Rhamnolipids enhance growth performance by improving the immunity, intestinal barrier function, and metabolome composition in broilers.

BACKGROUND: Rhamnolipids (RLS), well known as glycolipid biosurfactants, display low toxicity, high biodegradability, and strong antibacterial properties. This study was carried out to evaluate the use of RLS supplementation as a substitute for antibiotics, and particularly to evaluate its effects on growth performance, immunity, intestinal barrier function, and metabolome composition in broilers. RESULTS: The RLS treatment improved the growth performance, immunity, and intestinal barrier function in broilers. The 16S rRNA sequencing revealed that the genus Alistipes was the dominant genus in broilers treated by RLS. An ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based metabolomic analysis indicated that the sphingolipid metabolism, glycine, serine, and threonine metabolism, the gycerophospholipid metabolism, and the tryptophan metabolism were changed in broilers that were treated with RLS. CONCLUSION: l-Tryptophan may be the medium for RLS to regulate the growth and physiological metabolism. Rhamnolipids can be used as a potential alternative to antibiotics, with similar functions to antibiotics in the diet of broilers. The optimal level of supplemented RLS in the diet was 1000 mg kg-1 . © 2021 Society of Chemical Industry.