Effects of Coix Seed Extract, Bifidobacterium BPL1, and Their Combination on the Glycolipid Metabolism in Obese Mice

Abstract

Coix seed extract (CSE) and probiotics have been reported to regulate glycolipid metabolism via different modes of action. We tested the effects of CSE, Bifidobacterium BPL1, and their combination to determine their effects on glycolipid metabolism in obese mice. Male C57BL/6J mice were fed a high-fat diet for 8 weeks to establish an obesity model. Obese mice were selected and divided into four groups: the model control group and three intervention groups. After 10 weeks of continuous gavage intervention, the mice in the intervention groups exhibited lower body weight (lower about 2.31 g, vs. HFD mice 42.23 g) and epididymal (lower about 0.37 g, vs. HFD mice 2.5 g) and perirenal fat content (lower about 0.47 g, vs. HFD mice 0.884 g); decreased fasting blood glucose, total cholesterol, triglycerides, and VLDL; and increased HLDL, respiratory exchange ratio, energy expenditure, and amount of exercise performed. CSE, BPL1 and their combination can effectively control the weight gain in obese mice, reduce fat content, and regulate blood lipids and abnormal blood sugar. These results may be related to reduce the chronic inflammatory states, improve energy metabolism, exercise, relieve insulin sensitivity, and reduce lipid synthesis via the intervention of CSE, BPL1 and their combination. Compared with the single use of CSE alone, the combination of CSE + BPL1 can better exert the regulation function of intestinal flora, and change in the abundance of bacteria that could improve the level of inflammatory factors, such as increasing Bifidobacterium, reducing Lactococcus. Compared with the use of BPL1 alone, the combination of CSE and BPL1 can better regulate pancreatic islet and improve blood sugar. CSE may act directly on body tissues to exert anti-inflammatory effects. BPL1 and CSE + BPL1 may improve the structure and function of the intestinal flora, and reduce tissue inflammation.

Keywords: Bifidobacterium BPL1; Coix seed extract; glycolipid metabolism; gut flora; inflammation; obesity.

FIGURE 1

Results of body weight and feed intake. (A) Body weight during intervention. (B) End-of-intervention body weight in each group. (C) Total feed intake. (D) Total energy intake. Data are means ± SD (n = 12). a: P < 0.05, compared with ND. b: P < 0.05, compared with HFD.

FIGURE 2

Results of body fat distribution. (A) Total body fat weight. (B) Peritesticular fat. (C) Perirenal fat. (D) Lipid body ratio. (E) Live weight. (F) HE staining of liver tissue. Data are means ± SD (n = 12). a: P < 0.05, compared with ND. b: P < 0.05, compared with HFD.

FIGURE 3

Results of blood lipids levels. (A) TG (triglycerides). (B) TC (total cholesterol). (C) VLDL (very low-density lipoprotein). (D) HLDL (high density lipoprotein). Data are means ± SD (n = 12); a: P < 0.05, compared with ND. b: P < 0.05, compared with HFD.

FIGURE 4

Results of markers of glucose metabolism. (A) Fasting blood glucose. (B) OGTT (Oral glucose tolerance tests). (C) Serum INS (insulin) level. (D) HOMA-β (insulin β-cell function). (E) HOMA-IR (insulin resistance index). Data are means ± SD (n = 12); a: P < 0.05, compared with ND. b: P < 0.05, compared with HFD.

FIGURE 5

Energy Metabolism-Related Indicators. (A1) Change in the respiratory exchange ratio (RER) over time. (A2) Comparison of the mean RER of each group. (B1) Change in the energy expenditure (EE₁) over time. (B2) Comparison of the mean EE₁ of each group. (C1) Change in the energy expenditure (EE₂) over time. (C2) Comparison of the mean EE₂ of each group. (D1) Change in the energy expenditure (EE₃) over time. (D2) Comparison of the mean EE₃ of each group. The body weight was used to correct EE₁ to obtain EE₂, and the lean body mass was used to correct EE₂ to obtain EE₃. Data are means ± SD (n = 12); a: P < 0.05, compared with ND. b: P < 0.05, compared with HFD.

FIGURE 6

Results of serum glycolipid metabolism-related indicators. (A) Inflammatory factors IL-1β. (B) Inflammatory factors TNF-α. (C) Serum LEP (Leptin) level. (D) Serum ADP (Adiponectin) level. Data are means ± SD (n = 12); a: P < 0.05, compared with ND. b: P < 0.05, compared with HFD.

FIGURE 7

Results of glycolipid metabolism-related indicators in liver tissue. (A) LPL (lipoprotein lipase). (B) FAS (fatty acid synthase). (C) CYP7A1 (cholesterol 7α-hydroxylase). (D) SREBP-1 (Sterol regulatory element binding transcription factor-1). Data are means ± SD (n = 12). a: P < 0.05, compared with ND. b: P < 0.05, compared with HFD.

FIGURE 8

Results of gut microbiome. (A,B) Gut microbiota composition at the (A) phylum and (B) genus levels. (C–F) Intestinal flora diversity analysis. (C) Sob index and (D) ACE index of α diversity of intestinal flora. (E) β diversity of intestinal flora at the phylum levels. (F) β diversity of intestinal flora at the genus levels. (G,H) Gut microbiota functional analysis. (G) Comparison of microbiota function in obese and normal mice at the initiation of intervention. (H) Comparison of microflora function of each group at the end of the intervention. (I,J) The relationship between inflammatory factors and intestinal flora. (I) Correlation between gut microbiota and inflammatory factors. (J) The relationship between different groups of intestinal flora and inflammatory factors.