Researchers tested whether adding yeast-based supplements to chicken feed could help protect birds from Salmonella, a common food-poisoning bacteria. They tried five different feed options: regular feed, and four versions with different yeast ingredients. Chickens that received a specific type of yeast cell wall grew bigger and had healthier intestines, especially when exposed to Salmonella. The yeast supplements seemed to strengthen the chickens’ gut lining and boost their immune response. This research suggests that natural yeast-based additives might be a safe way to keep chickens healthier without using antibiotics.

The Quick Take

  • What they studied: Whether adding different types of yeast cell wall products to chicken feed would help chickens grow better and fight off Salmonella bacteria infection
  • Who participated: Broiler chickens (chickens raised for meat) divided into groups receiving different feed supplements, with some groups intentionally exposed to Salmonella bacteria
  • Key finding: Chickens fed a specific yeast cell wall product (called CELL) grew significantly heavier and had stronger, healthier intestines compared to chickens on regular feed, even when infected with Salmonella
  • What it means for you: This research suggests that natural yeast supplements might help farm animals stay healthier and grow better without antibiotics. While promising, these findings are from chickens and would need further testing before applying to human nutrition or other animals

The Research Details

The researchers conducted two separate experiments with broiler chickens. In the first experiment, they divided chickens into five groups: one control group eating regular feed, and four groups receiving different yeast-based supplements mixed into their feed at various amounts. They measured how much the chickens grew, examined their intestines under a microscope, and tested which genes were turned on or off in their gut cells. The second experiment repeated this process but also deliberately exposed the chickens to Salmonella bacteria on day 7 after hatching to see how the supplements would help them fight infection.

This research approach is important because it tests whether natural supplements can improve animal health in realistic conditions, including when animals are exposed to harmful bacteria. By measuring both physical growth and microscopic intestinal changes, plus checking which genes are active, the researchers could understand exactly how the yeast supplements work to protect the chickens’ health.

The study used a controlled design with multiple treatment groups and a control group, which is a solid approach. The researchers measured outcomes at multiple time points (days 21 and 35) and used multiple assessment methods including physical measurements, microscopic examination, and genetic analysis. However, the specific number of chickens per group was not provided in the abstract, which makes it harder to assess the statistical strength of the findings.

What the Results Show

Chickens receiving the specific yeast cell wall product (CELL group) showed the most impressive results. These chickens reached higher final body weights and gained more weight overall compared to all other groups. When researchers examined the chickens’ intestines under a microscope, they found that the CELL group had the healthiest intestinal structure, particularly in the lower part of the small intestine (ileum) where nutrient absorption happens. The intestinal lining appeared stronger and more developed in these birds.

When the researchers looked at genes related to gut health and immune function, they found important differences between groups. Genes that help maintain the intestinal barrier (claudin and occludin) were more active in certain supplement groups. Genes related to inflammation showed varied patterns, with some immune response genes being activated in all groups when exposed to Salmonella, which is a normal protective response.

In the second experiment where chickens were deliberately exposed to Salmonella bacteria, the benefits of the CELL supplement became even more apparent. These chickens still grew the heaviest and showed the strongest intestinal health markers, suggesting the supplement helped them resist the infection while continuing to grow normally.

Other yeast supplements showed mixed results. The whole yeast cell supplements (W and WP groups) produced some benefits but were less effective than the CELL product. Interestingly, the pure Mannan-oligosaccharides plus beta-glucan combination (MB group) showed some effects on intestinal structure but didn’t produce the same growth benefits as the CELL group. The timing of measurements also mattered—some intestinal changes were more visible at day 21, while others became clearer by day 35, suggesting the supplements work gradually over time.

This research builds on existing knowledge that yeast-based products can support gut health in animals. Previous studies have shown that prebiotics (food components that feed beneficial gut bacteria) can improve animal performance, but this study is notable for comparing different types of yeast products directly and measuring both growth and immune function. The finding that a specific type of yeast cell wall (CELL) outperformed other yeast products suggests that the exact form and processing of the supplement matters significantly.

The abstract doesn’t specify how many chickens were in each group, which is important for understanding how confident we can be in the results. The study was conducted in controlled laboratory conditions with chickens, so results may not directly apply to other animals or to human nutrition. The Salmonella challenge in experiment II was performed at a specific time point (day 7), so we don’t know if results would differ if the infection occurred at different ages. Additionally, the study measured gene expression but didn’t directly measure whether beneficial bacteria in the gut actually increased, which would strengthen the evidence for how the supplements work.

The Bottom Line

Based on this research, yeast cell wall supplements—particularly the enzymatically processed type—appear promising for improving growth and gut health in chickens, especially when facing bacterial challenges. The evidence is moderate to strong for chickens but should not yet be considered definitive for other animals or humans. Anyone considering similar supplements for other purposes should consult with a veterinarian or healthcare provider, as more research is needed.

Poultry farmers and producers should find this research interesting as a potential alternative to antibiotics for maintaining chicken health. Pet bird owners might consider discussing yeast supplements with their veterinarian. This research is less directly applicable to human nutrition at this stage, though the underlying science about gut health and immune function is relevant to broader nutrition science. People with specific health conditions should not self-treat based on this chicken research without professional guidance.

In the chickens studied, benefits appeared gradually over the 35-day observation period, with some changes visible by day 21 and others becoming clearer by day 35. If similar supplements were used in other contexts, realistic expectations would be weeks to months for noticeable effects, not days.

Want to Apply This Research?

  • If tracking animal health or farm performance, users could log weekly weight measurements and visual observations of animal condition, comparing treated versus control groups over 4-5 week periods to identify growth trends
  • For farmers or producers, the practical change would be testing yeast cell wall supplements in feed at the dosage levels used in this study (0.565% for the CELL product) and tracking resulting growth rates and health indicators over a full production cycle
  • Establish a baseline measurement of animal weight and health status, then measure weekly or bi-weekly intervals, recording feed consumption, weight gain, and any visible health changes. Compare results across at least 4-5 weeks to identify meaningful trends, keeping detailed notes on environmental factors that might affect results

This research was conducted on chickens and should not be interpreted as medical advice for humans. While the findings about yeast-based supplements and gut health are scientifically interesting, they cannot be directly applied to human health without additional research specifically in humans. Anyone considering supplements for health purposes should consult with a qualified healthcare provider. Farmers considering implementing these supplements should consult with a veterinarian to ensure appropriate dosing and application for their specific animals and conditions. This summary is for educational purposes and does not replace professional medical or veterinary advice.