Dose dependent anti-obesity effect of three different Lactobacillus sakei strains using a diet induced obese murine model

Overweight and obesity are considered as a major cause of various conditions related to metabolic syndrome. Yet, considering the complex interacting factors leading to pathogenicity and underlying mechanisms, it remains a poorly defined area. Some probiotics have a reputation of a relatively long history of safe use, and an increasing number of studies are confirming benefits including anti-obesity effects when administered in adequate amounts. Recent reports demonstrate that probiotic functions may widely differ with reference to either intra-species or inter-species related data. Such differences do not necessarily reflect or explain strain specific functions of a probiotic, and thus require further assessment at the intra-species level. Various anti-obesity clinical trials with probiotics have shown discrepant results and require more consolidated studies in order to clarify the correct dose of application for reliable and constant efficacy over a long period. In this study three different strains of Lactobacillus sakei were administered in a high fat diet induced obese murine model using three different doses, 1x10¹⁰ CFU, 1x10⁹ CFU and 1x10⁸ CFU, respectively, per day. Changes in body and organ weight were monitored, and serum chemistry analysis was performed for monitoring obesity associated biomarkers. The results show that only one strain of L. sakei (CJLS03) induced a dose dependent anti-obesity effect, while no correlation with either dose or body and adipose tissue weight loss could be detected for the other two L. sakei strains (L338 and L446). The body weight reduction mainly correlated with adipose tissue and obesity associated serum biomarkers such as triglycerides. This study suggests that anti-obesity effects of probiotics may vary in a strain and dose specific manner.