Lactiplantibacillus plantarum Y44 Complex Fermented\nMilk Regulates Lipid Metabolism in Mice Fed\nwith High-Fat Diet by Modulating Gut Microbiota

The benefits of fermented milk containing Lactiplantibacillus\nplantarum (L. plantarum) Y44, known for its weight loss properties, remain unclear. For\nthis, we evaluated the effects of the complex fermented milk (Y44-CFM),\nobtained through the cofermentation of cow’s milk and soybean\nmilk with L. plantarum Y44 and traditional\nstarters, on high-fat diet (HFD)-fed C57BL/6 mice. Our study found\nthat the oral administration of Y44-CFM significantly reduced body\nweight gain and hepatic lipid accumulation in HFD-fed mice while also\nmitigating liver injury. Additionally, Y44-CFM regulated the expression\nof enzymes associated with lipid metabolism in the serum, as well\nas the corresponding or related genes in the liver, such as fatty\nacid synthase. Furthermore, HFD-induced systemic inflammation, oxidative\nstress, and intestinal barrier dysfunction were improved. The primary\nalterations in hepatic metabolism involved glycerophospholipids and\namino acids, including the biosynthesis of valine, leucine, and isoleucine.\nThe diversity and overall structure of the gut microbiota were also\nregulated, resulting in a significant decrease in the ratio of <i>Firmicutes</i> to <i>Bacteroidetes</i> (F/B) and unclassified_f_<i>Lachnospiraceae</i>, along with a notable increase in <i>Oscillospiraceae</i>. The correlation analysis indicated that\nY44-CFM influenced hepatic lipid metabolism by mediating intestinal\nflora and its production of short-chain fatty acids, ultimately leading\nto weight reduction.