Mannan Oligosaccharides Application: Multipath Restriction From Aeromonas hydrophila Infection in the Skin Barrier of Grass Carp (Ctenopharyngodon idella)

The objective of this study was to evaluate the efficacy of dietary Mannan oligosaccharides (MOS) supplementation on skin barrier function and the mechanism of on-growing grass carp (Ctenopharyngodon idella). Five hundred forty grass carp were fed for 60 days from the growing stage with six different levels of MOS diets (0, 200, 400, 600, 800, and 1,000 mg kg(-1)). At the end of the growth trial, the 14-day Aeromonas hydrophila challenge experiment has proceeded. The obtained data indicate that MOS could (1) decline skin lesion morbidity after being challenged by the pathogenic bacteria; (2) maintain physical barrier function via improving antioxidant ability, inhibiting excessive apoptosis, and strengthening the tight junction between the epithelial cell and the related signaling pathway (Nrf2/Keap1, p38MAPK, and MLCK); and (3) regulate immune barrier function by modulating the production of antimicrobial compound and expression of involved cytokines and the related signaling pathway (TOR and NF kappa B). Finally, we concluded that MOS supplementation reinforced the disease resistance and protected the fish skin barrier function from Aeromonas hydrophila infection.

Automated summary

The study found that dietary Mannan oligosaccharides (MOS) supplementation can reduce skin lesion morbidity in grass carp challenged by pathogenic bacteria, maintain skin barrier function by improving antioxidant capacity, inhibiting cell apoptosis, and strengthening cell connections. Additionally, MOS can regulate immune barrier function by modulating the expression of immune factors and related signaling pathways.