Lactic Acid Bacteria Isolated from Japanese Fermented Fish (Funa-Sushi) Inhibit Mesangial Proliferative Glomerulonephritis by Alcohol Intake with Stress

Abstract

The aim of this study was to examine the effect of heat-killed Lactobacillus paracasei NFRI 7415 on kidney and bone in mice fed an ethanol-containing diet with stress. Eight-week-old Cril : CD1 mice were fed a control diet (CD), an alcohol diet (AD) (35.8% of total energy from ethanol), or an alcohol diet containing 20% heat-killed Lb. paracasei NFRI 7415 (10⁷ CFU/g) (LD) for 4 weeks. Mice in the AD and LD groups also underwent restraint stress for two weeks from 13 days. The mice were placed in a 50 mL plastic tube, which had a small hole drilled around its base to allow ventilation, and restrained for 1 h every day. High final body weight was in the following order: CD, LD, and AD (p < 0.05). The heat-killed Lb. paracasei NFRI 7415 lowered liver total cholesterol concentration and plasma glutamic-oxaloacetic transaminase (GOT) level. In addition, fecal bile acids of the LD group were higher than in the AD group (p < 0.05). The glomerulus of the kidney in the AD group was observed to be more fibrotic than in the CD and LD groups with azan stain. Immunostaining confirmed that brown areas indicating the existence of mesangial cells were increased in the AD group, but not in the CD and LD groups. These results indicated that the heat-killed Lb. paracasei NFRI 7415 inhibited mesangial proliferative glomerulonephritis by alcohol intake with stress.

Figure 1

Restraint stress. Mice were placed in a 50 ml plastic tube, which had a small hole drilled around its base to allow ventilation, and restrained for 1 h every day.

Figure 2

Body weight of mice during the experiment (n = 8). Arrow: start of restraint stress.

Figure 3

Plasma GOT level and plasma GPT level concentration of mice fed experimental diets. CD, control diet; AD, alcohol diet; LD, Lb. paracasei-containing alcohol diet. Values represent mean ±SD; n = 8. Values not sharing a common superscript letter are significantly different at p < 0.05.

Figure 4

Mesangiolysis in mice. (a)–(c) Azan staining of the glomerulus in the kidney. (a) The glomerulus in the kidney from a normal mouse fed with control diet (CD). Blue regions (white arrows) show collagen fiber. (b) The glomerulus in the kidney from a mouse fed with alcohol diet (AD). Blue regions (white arrows) show collagen fiber, which are increased compared to (a). (c) The glomerulus in the kidney from a mouse fed with AD containing Lb. paracasei. Blue regions (white arrows) show collagen fiber, which are reduced compared to (b). (d)–(f) Immunostaining of the glomerulus in the kidney. (d) The glomerulus in the kidney from a normal mouse fed CD. A mesangial cell (black arrow) is stained by desmin. (e) The glomerulus in the kidney from a mouse fed with AD. The number of mesangial cells (black arrows) is higher than in the normal kidney (d). (f) The glomerulus in the kidney from a mouse fed AD containing Lb. paracasei. The number of mesangial cells (black arrow) is fewer than that of animals fed AD (e).