From gut health models to science-based botanical solutions

Botanical additives can support gut health when selected through robust scientific evidence. Advanced in vitro models, from epithelial barrier systems and challenge assays to species-specific cells and enteroids, make gut integrity measurable. This helps identify compounds and combinations with greater potential to support intestinal resilience and growth performance in pigs and poultry.

In modern pig and poultry production, performance is measured through visible numbers: growth rate, feed conversion ratio, body weight, egg production or uniformity. However, behind these indicators lies a biological system that is not directly visible: the intestine.

A healthy intestine is like a symphonic orchestra: the microbiota, the intestinal mucosa and the immune system must play in harmony. When all sections are well coordinated, nutrients are efficiently digested, absorbed and directed toward growth. When this harmony is disturbed, nutrients can be diverted from performance toward inflammation, tissue repair and immune activation. The result is poorer feed efficiency, lower growth and reduced resilience.

In this “intestinal orchestra”, performance depends on balance. The microbiota, the intestinal mucosa and the immune barrier all have a specific role, but none can work properly if isolated. When one player is disturbed, as often happens under commercial farming conditions, the whole system loses its integrity. Supporting gut health therefore means helping the animal maintain coordination, efficiency and resilience when the production environment becomes more demanding.

BOTANICALS: FUNCTIONAL TOOLS FOR A COMPLEX SYSTEM
Among functional ingredients, botanicals offer an interesting opportunity to support this “intestinal orchestra”. They include plant-derived compounds, extracts, essential oils, oleoresins and synthetic nature-identical molecules. Their strength is based on a wide range of functions: as widely recognized in scientific literature, botanicals support gut function through antimicrobial effects, control of bacterial virulence, antioxidant activity, anti-inflammatory effects and immune modulation.

In this sense, they can act as functional conductors: they do not replace single players, but rather help the microbiota, the intestinal mucosa and the immune barrier return to a more coordinated rhythm when challenges arise.

However, the wide heterogeneity of botanicals available for animal nutrition can create confusion. Indeed, the key question for the feed industry is how to identify the right botanicals for maintaining gut health, and make sure that the “intestinal orchestra” delivers a balanced and resilient performance.

FROM ASSUMPTION TO MEASUREMENT
For many years, the selection of botanicals has relied on large and costly in vivo trials. While these remain essential, they are not the best first step when many candidates must be screened. At Vetagro, we have developed and streamlined a platform composed of several progressive in vitro models that support a rational, science-based selection of botanicals.

The first step of this platform is based on Caco-2 cells, one of the most established in vitro models for intestinal studies. These cells are able to differentiate into functional enterocytes and form a continuous epithelial monolayer when cultured on porous filters. In practical terms, this system reproduces a simplified intestinal barrier, with an apical side (representing the brush border exposed to the intestinal lumen) and a basolateral side (representing the submucosa).

This model becomes particularly useful because intestinal barrier integrity can be measured in a quantitative and non-invasive way through transepithelial electrical resistance (TER). TER measures the resistance that the epithelial monolayer offers to an electrical current. The stronger and tighter the barrier, the higher the TER value. In other words, TER gives a measurable signal of how well the “intestinal orchestra” is maintaining its structure.

For botanical screening, Caco-2 cells and TER monitoring make it possible to evaluate the direct effects of botanicals on epithelial integrity and identify the most promising candidates. This model is also useful to assess synergy between botanicals, when two or more compounds act together and generate an effect greater than the expected additive response. In the language of the “intestinal orchestra”, this means identifying different instruments that amplify each other to create a stronger, louder performance.

NOT ONLY INTEGRITY: TESTING GUT RESILIENCE
Evaluating epithelial integrity under normal conditions is only the first step. In real production systems, animals are constantly exposed to stressors that affect the harmony of the “intestinal orchestra”. This is why in vitro models must also reproduce challenging conditions, to understand if botanicals can help intestinal cells to resist, recover and return to balance.

Inflammatory stress can be reproduced by exposing Caco-2 cells to bacterial lipopolysaccharides (LPS) and pro-inflammatory cytokines, which damage tight junctions and reduce TER. Under these conditions, effective botanicals usually limit the loss of epithelial integrity during the challenge and support a faster recovery afterwards.

Oxidative stress is another relevant driver of intestinal damage. Reactive oxygen species (ROS) can damage membranes, proteins and tight junctions, weakening the barrier and promoting inflammation. In vitro, oxidative stress can be induced with hydrogen peroxide and ROS production can be measured. In this context, selected botanicals can help reduce oxidative stress through direct antioxidant activity and activation of endogenous defense pathways, including antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidases.

The most valuable botanicals are those able to help keep the “intestinal orchestra” playing in harmony even when the tempo changes: limiting disorder during the challenge, restoring rhythm after the stress and supporting gut integrity as it returns toward balance.

SPECIES-SPECIFIC MODELS: GETTING CLOSER TO PIGS AND POULTRY
Caco-2 cells are widely recognized for intestinal studies in vitro. However, they remain a general model, not specific to livestock species. For this reason, the next step of the botanical screening in the Vetagro platform for intestinal health is to move closer to the target animals. For pigs, IPEC-J2 cells offer a porcine intestinal epithelial model. These cells originate from the jejunum of neonatal piglets and retain enterocyte characteristics, allowing gut integrity studies in a species-specific context. With IPEC-J2 cells, the same logic applied in Caco-2 studies can be translated to pigs to evaluate botanicals in normal conditions and under inflammatory or oxidative stress.

For poultry, the situation is more complex: no commercially available avian intestinal cells exist. To address this gap, at Vetagro we have developed a cutting-edge chicken intestinal epithelial cell line, cIEC-H2, derived from immortalized primary chicken intestinal cells. This proprietary model can be easily maintained over time, expresses typical enterocyte markers and responds to relevant challenges, including inflammatory, pathogenic and heat stress.

With these specific models, botanical screening becomes more informative, helping to distinguish candidates that are only promising in a general model from those with stronger relevance for swine or poultry nutrition, also in the presence of species-specific pathogenic challenges. In other words, these models help verify whether botanicals can keep the “intestinal orchestra” in harmony even when the biological score becomes species-specific.

ENTEROIDS: BRIDGING IN VITRO AND IN VIVO
Although 2D intestinal cell models provide insightful information, the intestine is a three-dimensional tissue, where different cell types interact to ensure all digestive, barrier and immune functions. For this reason, intestinal organoids (or enteroids) represent the ultimate step of the Vetagro platform for botanical screening.

Derived from intestinal tissues of target species, these 3D structures self-organize and closely mimic the physiological complexity of the “intestinal orchestra”. Therefore, enteroids help close the gap between in vitro models and in vivo physiology, putting botanicals in front of a complete orchestra, where all instruments, in both homeostatic and challenging conditions, need to play together to ensure that intestinal health supports optimal animal growth.

A practical example is the evaluation of intestinal barrier function after an inflammatory challenge. As with other cell models, enteroids can also be exposed to LPS: when the intestinal structure is challenged, the barrier may become more permeable. This permeability can be measured using fluorescent markers such as Fluorescein Isothiocyanate-Dextran (FD4): the stronger the fluorescence signal inside the enteroids, the higher the permeability and the lower the integrity of the structure.

In this model, botanicals can be evaluated for their ability to preserve the architecture and function of the enteroid barrier during stress. If selected botanicals reduce FD4 permeability after the challenge, this indicates that the intestinal structure remains more protected and less disrupted.

A DECISION PLATFORM FOR FUNCTIONAL ADDITIVES
For feed producers and nutritionists, the key message is simple: modern gut health solutions must be selected through science and evidence. Botanical-based additives can help support animals in complex and variable production settings, but this requires decision tools able to measure how they modulate the intestinal barrier, immune response and overall gut resilience, ultimately supporting animal growth performance. In this context, advanced in vitro models do not replace in vivo trials, but rather make the development of botanical-based nutritional solutions more targeted and efficient.

Within the Vetagro platform, applied daily in research, each model adds a different level of information. Caco-2 cells help identify direct effects on epithelial integrity and reveal promising botanical synergies. Challenge models show whether botanicals can help intestinal cells resist stress and recover faster. Species-specific models, such as IPEC-J2 and Vetagro’s proprietary cIEC-H2 cells, bring the screening process closer to pig and poultry physiology. Species-specific enteroids finally add a more complex and physiologically relevant 3D system, bridging early screening and in vivo validation.

This progressive approach helps streamline the process and identify the most promising botanical-based solution for each production challenge, reaching the in vivo validation step with a more thoroughly characterized candidate and a higher likelihood of success. This platform underpins our latest generation of products, AviPower®2 for poultry and AviPower®5 for pigs, which exploit the synergistic action of selected botanical blends to address major production challenges, such as coccidiosis in poultry and E. coli-related weaning stress in piglets.

By turning gut integrity into something measurable, the Vetagro platform helps transform botanical complexity into targeted solutions, supporting the development of additives that are scientifically grounded, biologically relevant and designed to help keep the “intestinal orchestra” in tune under field conditions.

About Andrea Bonetti
Working as Innovation Manager for Monogastric Species at Vetagro, Andrea Bonetti is involved in product development, scientific dissemination and translating science into practical nutritional solutions for customers. He earned a Master’s Degree in Animal Biotechnology in 2019 and a Ph.D. in Veterinary Sciences in 2024 from the University of Bologna, where his research explored natural bioactive compounds to support animal health and performance. During his studies, he conducted research at the University of Maryland and North Carolina State University as a visiting scholar.

From gut health models to science-based botanical solutions yazısı ilk önce Feed & Additive Magazine üzerinde ortaya çıktı.