Relationship Of Intestinal Flora Changes, Insulin Resistance And Serum Levels Of LPS, TNF–α, IL-6in Patients With NAFLD

Objective To study the changes of intestinal microflora and colonization resistance inpatients with non-alcoholic fatty liver disease, and the relationship with insulinresistance, serum levels of lipopolysaccharide(LPS), tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6).Method1. Selected60patients with non-alcoholic fatty liver disease as the case group,30healthy volunteers as control group, fresh feces samples were collected, two kinds ofanaerobes (Bifidobacterium, Lactobacillus) and two kinds of aerobes(Enterobacteriaceae, Enterococcus) were cultured quantitatively by the methodestablished by Mit-suoka, we also calculated the B/E value (the ratio of Bifidobacteriumto Enterobacteriaceae), which is used to evaluate changes of intestinal microflora as theindex of intestinal colonization resistance.2. Collected serum samples of all subjects,we detected serum levels of ALT, AST, TG, FPG, FINS, LPS, TNF-α and IL-6,calculated homeostatic model assessment-insulin resistance (HOMA-IR) and analyzedthe correlation of B/E value and serum levels of LPS, TNF-α and IL-6.3. These resultswere statistically analyzed by software SPSS16.0. With x±s determination results,independent sample t-test was used to compare the groups, correlation analysis usingPearson correlation test. In P <0.05as inspection standards.Results1. Intestinal flora and colonization resistance: Compared with the control group,the number of Enterobacteriaceae of the case group increased significantly (9.33±0.17vs8.81±0.18，P＜0.05), Bifidobacteria and Lactobacilli decreased significantly (9.01 ±0.14vs9.73±0.69，9.33±0.17vs9.81±0.18，P＜0.05), and intestinal colonizationresistance B/E value lower significantly (0.97±0.02vs1.10±0.02，P＜0.05); betweenthe two groups Enterococcus difference was not statistically significant.2. Serologicalmarkers: the case group serum levels of ALT(41.88±24.07vs22.27±6.40), AST(29.97±5.60vs26.60±4.74), TG(2.00±0.97vs1.14±0.36), FPG(5.14±0.59vs4.26±0.40), FINS(17.09±2.86vs9.35±0.88), LPS(0.05±0.07vs0.02±0.02), TNF-α(0.97±0.44vs0.61±0.37), and IL-6(0.98±0.37vs0.55±0.36)increased significantly, P＜0.05. HOMA-IR increased significantly (3.91±0.82vs1.77±0.20, P＜0.05).3.Correlation analysis: There was a significant negative correlation between B/E andHOMA-IR, LPS, TNF-α and IL-6, in which B/E value associated with the LPS is weak(r=-0.284, P <0.01), the B/E value of very strong relationship with HOMA-IR(r=-0.805, P <0.01), the value of B/E and TNF-α relationship is weak, the relationshipwith IL-6is moderate (r=-0.321,-0.441, P <0.01).Conclusions1. Patients with non-alcoholic fatty liver disease exists the phenomenon ofintestinal dysbacteriosis and damage of intestinal colonization resistance, specificallymanifested as significantly reduction of the beneficial bacteria (Bifidobacterium andLactobacillus), increase of the potential pathogenic enterobacteria (Enterobacteriaceae),and reduction of B/E value.2. Imbalance of intestinal flora and damage of colonizationresistance are closely related with insulin resistance, endotoxin and inflammatorycytokines in nonalcoholic fatty liver disease. They are involved in the developmentprocess of nonalcoholic fatty liver disease together.