Enhancement of the Anti-Inflammatory Activity of Lactobacillus Plantarum Strains by Optimization of Their Culture Condition

Background and Rationale: Recent reports suggest that culture conditions of lactic acid bacteria (LAB) affect their immunomodulatory properties. The anti-inflammatory activity of LAB is deduced to be an essential mechanism of their anti-metabolic disorder effects. Studies on the health-promoting effects of LAB are numerous, but few have comprehensively investigated the relationship between LAB functionality and their culture conditions.

Objectives: In the present study, we verified the effect of differences in culture conditions on Lactobacillus plantarum OLL2712 (OLL2712) functionality; this strain exhibits anti-inflammatory activity and preventive effects against metabolic disorders.

Methodology: We measured cytokine productions in murine immune cells treated with OLL2712 cells prepared under various culture conditions. We also verified the preventive effects of OLL2712 cells at different culture conditions against inflammation and metabolic disorders in obese and diabetic mice.

Results: The results showed that IL-10-inducing activity of OLL2712 cells differed dramatically between OLL2712 groups at different culture phases, and under different culture medium components, temperatures, and neutralizing pH. We demonstrated several culture conditions of OLL2712 for higher anti-inflammatory activity. In particular, exponential phase cells had much more IL-10-inducing activity than stationary phase cells, and adding decaglycerol mono-oleic acid ester further improved the IL-10-inducing activity. Similar phenomena were observed in another strain of L. plantarum. These differences in IL-10-inducing activity were linked to differences in the toll-like receptor (TLR) 2 stimulation activity. We also demonstrated functional differences by culture phases in vivo; OLL2712 cells at exponential phase had more anti-inflammatory activity and anti-metabolic disorder effects on obese and diabetic mice than those at stationary phase.

Conclusions: We confirmed that the functionality of OLL2712 cells differed by their culture conditions in vitro and in vivo. Our results suggest that culture conditions of LAB affect the anti-inflammatory activity, and optimization of culture conditions is quite important for their health-promoting functionality.