Effects of the Novel LaPLa-Enriched Medium- and Long-Chain Triacylglycerols on Body Weight, Glycolipid Metabolism, and Gut Microbiota Composition in High Fat Diet-Fed C57BL/6J Mice

Abstract

The roles of medium- and long-chain triacylglycerols (MLCT) on health benefits under high fat diet (HFD) conditions remain in dispute. This study was conducted to investigate the effects of novel LaPLa-rich MLCT on the glycolipid metabolism and gut microbiota in HFD-fed mice when pork fat is half replaced with MLCT and palm stearin (PS). The results showed that although MLCT could increase the body weight in the mouse model, it can improve the energy utilization, regulate the glucose and lipid metabolism, and inhibit the occurrence of inflammation. Furthermore, 16S rRNA gene sequencing of gut microbiota indicated that PS and MLCT affected the overall structure of the gut microbiota to a varying extent and specifically changed the abundance of some operational taxonomic units (OTUs). Moreover, several OTUs belonging to the genera Dorea, Streptococcus, and g_Eryipelotrichaceae had a high correlation with obesity and obesity-related metabolic disorders of the host. Therefore, it can be seen that this new MLCT has different properties and functions from the previous traditional MLCT, and it can better combine the advantages of MLCT, lauric acid, and sn-2 palmitate, as well as the advantages of health function and metabolism. In summary, this study explored the effects of LaPLa-enriched lipids on glycolipid metabolism in mice, providing theoretical support for future studies on the efficacy of different types of conjugated lipids, intending to apply them to industrial production and subsequent development of related products.

Keywords: MLCT; glucose homeostasis; gut microbiota; inflammation; lipid metabolism.

Figure 1

Body weight gain and energy intake. (A) Body weight of mice over 10 weeks. (B) Body weight gain percentage. (C) Body weight gain. (D) Total energy intake. In (B,C), means with the different lowercased letters differ significantly (p < 0.05) according to one-way ANOVA analysis followed by Tukey’s tests.

Figure 2

Organ indexes and morphological changes. (A) The weight percentage of organs. (B) Adipocyte size of eWAT (n = 6). (C) H&E staining of eWAT. (D) H&E staining of liver tissues. In (B), means with the different lowercased letters differ significantly (p < 0.05) according to one-way ANOVA analysis followed by Tukey’s tests.

Figure 3

Effects of MLCT on serum lipid profiles. (A) TG. (B) TCHO. (C) LDL-C. (D) HDL-C. Data were shown as mean ± SE (n = 8). In (A–D), means with the different lowercased letters differ significantly (p < 0.05) according to one-way ANOVA analysis followed by Tukey’s tests.

Figure 4

Effects of MLCT on glucose homeostasis. (A) Glucose tolerance test (GTT). (B) Area under curve (AUC) from GTT. (C) Fasting serum glucose. (D) Fasting serum insulin. (E) HOMA-IR. Data were shown as mean ± SE (n = 8). In (B,C,E), means with the different lowercased letters differ significantly (p < 0.05) according to one-way ANOVA analysis followed by Tukey’s tests.

Figure 5

Effects of MLCT on serum hormones and cytokines. (A) LEP. (B) ADP. (C) GPT. (D) GOT. (E) LPS. (F) LBP. (G) ALP. Data were shown as mean ± SE (n = 8). In (B–D), means with the different lowercased letters differ significantly (p < 0.05) according to one-way ANOVA analysis followed by Tukey’s tests.

Figure 6

Effects of MLCT on diversity of the gut microbiota. (A) Sobs. (B) Chao1. (C) Shannon. (D) Simpson. (E) OTUs Venn Diagram. (F) PCoA plot (weighted UniFrac distances). Data were shown as mean ± SE (n = 8). In (A–D), means with the different lowercased letters differ significantly (p < 0.05) according to one-way ANOVA analysis followed by Tukey’s tests.

Figure 7

Effects of MLCT on the gut bacteria composition. (A) Heatmap analysis on genus level (the relative abundance of OTUs > 0.25%); (B) The LEfSe analysis (LDA > 3.0). (C) The relative abundance of g_unclassified_f_Desulfovibrionaceae, Dorea, g_unclassified_f_Lachnospiraceae, Streptococcus, Lactococcus, Clostridium_sensu_stricto, Anoxybacillus, and g_unclassified_Erysipelotrichaceae. (D) Correlations between intestinal microflora and biochemical indicators. In (A), p < 0.05 marked with “*” compared with HFD group. In (D), p < 0.001 marked with “***”, p < 0.01 marked with “**”, p < 0.05 marked with “*”. In (C), means with the different lowercased letters differ significantly (p < 0.05) according to one-way ANOVA analysis followed by Tukey’s tests.