AUTHOR=Hou Gaifeng , Yin Jie , Wei Liangkai , Li Rui , Peng Wei , Yuan Yong , Huang Xingguo , Yin Yulong 

TITLE=Lactobacillus delbrueckii might lower serum triglyceride levels via colonic microbiota modulation and SCFA-mediated fat metabolism in parenteral tissues of growing-finishing pigs

JOURNAL=Frontiers in Veterinary Science

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.982349

DOI=10.3389/fvets.2022.982349

ISSN=2297-1769

ABSTRACT=<p>Gut microbiota and its metabolites play a key role in host metabolism. Our previous study found supplemental <italic>Lactobacillus delbrueckii</italic> affected lipid metabolism of pigs, however, the underlying mechanism is unclear. In this study, we investigated the effects of <italic>L. delbrueckii</italic> on colonic bacteria composition and its metabolites, serum lipids and hormone levels, fat metabolism related enzyme activity and gene expression in various tissues of growing-finishing pigs. Twelve pigs were randomly distributed into two groups (<italic>n</italic> = 6), and pigs in each group were fed diets with (Con + LD) or without (Con) 0.1 % <italic>L. delbrueckii</italic> for 28 days. Results exhibited the deceased triglyceride (TG) levels and elevated free fatty acid (FFA) contents in serum and increased concentrations of butyric acid in colonic digesta after <italic>L. delbrueckii</italic> supplementation. Dietary <italic>L. delbrueckii</italic> increased abundance of <italic>Lactobacillus</italic> and <italic>Butyrivibri</italic> and tended to increase abundance of <italic>Akkermansia and Megasphaera</italic> in colonic digesta. <italic>L. delbrueckii</italic> consumption up-regulated glucagon-like peptide1 (<italic>GLP-1</italic>), monocarboxylate transporter1 (<italic>MTC1)</italic> and sodium-dependent monocarboxylate transporter1 (<italic>SMCT1</italic>) expression in colonic tissue. Administration of <italic>L. delbrueckii</italic> tended to increase lipoprotein lipase (LPL) activity, up-regulated <italic>CPT-1</italic>, angiopoietin-like protein 4 (<italic>Angpt14</italic>), <italic>LPL</italic> and triglyceride hydrolase (<italic>TGH</italic>) expression and down-regulated fatty acid synthetase (<italic>FAS</italic>), G protein-coupled receptor 41(<italic>GPR41</italic>) and <italic>GPR43</italic> expression in the liver. <italic>L. delbrueckii</italic> addition increased adenosine monophosphate activated protein kinase (<italic>AMPK</italic>) expression in <italic>longissimus dorsi</italic>, upregulated <italic>LPL, CPT-1, Angptl4</italic> and cluster of differentiation 36 (<italic>CD36</italic>) expression in subcutaneous fat, and enhanced <italic>LPL, CPT-1, TGH</italic>, adipocyte determination and differentiation-dependent factor 1 (<italic>ADD1</italic>) and hormone sensitive lipase (<italic>HSL</italic>) expression in leaf lard. These findings suggested that <italic>L. delbrueckii</italic> might enhance lipolysis and fatty acid β-oxidation to lower serum TG levels via colonic microbiota modulation and short chain fatty acids-mediated lipid metabolism of growing-finishing pigs.</p>