Background and Aim Hypothyroidism might play a crucial role in the pathogenesis of non‐alcoholic fatty liver disease (NAFLD). The association of subclinical hypothyroidism with NAFLD has been inconsistent. The relationship of NAFLD with thyroid function parameters and subclinical hypothyroidism was determined. Methods This cross‐sectional study included 70 patients with subclinical hypothyroidism and 70 controls with euthyroidism matched according to gender, age, and body mass index (BMI). NAFLD was diagnosed via abdominal ultrasonography. The association between NAFLD and subclinical hypothyroidism was analyzed. Results The prevalence of NAFLD was significantly higher in patients with subclinical hypothyroidism than in those with euthyroidism. Multivariate analysis showed that subclinical hypothyroidism was an independent risk factor of NAFLD adjusted by metabolic‐related factors, such as BMI, triglyceride, high‐density lipoprotein‐cholesterol, hypertension, and diabetes. Thyroid‐stimulating hormone (TSH) was an independent risk factor of NAFLD adjusted by the same metabolic‐related factors, but free thyroxine (FT4) was not a risk factor. The FIB‐4 index, a noninvasive marker of liver fibrosis was significantly higher in patients with subclinical hypothyroidism than in those with euthyroidism. Compared with patients with euthyroidism, the proportion of the FIB‐4 index ≥2.67 was significantly higher, and the proportion of the FIB‐4 index <1.30 was lower in patients with subclinical hypothyroidism. Conclusions TSH elevation even within the euthyroid range is an independent risk factor of NAFLD and may influence the progression of liver fibrosis, even with a normal FT4 level.

Rifaximin is a poorly absorbable antibiotic against hepatic encephalopathy (HE). This observational study aimed to elucidate the effect of rifaximin on intestinal permeability and gut microbiota in patients with decompensated cirrhosis. Thirty patients with decompensated cirrhosis were assessed by ammonia level, neuropsychological testing, endotoxin activity (EA), and serum proinflammatory cytokines at baseline and after four weeks of rifaximin treatment (1200 mg/day). Intestinal permeability was indicated by serum soluble CD163 (sCD163), mannose receptor (sMR), and zonulin levels. To evaluate the gut microbiome, 16S ribosomal RNA gene sequencing was applied. Rifaximin ameliorated hyperammonemia and cognitive dysfunction, although it did not change the serum proinflammatory cytokine levels. It decreased EA levels as well as serum levels of sCD163 and sMR, but not zonulin, and both decreases in sCD163 and sMR showed positive correlations with EA decrease (ΔsCD163: Correlation coefficient (R) = 0.680, p = 0.023; ΔsMR: R = 0.613, p = 0.014, vs. ΔEA). Gut microbial analysis revealed that the richness and complexity of species were unchanged while the abundance of the Streptococcus genus was reduced after treatment with rifaximin. Collectively, rifaximin alleviated HE and endotoxemia with improved intestinal hyperpermeability in patients with decompensated cirrhosis, and this effect is partially involved in a gut microbial change.

The progression of nonalcoholic steatohepatitis (NASH) is complicated. The multiple parallel-hits theory is advocated, which includes adipocytokines, insulin resistance, endotoxins, and oxidative stress. Pathways involving the gut–liver axis also mediate the progression of NASH. Angiotensin-II receptor blockers (ARB) suppress hepatic fibrosis via the activation of hepatic stellate cells (HSCs). Rifaximin, a nonabsorbable antibacterial agent, is used for the treatment of hepatic encephalopathy and has been recently reported to improve intestinal permeability. We examined the inhibitory effects on and mechanism of hepatic fibrogenesis by combining ARB and rifaximin administration. Fischer 344 rats were fed a choline-deficient/l-amino acid-defined (CDAA) diet for 8 weeks to generate the NASH model. The therapeutic effect of combining an ARB and rifaximin was evaluated along with hepatic fibrogenesis, the lipopolysaccharide–Toll-like receptor 4 (TLR4) regulatory cascade, and intestinal barrier function. ARBs had a potent inhibitory effect on hepatic fibrogenesis by suppressing HSC activation and hepatic expression of transforming growth factor-β and TLR4. Rifaximin reduced intestinal permeability by rescuing zonula occludens-1 (ZO-1) disruption induced by the CDAA diet and reduced portal endotoxin. Rifaximin directly affect to ZO-1 expression on intestinal epithelial cells. The combination of an ARB and rifaximin showed a stronger inhibitory effect compared to that conferred by a single agent. ARBs improve hepatic fibrosis by inhibiting HSCs, whereas rifaximin improves hepatic fibrosis by improving intestinal permeability through improving intestinal tight junction proteins (ZO-1). Therefore, the combination of ARBs and rifaximin may be a promising therapy for NASH fibrosis.

It is unclear whether the link between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) is mediated by common risk factors. We aimed to elucidate the association between NAFLD and CKD using propensity score (PS)-matched analysis. We assessed 3725 Japanese individuals, excluding those with hepatitis B or C infection and men and women who consumed >30 and >20 g/day of alcohol, respectively. Of these, we enrolled 1097 Japanese subjects with NAFLD diagnosed by ultrasonography and 1097 PS-matched subjects without NAFLD. The prevalence of CKD was higher in subjects with NAFLD than in those without NAFLD before PS matching, but there was no significant difference between these groups in terms of CKD prevalence after PS matching. There was no difference in the prevalence of CKD between those with and without NAFLD in the subgroup analyses. Logistic regression analysis demonstrated that obesity, hypertension, and hyperuricemia were independent predictors of CKD, but NAFLD was not independently associated with CKD. In subjects with NAFLD, obesity, hypertension, and hyperuricemia were independent predictors of CKD. Thus, the link between NAFLD and CKD may be mediated by common risk factors. We recommend screening for CKD when patients with NAFLD have the aforementioned comorbidities.

The farnesoid X receptor (FXR) agonist, a bile acid‐activated nuclear receptor, has been shown to improve the histologic features of nonalcoholic steatohepatitis (NASH); however, a satisfactory effect on hepatic fibrosis has not been achieved. We aimed to investigate the combined effect of FXR agonist and angiotensin II type 1 receptor blocker on hepatic fibrogenesis in rat models of NASH. For 8 weeks, two rat models of NASH were developed. Otsuka Long‐Evans Tokushima Fatty (OLETF) rats were administered intraperitoneal injections of 1 mL/kg pig serum (PS) twice a week, whereas Fischer‐344 rats were fed a choline‐deficient, L‐amino acid‐defined diet (CDAA). The in vitro and in vivo effects of an FXR agonist (INT747) and an angiotensin II type 1 receptor blocker (losartan) on hepatic fibrogenesis were evaluated. In PS‐administered OLETF rats, INT747 and losartan had potent inhibitory effects on hepatic fibrogenesis with suppression of hepatic stellate cell (HSC) activation and expression of transforming growth factor β1 and toll‐like receptor 4. INT747 decreased intestinal permeability by ameliorating zonula occuludens‐1 disruption, whereas losartan directly suppressed activated‐HSC (Ac‐HSC) regulation. The in vitro inhibitory effects of INT747 and losartan on messenger RNA expressions of transforming growth factor β1, toll‐like receptor 4, and myeloid differentiation factor 88 and phosphorylation of nuclear factor‐κB and mothers against decapentaplegic homolog 3 in Ac‐HSC were almost in parallel. Losartan directly inhibited the regulation of Ac‐HSC. Likewise, INT747 in combination with losartan was beneficial on hepatic fibrogenesis in rats fed with CDAA diet. The therapeutic effects of these agents were almost comparable between PS‐administered OLETF and CDAA‐treated rats. Conclusion: INT747 and losartan synergistically suppressed hepatic fibrogenesis by reversing gut barrier dysfunction and inhibiting Ac‐HSC proliferation. Combined therapy may represent a promising novel approach for NASH. (Hepatology Communications 2017;1:928–945)