Targeted and untargeted lipidomics with integration of liver dynamics and microbiome after dietary reversal of obesogenic diet targeting inflammation-resolution signaling in aging mice.

Obesity, a global epidemic linked to around 4 million deaths yearly, arises from lifestyle imbalances impacting inflammation-related conditions like non-alcoholic fatty liver disease and gut dysbiosis. But the long-term effects of inflammation caused by lifestyle-related dietary changes remain unexplained. In this study, we used young male C57Bl/6 mice which were fed either an obesogenic diet (OBD) or a control diet (CON) for six months. Later, a group of mice from the OBD group were intervened to the CON diet (OBD-R) for four months, while another OBD group remained on the OBD diet. The OBD induced distinct changes in gut microbial, notably elevating Firmicutes and Actinobacteria, while reducing Bacteroidetes and Tenericutes. OBD-R restored microbial abundance like CON. Analyzing liver, plasma, and fecal samples revealed OBD-induced alterations in various structural and bioactive lipids, which were normalized to CON in the OBD-R, showcasing lipid metabolism flexibility and adaptability to dietary shifts. OBD increased omega 6 fatty acid, Arachidonic Acid (AA) and decreased omega 3-derived lipid mediators in the OBD mimicking non-alcoholic fatty liver disease thus impacting inflammation-resolution pathways. OBD also induced hepatic inflammation via increasing alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and proinflammatory markers CCR2, TNF-α, and IL-1β in liver. Transitioning from OBD to CON mitigated inflammatory gene expression and restored lipid and cholesterol networks. This study underscores the intricate interplay between lifestyle-driven dietary changes, gut microbiota, lipid metabolism, and liver health. Notably, it suggests that shift from an OBD (omega-6 enriched) to CON partially alleviates signs of chronic inflammation during aging. Understanding these microbial, lipidomic, and hepatic inflammatory dynamics reveals potential therapeutic avenues for metabolic disorders induced by diet, emphasizing the pivotal role of diet in sustaining metabolic health.