Integrating Serum Metabolome and Gut Microbiome to Evaluate the Benefits of Lauric Acid on Lipopolysaccharide- Challenged Broilers

Abstract

Lauric acid (LA) is a crucial medium-chain fatty acid (MCFA) that has many beneficial effects on humans and animals. This study aimed to investigate the effects of LA on the intestinal barrier, immune functions, serum metabolism, and gut microbiota of broilers under lipopolysaccharide (LPS) challenge. A total of 384 one-day-old broilers were randomly divided into four groups, and fed with a basal diet, or a basal diet supplemented with 75 mg/kg antibiotic (ANT), or a basal diet supplemented with 1000 mg/kg LA. After 42 days of feeding, three groups were intraperitoneally injected with 0.5 mg/kg Escherichia coli- derived LPS (LPS, ANT+LPS and LA+LPS groups) for three consecutive days, and the control (CON) group was injected with the same volume of saline. Then, the birds were sacrificed. Results showed that LA pretreatment significantly alleviated the weight loss and intestinal mucosal injuries caused by LPS challenge. LA enhanced immune functions and inhibited inflammatory responses by upregulating the concentrations of immunoglobulins (IgA, IgM, and IgY), decreasing IL-6 and increasing IL-4 and IL-10. Metabolomics analysis revealed a significant difference of serum metabolites by LA pretreatment. Twenty-seven serum metabolic biomarkers were identified and mostly belong to lipids. LA also markedly modulated the pathway for sphingolipid metabolism, suggesting its ability to regulate lipid metabolism. Moreover,16S rRNA analysis showed that LA inhibited LPS-induced gut dysbiosis by altering cecal microbial composition (reducing Escherichia-Shigella, Barnesiella and Alistipes, and increasing Lactobacillus and Bacteroides), and modulating the production of volatile fatty acids (VFAs). Pearson’s correlation assays showed that alterations in serum metabolism and gut microbiota were strongly correlated to the immune factors; there were also strong correlations between serum metabolites and microbiota composition. The results highlight the potential of LA as a dietary supplement to combat bacterial LPS challenge in animal production and to promote food safety.

Lactobacillus plantarum-derived postbiotics prevent Salmonella-induced neurological dysfunctions by modulating gut–brain axis in mice

“…In this study, we demonstrated that LP postbiotics, particularly the metabolites, exhibited a stronger capacity in alleviating Salmonella -induced injuries, as evidenced by the significant inhibition of weight loss, suppression of ST translocation, and alleviation of tissue injuries and neurological dysfunctions. Consistently with our findings, it was reported that Lactobacillus -derived postbiotics showed immunomodulatory and protective capacity against Salmonella infection in mice ( 30 ).…”

“…The concentration of SCFAs (acetatic acid, propionic acid, butyric acid, isobutyric acid, valeratic acid, and isovaleric acid) was detected using the headspace sampler gas chromatography based on our previous study ( 30 ). Briefly, 0.3-g cecal contents from each sample were diluted with 1.2 ml sterile water and centrifuged at 12,000 g for 10 min at 4°C.…”

Modified Montmorillonite Improved Growth Performance of Broilers by Modulating Intestinal Microbiota and Enhancing Intestinal Barriers, Anti-Inflammatory Response, and Antioxidative Capacity

“…However, decreased Olsenella in MMT group was positively correlated with MDA, MPO, NO, DAO, and D-LA, and negatively correlated with IgG, IgA, IgM, T-SOD, T-AOC, and CAT. Consistently, it was reported that Bacteroides could significantly reduce the fasting hyperglycemia and high plasma concentrations of proinflammatory cytokines in mice [ 60 ], and exhibited a marked anti-inflammatory activity against E.coli -induced IL-8 release, and showing that an increased abundance of Bacteroides might suppress inflammatory responses [ 61 , 62 ]. Furthermore, the antioxidant and immune functions were positively correlated with the pyruvate metabolism, ribosome, glycolysis/gluconeogenesis, and pyrimidine metabolism of microbial communities, but negatively with metabolic pathways, microbial metabolism, and carbon metabolism of microbial communities.…”

Dietary γ-Aminobutyric Acid Supplementation Inhibits High-Fat Diet-Induced Hepatic Steatosis via Modulating Gut Microbiota in Broilers

“…Barnesiella has an immunomodulatory effect, which can prevent the colonization of drug-resistant pathogens in the intestine [ 30 ]. The increase of Barnesiella abundance is beneficial to improving the resistance of broilers to lipopolysaccharide challenge, alleviating inflammatory response [ 31 ]. Inflammation is an important factor inducing and aggravating hepatic steatosis in chicken [ 32 ].…”