Using combined Lactobacillus and quorum quenching enzyme supplementation as an antibiotic alternative to improve broiler growth performance, antioxidative status, immune response, and gut microbiota.

To seek viable alternatives to antibiotics, we determined the combinatorial effects of Lactobacillus and a quorum quenching enzyme (QQE) on broiler growth performance, antioxidant capacity, immune responses, and cecal microbial populations. In total, 360 one-day-old male broilers (Ross 308) were randomly allotted to 3 dietary treatments, with 12 replicate pens/treatment and 10 birds/replicate pen. Dietary treatments lasted 42 d and comprised: corn-soybean meal basal diet (control group, CON); control plus antibiotic growth promoter supplement group (AGP); and control plus Lactobacillus and QQE supplement group (LQ). Dietary LQ supplementation significantly increased final body weight (BW) and average daily gain (ADG) when compared with CON and AGP groups between 22 and 42 d and 1 to 42 d (P < 0.05). No significant differences were observed for serum superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels between treatments (P > 0.05). A higher concentration of total antioxidant capacity (T-AOC) was observed on d 42 in the LQ group (P = 0.06). Feeding LQ significantly increased serum immunoglobulins (IgA and IgG) levels when compared with other treatments (P < 0.05). A statistical trend was also observed for increased cecal butyrate levels (P = 0.06) in the LQ group. Bacterial α-diversity was unaffected by dietary treatments (P > 0.05). However, from principal component analysis (PCoA), the microbial community structure was different between the LQ and AGP groups. Diet supplemented with LQ significantly (P < 0.05) decreased the relative abundance of Synergistota and Proteobacteria and significantly (P < 0.05) increased the proportion of Ruminococcaceae and Faecalibacterium. Thus, supplemental LQ improved growth performance, immune status, and modulated intestinal microbial communities in broilers. We provide a new perceptive on antibiotic substitutes in the poultry industry.