Smirnova, Ekaterina

The perturbations in bile acids (BAs) in alcohol‐associated hepatitis (AH) and its relationship to disease severity is not well defined. The aims of this study were to define (1) the effects of heavy alcohol consumption on BAs and related microbiome, (2) the additional changes with AH, and (3) the relationship of these changes to disease severity. In this multicenter study, plasma and fecal BAs and related microbiome were interrogated in healthy individuals, heavy drinking controls (HDCs) without overt liver disease, and AH. Compared to healthy controls, HDCs had increased glycine‐conjugated 7α and 27α primary BAs and increased secondary BA glycocholenic sulfate (multiple‐comparison adjusted P < 0.05 for all). Plasma‐conjugated cholic and chenodeoxycholic acid increased in AH along with the secondary BAs ursodeoxycholic and lithocholic acid (P < 0.001 for all), whereas deoxycholic acid decreased; however fecal concentrations of both deoxycholic acid and lithocholic acid were decreased. Glycocholenic acid further increased significantly from HDCs to AH. HDCs and AH had distinct plasma and fecal BA profiles (area under the curve, 0.99 and 0.93, respectively). Plasma taurochenodeoxycholic acid and tauroursodeoxycholic acid were directly related to disease severity, whereas fecal ursodeoxycholic acid was inversely related. The fecal abundance of multiple taxa involved in formation of secondary BAs, especially deoxycholic acid (Clostridium cluster XIVa) was decreased in AH. Multiple genera containing taxa expressing 3α, 3β, 7α, and 7β epimerases were decreased with concordant changes in fecal BAs that required these functions for formation. Conclusion: There are distinct changes in BA‐transforming microbiota and corresponding BAs in AH that are related to disease severity.

Background and Aims The role of the intestinal microbiome in alcoholic hepatitis is not established. The aims of this study were to (1) characterize the fecal microbial ecology associated with alcoholic hepatitis, (2) relate microbiome changes to disease severity, and (3) infer the functional relevance of shifts in microbial ecology. Approach and Results The fecal microbiome in patients with moderate alcoholic hepatitis (MAH) or severe alcoholic hepatitis (SAH) was compared with healthy controls (HCs) and heavy drinking controls (HDCs). Microbial taxa were identified by 16S pyrosequencing. Functional metagenomics was performed using PICRUSt. Fecal short chain fatty acids (SCFAs) were measured using a liquid chromatography–mass spectrometry platform. A total of 78 participants (HC, n = 24; HDC, n = 20; MAH, n = 10; SAH, n = 24) were studied. HDC had a distinct signature compared with HC with depletion of Bacteroidetes (46% vs. 26%; P = 0.01). Alcoholic hepatitis was associated with a distinct microbiome signature compared with HDC (area under the curve = 0.826); differential abundance of Ruminococcaceae , Veillonellaceae , Lachnospiraceae , Porphyromonadaceae , and Rikenellaceae families were the key contributors to these differences. The beta diversity was significantly different among the groups (permutational multivariate analysis of variance [PERMANOVA] P < 0.001). SAH was associated with increased Proteobacteria (SAH 14% vs. HDC 7% and SAH vs. HC 2%, P = 0.20 and 0.01, respectively). Firmicutes abundance declined from HDC to MAH to SAH (63% vs. 53% vs. 48%, respectively; P = 0.09, HDC vs. SAH). Microbial taxa did not distinguish between MAH and SAH (PERMANOVA P = 0.785). SCFAs producing bacteria (Lachnospiraceae and Ruminococcaceae) were decreased in alcoholic hepatitis, and a similar decrease was observed in fecal SCFAs among alcoholic hepatitis patients. Conclusions There are distinct changes in fecal microbiome associated with the development, but not severity, of alcoholic hepatitis.