Metabolomic remodeling of pigeon pea by Lacticaseibacillus rhamnosus NTTU 007 reveals anti-obesity effects in high-fat diet rats

Abstract

Fermentation of non-dairy substrates by lactic acid bacteria can enhance the functional properties of their products. post-fermentation untargeted metabolomic profiling via ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and aroma analysis via gas chromatography-ion mobility spectrometry (GC-IMS) assessed biochemical and volatile changes, while an 8-week, 1 g kg⁻¹ daily dose was tested in high-fat diet-induced obese rats for body weight, fat mass, lipid, enzyme, and microbiota outcomes. Fermentation increased total polyphenol and flavonoid contents by 45% and 60%, respectively, and enriched metabolic pathways related to amino acid metabolism, purine degradation, and pantothenate-CoA biosynthesis. GC-IMS analysis revealed a 70% reduction in sulfur- and lipid-derived off-flavors and a 50% increase in fruity esters (e.g., ethyl acetate, hexyl acetate) and creamy ketones. Network analysis identified jasmonic acid, betaine, and trans-aconitic acid as key metabolic hubs. In vivo, treated rats exhibited an 18% reduction in body weight gain, 25% less visceral fat, and a 30% decrease in hepatic triglycerides (p < 0.01), accompanied by elevated pancreatic lipase and lipoprotein lipase activities and a 40% enrichment of butyrate-producing gut taxa. These findings demonstrate that fermentation by L. rhamnosus NTTU 007 significantly remodels the metabolome and aroma profile of pigeon pea, conferring robust antioxidant and anti-obesity functionalities and supporting its potential as a novel non-dairy synbiotic ingredient in health-promoting foods.