PepsiCo closed its acquisition of Poppi on 19 May 2025 for US$1.95 billion, including US$300 million of anticipated cash tax benefits.^[3] Coca-Cola entered the category in February 2025 with Simply Pop, starting in the US West Coast and Southeast.^[4]

Why the market size is hard to pin down

Published market sizes depend on how a report defines the category. Persistence Market Research puts the global prebiotic soda market at US$286.6 million in 2026, rising to US$470.8 million by 2033 (5.8% CAGR), with North America at 46.7% of the total.^[5] That global figure is lower than the sales Olipop reported for one brand in one country,^[1][2] so the report’s scope must be narrower than retail sales of the brands consumers think of as prebiotic soda. Treat any single market size as one estimate, and check its definition before you use it in a business case.

Table 1. Gut-health demand evidence: measured, reported and estimated

For the same demand question in the Gulf, see FRL’s analysis of functional beverage demand in the UAE.

The formats driving demand

Prebiotic soda and functional soda

Prebiotic soda pairs a familiar fizzy format with added fibre and low or no added sugar, so it doubles as a sugar-reduction product. The fibre is typically inulin or resistant starch.^[1] Fibre per can varies widely between brands: Simply Pop has 6 g of prebiotic fibre and no added sugar per 350 ml can,^[1] Olipop has 9 g,^[4] and court papers in the US class action against Poppi describe at most 2 g of prebiotic fibre per can.^[14]

Europe has its own launches, though no source we found sizes the EU category. In the Netherlands, Lazipop sells prebiotic sodas with chicory root inulin, B vitamins, L-theanine and magnesium.^[1] FRL has covered other launches, such as PepsiCo’s prebiotic cola.

Kefir and fermented foods

Kefir and other fermented drinks deliver live cultures rather than added fibre, which raises different product questions: strain identity and viable count at the end of shelf life. Human evidence for kefir is still early. In a small 2025 randomised trial in healthy young adults (28 completers, 150 ml a day for two weeks), no group showed a significant change in gut microbial alpha diversity. Kefir raised several lactate-producing species, including Bifidobacterium breve, but the Bifidobacterium genus also rose in the milk and yogurt groups, and differences in self-reported gut symptoms between groups were not significant.^[7]

Live cultures and postbiotics need different evidence and different claim routes. FRL covers how counts are tested and labelled in CFU meaning in probiotics, and kefir formulation in this Inside the Lab project.

Fibre and prebiotic ingredients

Fibre is the gap these products aim to fill. In a February 2026 discussion of the 2025–2030 US Dietary Guidelines, dietitian Catherine McManus said Americans “consistently fall far short of recommended fiber intake across the lifespan”.^[8] In the US, FDA has said inulin and inulin-type fructans and high-amylose (resistant) starch meet its dietary fibre definition for nutrition labelling.^[13] In the EU, chicory inulin has one authorised health claim, with strict conditions (see below).^[9]

US vs EU: how the markets differ

Market weight and channels

On the Persistence estimate, North America accounts for 46.7% of the 2026 global prebiotic soda market. The report names Germany, the UK, France, Italy and the Nordic region as key European markets but gives no European figure in its public summary.^[5] The US market is led by large, well-funded brands and, since 2025, by the two biggest soft-drink companies.^[3][4] We found no comparable sourced figures for the EU, so treat EU demand as real but unsized.

Claims and labelling constraints

The bigger difference is what a label may say. In the US, a dietary supplement making a structure/function claim must notify FDA within 30 days of first marketing and carry the standard disclaimer.^[11] A conventional food or drink such as a soda may make a structure/function claim based on nutritive value without notifying FDA and without the disclaimer.^[12] In the EU, health claims are prohibited unless authorised, and a general reference such as “good for gut health” may only be used alongside a specific authorised claim.^[10]

Table 2. US and EU claim routes for gut-health products

US claims carry litigation risk even when FDA does not act. In In re VNGR Beverage, LLC Litigation, purchasers alleged that Poppi’s “gut healthy” marketing was misleading because each can held at most 2 g of prebiotic fibre. The court granted preliminary approval of a US$8.9 million settlement on 23 May 2025.^[14] For the label wording itself, see FRL’s guide to probiotic claims in the EU and US.

Where gut-health products fall short

Three gaps recur. First, evidence lags marketing: the 2025 kefir trial found no significant diversity or symptom differences.^[7] Second, taste and stability are hard. In FRL’s prebiotic drink project, chicory and kudzu root extracts brought bitterness that needed a blend of sweeteners to mask, and some prototypes showed sedimentation and aftertaste. Third, the fibre dose per can is usually well below the dose behind the only EU fibre claim for inulin.

Dose gap check: can one serving reach the claim dose?

The EU chicory inulin claim applies only to foods that provide at least 12 g of native chicory inulin a day, with a mean degree of polymerisation of 9 or more.^[9] It does not cover other fibres, even inulin from agave or other plants. Compare that with the fibre in one can:

Table 3. Fibre per can versus the EU chicory inulin claim dose

Shares are calculated by FRL (fibre per can ÷ 12 g) and apply only if the fibre were native chicory inulin. The sources do not state that any of these products uses that fibre.

Formulator’s takeaway: one serving rarely carries the claim dose. Either raise the fibre dose and the fibre type to meet the claim conditions, which affects taste, stability and digestive tolerance, or keep EU pack copy general and leave the benefit wording out.

For brands & formulators

• Match the format to the evidence. A prebiotic soda must prove its fibre content and tolerance; a kefir must prove viable cultures through shelf life. The 2025 kefir trial found no significant symptom differences,^[7] so avoid benefit claims the evidence does not support.
• Design dose and taste together. Set the fibre type and dose against the claim you want: Simply Pop carries 6 g per can,^[1] while the EU inulin claim needs 12 g of native chicory inulin a day.^[9] Test bitterness, sedimentation and mouthfeel at the final dose, with the sweetener and carbonation system in place. FRL’s beverage formulation team works on these trade-offs, and our gut-health beverage formulation guide covers the ingredient options.
• Prove shelf life. Test fibre content, sedimentation, pH and flavour at the start, middle and end of shelf life, under the storage conditions printed on the pack; for kefir, track live-culture counts too. See FRL’s shelf-life studies, our prebiotic beverage shelf-life project and our note on beverage stability testing.
• Write US and EU labels separately. In the US, check whether the product is a conventional food or a supplement, because the claim rules differ.^[11][12] In the EU, use only authorised claims under their conditions of use.^[10] FRL’s regulatory and scientific research team can review claims for each market before artwork is locked.

1. Wiles, T. (2025, March 24). The growth of gut health functional sodas. Vitafoods Insights. https://www.vitafoodsinsights.com/functional-food-beverages/the-growth-of-gut-health-functional-sodas (cited for Olipop 2023–2024 sales, Simply Pop fibre and sugar per 350 ml can, typical fibre sources, Lazipop)
2. Doering, C. (2025, February 12). Olipop valued at nearly $2B following latest funding round. Food Dive. https://www.fooddive.com/news/olipop-valued-at-nearly-2b-following-latest-funding-round/739907/ (cited for Olipop 2024 sales of about $400 million, as reported by the company)
3. PepsiCo. (2025, May 19). PepsiCo completes acquisition of poppi, accelerating strategic portfolio transformation [Press release]. https://www.pepsico.com/newsroom/press-releases/2025/pepsico-completes-acquisition-of-poppi-accelerating-strategic-portfolio-transformation (cited for the $1.95 billion price, $300 million cash tax benefits and closing date)
4. Lucas, A. (2025, February 18). Coca-Cola takes on Olipop and Poppi with new prebiotic soda brand, Simply Pop. CNBC via NBC News. https://www.nbcnews.com/news/rcna192655 (cited for the Simply Pop launch timing and regions, and Olipop’s 9 g of fibre)
5. Persistence Market Research. (2026, February). Prebiotic soda market size, share, growth, and regional forecast, 2026–2033. https://www.persistencemarketresearch.com/market-research/prebiotic-soda-market.asp (cited for the 2026 and 2033 market estimates, CAGR, North America share and named European markets)
6. International Food Information Council. (2022, April 13). IFIC spotlight survey: Consumer insights on gut health & probiotics. https://ific.org/?p=995 (cited for the 24% and 32% survey figures, n = 1,000 US adults)
7. Choi, Y., Keum, G. B., Kang, J., Doo, H., Kwak, J., Kim, H., Chae, Y., Lee, S., Yang, H., Kim, S., Sun, X., Kim, H. B., & Yoo, S. J. (2025). Evaluation of kefir consumption on gut microbial diversity in a healthy young population using full-length 16S rRNA sequencing. Frontiers in Microbiology, 16, 1587831. https://doi.org/10.3389/fmicb.2025.1587831 (cited for the kefir trial design and results)
8. Consultant Live. (2026, February 5). Fiber, whole grains, and other gaps in the 2025–2030 guidelines. Consultant Live. https://www.consultantlive.com/view/fiber-whole-grains-and-other-gaps-in-the-2025-2030-guidelines (cited for the quote on US fibre intake)
9. European Commission. (2015). Commission Regulation (EU) 2015/2314 of 7 December 2015 authorising a health claim made on foods, other than those referring to the reduction of disease risk and to children’s development and health, and amending Regulation (EU) No 432/2012. Official Journal of the European Union, L 328. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32015R2314 (cited for the chicory inulin claim wording and conditions of use: 12 g a day of native chicory inulin, mean degree of polymerisation ≥ 9)
10. European Parliament & Council of the European Union. (2006). Regulation (EC) No 1924/2006 on nutrition and health claims made on foods. Official Journal of the European Union, L 404, 9–25. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32006R1924 (cited for the prohibition of unauthorised health claims and the Article 10(3) rule on general claims)
11. U.S. Food and Drug Administration. (2023). Notifications for structure/function and related claims in dietary supplement labeling. https://www.fda.gov/food/information-industry-dietary-supplements/notifications-structurefunction-and-related-claims-dietary-supplement-labeling (cited for the 30-day notification and disclaimer for supplements)
12. U.S. Food and Drug Administration. (2024). Structure/function claims. https://www.fda.gov/food/nutrition-food-labeling-and-critical-foods/structurefunction-claims (cited for structure/function claims on conventional foods: nutritive value basis, no notification or disclaimer)
13. U.S. Food and Drug Administration. (2018, June). Review of the scientific evidence on the physiological effects of certain non-digestible carbohydrates. https://www.fda.gov/media/113659/download (cited for inulin-type fructans and high-amylose starch meeting FDA’s dietary fibre definition)
14. United States District Court for the Northern District of California. (2025, May 23). In re VNGR Beverage, LLC Litigation, No. 4:24-cv-03229-HSG, Order granting preliminary approval (Dkt. No. 61). https://www.classaction.org/media/in-re-vngr-beverage-llc-litigation-prelim-approval-order.pdf (cited for the Poppi allegations, at most 2 g fibre per can, and the $8.9 million settlement)