Effect of Lacticaseibacillus paracasei K56 with galactooligosaccharide synbiotics on obese individuals: an in vitro fermentation model

Abstract BACKGROUND The use of synbiotics is emerging as a promising intervention strategy for regulating the gut microbiota and for preventing or reducing obesity, in comparison with the use of probiotics or prebiotics alone. A previous in vivo study revealed that Lacticaseibacillus paracasei K56 ( L. paracasei K56) could alleviate obesity induced in high‐fat‐diet mice; however, the effect of the synbiotic combination of L. paracasei K56 and prebiotics in obese individuals has not been explored fully. RESULTS The effect of prebiotics on the proliferation of L. paracasei K56 was determined by spectrophotometry. The results showed that polydextrose (PG), xylooligosaccharide (XOS), and galactooligosaccharide (GOS) had a greater potential to be used as substrates for L. paracase i K56 than three other prebiotics (melitose, stachyose, and mannan‐oligosaccharide). An in vitro fermentation model based on the feces of ten obese female volunteers was then established. The results revealed that K56_GOS showed a significant increase in GOS degradation rate and short‐chain fatty acid (SCFA) content, and a decrease in gas levels, compared with PG, XOS, GOS, K56_PG, and K56_XOS. Changes in these microbial biomarkers, including a significant increase in Bacteroidota , Bifidobacterium, Lactobacillus, Faecalibacterium , and Blautia and a decrease in the Firmicutes / Bacteroidota ratio and Escherichia‐Shigella in the K56_GOS group, were associated with increased SCFA content and decreased gas levels. CONCLUSION This study demonstrates the effect of the synbiotic combination of L. paracasei K56 and GOS on obese individuals and indicates its potential therapeutic role in obesity treatment. © 2024 Society of Chemical Industry.