The study is aimed to develop a relevant synbiotic to promote growth performance of the whiteleg shrimp, Litopenaeus vannamei. For this, four common natural fiber extracts from Arcera banana, Siamese banana, yellow sweet potato, and white sweet potato were screened for supporting the growth of Lactobacillus sp. which was isolated from whiteleg shrimp intestines with probiotic activity, prebiotic score, and ability to induce bacterial enzyme activities of protease, leu-aminopeptidase, and a-amylase. Results showed that Lactobacillus sp. was able to utilize all extracts from banana and sweet potato as the sole carbon sources. At 24 hours of culture, the growth of Lactobacillus sp. was highest after adding the extract from white sweet potato as the sole carbon source. Considering pathogenic bacteria, including Vibrio parahaemolyticus, white sweet potato extract had the highest prebiotic score with a mean of 0.25 as compared with those of V. harveyi with a mean of 0.16. White sweet potato extract induced the highest activities of protease. These results indicated that white sweet potato extract was more suitable for combining with Lactobacillus sp. as a synbiotic for shrimp culture.