Research shows that wild thyme powder combined with probiotics significantly improved chicken growth, feed efficiency, and intestinal barrier strength compared to untreated chickens, performing as well as or better than antibiotic-treated chickens in a 28-day study of 546 broilers. According to Gram Research analysis, the thyme-probiotic combination synergistically increased intestinal barrier proteins and beneficial gut bacteria while reducing inflammation markers, suggesting it could replace antibiotics in chicken farming without compromising health or growth.
Scientists tested whether wild thyme powder could replace antibiotics in chicken farming. They studied 546 chickens over 28 days, comparing thyme alone, thyme mixed with probiotics (good bacteria), thyme mixed with prebiotics (food for good bacteria), and antibiotics. According to Gram Research analysis, chickens that received thyme, especially when combined with probiotics, grew faster, had better digestion, and developed stronger intestinal barriers. The findings suggest that natural plant-based supplements could help farmers raise healthier chickens without relying on antibiotics, which is important because overusing antibiotics creates resistant bacteria that threaten human health.
Key Statistics
A 2026 study of 546 broiler chickens found that those receiving wild thyme powder combined with probiotics achieved final body weights and weight gains comparable to or exceeding antibiotic-treated chickens, with improved feed conversion efficiency.
In a 28-day trial of 546 chickens, all natural supplement groups (thyme, probiotics, and prebiotics) reduced serum malondialdehyde inflammation markers and enhanced interferon-gamma immune response compared to untreated controls.
Chickens receiving thyme combined with probiotics showed synergistic increases in intestinal occludin protein concentrations, which strengthens the intestinal barrier and prevents harmful bacteria from entering the bloodstream.
A 2026 study of 546 broiler chickens found that probiotic-inclusive diets significantly increased cecal propionic acid and total short-chain fatty acids while increasing ileal villus surface area by up to 28% compared to control groups.
The Quick Take
- What they studied: Whether wild thyme powder, alone or mixed with probiotics or prebiotics, could replace antibiotics in chicken feed while keeping chickens healthy and growing well.
- Who participated: 546 male broiler chickens (the type raised for meat) divided into seven groups, each tested for 28 days. One bird from each group was examined for detailed health measurements.
- Key finding: Chickens receiving thyme combined with probiotics showed the best results: they gained more weight, converted feed more efficiently, and had stronger intestinal barriers compared to control chickens. All natural supplement groups showed reduced inflammation markers and improved immune function.
- What it means for you: If you eat chicken, this research suggests farmers may soon have safer alternatives to antibiotics for raising healthier birds. This matters because antibiotic overuse in farming contributes to antibiotic-resistant bacteria that can affect human health. However, these results are from controlled lab conditions with healthy chickens, so real-world farm results may differ.
The Research Details
Researchers divided 546 young chickens into seven equal groups and fed them different diets for 28 days. One group received normal feed (control), one received antibiotic-treated feed (the current standard), and five groups received various combinations of wild thyme powder, probiotics (beneficial bacteria), and prebiotics (food that feeds good bacteria). The researchers measured how much the chickens grew, how efficiently they converted feed to body weight, and collected samples to examine their gut bacteria, immune markers, and intestinal health.
This experimental design is called a randomized controlled trial because each chicken was randomly assigned to a group, and one group served as a control for comparison. By testing multiple combinations (thyme alone, thyme plus probiotics, thyme plus prebiotics), the researchers could see whether combining supplements worked better than using them individually.
The study measured multiple health indicators: body weight gain, feed efficiency, blood markers of inflammation and oxidative stress, immune response proteins, gut bacteria composition, beneficial short-chain fatty acids produced in the cecum (part of the chicken’s digestive system), and the physical structure of the intestinal lining.
This research approach matters because it tests real-world farming solutions. Instead of just studying one supplement in isolation, the researchers tested combinations that farmers might actually use. They also measured many different health outcomes, not just growth, but immune function, gut bacteria balance, and intestinal barrier strength, which gives a complete picture of chicken health. The 28-day study period covers most of a broiler chicken’s productive life, making the results practically relevant.
Strengths: Large sample size (546 chickens), multiple replicates (13 per group), comprehensive measurements across multiple body systems, and comparison to both untreated and antibiotic-treated controls. Limitations: Study used only one dose level of thyme (1.0 g/kg), one plant source, and only healthy chickens in controlled conditions, not real farm environments or sick chickens. The researchers acknowledge these limitations and call for further research with different doses, disease challenges, and diverse plant sources.
What the Results Show
Chickens receiving thyme powder (alone or combined with probiotics/prebiotics) achieved significantly higher final body weight and weight gain compared to control chickens. The improvement was comparable to or better than chickens receiving antibiotics. Feed conversion ratio, a measure of how efficiently chickens convert feed into body weight, improved most in chickens receiving thyme alone, probiotics alone, or thyme plus probiotics. The thyme-plus-probiotic combination showed the best overall performance, though the improvement wasn’t statistically greater than the individual supplements combined.
All natural supplement groups (thyme, probiotics, and prebiotics) reduced serum malondialdehyde, a marker of cellular damage and inflammation. This indicates that these supplements protected chicken cells from oxidative stress. Additionally, all natural supplement groups enhanced interferon-gamma, an important immune protein that helps fight infections. Chickens receiving thyme plus prebiotics showed increased tumor necrosis factor-alpha (another immune marker), while chickens receiving thyme alone or prebiotics alone showed reduced levels, suggesting different immune-balancing effects.
The most significant finding involved intestinal health: chickens receiving probiotics (with or without thyme) showed dramatically increased propionic acid and total short-chain fatty acids in their cecum. These fatty acids are produced by beneficial bacteria and are crucial for intestinal health and nutrient absorption. Chickens receiving probiotics also had larger intestinal villi (finger-like projections that absorb nutrients), increasing their absorption surface area.
Crucially, combining thyme with either prebiotics or probiotics synergistically increased occludin concentrations in the intestinal lining. Occludin is a protein that seals gaps between intestinal cells, strengthening the barrier that prevents harmful bacteria from entering the bloodstream. This synergistic effect, where the combination worked better than either supplement alone, was the study’s most important finding for intestinal barrier integrity.
All natural supplement groups promoted healthy gut bacteria balance (eubiosis) by increasing Lactobacillus species (beneficial bacteria) while decreasing Clostridium species (potentially harmful bacteria). This shift toward beneficial bacteria is important because it can improve digestion, nutrient absorption, and immune function. The prebiotic group showed the most dramatic reduction in Clostridium, suggesting that prebiotics specifically promote beneficial bacteria growth. The probiotic groups showed the highest Lactobacillus levels, as expected since probiotics directly introduce these beneficial bacteria.
These findings align with previous research showing that plant-based supplements can partially replace antibiotics in poultry farming. However, this study is notable for testing combinations rather than single supplements, and for measuring intestinal barrier integrity (occludin) as a key outcome. The synergistic effect of thyme plus probiotics is particularly novel: it suggests that combining different types of supplements may be more effective than using them individually. The results support the growing body of evidence that natural alternatives can maintain chicken health without antibiotics, though this study is among the first to demonstrate synergistic effects of specific combinations.
The study tested only one dose level of thyme (1.0 g/kg), so researchers don’t know if higher or lower doses would work better. Only one plant source (wild thyme) was tested, so results may not apply to other herbs. The study used only healthy chickens in controlled laboratory conditions, not real farm environments where chickens face disease, stress, and variable conditions. The 28-day study period, while covering most of a broiler’s productive life, doesn’t show long-term effects. The researchers acknowledge these limitations and recommend future studies with dose-response testing, disease-challenge models, and diverse plant sources before claiming these results apply broadly to commercial farming.
The Bottom Line
Based on this research, wild thyme powder combined with probiotics appears to be a promising antibiotic alternative for broiler chicken farming. The evidence is strong for growth performance and intestinal health in healthy chickens under controlled conditions. Moderate confidence: Results may apply to commercial farms, but real-world testing is needed. Low confidence: Results may not apply to sick chickens, different thyme doses, or other plant sources. Farmers should consult veterinarians before implementing these supplements in place of antibiotics, especially in disease-prone environments.
Poultry farmers and veterinarians should care about this research because it offers a practical alternative to antibiotics, which are increasingly restricted due to antibiotic resistance concerns. Consumers concerned about antibiotic use in food production should care because this research supports antibiotic-free farming methods. Public health officials should care because reducing antibiotic use in agriculture helps combat antibiotic-resistant bacteria. People with no connection to chicken farming may not need to apply these findings directly, but the research contributes to broader food safety and public health.
In this study, benefits appeared within 28 days, the chickens receiving thyme-based supplements showed improved growth and intestinal health by the end of the study period. On a commercial farm, farmers would likely see improved feed efficiency and growth rates within 2-4 weeks of switching to these supplements. However, the full benefits to intestinal barrier integrity and immune function may take several weeks to develop. Long-term benefits (beyond 28 days) are unknown and require further research.
Frequently Asked Questions
Can thyme replace antibiotics in chicken farming?
Research suggests wild thyme combined with probiotics performs as well as antibiotics for growth and intestinal health in healthy chickens under controlled conditions. However, real-world farm testing is needed before fully replacing antibiotics, especially in disease-prone environments.
What are the benefits of probiotics and prebiotics for chickens?
Probiotics (beneficial bacteria) and prebiotics (food for beneficial bacteria) increase short-chain fatty acids in the chicken’s digestive system, improve nutrient absorption, strengthen the intestinal barrier, and promote healthy gut bacteria balance while reducing harmful bacteria.
How quickly do natural supplements improve chicken growth?
In this 28-day study, chickens receiving thyme-based supplements showed improved growth rates and feed efficiency within the study period. Farmers might expect to see measurable improvements in growth and feed conversion within 2-4 weeks of introducing these supplements.
Does combining thyme with probiotics work better than using them separately?
Yes, the study found synergistic effects: thyme combined with probiotics showed greater improvements in intestinal barrier integrity (occludin protein) than either supplement alone, suggesting combinations may be more effective than individual supplements.
Are these natural supplements safe for chickens?
This study found no adverse effects in healthy chickens receiving thyme, probiotics, or prebiotics at the tested doses. However, safety in sick chickens, at different doses, or in real farm conditions requires further research before widespread commercial use.
Want to Apply This Research?
- If you raise chickens or manage a poultry farm, track weekly body weight gain, feed conversion ratio (feed consumed divided by weight gained), and any health issues. Compare these metrics before and after introducing thyme-based supplements to measure real-world effectiveness on your farm.
- If using a farm management app, log daily feed type and quantity, weekly chicken weights, and any visible health changes. Set reminders to weigh chickens weekly and calculate feed conversion ratios. Document any changes in chicken behavior, feather quality, or digestive health after introducing thyme supplements.
- Establish a baseline of your current metrics (growth rate, feed efficiency, health issues) over 2-4 weeks. Then introduce thyme-based supplements and continue tracking the same metrics for 4-8 weeks. Compare the two periods to determine whether the supplements improved your results. Track not just growth, but also visible health indicators like feather quality, activity level, and digestive health.
This research describes results from a controlled laboratory study of healthy broiler chickens and should not be interpreted as medical or veterinary advice. The findings are limited to the specific thyme dose (1.0 g/kg), probiotic strain (Bacillus licheniformis), and prebiotic formulation (MOS/β-glucan) tested. Results may not apply to other plant sources, different doses, sick chickens, or real farm environments. Farmers considering replacing antibiotics with these supplements should consult with a veterinarian, especially in disease-prone settings. This research does not replace professional veterinary guidance or established biosecurity practices. Further research is needed to confirm these findings in commercial farm conditions and disease-challenge scenarios.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
