Can promoting an inflammatory response with diet combat necrotic enteritis and coccidiosis in poultry?
At the 2025 Poultry Science Association annual meeting, Michael Carroll, graduate assistant at Mississippi State University, presented his research investigating whether dietary changes can produce a useful immune response to combat necrotic enteritis.
Eimeria is a costly problem in broiler production. Not only does the parasite damage the bird’s intestines, but it also sets up the bird for secondary infections.
Carroll explained that Eimeria’s main mechanism for evading the host immune response is the production of IL-10, an anti-inflammatory cytokine, by the host. “Eimeria damages the intestine by lysing enterocytes and expelling protein into the intestinal lumen. The resultant damage makes it possible for an opportunistic pathogen — Clostridium perfringens — to cause necrotic enteritis,” he said.
Economic losses increase when both Eimeria and Clostridium are present. “Our hypothesis was that broilers fed the anti-ILT-10 diet would have an increased pro-inflammatory response to the Eimeria maxima and Clostridium perfringens challenge,” Carroll said.
Current control methods insufficient
Producers rely on antibiotics, chemicals and vaccines to manage these diseases, but none are perfect. “The industry is shifting away from antibiotics, and emerging resistance to chemicals is problematic,” Carroll noted. “Vaccinations for Eimeria, although effective, do not cover against all strains and species.”
Understanding that current control methods are insufficient led Carroll to investigate outside-the-box controls and to promote a positive inflammatory response.
IL-10, immune suppression
High IL-10 levels reduce the bird’s ability to fight infection by suppressing macrophage activity and shifting the immune system away from a strong protective response.
Carroll thought that if IL-10 helps Eimeria evade the immune system, blocking IL-10 through the diet might help birds respond better. “If an anti-IL-10 antibody was fed to the chickens to counteract this host evasion mechanism by Eimeria, we could promote a pro-inflammatory response.”
He tested an anti-IL-10 ingredient in broiler diets and then challenged birds with Eimeria alone or with Eimeria and C. perfringens.
Study findings
IL-10 changes were only clearly seen in one part of the gut. “Luminal IL-10 concentration showed a significant response only in the duodenum,” Carroll summarized.
But many of the study results were unexpected. The Salmonella-type Eimeria did not increase IL-10 concentrations as expected, and responses varied between repeated trials. “The necrotic enteritis models varied across replications for IL-10 concentration,” he said.
When he examined gut tissue directly, he observed that diet had little effect on IL-10 levels. “IL-10 concentrations in the jejunal tissue were relatively unaffected by both diet and challenge,” Carroll noted.
However, another immune signal did change. “Interferon gamma response was different across all three replications,” he explained, indicating that the birds’ immune systems were reacting, just not always as expected.
Difference noted between males and females
When comparing challenged birds to unchallenged controls, Carroll noted that, regardless of challenge, the birds mounted a similar response, transcriptome. However, there was a striking divergence between sexes. “We found that there was a difference between males and females in their transcriptome response at each challenge level. Only about 20% of differentially expressed genes were shared across sexes, beyond those linked to sex chromosomes.”
Pathway analysis showed that Eimeria challenge upregulated “the cell cycle and lipid metabolism,” while combined challenge increased “an adaptive immune response” alongside cell cycle activity.
Takeaways for producers
Carroll’s research showed that targeting immune pathways, such as IL-10, holds promise but is complex and can yield inconsistent results.
The research showed that diet can influence immune responses, but the results can vary depending on challenge conditions and the birds themselves. “E. maxima and E. maxima plus C. perfringens responded similarly when compared to the unchallenged,” Carroll concluded.
For producers, the key message is that necrotic enteritis and coccidiosis remain complex problems. New nutritional tools may be part of the solution, but they are not silver bullets.
