A specific probiotic bacteria called Lactiplantibacillus plantarum IDCC 3501 helped weaned piglets grow about 15% faster and reduced stress hormones and inflammation markers in their blood during the critical first weeks after weaning, according to a 2026 study of 48 pigs published in the Journal of Animal Science. The bacteria appeared to work by strengthening the intestinal barrier and reducing the body’s inflammatory response, suggesting it could be a natural alternative to antibiotics for protecting young pigs during this vulnerable transition period.
When piglets are weaned from their mothers, they often get sick and don’t grow well. Researchers tested whether adding a specific type of helpful bacteria called Lactiplantibacillus plantarum to piglet feed could solve this problem. In a study of 48 young pigs, those that received the bacteria grew faster, had fewer digestive problems, and showed signs of less stress and inflammation in their bodies. The bacteria appeared to strengthen the pigs’ intestines and boost their immune systems. According to Gram Research analysis, this probiotic supplement shows promise as a natural way to help weaned pigs stay healthier and grow better without antibiotics.
Key Statistics
A 2026 study of 48 weaned piglets found that those receiving Lactiplantibacillus plantarum IDCC 3501 had significantly greater average daily gain from day 15 to 28 compared to control pigs, with improvements in feed efficiency during the same period.
According to research published in the Journal of Animal Science in 2026, piglets fed the probiotic had lower serum cortisol (stress hormone) levels on day 7 and reduced inflammatory markers TNF-α and IL-6 compared to control pigs, suggesting reduced weaning stress.
A 2026 animal study of 48 piglets showed that dietary supplementation with Lactiplantibacillus plantarum upregulated tight junction protein genes (CLDN1 and CLDN4) while downregulating inflammatory genes (TNFA and IL8), indicating improved intestinal barrier function.
Research reviewed by Gram in 2026 found that weaned pigs receiving the probiotic had a trend toward lower diarrhea frequency during days 8-14 and lower hematocrit levels on day 14, suggesting reduced dehydration and digestive distress.
The Quick Take
- What they studied: Whether adding a specific probiotic bacteria to piglet feed could help them grow better and get sick less often after being separated from their mothers
- Who participated: 48 young piglets that were 28 days old and weighed about 6.6 kilograms at the start. Half received regular feed, and half received feed with added bacteria. The study lasted 28 days
- Key finding: Piglets that ate the probiotic bacteria grew about 15% faster during the second half of the study and had fewer digestive problems. They also had lower stress hormones and less inflammation in their blood
- What it means for you: This research suggests probiotics could be a natural alternative to antibiotics for keeping young farm animals healthy during stressful transitions. However, these results are from pigs, and more research is needed to understand if similar benefits apply to other animals or humans
The Research Details
Researchers divided 48 weaned piglets into two equal groups. One group ate a standard nursery diet made from corn and soybean meal. The other group ate the same diet but with added Lactiplantibacillus plantarum bacteria (a type of probiotic). Each group had six separate pens with four pigs per pen to make sure results were reliable. The study ran for 28 days, and researchers measured many things: how fast the pigs grew, how often they got diarrhea, their blood health, their intestine structure, stress hormones, and inflammation markers.
The researchers chose this design because weaning is a stressful time for piglets. When piglets stop nursing and start eating solid food, their bodies go through big changes. They face new environments, new foods, and separation from their mothers. These stresses often cause digestive problems and slow growth. By testing one specific probiotic strain, researchers could see if this particular bacteria could help pigs handle weaning better.
This type of study is important because it tests a real-world solution in controlled conditions. The researchers could carefully measure exactly what the bacteria did to the pigs’ bodies and health.
Understanding how probiotics work helps farmers find natural ways to keep animals healthy without overusing antibiotics. Antibiotic overuse is a major problem worldwide because bacteria are becoming resistant to these medicines. If probiotics can prevent disease and improve growth, they could replace some antibiotic use. This study specifically looked at one bacterial strain to understand its exact effects, which is important because different probiotic strains work differently.
This study has several strengths: it used multiple pens per treatment group (six replicates), which makes results more reliable; it measured many different health markers rather than just one; and it tracked changes over time. The study was published in a peer-reviewed scientific journal, meaning other experts reviewed it before publication. However, the study only included 48 pigs, which is a relatively small number. The results are specific to one probiotic strain and one type of pig feed, so results might differ with other strains or diets. The study was conducted in controlled farm conditions, which is realistic but different from how pigs live on actual farms.
What the Results Show
Piglets that received the probiotic bacteria grew significantly faster than control piglets during days 15-28 of the study. They also showed a trend toward better feed efficiency, meaning they gained more weight from the same amount of food. The bacteria-fed pigs had fewer cases of diarrhea during the early weaning period (days 8-14), though this difference was not quite statistically significant.
The probiotic had strong effects on stress and inflammation markers. On day 7, piglets receiving the bacteria had lower cortisol levels (a stress hormone) in their blood. They also had lower levels of TNF-alpha and IL-6 (inflammatory proteins) on day 7, and lower IL-6 on day 14. These results suggest the bacteria helped pigs handle weaning stress better.
At the microscopic level, the bacteria improved intestinal structure. Piglets receiving the probiotic had wider and larger villi (tiny finger-like structures in the small intestine that absorb nutrients) in their jejunum (part of the small intestine). This suggests better nutrient absorption. Additionally, the bacteria changed gene expression in intestinal tissue: it increased genes that build tight junctions (which keep the intestinal barrier strong) and decreased genes that cause inflammation.
Piglets receiving the probiotic had lower hematocrit levels (the percentage of red blood cells in blood) on day 14. This may indicate less dehydration, since diarrhea causes fluid loss. The bacteria also appeared to improve overall intestinal health by strengthening the barrier that prevents harmful substances from entering the bloodstream. Gene expression changes showed that the probiotic upregulated CLDN1 and CLDN4 genes (which code for tight junction proteins) while downregulating TNFA and IL8 genes (which promote inflammation). These molecular changes suggest the bacteria work by both strengthening the intestinal barrier and reducing the body’s inflammatory response.
This study adds to growing evidence that probiotics can help during stressful periods in animal production. Previous research has shown that lactic acid bacteria (the family this probiotic belongs to) can improve gut health and reduce disease in various animals. However, this study is notable because it tested one specific strain and documented exactly how it works at the molecular level. The findings align with other probiotic research showing reduced inflammation and improved intestinal function, but this is one of the first studies to show these specific benefits with this particular L. plantarum strain in weaned pigs.
The study only included 48 pigs, which is a relatively small sample size. Results might differ with larger numbers. The study lasted only 28 days, so we don’t know if benefits continue longer or if pigs build tolerance to the bacteria over time. The study used one specific probiotic dose (0.02% in feed), so different amounts might work better or worse. The pigs were all the same age and breed in controlled conditions, so results might not apply to different pig types or farm conditions. Finally, this research was conducted in pigs, not humans or other species, so we cannot assume the same benefits would occur in other animals.
The Bottom Line
Based on this research, adding this specific Lactiplantibacillus plantarum strain to piglet feed appears safe and beneficial for growth and health during weaning. The evidence is moderately strong for improved growth and reduced stress markers, with good evidence for reduced inflammation. However, this is one study in one species, so farmers should consider consulting with veterinarians before implementing this on their farms. The probiotic appears most beneficial during the critical first two weeks after weaning.
Pig farmers and veterinarians should care about this research, especially those looking to reduce antibiotic use. Feed manufacturers might consider adding this probiotic to nursery pig diets. Researchers studying probiotics in other animals should note these findings. This research is less directly relevant to humans, though it contributes to our understanding of how probiotics work in general. People interested in sustainable farming practices may find this relevant as an alternative to antibiotics.
Based on this study, benefits appeared within the first week (stress hormone reduction) and continued through four weeks. Growth improvements were most noticeable during the second half of the weaning period (days 15-28). Farmers should expect to see results within 2-4 weeks of adding the probiotic to feed. Long-term effects beyond 28 days are unknown from this study.
Frequently Asked Questions
Can probiotics help piglets stay healthy after weaning?
Research shows that Lactiplantibacillus plantarum IDCC 3501 improved growth, reduced stress hormones, and decreased inflammation in weaned piglets over a 28-day study. The bacteria appeared to strengthen intestinal barriers and reduce diarrhea, suggesting probiotics can help during this vulnerable transition period.
How do probiotics help young pigs after they stop nursing?
The probiotic bacteria strengthen the intestinal barrier by increasing tight junction proteins and reduce inflammation by lowering inflammatory markers like TNF-α and IL-6. This helps pigs absorb nutrients better and handle weaning stress, leading to faster growth and fewer digestive problems.
What dose of this probiotic was used in the pig study?
The study used 0.02% Lactiplantibacillus plantarum IDCC 3501 (containing 2.4 × 10⁶ CFU per gram) mixed into the nursery feed. This dose was added to standard corn and soybean meal-based diets for 28 days starting at weaning.
How quickly do probiotics work in weaned pigs?
Benefits appeared within the first week, with reduced stress hormones (cortisol) and inflammatory markers (TNF-α, IL-6) on day 7. Growth improvements were most noticeable during the second half of the 28-day study period (days 15-28).
Could this probiotic work the same way in humans?
This study was conducted only in pigs, so we cannot assume identical benefits in humans. However, the mechanisms (strengthening intestinal barriers and reducing inflammation) are similar across species, making this research potentially relevant for understanding probiotics in general.
Want to Apply This Research?
- For farmers using this probiotic: track daily weight gain (in grams per day), diarrhea frequency (number of affected pigs per pen per day), and feed conversion ratio (kilograms of feed per kilogram of weight gain) weekly for the first 4 weeks after weaning
- Implement a consistent feeding protocol: add the probiotic at the recommended dose (0.02%) to all nursery pig feed starting on weaning day, maintain consistent feed quality and storage, and monitor individual pig health daily for signs of improvement or problems
- Create a 4-week tracking dashboard comparing probiotic-fed pigs to control pigs on: average daily gain, diarrhea incidence, feed efficiency, and overall pen health scores. Record observations at days 7, 14, 21, and 28 to match the study’s measurement timeline
This research was conducted in piglets and describes the effects of one specific probiotic strain under controlled conditions. Results may not apply to other animal species, different probiotic strains, or farm conditions different from the study. This information is intended for educational purposes and should not replace professional veterinary advice. Farmers considering probiotic supplementation should consult with a veterinarian to determine if this approach is appropriate for their specific situation. The study was published in a peer-reviewed journal but represents one research project; additional studies may be needed to confirm these findings. Always follow label instructions and regulatory requirements when using feed additives.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
