Cinnamaldehyde as a dietary modulator of gut microbiota and growth in broilers under low-protein feeding conditions

Cinnamaldehyde (CM), recognized for its antimicrobial and anti-inflammatory capabilities, is increasingly valued as an animal feed additive, primarily for its potential to augment gut health and promote general animal welfare. However, our understanding of CM as a feed additive to a low-protein diet on broilers' growth performance and microbial composition is still limited. To investigate the effect of CM supplementation on the growth performance and microbial composition of broilers within a low-protein diet administration, we employed a combination of serum biochemical tests, growth parameters, and high-throughput sequencing (HTS) techniques. The results indicated a significant increase in body weight (N = 40) and feed efficiency ratio (N = 40; P < 0.05) following CM administration. Meanwhile, the microbial taxonomic analysis found that feeding CM increased the richness of Firmicutes, Faecalibacterium, and Lactobacillus while diminishing the diversity of Bacteroidetes, Actinobacteria, Oscillospira, and Bacteroides. Besides, serum biochemical tests revealed that the CM administration significantly increased the immunity factors (IgA and IgE) than the low-protein (LP) group. These findings offer crucial insights into the interplay between gut microbiota and animal growth performance, elucidating the role of CM supplementation in the context of low-protein diets.