Prebiotic evaluation of acacia gum for Lactobacillus casei strain Shirota

Probiotics have gained significant attention recently due to their extensive use in the food and health sectors. The Lactobacillus casei strain Shirota is a well-known probiotic with various health advantages. Different gums can aid probiotics in colonizing the human colon, transferring their beneficial health properties. Partially hydrolyzed arabic gum (PHAG) has been investigated for its potential in probiotic encapsulation and as a prebiotic material. Glucose-enriched MRS liquid media showed superior cell growth at 6.0x10^9 CFU/ml, while PHAG-enriched MRS media also supported growth at 8.0x10^8 CFU/ml. The decrease in the total sugar content in the culture media after bacterial growth in the PHAG-supplemented MRS media confirms that probiotics utilize PHAG as a carbon source, indicating its promise as a prebiotic. The enzyme activities of β-glucosidase and phosphoglucosidase in the PHAG-inoculated media were 14.5 mU/mg/min and 21.76 mU/mg/min, respectively. The analysis of the total reducing sugars using the BCA method showed that they were consumed post-inoculation, highlighting them as preferred substrates for the bacteria. An in silico comparison of the L. casei strain Shirota with other Lactobacillus strains showed a higher relative abundance of genes for mannose and galactose metabolism. Notably, mannose and galactose are major components of natural gums like arabic gum, indicating its potential as a prebiotic for this strain.