The microbiome field has substantially evolved over the past decade, but there are still many key hurdles to overcome before the segment of pre-, pro-, and postbiotics can realize its full potential for human health.

The industry still needs to create systems that can translate vast swathes of health data into actionable recommendations. On a similar note, standards need to be set for how data is collected from microbiome tests and other means, along with how that data is presented to the end consumer.

At SupplySide Global, George Paraskevakos, executive director of the International Probiotics Association (IPA); Jessica Younes, scientific director at IPA; and Kelly Swanson, PhD, a professor at the University of Illinois Urbana-Champaign specializing in nutrigenomics and gut physiology, and member of the International Scientific Association for Probiotics and Prebiotics, discussed the state of the microbiome market, and their projections for future growth.

Hot Markets

IPA estimated that the global probiotic supplements market is $9.3 billion, with a historic CAGR of 8.4% from 2020-2024.

The Asia-Pacific region leads the probiotic supplements market at $3.7 billion, while the U.S. had the biggest market as an individual country at $2.6 billion in 2024, accounting for 34% of the global marketplace. The markets poised for the highest growth in the coming years include Brazil, Mexico, Colombia, and China, said Paraskevakos.

IPA has grown substantially in parallel with the market, including with regional offices in Europe and China, and nine recently-introduced committees within the organization, for microbiome applications such as prebiotics, postbiotics, infant formulas, companion animal products, and more, Paraskevakos noted.

Making Personalization More than a Buzzword

Paraskevakos noted that the industry has “put the cart before the horse,” making promises it can’t deliver on regarding microbiome solutions that are personally tailored to the individual.

But innovations in a number of key areas will reshape the industry’s ability to tailor products to the individual, such as novel AI platforms, alternative testing methods, next-gen delivery systems, biotech and novel ingredients, and digital health integration, he noted.

The sea of data on the human gut microbiome, and its various differences across global populations, is created by teams of researchers that exist in silos. Harnessing this data in a meaningful way is a tall order. New means of predictive modeling, strain selection, mechanism of action research, and more can help to create diagnostics more specific to an individual, Paraskevakos said, but the ability to generate ongoing, real-world feedback from the individual taking a microbiome product, via more accessible microbiome tests, is also required. 

“Citizen science has come into the mix, and collaboration and co-creating with the public during the research process has to be part of the equation,” he noted.

IPA recently created a new testing kit committee, with the intent of steering the industry toward solutions that will overcome key issues such as a lack of quality control, variability of competing test methods, ethical issues associated with data collection, pressure for regulatory oversight over consumer-grade testing kits, accessible pricing, and more.

Creating Standards for Sample Collection

Creating a credible future for the marketplace of direct-to-consumer microbiome test kits will require a great deal of standardization, noted Younes.

The analytes a company prioritizes — which can include or exclude microbes, nutrients, microbial metabolites, fungi, and viruses — impact the insights that are delivered to the end consumer. These individual factors must then be compared against a “healthy” composite microbiome representative of the person’s age, sex, genes, diet, lifestyle, and other factors. “It’s a complicated workflow, and there’s a lot to decide in how to chew up information and spit it out to the end consumer,” Younes said.

Most direct-to-consumer test kit companies offer 16S testing, a PCR-based technology that looks at genes from a bacteria, excluding yeast or fungi; these types of tests make up about 50% of the market. Shotgun sequencing (30% of the market), by contrast, looks at all DNA from a sample; it’s much more expensive and complicated. Other next-gen sequencing techniques are used by about 15% of consumer-grade testing companies.

“No one test is better, but each will generate a different report. As the scientific community already knows, there’s a lack of standardization, with different methods being used from one lab to the next,” Younes noted, and, even when using the same testing technology, the National Institute of Standards and Technology (NIST) recently reported major discrepancies across different labs testing the same sample, that were about as variable as the biological variations of one donor to the next.

“This level of divergence is a major problem for the industry at large, degrading any company that conducts testing and interprets information well,” said Younes.

Until companies have a standard for what a “healthy” microbiome looks like, validated by peer-reviewed literature, the credibility of their recommendations is limited, Younes noted, and only one company on the market today discloses the clinical study cohort they use as a reference to a “healthy” population. “It’s like a big pile of dirty dishes that no one wants to wash, and our task force is going to do it. We’re looking for public and non-public information from test kit companies, to map out a global landscape, get perspectives on standards and practices, and achieve uniformity in methods and analysis.”

The degree of transparency, and level of details offered in reports to consumers can also vary significantly, Younes noted. NIST found that many direct-to-consumer test kit companies don’t share their quality standards or analytical methods, and whether or not companies present data in a way that breaks down the probiotics and beneficial taxa versus species-level analysis, or an analysis of pathogens and functional/metabolic features, varies.

“There are standards for many pieces of this workflow, but no one is talking about them, and they’re not consolidated for this purpose,” Younes said.

Finally, companies will need to reach a more accessible price point in order to achieve widespread adoption. “The average stool testing kit costs $300 right now, and consumers are only willing to pay about $150 to get their microbiome tested, so we need to deliver on that front as well.”

Broadening the Definition of Prebiotics

Swanson discussed the rationale behind the International Scientific Association for Probiotics and Prebiotics’ (ISAPP) decision to broaden the definition of the word “prebiotic,” based on years of new findings related to the prebiotic activity of a broader range of bioactive compounds.

The original definition — which was a “nondigestible food ingredient that beneficially effects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health” — turned out to be quite exclusive of a number of products that confer health benefits via interactions with the gut, such as digestible substrates, resistant starches, fermented foods, polyphenols, and more.

Additionally, the definition is rooted in the simplistic view that all bacteria fall into either “good” or “bad” camps, rather than prioritizing the human health benefits, Swanson noted.

With non-linear advances in how the human microbiome is researched, “there was a need for updates to prevent confusion or misuse of the term,” Swanson noted.

The new definition — “a substrate that is selectively utilized by host microorganisms, conferring a host benefit” — has enabled several advances, Swanson noted.

“When it comes to host-biotic relationships, we’re looking at more kinds of mechanistic data all the time,” he said. For instance, newer research has demonstrated the gut barrier and immune-modulating benefits of many of the more than 200 milk oligosaccharides. Certain forms of resistant starch have been shown to induce changes to the microbiota, resulting in gut barrier function, stool quality, and even an FDA-qualified health claim related to a reduction in type 2 diabetes risk, Swanson noted.

Further, of the over 10,000 polyphenols that exist in nature, many — such as anthocyanins in blueberries and proanthocyanidins in cocoa and cranberries — are indigestible, and potentially exhibit their cardiovascular and inflammatory modulating benefits at least in part through interactions with the microbiome.

Many challenges exist for driving the prebiotic segment forward, including: shifting focus from bacterial taxonomy and a reliance on fecal samples to more direct human health benefits; determining the reasons why there are non-responders to certain prebiotic interventions; fulfilling the need for more longitudinal studies, and more.