Impact of dietary supplementation with Eleutherine bulbosa (Mill.) Urb. on intestinal microbiota diversity and growth of white shrimp, Litopenaeus vannamei

Abstract

Eleutherine bulbosa (Mill.) Urb. contains oligosaccharides that can stimulate the growth of probiotic microorganisms. However, its potential as a prebiotic for white shrimp, Litopenaeus vannamei, has not been investigated. The purpose of this study was to evaluate the effect of dietary supplementation with powder and crude extract from E. bulbosa on intestinal microbiota diversity and growth of white shrimp. E. bulbosa powder was added to shrimp food at three dosage levels, 6.25 g kg−1 (P6.25), 12.5 g kg−1 (P12.5), and 25 g kg−1 (P25). E. bulbosa crude extract was added at one level, 1.25 g kg−1 (E1.25). Control shrimp received feed without powder or extract. Shrimp were fed supplemented diets for 30 days. Intestinal microbiota diversity in test shrimp was analyzed using Polymerase Chain Reaction/Denaturing Gradient Gel Electrophoresis (PCR-DGGE) based on the V3 region of 16S rRNA genes. Dietary supplementation with powder and crude extract altered microbiota diversity. Dominant phyla were Proteobacteria from genera Vibrio and Pseudoalteromonas, and uncultured bacteria. The highest diversity was found with P12.5 supplementation. Feeding with E. bulbosa powder or extract also increased activities of digestive enzymes (protease, lipase, and amylase) and increased perimeter ratio and microvilli density of the intestine. P25 supplementation induced the greatest impact, but was not significantly different from impact observed with P12.5 supplementation (p > 0.05). E. bulbosa powder also produced significant effects on food consumption, final biomass, body weight gain, specific growth rate, feed conversion rate, protein efficiency ratio, protein retention, lipid retention, protein digestibility, and total digestibility as compared to controls (p < 0.05). The largest effects were observed with P12.5 supplementation, but were not significantly different (p > 0.05) from P25 supplement. These results E. bulbosa powder was more efficacious than the extract and may prove more practical for use in aquaculture.