Application of lactobacillus in the preparation of medicine for treating chronic ulcerative colitis combined with non-alcoholic fatty liver

Abstract

The present invention discloses the use of lactobacillus in the preparation of a drug for treating chronic ulcerative colitis combined with non-alcoholic fatty liver disease. The present invention uses intermittent sodium dextran sulfate to induce chronic ulcerative colitis, and daily high-fat diet to induce the establishment of a non-alcoholic fatty liver model. During the entire research process, lactobacillus is given daily for intervention to evaluate the effect of lactobacillus on the disease. The results show that lactobacillus has a therapeutic effect on chronic ulcerative colitis, and its mechanism includes reducing the body's inflammatory response, regulating intestinal flora, promoting mucosal healing, and improving colon mucosal integrity. In addition, lactobacillus has a preventive effect on non-alcoholic fatty liver disease secondary to chronic ulcerative colitis, and its mechanism includes regulating blood lipid metabolism, improving inflammatory defense capabilities, and protecting the intestinal mucosal barrier.

Description

Technical Field

[0001] The invention relates to the field of medicine, and in particular to the use of lactobacillus in the preparation of a medicine for treating chronic ulcerative colitis combined with non-alcoholic fatty liver. Background Art

[0002] In recent years, non-alcoholic fatty liver disease (NAFLD) has become one of the most important obesity-related comorbidities. According to statistics, about 25% of adults worldwide currently suffer from NAFLD. The liver and the intestine have the same embryonic origin, so to a certain extent, they maintain many "natural" anatomical and functional connections. For example, blood supply. The blood supply of the liver mainly comes from the portal vein and the hepatic artery, and the blood supply of the portal vein accounts for about 70% of the total blood supply of the liver, while the blood supply of the portal vein mostly comes from the superior mesenteric vein and the inferior mesenteric vein. These veins usually contain metabolites from the digestive tract and intestinal microbial products. The concept of "gut-liver axis" was proposed by Marshall in 1998. The "liver-gut axis" refers to the liver and intestines being closely connected mainly through the portal vein system. The two are interconnected and cooperate with each other in terms of immunity, metabolism, defense, etc. The intestine has the function of digesting and absorbing nutrients, and is also the largest immune system of the body. Under normal physiological conditions, the intestinal mucosal barrier, as the first line of defense of the body, can meet the needs of digestion and absorption of nutrients, while maintaining peaceful coexistence with symbiotic bacteria and protecting the body from infection.

[0003] Miele, L et al. (Increased intestinal permeability and tight junction alterations in nonalcoholic fatty liver disease. 2009; 49(6): 1877-1887) studied 35 patients diagnosed with nonalcoholic fatty liver disease by liver biopsy, and measured 51Cr-EDTA excretion time and duodenal ZO-1 protein expression. The study found that the intestinal mucosal permeability of NAFLD patients was significantly changed, and bacterial overgrowth occurred. It is speculated that NAFLD may promote fat accumulation by destroying the tight junctions between cells and inducing increased intestinal mucosal permeability. This effect is positively correlated with the degree of fatty lesions in the liver of NAFLD.

[0004] Due to infection or other diseases, "intestinal permeability" may increase, leading to intestinal barrier dysfunction, contributing to the early progression of inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) and colon cancer. In IBD, permeability changes increase the translocation of proinflammatory stimuli to the lamina propria, thereby triggering tight junction changes mediated by inflammatory cytokines. Bessissoow et al. (Incidence and Predictors of Nonalcoholic Fatty Liver Disease by Serum Biomarkers in Patients with Inflammatory Bowel Disease. 2016; 22(8):1) confirmed that the prevalence of NAFLD commonly diagnosed in IBD patients was 33.6%. Previous studies have shown that the integrity of the intestinal mucosa is also a treatment strategy for NAFLD.

[0005] Chronic ulcerative colitis is a relatively common chronic nonspecific inflammation. For patients with chronic ulcerative colitis combined with non-alcoholic fatty liver disease, developing drugs to treat chronic ulcerative colitis combined with non-alcoholic fatty liver disease is a technical solution that technical personnel in this field need to solve. Summary of the invention

[0006] To this end, the present invention proposes the use of lactobacillus in the preparation of a medicine for treating chronic ulcerative colitis combined with non-alcoholic fatty liver.

[0007] The technical solution of the present invention is the use of lactobacillus in the preparation of a medicine for treating chronic ulcerative colitis combined with non-alcoholic fatty liver.

[0008] The lactobacillus is used in the preparation of a medicine for treating chronic ulcerative colitis combined with non-alcoholic fatty liver disease, wherein the chronic ulcerative colitis is chronic ulcerative colitis induced by sodium dextran sulfate.

[0009] The lactobacillus is used in the preparation of a drug for treating chronic ulcerative colitis combined with non-alcoholic fatty liver disease, wherein the non-alcoholic fatty liver disease is non-alcoholic fatty liver disease induced by a high-fat diet.

[0010] Lactobacillus is a powder made by fermenting skim milk powder with Lactobacillus acidophilus. Lactic acid and short-chain fatty acids are the main metabolites. Calculated on a dry basis, the total acid content should not be less than 10% in terms of lactic acid, and the total nitrogen content should not be less than 4.4%. Probiotics such as Lactobacillus CQPC06, Lactobacillus plantarum NA136 and Lactobacillus plantarum 136 improve non-alcoholic fatty liver disease by regulating intestinal microbiota, improving intestinal barrier integrity and reducing inflammation. The diversity and composition of intestinal microbiota are significantly related to the disease progression of NAFLD. Based on the regulatory effect of lactobacillus on intestinal flora, the present invention uses intermittent dextran sulfate sodium salt (DSS) to induce chronic ulcerative colitis, and daily high-fat diet to induce the establishment of non-alcoholic fatty liver model. During the entire study, lactobacillus is given daily to intervene and evaluate the effect of lactobacillus on the disease. The results show that lactobacillus has a therapeutic effect on chronic ulcerative colitis, and its mechanism includes reducing the body's inflammatory response, regulating intestinal flora, promoting mucosal healing, and improving colon mucosal integrity. In addition, lactobacillus has a preventive effect on non-alcoholic fatty liver secondary to chronic ulcerative colitis, and its mechanism includes regulating blood lipid metabolism, improving inflammatory defense ability and protecting the intestinal mucosal barrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and / or additional aspects and advantages of the embodiments of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0012] Figure 1 is the disease activity index (DAI) of mice in each group during DSS administration, where Con: normal control group, Mod: model group, JL: low-dose lactobacillus group, JH: high-dose lactobacillus group. Compared with the model group, * indicates significant difference P < 0.05;

[0013] Figure 2 (A) is the colon length of mice in each group, (B) is the comparison of the significant difference of colon length of mice in each group, where the mean ± standard deviation (n = 10 per group), # compared with the normal control group, ###p < 0.001; * compared with the model group, *p < 0.05, **p < 0.01, Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group; JH represents the high-dose lactobacillus group;

[0014] Figure 3 The HE staining of colon tissues of mice in each group (200 times), where Con: normal group; Mod: model group; JL: low-dose lactobacillus group; JH: high-dose lactobacillus group;

[0015] Figure 4The jejunal tissue HE staining (200 times) of mice in each group, where Con: normal group; Mod: model group; JL: low-dose lactobacillus group; JH: high-dose lactobacillus group;

[0016] Figure 5 is the immunofluorescence staining of tight junction protein in colon tissue of mice in each group (200 times), where Con: normal group; Mod: model group; JL: low-dose lactobacillus group; JH: high-dose lactobacillus group, mean ± standard deviation (n = 10 per group), # compared with the normal control group, #p < 0.05; * compared with the model group, *p < 0.05;

[0017] Figure 6 is the concentration of mannitol in the blood of mice in each group, where mannitol: mannitol, mean ± standard deviation (n = 10 per group), # compared with the normal control group, ###p < 0.001; * compared with the model group, *p < 0.05; Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group; JH represents the high-dose lactobacillus group;

[0018] Figure 7 Comparison of serum liver function indexes of mice in each group (AST: aspartate aminotransferase; ALT: alanine aminotransferase), where the mean ± standard deviation (n = 10 per group), # compared with the normal control group, ###p < 0.001; * compared with the model group, *p < 0.05, **p < 0.01; Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group; JH represents the high-dose lactobacillus group;

[0019] Figure 8 It is a comparison chart of blood lipid metabolism indexes of mice in each group, among which, TC: total cholesterol; TG: total triglyceride; LDL: low-density lipoprotein; HDL: high-density lipoprotein, mean ± standard deviation (n = 10 per group), # compared with the normal control group, ###p < 0.001; * compared with the model group, *p < 0.05, **p < 0.01; Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group, and JH represents the high-dose lactobacillus group;

[0020] Fig. 9 It is a comparison chart of the contents of inflammatory factors monocyte chemoattractant protein 1 (MCP-1) and tumor necrosis factor-α (TNF-α) in the serum of mice in each group, wherein, mean ± standard deviation (n = 10 per group), # compared with the normal control group, ###p < 0.001; * compared with the model group, *p < 0.05; Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group, and JH represents the high-dose lactobacillus group;

[0021] Fig.10 The effect of lactobacillus on the pathological changes of liver tissue (HE staining, 200x), where Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group, and JH represents the high-dose lactobacillus group;

[0022] Fig.11 The effect of lactobacillus on the pathological changes of liver tissue (oil red staining), where Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group, and JH represents the high-dose lactobacillus group;

[0023] Fig.12 It is the PCoA analysis diagram of the intestinal flora of each group, where Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group, and JH represents the high-dose lactobacillus group;

[0024] Fig.13 It is the NMSD analysis diagram of the intestinal flora of each group, where Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group, and JH represents the high-dose lactobacillus group;

[0025] Fig.14 This is a comparison chart of the differences of key bacterial genera at the family level in each group, where Con represents the normal group; Mod represents the model group; JL represents the low-dose lactobacillus group, and JH represents the high-dose lactobacillus group;

[0026] Fig.15 This is a comparison of the differences in key bacterial genera between the high-dose lactobacillus group and the model group at the family level, where Mod represents the model group and JH represents the high-dose lactobacillus group. DETAILED DESCRIPTION

[0027] In the embodiment of the present invention, intermittent DSS was used to induce chronic ulcerative colitis, and a high-fat diet was used daily to induce a non-alcoholic fatty liver model. During the entire study, lactobacillus was given daily to intervene and evaluate the effect of lactobacillus on the disease.

[0028] 1. Materials

[0029] Animals: C57BL / 6J mice, male, 6-8 weeks old, 40 in total. Purchased from Jiangsu Jicui Yaokang Biotechnology Co., Ltd., certificate number SCXK (Su) 2018-0008, room temperature (22 ± 1) °C, relative humidity 30%-60%, 12 h light / 12 h dark, free access to food and water.

[0030] Reagents: lactobacillus (provided by Jiangzhong Pharmaceutical Co., Ltd., batch number: 20211022); dextran sulfate sodium salt (DSS, batch number: S5036, MP Biomedicals); D-mannitol (batch number: 1103G031, purity: 98%, Solarbio), D-mannitol ELISA kit (batch number: 202110, mlbio); endotoxin quantification kit (batch number: OEC6C70000, ThermoFisher ELISA kits for TNF-α (batch number: 24117791019), MCP-1 (batch number: 27301917931), IL-6 (batch number: 13217691019) and adiponectin (batch number: 301171061019) were purchased from Wuhan Boster Biotechnology Co., Ltd.; alanine aminotransferase (ALT, batch number: 140121007), aspartate aminotransferase (AST, batch number: 140221005), triglyceride (TG, batch number: 141721006), total cholesterol (TC, batch number: 141621006), low-density lipoprotein cholesterol (LDL, batch number: 142021005) and high-density lipoprotein cholesterol (HDL, batch number: 142121007) (Mindray) activity assay kits.

[0031] 2. Methods

[0032] Establishment of non-alcoholic fatty liver disease model secondary to chronic ulcerative colitis: After 1 week of adaptive feeding of mice, 10 mice were randomly selected as the normal group, and the remaining mice were induced intermittently with 1% DSS in drinking water, with 1% DSS for 7 days and pure water for 10 days in each cycle, for a total of 6 cycles, and were given a high-fat diet at the same time. The normal control group was given sufficient standard feed and drinking water.

[0033] Animal grouping and drug administration: normal control group (Con), model group (Mod, DSS and high-fat diet treatment), model group treated with low-dose lactobacillus (JL, 0.6 g / kg), model group treated with high-dose lactobacillus (JH, 1.2 g / kg), intragastric volume 10 mL·Kg -1 The blank control group and the model control group were given normal saline once a day, with an intragastric volume of 10 mL·Kg -1 , for 102 consecutive days.

[0034] Observation indexes and detection methods: The disease activity index of each group of mice was scored according to the standards in Table 1. The weight, stool characteristics, and occult blood in stool of the mice were recorded every day, and the disease activity index (DAI) was scored and calculated.

[0035] Table 1 Scoring criteria for disease activity index in mice

[0036]

[0037] 3. Results

[0038] 3.1 Effect of lactobacillus on the disease activity index of mice with chronic ulcerative colitis and high-fat diet

[0039] from Figure 1 It can be seen that during each cycle of drinking pure water, except for the normal group, the colitis symptoms of mice in each group gradually alleviated, and the DAI index decreased. During the drinking period of 1% DSS, all animals showed weight loss, and most animals showed more or less rectal bleeding and loose stools. Over time, the symptoms gradually worsened after drinking DSS. The disease activity index of mice in the high-dose lactobacillus group was significantly lower than that in the model group at the eighth, eleventh, fourteenth and fifteenth weeks (P<0.05).

[0040] In the DSS-induced chronic ulcerative colitis and secondary fatty liver model, colon mucosal edema was observed in the model group mice, and the colon was shortened to varying degrees. Figure 2 It can be seen that compared with the normal group, the colon length of the model group mice was significantly reduced (P<0.001), and compared with the model group, the colon length of the high and low doses of lactobacillus groups was significantly increased (P<0.05, P<0.01). Under the naked eye, the colon mucosa of the normal group mice was smooth, without adhesion and ulcer formation, the colon tissue of the model group mice was significantly enlarged, and the colon enlargement of the high and low doses of lactobacillus groups was significantly reduced.

[0041] 3.2 Effects of lactobacilli on histopathological and biochemical parameters in mice with chronic ulcerative colitis and high-fat diet

[0042] Figure 3 Respectively represent the morphological changes of the colon tissue of each group of mice. Compared with the normal group, the model group showed the loss of single-layer columnar epithelium on the surface of the intestinal mucosa, atrophy of intestinal crypts, reduction in the number of crypts, irregular shapes of goblet cells in the crypts, and most of them were missing. The thickness of the crypt base increased significantly. The intestinal villus vacuoles on the surface of the colon were obvious. Compared with the model group, in the colon sections of mice treated with high and low doses of lactobacillus, the intestinal crypt structure was more complete, the goblet cells were arranged more neatly, the intestinal villi were more complete, and there was also a widening of the crypt opening, an uneven mucosal surface, and a villus-like change.

[0043] Figure 4 The morphological changes of the jejunum in each group of mice are shown in Figure 2. Compared with the normal group, the intestinal crypts in the model group were significantly reduced, loosely arranged, and the intestinal villi were swollen or even missing, and the depth of the jejunal crypts was significantly different. In the colon sections of rats treated with lactobacillus, the intestinal crypt structure was relatively complete, the goblet cells were neatly arranged, and the edges of the intestinal villi and intestinal mucosa were relatively neat.

[0044] The integrity of the intestinal mucosa is determined by the protective layer of defensins on the intestinal surface of intestinal epithelial cells, tight junctions (TJs) proteins between intestinal epithelial cells, and the function of intestinal immune cells on the intestinal wall. Figure 5 As shown in the figure, compared with the normal group, the model group significantly reduced the expression of tight junction protein (ZO-1) and mucin 2 (MUC-2) (p<0.05). Compared with the model group, the high-dose lactobacillus group significantly increased the expression of ZO-1 and MUC-2 (p<0.05).

[0045] See also Figure 6 The mice in each group were gavaged with mannitol 6 hours before being killed. The concentration of mannitol in serum was measured after being killed. The difference in intestinal permeability of mice was compared. The results showed that the concentration of mannitol in serum of the model group was significantly higher than that of the normal group (P < 0.001), and the concentration of mannitol in the high-dose lactobacillus group was significantly lower than that of the model group (P < 0.05). Lactobacillus has a significant effect on protecting intestinal permeability and intestinal mucosal integrity.

[0046] Chronic ulcerative colitis combined with a high-fat diet leads to liver tissue lesions, inducing abnormal liver indicators AST and ALT. Figure 7 Compared with the normal group, the serum ALT and AST of the mice in the model group were significantly increased (P<0.01), while the serum ALT and AST of the mice in the high- and low-dose groups of lactobacillus were significantly reduced (P<0.01, P<0.05), which significantly improved the liver function related indicators. This shows that lactobacillus has the effect of protecting liver damage.

[0047] A high-fat diet induces a large accumulation of TG in the body, which is one of the key factors that induce non-alcoholic fatty liver disease. Figure 8 It can be seen that due to the high-fat diet, the levels of TG and TC in the serum of the model group mice were significantly higher than those of the normal group (#p<0.05), and the levels of TG in the serum of the mice in the high- and low-dose lactobacillus groups were significantly lower than those in the model group (*p<0.05). The high-density lipoprotein (HDL) in the model group was extremely significantly lower than that in the normal group (###p<0.001), and the levels of HDL in the serum of the mice in the high- and low-dose lactobacillus groups were significantly higher than those in the model group (*p<0.05, **p<0.01).

[0048] from Fig. 9 It can be seen that the results of serum inflammatory indicators of mice in each group, monocyte chemoattractant protein 1 (MCP-1) and tumor necrosis factor-α (TNF-α), showed that compared with the normal group, the model group had significantly increased MCP-1 and TNF-α, and the lactobacillus group had a decreasing trend compared with the model group. Compared with the model group, the high-dose lactobacillus group had significant differences in the levels of MCP-1 (*p<0.05) and TNF-α (*p<0.05).

[0049] 3.3 Comparison of liver histopathology in each group of mice

[0050] from Fig.10 The results of HE staining of liver tissue showed that the liver lobule structure of the normal group mice was clear, the hepatic cords were neatly arranged, the hepatocyte cytoplasm was abundant, the nucleus was large and round, centered, the cell morphology was symmetrical, the structure was normal, the hepatic sinusoids did not show obvious expansion or extrusion, and no obvious lipid droplets were seen. The liver tissue of the model group mice showed obvious fatty degeneration, and more round vacuoles (lipid droplets) were seen in the cytoplasm. The hepatocytes were enlarged and swollen, the cytoplasm was loose, the nucleus was shrunken and smaller, and the boundaries between cells were unclear. Compared with the model group, the liver lobule structure of the high-dose lactobacillus group was clear, the hepatic cords were neatly arranged, the hepatocyte cytoplasm was abundant, and the morphology and structure were normal. The above results show that high and low doses of lactobacillus can reduce fat accumulation in the liver of mice, prevent fatty degeneration of liver tissue and the formation of secondary non-alcoholic fatty liver.

[0051] Fig.11 Oil red staining showed that in the model group, a large number of red lipid droplets gathered, and the lipid droplets were large and round, indicating that chronic ulcerative colitis combined with a high-fat diet successfully induced secondary non-alcoholic fatty liver disease in mice. After intervention with high- and low-dose lactobacillus groups, the color and number of red lipid droplets stained with oil red in the liver of the high-dose lactobacillus group were significantly reduced, indicating that the accumulation of triglycerides in the liver tissue of the drug-treated group was reduced. Lactobacillus has a significant inhibitory effect on non-alcoholic fatty liver disease.

[0052] In the DSS-induced chronic ulcerative colitis and secondary non-alcoholic fatty liver disease models, lactobacilli showed good results in hematological indicators related to liver function, systemic inflammation, lipid metabolism, and intestinal permeability.

[0053] 3.4 Effects of lactobacilli on intestinal flora in mice with chronic ulcerative colitis and high-fat diet

[0054] 3.4.1 Analysis of the effect of lactobacillus tablets on intestinal microbial diversity in mice with ulcerative colitis and high-fat diet

[0055] 3.4.1.1 Analysis of intestinal flora structure and composition

[0056] Analysis of intestinal flora structure and composition can be found in Fig.12 and Fig.13 In the PCoA score diagram, the percentages of PC1 and PC2 explaining the overall variance were 46.97% and 10.26%, respectively. The sample points in the model group could be completely separated from the sample points in the normal group. The sample points in the model group had large differences. The sample points in the model group were mostly separated from the sample points in the lactobacillus tablets group, indicating that the overall structure and composition of the intestinal flora in the lactobacillus tablets group had changed significantly compared with the model group, and were closer to the normal group.

[0057] 3.4.2 Analysis of species differences in intestinal flora

[0058] According to the analysis of the overall structure of the intestinal flora, the intestinal flora diversity of the high-dose and low-dose lactobacillus groups was significantly different from that of the model group, with a decrease in the relative abundance of Erysipelotrichaceae (Erysipelotrichaceae) and an increase in the relative abundance of Lachnospiraceae (Lachnospiraceae), Muribaculaceae (Salviaceae), Prevotallaceae (Prevotallaceae), Oscillospiraceae (Oscillospiraceae), and Desulfovibrionaceae (Desulfovibrionaceae). Fig.14 It can be seen that compared with the normal group, the model group had a significantly increased level of Erysipelotrichaceae (Erysipelotrichaceae) (P < 0.01). Studies have shown that Erysipelotrichaceae (Erysipelotrichaceae) is significantly positively correlated with acute ulcerative colitis. The high and low dose groups of lactobacillus significantly reduced the abundance of Erysipelotrichaceae (Erysipelotrichaceae) and alleviated the symptoms of ulcerative colitis. Muribaculacease can inhibit immune cell CD8 + The activation of T cells, thus tolerating immune stimulation and negatively correlated with the inflammatory state. Compared with the normal group, the abundance of Muribaculacease (Salviniaceae) in the model group was significantly reduced (P < 0.01), which was consistent with the higher level of inflammation in the model group mice. The high and low doses of lactobacillus significantly increased the abundance of Muribaculacease (Salviniaceae), which had a certain inhibitory effect on the activation of immune cells and the inflammatory state in the body.

[0059] See also Fig.15, the difference comparison analysis of the intestinal flora diversity between the high-dose lactobacillus group and the model group showed that the high-dose lactobacillus group significantly increased Lachnospiraceae, Prevotallaceae, Bacteroidaceae, Oscillospiraceae, Eubacterium_coprostanoligenes_group, and Peptococcaceae. It is worth noting that Lachnospiraceae belongs to the core flora in the intestine. Studies have shown that after humans and mice suffer from ulcerative colitis, the abundance of Lachnospiraceae in the intestine is significantly reduced, and increasing the abundance of Lachnospiraceae can significantly improve the symptoms of ulcerative colitis. The present invention shows that lactobacillus significantly increases the abundance of Lachnospiraceae in the intestine of mice with acute ulcerative colitis, and significantly alleviates the symptoms of chronic ulcerative colitis in mice, which is consistent with previous studies.

[0060] A high-fat diet has a certain effect on intestinal diversity and intestinal integrity, and can lead to a significant reduction in Eubacterium_coprostanoligenes_group (Eubacterium family) in the intestine. Eubacterium_coprostanoligenes_group (Eubacterium family) can produce beneficial short-chain fatty acids and reduce intestinal inflammation. Studies have shown that Eubacterium_coprostanoligenes_group has a significant improvement effect on dyslipidemia caused by a high-fat diet. The present invention shows that lactic acid bacteria significantly increases the abundance of Eubacterium_coprostanoligenes_group. Combined with the index analysis of blood lipid biochemistry related results, lactic acid bacteria have a significant effect on blood lipid regulation.

[0061] IV. Conclusion

[0062] In summary, compared with the model group, the DAI scores of the high-dose lactobacillus group at the eighth, eleventh, fourteenth and fifteenth weeks were significantly lower than those of the model group (P<0.05). At the same time, the colon length of mice in the high- and low-dose lactobacillus groups increased significantly (P<0.05); serum triglyceride (TG) and high-density lipoprotein (HDL) levels were significantly reduced (P<0.05); serum inflammatory factor tumor necrosis factor (TNF-α) was significantly reduced (P<0.05), monocyte chemoattractant protein-1 (MCP-1) level was significantly reduced (P<0.05); liver function indicators aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels were significantly reduced (P<0.05), and mannitol (Mannitol) level was significantly reduced (P<0.05). The pathological features of jejunum and colon tissue were significantly improved, and the expression of mucin 2 (MUC-2) and tight junction protein (ZO-1) in colon tissue was significantly higher than that in the model group, indicating that lactobacillus has a good effect in protecting the integrity of intestinal mucosa. In addition, compared with the model group, HE staining and Oil Red O staining of liver tissue in the lactobacillus group were significantly improved (P < 0.05, P < 0.05). The results of intestinal flora analysis showed that the intestinal flora composition of the model group and the lactobacillus group was significantly different. The comparative analysis of the intestinal flora diversity between the high-dose lactobacillus group and the model group showed that the high-dose lactobacillus group significantly increased the Lachnospiraceae, Prevotallaceae, Bacteroidaceae, Oscillospiraceae, Eubacterium_coprostanoligenes_group, and Peptococcaceae.

[0063] Long-term intake of a high-sugar, high-fat diet can easily lead to disorders in the synthesis and secretion of total cholesterol in the body, which in turn increases the total cholesterol content in the serum, further leading to the accumulation of total cholesterol in the liver, and easily induces non-alcoholic fatty liver. In the DSS-induced chronic ulcerative colitis and secondary fatty liver model, lactic acid bacteria intervention can effectively regulate the body's blood lipid metabolism, inhibit the accumulation of total cholesterol in the liver, delay the progression of fatty liver, protect the morphological integrity of the colon and ileum, and maintain the permeability of colon tissue. Through the analysis of the effect of lactic acid bacteria on intestinal flora, it was found that lactic acid bacteria can effectively regulate the composition of intestinal flora in mice, significantly increase the abundance of flora that improves the symptoms of ulcerative colitis and regulates blood lipids. In summary, lactic acid bacteria have a good preventive effect on chronic ulcerative colitis combined with non-alcoholic fatty liver induced by a high-fat diet. Among them, lactic acid bacteria have a therapeutic effect on chronic ulcerative colitis, and its mechanism includes alleviating the body's inflammatory response, regulating intestinal flora, promoting mucosal healing, and improving colon mucosal integrity. In addition, lactobacilli have a preventive effect on non-alcoholic fatty liver disease secondary to chronic ulcerative colitis. Its mechanisms include regulating blood lipid metabolism, improving inflammatory defense capabilities and protecting the intestinal mucosal barrier.

[0064] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. Application of lactobacillus in the preparation of medicines for treating chronic ulcerative colitis combined with non-alcoholic fatty liver disease.

2. The use of lactobacillus according to claim 1 in the preparation of a medicament for treating chronic ulcerative colitis combined with non-alcoholic fatty liver disease, characterized in that: The chronic ulcerative colitis is chronic ulcerative colitis induced by dextran sulfate sodium.

3. Use of the lactobacillus according to claim 1 in the preparation of a medicament for treating chronic ulcerative colitis combined with non-alcoholic fatty liver disease, characterized in that: The non-alcoholic fatty liver disease is non-alcoholic fatty liver disease induced by a high-fat diet.

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