The dietary impacts of turmeric, curcumin, and nanomicelle curcumin on the digestive enzyme activities, intestinal histology, and gut microbiota of the Pacific white shrimp, Litopenaeus vannamei, were assessed. The shrimps (2.96 ± 0.10 g) were fed with different dosages (g kg−1 diet) of turmeric (TUR 2.5, TUR 5, and TUR 10), curcumin (CUR 0.075, CUR 0.150, and CUR 0.300), nanomicelle curcumin (NMC 0.075, NMC 0.150, and NMC 0.300) and a control diet with no feed additives. Experimental treatments improved the intestinal amylase, protease, and lipase enzyme activities compared with the control group. The intestine enzymes recorded the highest activities in shrimp groups fed with NMC 0.150 (P < 0.05). TUR, CUR, and NMC treatments also increased the intestinal muscle thickness, villus height, and villus width in comparison to the control group. The intestine histomorphological indices were the highest in feeding with NMC 0.150 among all the treatments (P < 0.05). The study of the intestinal microbiota indicated that the total bacterial counts (TBC) and total Vibrio sp. counts decreased significantly when the shrimps were fed with experimental feed additives. Of interest, NMC treatments showed lower TBC and Vibrio sp. counts compared with CUR and TUR treatments (P < 0.05). TBC and total Vibrio sp. counts of the intestine were the highest in the control group (P < 0.05). To conclude, the application of nanomicellar carriers was proven promising as nanomicelle curcumin promoted the activities of digestive enzymes, gut microbiota, and intestinal health of L. vannamei through more efficient delivery of dietary immunostimulants.
