Protective Effects of Mycotoxin Biodegradation Agents on Pigeon Health and Gut Microbiota

Mycotoxin contamination in feed poses a major threat to animal health and productivity, particularly in pigeons. This study evaluated the protective effects of three mycotoxin biodegradation agents (MBAs) in pigeons subchronically co-exposed to a mycotoxin-contaminated (MYC) diet for 60 days. The MYC diet was prepared by mixing 3% naturally mold-contaminated corn with 97% basal diet, yielding final dietary concentrations of fumonisin B1 (7829.41 µg/kg), aflatoxin B1 (201.16 µg/kg), zearalenone (1675.46 µg/kg), T-2 toxin (7721.41 µg/kg), and deoxynivalenol (1211.77 µg/kg). Birds were allocated to five groups (n = 18/group): CON (basal diet); MYC (MYC diet alone); and TRT1-TRT3 fed the MYC diet supplemented with 1.5 g/kg of MBA I (Bacillus subtilis + Bacillus licheniformis + Devosia sp.), MBA II (Bacillus licheniformis + Saccharomyces cerevisiae), or MBA III (Bacillus subtilis + glucose oxidase), respectively. Subchronic co-exposure to the MYC diet significantly increased serum pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), whereas all three MBAs effectively attenuated these elevations. Histopathological examination revealed inflammatory infiltration and tissue damage in the jejunum and liver of MYC birds, which were markedly alleviated by MBA supplementation. Gut microbiota analysis showed that mycotoxins decreased Firmicutes and Lactobacillus and increased Proteobacteria and Streptococcus, whereas MBAs partially restored microbial balance. Among the three MBAs, MBA II exhibited the strongest protective effect, as reflected by the greatest improvements in serum biochemistry, intestinal morphology, and microbial composition. Liver transcriptome analysis showed that mycotoxin mainly affected pathways related to cell cycle and DNA replication, whereas MBA II enhanced pathways associated with intestinal immune function and antigen processing and presentation. Collectively, these findings suggest that MBA II offers effective protection against combined mycotoxin-induced toxicity in pigeons and may serve as a promising feed additive for mitigating mycotoxin contamination in poultry production.