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Abstract Metabolic‐associated fatty liver disease (MAFLD) induced‐severe hepatic steatosis poses significant health risks. Early prediction of this condition is crucial for prompt intervention. Short‐chain fatty acids (SCFAs) and tryptophan are gut metabolites correlated with MAFLD pathogenesis in the gut–liver axis. This study aims to construct prediction models for severe hepatic steatosis by including SCFAs and tryptophan metabolites. This study enrolled 83 participants from the outpatient department in 2023. Physical measurements, serum metabolic and inflammatory markers, metabolites of serum SCFAs and tryptophan were collected. Severe hepatic steatosis was diagnosed using vibration‐controlled transient elastography and abdominal sonography. All 40 (48.2%) participants diagnosed with severe hepatic steatosis had MAFLD, while approximately three‐quarters of those without severe hepatic steatosis had MAFLD. In comparison to the non‐severe hepatic steatosis group, individuals with severe hepatic steatosis exhibited higher levels of waist and arm circumference, serum triglyceride (TG), and lower levels of serum high‐density lipoprotein cholesterol (HDL‐C) and AST/ALT ratio. They also had higher serum levels of lipopolysaccharide‐binding protein, isovaleric acid, and propionic acid, and lower levels of 3‐methylvaleric acid, indole‐3‐propionic acid, and indoxyl sulfate. Models incorporating these markers predicted severe hepatic steatosis. One model additionally included waist circumference and triglyceride‐glucose index, while the other incorporated arm circumference and TG/HDL‐C ratio. The area under the curve reached 0.958 and 0.938, respectively (p

Abstract Background Diet and gut microbiota contribute to non-alcoholic steatohepatitis (NASH) progression. High-fat diets (HFDs) change gut microbiota compositions, induce gut dysbiosis, and intestinal barrier leakage, which facilitates portal influx of pathogen-associated molecular patterns including lipopolysaccharides (LPS) to the liver and triggers inflammation in NASH. Current therapeutic drugs for NASH have adverse side effects; however, several foods and herbs that exhibit hepatoprotection could be an alternative method to prevent NASH. Methods We investigated ginger essential oil (GEO) against palm oil-containing HFDs in LPS-injected murine NASH model. Results GEO reduced plasma alanine aminotransferase levels and hepatic pro-inflammatory cytokine levels; and increased antioxidant catalase, glutathione reductase, and glutathione levels to prevent NASH. GEO alleviated hepatic inflammation through mediated NLR family pyrin domain-containing 3 (NLRP3) inflammasome and LPS/Toll-like receptor four (TLR4) signaling pathways. GEO further increased beneficial bacterial abundance and reduced NASH-associated bacterial abundance. Conclusion This study demonstrated that GEO prevents NASH progression which is probably associated with the alterations of gut microbiota and inhibition of the LPS/TLR4/NF-κB pathway. Hence, GEO may offer a promising application as a dietary supplement for the prevention of NASH.

ABSTRACTDietary patterns and corresponding gut microbiota profiles are associated with various health conditions. A diet rich in polyphenols, primarily plant-based, has been shown to promote the growth of probiotic bacteria in the gastrointestinal tract, subsequently reducing the risk of metabolic disorders in the host. The beneficial effects of these bacteria are largely due to the specific metabolites they produce, such as short-chain fatty acids and membrane proteins. In this study, we employed a metabolomics-guided bioactive metabolite identification platform that included bioactivity testing using in vitro and in vivo assays to discover a bioactive metabolite produced from probiotic bacteria. Through this approach, we identified 5’-methylthioadenosine (MTA) as a probiotic bacterial-derived metabolite with anti-obesity properties. Furthermore, our findings indicate that MTA administration has several regulatory impacts on liver functions, including modulating fatty acid synthesis and glucose metabolism. The present study elucidates the intricate interplay between dietary habits, gut microbiota, and their resultant metabolites.

Abstract Dietary emulsifiers are linked to various diseases. The recent discovery of the role of gut microbiota–host interactions on health and disease warrants the safety reassessment of dietary emulsifiers through the lens of gut microbiota. Lecithin, sucrose fatty acid esters, carboxymethylcellulose (CMC), and mono- and diglycerides (MDG) emulsifiers are common dietary emulsifiers with high exposure levels in the population. This study demonstrates that sucrose fatty acid esters and carboxymethylcellulose induce hyperglycemia and hyperinsulinemia in a mouse model. Lecithin, sucrose fatty acid esters, and CMC disrupt glucose homeostasis in the in vitro insulin-resistance model. MDG impairs circulating lipid and glucose metabolism. All emulsifiers change the intestinal microbiota diversity and induce gut microbiota dysbiosis. Lecithin, sucrose fatty acid esters, and CMC do not impact mucus–bacterial interactions, whereas MDG tends to cause bacterial encroachment into the inner mucus layer and enhance inflammation potential by raising circulating lipopolysaccharide. Our findings demonstrate the safety concerns associated with using dietary emulsifiers, suggesting that they could lead to metabolic syndromes.

ABSTRACT Diet and gut microbiota impact the progression of non-alcoholic steatohepatitis (NASH). An unhealthy diet, rich in fat and sugar, promotes gut microbiota dysbiosis, leading to the translocation of lipopolysaccharides (LPS) and other harmful pathogen-associated molecular patterns to the liver, triggering hepatic inflammation and aggravating NASH. Currently, there are no approved pharmacological treatments for NASH, although novel drugs, such as obeticholic acid (OCA), have demonstrated beneficial effects. Healthy dietary modifications have been proposed to prevent and treat NASH. However, the therapeutic effect of the combined implementation of a healthy dietary intervention with pharmaceutical agents or dietary supplements for NASH treatment and how it interplays with the gut microbiota and associated pathways remains poorly understood. This study aims to investigate the therapeutic efficacy of a healthy dietary modification, either alone or in combination with a dietary supplement [ginger essential oil (GEO)] or drug (OCA), in a Gubra-Amylin diet-induced NASH mouse model. NASH was induced for 12 weeks, after which the interventions were administered for a subsequent 3-week period. Our findings revealed that healthy dietary intervention primarily restores obesity, lipidemia, and NASH. In contrast, GEO and OCA have additional benefits by suppressing pro-inflammatory cytokines by partially modulating the NLRP3/ASC/caspase-1 pathways. Moreover, healthy dietary intervention restores gut microbiota composition and function from dysbiosis, while GEO and OCA partially mediate the gut-derived LPS/toll-like receptor 4/nuclear factor kappa B pathway. Therefore, adherence to healthy dietary patterns plays a primary role in NASH reversion, and additional supplementation of GEO or OCA could offer extra benefits in suppressing hepatic inflammation and preventing disease progression. IMPORTANCE The link between gut microbiota and diet is crucial in the development of non-alcoholic steatohepatitis (NASH). This study underscores the essential role of a healthy diet in preventing and treating NASH by reversing obesity, lipidemia, and gut microbiota dysbiosis. Moreover, the supplementation of functional food or drug to the diet can provide additional advantages by inhibiting hepatic inflammation through the modulation of the hepatic inflammasome signaling pathway and partially mediating the gut microbiota and lipopolysaccharide signaling pathway. This study highlights the importance of adopting healthy dietary habits in treating NASH and proposes that supplementing with ginger essential oil or obeticholic acid may offer additional benefits. Nonetheless, further clinical studies are necessary to validate these findings.

Background/Aims: Ineffective esophageal motility (IEM) is common in patients with gastroesophageal reflux disease (GERD) and can be associated with poor esophageal contraction reserve on multiple rapid swallows. Alterations in the esophageal microbiome have been reported in GERD, but the relationship to presence or absence of contraction reserve in IEM patients has not been evaluated. We aim to investigate whether contraction reserve influences esophageal microbiome alterations in patients with GERD and IEM. Methods: We prospectively enrolled GERD patients with normal endoscopy and evaluated esophageal motility and contraction reserve with multiple rapid swallows during high-resolution manometry. The esophageal mucosa was biopsied for DNA extraction and 16S ribosomal RNA gene V3-V4 (Illumina)/full-length (Pacbio) amplicon sequencing analysis. Results: Among the 56 recruited patients, 20 had normal motility (NM), 19 had IEM with contraction reserve (IEM-R), and 17 had IEM without contraction reserve (IEM-NR). Esophageal microbiome analysis showed a significant decrease in microbial richness in patients with IEM-NR when compared to NM. The beta diversity revealed different microbiome profiles between patients with NM or IEM-R and IEM-NR (P = 0.037). Several esophageal bacterial taxa were characteristic in patients with IEM-NR, including reduced Prevotella spp. and Veillonella dispar, and enriched Fusobacterium nucleatum. In a microbiome-based random forest model for predicting IEM-NR, an area under the receiver operating characteristic curve of 0.81 was yielded. Conclusions: In symptomatic GERD patients with normal endoscopic findings, the esophageal microbiome differs based on contraction reserve among IEM. Absent contraction reserve appears to alter the physiology and microbiota of the esophagus. [ABSTRACT FROM AUTHOR]