How to Naturally Improve Gut Health in Pigs

A healthy gut promotes a healthy pig. It’s that simple. A pig’s digestive system is more than just a group of organs that process nutrients, it’s the engine driving growth, immune function, overall performance and health. When gut health suffers, pigs eat less, grow slower and become more vulnerable to disease.

The biggest threats to efficient production are stress and illness. They redirect energy away from growth, trigger inflammation and leave the gut more susceptible to opportunistic pathogens.

Producers can take practical steps to support gut health through nutrition, management and targeted feed technologies. Steps could include using feed additives that maintain gut integrity, encourage beneficial bacteria and deliver nutrients when they’re most effective. These strategies can be used individually or layered to build a stronger foundation for maximum health and profitability.

Gut Health is Immune Health

Gut and immune health are intricately linked; a healthy gut microbiome is crucial for a robust immune system. Around 70% of the immune cells reside in the gastrointestinal tract. These cells create the gut-associated lymphoid tissue (GALT), which constantly monitors and responds to microbial changes in the gastrointestinal tract.

A balanced microbiome improves immune function in several ways. It helps the host recognize harmful microbes from beneficial ones, produces molecules that stimulate immune response and strengthens the gut barrier to block pathogens and toxins from entering the bloodstream.

The gut microbiome also plays a role in neurophysiological regulation, meaning it helps control how the brain and nervous system communicate with the rest of the body. This is often referred to as the gut-brain axis. (1)

Research suggests there is a strong connection between the gut microbiome and the body’s hormonal response to stress. (2) The same neurotransmitters, or chemical messengers that send signals in the brain, are also found in the gut. These neurotransmitters influence how nutrients are absorbed and how the immune system responds.(3) They help regulate blood flow, influence lumen flow (gut motility), support immune function and a healthy balance of gut bacteria.

How to Strengthen the Gut Wall

Short-chain fatty acids (SCFAs) are key compounds produced when beneficial gut bacteria ferment dietary fiber. An important SCFA is butyrate. It fuels colonic epithelial cells, which help maintain the gut lining and support overall barrier integrity. Butyrate production also lowers gut pH, creating an environment that limits the growth of harmful pathogens. (14)

A strong gut barrier depends on tight junctions, or the structures that seal the spaces between cells in the intestinal lining. When these junctions are damaged, it can lead to increased permeability, often referred to as “leaky gut.” This occurs when toxins and pathogens pass through the gut wall, triggering inflammation and increasing the risk of disease. Butyrate helps preserve these tight junctions and reduces inflammation, contributing to a stronger, healthier gut. (4,5)

Chart 1: How Actifibe Impacts Butyrate in the Gut

Ralco’s Actifibe® technology is designed to support butyrate production. It contains a hemicellulose extract that selectively feeds beneficial bacteria like Bifidobacteria and Lactobacilli. The breakdown of this product by these bacteria produces more butyrate during fermentation, which helps reinforce the intestinal wall. (4,5) Unlike many prebiotic fibers, Actifibe shifts the profile of volatile fatty acids towards more butyrate production, as shown in chart 1. 

Butyrate also plays a key role in immune function. It supports the production of IgA antibodies, neutrophils and goblet cells, which are vital to mucosal immunity.¹⁰ Mucosal immunity is the body’s first line of defense in the gut. It protects the lining of the gastrointestinal tract by trapping and neutralizing harmful microbes before they can cross into the body. Goblet cells produce mucus that forms a physical barrier, while IgA antibodies work within that barrier to target pathogens directly. Increased SCFA levels, particularly butyrate, help stimulate the GALT to produce these immune components and maintain a balanced immune response. (6)

When Actifibe is combined with essential oils through Ralco’s patented Microfusion® technology, it supports a healthy microbial profile by protecting beneficial populations. Essential oils alone can have an antimicrobial effect that may negatively impact both good and bad bacteria, but when paired with Actifibe, the Microfused Essential Oils can create a more selective approach to gut health management. (15)

Graphic 1: How Actifibe Impacts the Gut Environment

Why Intestinal Integrity Matters for Nutrient Absorption

The structure of the intestinal lining itself plays a major role in how well pigs absorb nutrients. Two key indicators of gut health are villi height and crypt depth. Villi are small, finger-like projections that line the inside of the intestine. Taller villi provide more surface area for nutrient absorption. Crypts are the spaces between the villi where new cells are produced. Shallow crypts typically indicate less inflammation and more stable cell turnover. (11, 12, 13)

For reference, below is the difference between healed versus injured gut. In a healthy gut, villi height should be long and crypt depth should be shallow.

Graphic 2: Healed vs. Injured Villi and Crypts in the Gut

Graphic credit: Research gate, Baseline quantitative histology (16)

When the gut is under stress, whether from disease, diet changes or environmental challenges, these structures can be damaged. Villi may shorten, crypts may deepen and overall nutrient absorption declines. At the same time, the gut barrier may weaken, allowing pathogens and toxins to pass into the bloodstream.

Graphic 3: Villi and Crypt Depth in the Gut Using Microfused Essential Oils

These histological images (tissues samples under a microscope) in graphic 3 show the intestinal lining differences using Ralco’s Microfused Essential Oil technology. These images show taller villi, shallower crypt depths and overall improved gut integrity, all of which contribute to healthier pigs with better performance.

 

How to Support Gut Health Before and After Birth

Gut health in piglets begins before birth and is influenced by the sow’s nutrition and immune status. One of the most critical early-life inputs that impacts gut health is colostrum. This first milk delivers essential nutrients, antibodies and immune-supporting compounds that help piglets build a strong foundation for health.

Research shows that sows fed Ralco’s oregano-based essential oils produced colostrum with higher levels of insulin-like growth factor 1 (IGF-1) and an increased number of T-lymphocytes. IGF-1 supports growth and development in piglets, while T-lymphocytes are immune cells that help the body recognize and respond to disease. Piglets from these sows also showed increased activity of natural killer cells, which play a role in detecting and attacking invading pathogens. (7)

Overall, these findings suggest that supporting the sow’s gut microbiome and immune function during gestation can improve colostrum quality and enhance piglet gut health and survivability.

Swine Diet Transitions and Gut Health Challenges

Weaning is one of the most stressful periods in a pig’s life. As piglets move from sow’s milk to nursery feed, they often struggle to maintain consistent intake. This can disrupt gut health and increase the risk of scours. Setbacks during this time can lead to higher mortality and reduced long-term performance. Supporting gut health during the transition to nursery feed is essential for setting the stage for healthy growth.

When pigs stop eating due to weaning stress or other challenges, they also stop producing stomach acid.(8) Stomach acid is an important defense mechanism that helps protect against harmful bacteria, especially while the stomach is still developing. Without regular feed intake, villi begin to atrophy (waste away). This reduces nutrient absorption and compromises the gut barrier.

Ralco’s Tactical Start® nursery nutrition is specially formulated to support gut health during this vulnerable window. It includes highly digestible, complex ingredients that are gentle on the gut and encourage early feed intake. These diets also help maintain pH balance, easing the transition from milk to solid feed and supporting piglets during weaning.

Swine Diet Formulations for Heat and Oxidative Stress

Heat stress is another widespread stress-related challenge that impacts gut health. Elevated body temperature can cause pigs to eat less during the day. As temperatures cool at night, pigs often overeat, leading to gut issues such as hemorrhagic bowel syndrome (HBS).

Adjusting the diet can help manage this response. Reducing dietary protein, for example, lowers the energy required for digestion. Because protein digestion generates more metabolic heat, a lower-protein diet can reduce internal heat load. Ralco’s EnMAX® nutrition program supports this approach by helping producers reduce dietary protein without sacrificing performance.

Heat or any other stressors can also trigger oxidative stress within the animal, which is a condition where free radicals (molecules with unpaired electrons) overwhelm the body’s antioxidant defenses. Free radicals are unstable molecules that can damage cells, proteins and DNA. They are produced naturally during metabolism and immune activity but can also result from environmental stressors. If they are not neutralized, free radicals contribute to inflammation and tissue damage, which can lead to disease and poor performance.

Ralco’s Microfused Essential Oils help pigs respond to these stressors in two key ways. First, they support microbial balance in the gut. Second, they provide powerful antioxidant properties for protection.

Lab testing using ORAC (Oxygen Radical Absorbance Capacity) standards has shown that the antioxidant strength of Microfused Essential Oils is 40 times greater than natural vitamin E, the traditional standard. These essential oils help neutralize five types of reactive oxygen species (highly reactive oxygen-containing molecules), minimizing the damaging effects of oxidative stress in pigs.

Prevention is Better Than Treatment

Waiting until gut health declines can lead to lost performance and higher treatment costs. A proactive approach is always better for maintaining swine health and long-term success.

Ralco’s Swine Health Program is built with prevention in mind. It combines patented essential oil technology with targeted nutrition strategies to support pigs before challenges appear.

Focusing on gut health early helps improve performance throughout production. The Ralco Swine Health Program provides natural, research-backed solutions from weaning through finishing and can be implemented for less than $0.60 per pig in the nursery.

Ralco’s Swine Health Program includes:

• Essential-Lyte™ – A water additive to encourage early feed and water intake post-weaning, rehydrate pigs and support beneficial gut microflora.

• Dual Defender® – A feed additive that strengthens gut integrity, boosts immune response and helps reduce health setbacks.

• ProsperEO™ – A feed additive designed to maintain pig health, manage stress and enhance growth efficiency with its antioxidant-rich essential oil blend.

Ralco’s Swine Health Program is a proven, cost-effective way to protect gut health and improve performance from weaning to finishing. Call 1-800-533-5306 to talk with a swine specialist and build a customized plan for your operation.

Article Written By:

Dr. Chad Bierman holds a bachelor’s and master’s degree in animal science from South Dakota State University and earned his Ph.D. in animal science from the University of Wisconsin–Madison. Chad brings a strong combination of education and industry experience to help producers improve performance and profitability.

Dr. Josh Knapp earned his bachelor’s degree in animal science from Kansas State University, his master’s from the University of Arkansas and his Ph.D. from the University of Nebraska. Throughout his academic and research career, Josh focused on enzymes, probiotics and other nutritional tools, building a solid foundation to support producers with science-driven solutions.

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