Influence of Lactobacillus plantarum on anthropometric and inflammatory parameters in obesity: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials.

BACKGROUND

The global obesity epidemic, rooted in chronic inflammation and metabolic dysfunction, necessitates novel interventions; however, evidence regarding the efficacy of Lactobacillus plantarum remains inconsistent.

OBJECTIVE

To evaluate the impact of L. plantarum on obesity-related outcomes in adults via a systematic review and meta-analysis of RCTs.

METHODS

Following PRISMA guidelines and registered in PROSPERO (CRD420251102722), we systematically searched PubMed, Cochrane Library, and Google Scholar through May 2025. Eighteen RCTs (1310 participants) involving non-diabetic adults with BMI ≥ 25 kg/m² were included. Primary outcomes were body weight and BMI; secondary outcomes included lipid profile, glycemic indices, inflammatory biomarkers, liver enzymes, and body composition. ROB 2.0 and GRADE were used to assess bias and evidence certainty.

RESULTS

L. plantarum supplementation significantly reduced body weight (MD = -1.23 kg; 95% CI: -1.97 to -0.49; p = 0.001; I² = 49%) and BMI (MD = -0.28; 95% CI: -0.54 to -0.02; p = 0.03; I² = 77%). Subgroup analysis suggested these reductions were more pronounced with multi-strain formulations than single-strain L. plantarum; however, tests for subgroup interaction were non-significant, indicating insufficient evidence to confirm a true difference in effect by formulation type. Improvements were also noted in waist circumference (MD = -1.36 cm; p = 0.003) and liver enzymes. High-certainty evidence supported body weight reduction; moderate-certainty evidence supported reductions in BMI, waist circumference, fat mass, and liver enzymes; low-certainty evidence was found for lipid, glycemic, and inflammatory outcomes.

CONCLUSIONS

L. plantarum, particularly in multi-strain formulations, may provide modest yet clinically meaningful benefits in obesity management. Standardized, long-term trials are warranted. REGISTRY AND REGISTRY NUMBER FOR SYSTEMATIC REVIEWS OR META-ANALYSES: The systematic review and meta-analysis were registered on PROSPERO under the ID: CRD420251102722.