Reduced meal frequency alleviates high-fat diet-induced lipid accumulation and inflammation in adipose tissue of pigs under the circumstance of fixed feed allowance

Abstract

Purpose: The present study was conducted to determine whether reduced meal frequency (MF) could restore high-fat diet (HFD)-modified phenotypes and microbiota under the condition of fixed feed allowance.

Methods: A total of 32 barrows with initial weight of 61.6 ± 0.8 kg were assigned to two diets [control diet (CON) versus HFD] and two meal frequencies [12 equal meals/day (M12) versus 2 equal meals/day (M2)], the trial lasted 8 weeks. The lipid metabolism and inflammatory response in adipose tissue as well as the profiles of intestinal microbiota and bacterial-derived metabolites were determined.

Results: M2 versus M12 feeding regimen decreased perirenal fat weight and serum triglyceride and liposaccharide (LPS) concentrations in HFD-fed pigs (P < 0.05). Reduced MF down-regulated mRNA expression of lipoprotein lipase, CD36 molecule, interleukin 1 beta, tumor necrosis factor alpha, toll-like receptor 4, myeloid differentiation factor 88 (MYD88), and nuclear factor kappa beta 1 as well as protein expression of MYD88 in perirenal fat of HFD-fed pigs (P < 0.05). M2 feeding regimen increased abundance of Prevotella and decreased abundance of Bacteroides in colonic content of HFD-fed pigs (P < 0.05). No difference in short-chain fatty acids (SCFAs) profile in colonic content was observed among four groups (P > 0.05).

Conclusion: Our results suggested that M2 versus M12 feeding regimen ameliorated HFD-induced fat deposition and inflammatory response by decreasing fatty acid uptake and deactivating LPS/TLR4 signaling pathway in adipose tissue and restoring microbiota composition in distal intestine, without affecting SCFAs profile in distal luminal content.

Keywords: High-fat diet; Inflammation; Lipid metabolism; Meal frequency; Microbiota; Short-chain fatty acids.