Pet health is often marketed in neat sections: digestion, mobility, skin and coat, calming, immune support and senior care. Those categories make it easier to shop and formulate around by labeling a common or recognizable need.

But an animal’s biology is not organized like a store shelf.

Digestion affects nutrient availability. The intestinal environment is closely linked to immune activity. Appetite and nutrient response are part of metabolic health. Age can change all these systems at once. As we learn more about those connections, formulators can think beyond the immediate symptom and consider how a product fits into the animal’s overall health.

That does not mean one formula should promise everything. It means products can be designed—and explained—with a more connected view of the animal.

The Gut Makes the Connections Visible

The microbiome has brought that systems view into sharper focus. The gut is home to a microbial community that interacts with nutrients, produces metabolites and helps shape the intestinal environment.

We are still learning exactly how those activities connect to digestion, nutrient use, immune function and metabolism.4,5 The relationships are complex. But they help explain why the gut has become one of the most active areas of pet-nutrition innovation.

Companion-animal microbiome research is also showing that species and life stage matter. A recent feline genomic atlas highlighted the distinctiveness of the feline gut microbiome, while Dog Aging Project research identified age-related patterns in companion dogs.6,7

Probiotics introduced many consumers to the idea that microbes could matter to health. Prebiotics and postbiotics widened the options. All three remain important, but they are part of a larger story now.

Innovation Is Moving Beyond the Biotics

The next step in gut-focused nutrition is bigger than another probiotic strain or a generic gut-health badge.

Not all fibers behave the same way. Their structure and fermentability can influence how they interact with the microbial environment. Plant-derived compounds, including polyphenols, may also affect the microbial environment and its metabolic products. Fermentation-derived ingredients can offer different formulation and stability characteristics from live organisms. And combinations of nutrients and bioactives may be designed with complementary roles in mind.

The more useful question is not simply whether a product contains a probiotic or prebiotic. It is what the complete formula is designed to support, how its components work together and whether the format makes sense for daily use.

Palatability, processing stability and tolerability belong in the same conversation. A sophisticated formula has limited value if an animal will not consume it reliably, or if its functional compounds do not make it through manufacturing and storage.

Metabolic Health Enters the Conversation

Growing interest in metabolic health is adding another dimension. In pet nutrition, metabolic health is often discussed through body condition and weight. More broadly, it involves how an animal responds to food, uses nutrients and maintains appropriate energy balance over time.

GLP-1 is one timely example of why there is more interest in gut-to-body signaling. It is a naturally occurring hormone in dogs and cats involved in nutrient response and metabolic regulation. But it is not a carbon copy of the human story. Species, diet and feeding pattern all affect the response.1-3 That is a reason to ask better questions in pet nutrition, not borrow the pharmaceutical language of human health.

The visibility of GLP-1 medicines has made more people interested in appetite regulation, nutrient response and gut-to-body signaling. For pet nutrition, the opportunity is to better understand how diet and ingredients interact with the animal’s own physiology and where nutrition may offer responsible support.

The research is still developing. The distinction between nutritional support and pharmaceutical action needs to remain clear.

A Wider View Requires More Thoughtful Formulation

A more connected view of health also requires disciplined formulation and claims that reflect the available evidence. Interacting systems do not mean every ingredient affects every system, or that every mechanism predicts a meaningful benefit.

Ingredient identity and standardization matter. Ingredients that share a name can have very different profiles of active compounds. Presence is not the same as an effective dose. Safety and tolerability matter across species, breeds, life stages and health conditions. Delivery matters because a potential benefit must make the journey from raw material to consistent consumption.

The language must match the evidence. Human nutrition research can generate useful hypotheses for a pet application. Laboratory and ex vivo models can examine mechanisms and help prioritize the next questions. Companion-animal research can then clarify what holds true in the animal the product is intended to serve.5

That does not make it an all-or-nothing question. Each type of research has a role. The important thing is being clear about which question the research answers.

From Promising Mechanism to Useful Product

This is where ingredient innovation becomes formulation work. Research may point to a mechanism, but pets experience a product as a daily routine: a particular format, dose, diet context and feeding pattern.

Formulators must consider how ingredients interact, whether they remain stable through processing and storage, and whether an animal will consume the product consistently enough for it to serve its intended role.

The best innovations bring together a clear ingredient rationale, thoughtful formulation and language proportionate to the evidence.

At Ingredients by Nature, human research on citrus flavonoids has helped us identify questions worth exploring in new applications, including companion-animal nutrition.8 In-vitro research and emerging canine microbiome work are separate stages of discovery. Each can help inform what to investigate, how to formulate and which questions should come next.

Designing for Whole-body Support

Moving beyond the symptom shelf does not mean moving away from digestion, mobility or other specific needs. Those categories remain useful. The advancement is recognizing that the animal behind every need is a connected biological system.

Whole-body support should not mean that one product claims to do everything. It should mean the formula has been designed with those connections in mind, built from well-characterized ingredients, delivered in a form pets can use consistently and explained with appropriate care.

For formulators, the challenge is to recognize those connections while remaining specific about what each ingredient and formula is designed to support. That combination of broader thinking and disciplined evidence can move functional pet nutrition forward. NIE

References:

1 Model JFA. Physiological and pharmacological actions of glucagon-like peptide-1 (GLP-1) in domestic animals. Veterinary Animal Science. 2022;16:100245. https://pmc.ncbi.nlm.nih.gov/articles/PMC8966211/.

2 Wen J, Phillips SF. PYY and GLP-1 contribute to feedback inhibition from the canine ileum and colon. American Journal of Physiology. 1995;269(6 Pt 1):G945–G952. https://pubmed.ncbi.nlm.nih.gov/8572226/.

3 Bosch G, et al. Dietary macronutrients and feeding frequency affect fasting and postprandial concentrations of hormones involved in appetite regulation in adult dogs. Journal of Animal Science. 2010;88(12):3945–3953. https://pubmed.ncbi.nlm.nih.gov/20729279/.

4 Suchodolski JS. The role of the canine gut microbiome and metabolome in health and gastrointestinal disease. Frontiers in Veterinary Science. 2019;6:498. www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2019.00498/full.

5 Vuthisopon S, et al. Advances in Functional Pet Food Research: Health-Driven Innovation, Scientific Evidence, and Future Perspectives. 2026. https://pmc.ncbi.nlm.nih.gov/articles/PMC13113406/.

6 Feline microbiome genomic atlas. npj Biofilms and Microbiomes. 2026. https://doi.org/10.1038/s41522-026-01088-3.

7 Dog Aging Project microbiome analysis. Nature Communications. 2026. www.nature.com/articles/s41467-026-73193-y.

8 Ramos FM, et al. The citrus flavonoid eriocitrin modifies gut microbiota and improves markers of glycemic control in adults with prediabetes. Food Science & Nutrition. 2023;11:7283–7295. https://pubmed.ncbi.nlm.nih.gov/34209219/.

Rob Brewster is the president of California-based Ingredients by Nature. As a third-generation ingredient manufacturer for the natural products industry, Brewster is proud to be part of the health and wellness world. He followed in his grandfather’s and father’s footsteps, helping their company Brewster Foods grow since he joined in the 1990s and then partnering with Syntech to form Ingredients by Nature, a world leader in citrus bioflavonoids and extracts. As president, Brewster invests heavily in citrus flavonoid science for condition-specific applications and holistic wellness. For more information, visit IngredientsbyNature.com.