Lactiplantibacillus plantarum JCM 1149T Growth Response to Chlorella sp. KLSc61 Crude Extract under Simulated Gastrointestinal Conditions

This study investigated the potential of crude extracts derived from the microalga Chlorella sp. KLSc61 to promote the growth of the probiotic bacterium Lactiplantibacillus plantarum JCM 1149T under simulated gastrointestinal conditions. Crude extracts were prepared from intracellular contents and dried cell debris using 30% and 70% (v/v) ethanol as extraction solvents. The effects of the Chlorella extracts at concentrations of 2.5% and 5% (w/v) were evaluated under simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) conditions. The results demonstrated that the 2.5% (w/v) extracts prepared with 30% ethanol, derived from both intracellular contents and cell debris, exhibited the strongest growth-promoting effects on L. plantarum JCM 1149T. These treatments resulted in significantly higher colony-forming unit (CFU) counts compared with the control and all other treatment groups (p < 0.05). In contrast, extracts prepared with 70% ethanol showed comparatively lower probiotic growth enhancement. These findings suggest that crude extracts from Chlorella sp. KLSc61 possess promising prebiotic potential by effectively supporting the growth of probiotic bacteria under gastrointestinal-like conditions. Further studies will focus on the characterization of bioactive compounds and the investigation of additional prebiotic properties to support the potential application of Chlorella sp. KLSc61 in functional and health-promoting food products.