Synbiotic supplementation modulates humoral immunity and cecal microbiota in broiler chickens exposed to subclinical levels of fumonisins and deoxynivalenol

Authors: DASIREDDY, JOSEPH RISHITHA - University Of Georgia; KAPPARI, LAHARIKA - University Of Georgia; SELVARAJ, RAMESH - University Of Georgia; APPLEGATE, TODD - University Of Georgia; Shanmugasundaram, Revathi

Submitted to: Frontiers in Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2026
Publication Date: 4/21/2026
Citation: Dasireddy, J., Kappari, L., Selvaraj, R.K., Applegate, T.J., Shanmugasundaram, R. 2026. Synbiotic supplementation modulates humoral immunity and cecal microbiota in broiler chickens exposed to subclinical levels of fumonisins and deoxynivalenol. Frontiers in Physiology. 7, p.1808482.. https://doi.org/10.3389/fphys.2026.1808482.
DOI: https://doi.org/10.3389/fphys.2026.1808482

Interpretive Summary: Grains used in poultry feed often contain small amounts of natural toxins made by molds. Two common toxins fumonisins and deoxynivalenol can harm chickens by damaging their gut and weakening their immune system, even when levels are too low to cause visible symptoms. This hidden damage can reduce bird health and lead to lower productivity, which affects farm profits. To help protect chickens, we tested a feed additive called a synbiotic, which combines beneficial bacteria with special fibers. We wanted to see if this synbiotic could reduce the harmful effects of these toxins. Our study showed that chickens fed synbiotics had stronger immune responses and healthier gut bacteria. They produced more protective antibodies and had gut microbes linked to better digestion and disease resistance. While the toxins still affected the gut, the synbiotic helped reduce some of the damage. These results suggest that synbiotics can help chickens stay healthier and perform better, even when their feed contains low levels of toxins. This approach may help poultry producers reduce losses and improve flock health. It also gives nutrition experts new ideas for using gut-friendly feed additives to protect poultry from feed-related challenges.

Technical Abstract: Synbiotics modulate the cecal microbiota in chickens by promoting the growth of beneficial bacteria, which have the potential to mitigate the negative effects of mycotoxins such as fumonisins (FUM) and deoxynivalenol (DON) and improve immune responses. This study aimed to identify the effect of supplementation of synbiotic at 0.05% on the bile IgA, serum IgY, cecal microbiota composition, diversity, and short-chain fatty acid (SCFA) profile in broilers exposed to subclinical concentrations of FUM and DON. A total of 360 one-day-old broilers were distributed into 4 treatments: Control, Mycotoxin (8.5 FUM+3.8 DON mg/kg diet), Synbiotic, and Mycotoxin + Synbiotic. FUM and DON specific IgA in bile and IgY in serum were quantified using indirect ELISA. Cecal contents were collected on d21 and d35, and bacterial compositions were identified by analyzing the V3–V4 region of the 16S rRNA gene using Illumina sequencing. Relative abundance of families and alpha diversity indices were analyzed using the Kruskal-Wallis H Test, and IgA, IgY, and SCFAs were analyzed using two-way ANOVA. On d35, there were no interaction effects between FUM + DON and synbiotic supplementation on bile FUM and DON specific IgA concentrations and serum FUM and DON specific IgY concentrations (p > 0.05). However, FUM + DON has a trend in the main effect and decreased bile FUM-specific IgA concentrations by 8.4% compared to no mycotoxin treatment groups (p = 0.09). Synbiotic supplementation increased the DON-specific IgA concentrations in the bile by 17.4% compared to the no synbiotic group (p = 0.08). There were no significant interactions between FUM + DON and synbiotic supplementation on the cecal SCFA levels on d21 and d35 (p > 0.05). But on d35, there was a trend on the main effect of FUM + DON on the cecal propionate concentration. Propionate concentration was decreased by 36.4% compared to the no mycotoxin treatment groups (p = 0.09). There were no significant differences in the Shannon diversity index between treatment groups (p > 0.05). On d35, FUM + DON increased the ratio of relative abundances of Firmicutes to Bacteroidetes in the treatment groups, while synbiotic supplementation further increased the Firmicutes to Bacteroidetes ratio in FUM + DON treatment group. In conclusion, synbiotic supplementation mitigated the adverse effects of FUM + DON by improving the humoral immune response and altering the cecal microbiota composition. KEY WORDS: Synbiotic, Microbiota, SCFA, Fumonisins, Deoxynivalenol