Gut microbiota in nonalcoholic fatty liver disease: a PREDIMED-Plus trial sub analysis

To evaluate the changes in the gut microbiota associated with changes in the biochemical markers of nonalcoholic fatty liver disease (NAFLD) after a lifestyle intervention with the Mediterranean diet. Participants (n = 297) from two centers of PREDIMED-Plus trial (Prevención con Dieta Mediterránea) were divided into three different groups based on the change tertile in the Hepatic Steatosis Index (HSI) or the Fibrosis-4 score (FIB-4) between baseline and one year of intervention. One-year changes in HSI were: tertile 1 (T1) (-24.9 to -7.51), T2 (-7.5 to -1.86), T3 (-1.85 to 13.64). The most significant differences in gut microbiota within the year of intervention were observed in the T1 and T3. According to the FIB-4, participants were categorized in non-suspected fibrosis (NSF) and with indeterminate or suspected fibrosis (SF). NSF participants showed higher abundances of Alcaligenaceae, Bacteroidaceae, Bifidobacteriaceae, Clostridiaceae, Enterobacteriaceae, Peptostreptococcaceae, Verrucomicrobiaceae compared to those with SF. Then, participants were divided depending on the FIB-4 tertile of change: T1 (-89.60 to -5.57), T2 (-5.56 to 11.4), and T3 (11.41 to 206.24). FIB-4 T1 showed a decrease in Akkermansia and an increase in Desulfovibrio. T2 had an increase in Victivallaceae, Clostridiaceae, and Desulfovibrio. T3 showed a decrease in Enterobacteriaceae, and an increase in Sutterella, Faecalibacterium, and Blautia. A relation between biochemical index changes of NAFLD/NASH (HSI and FIB-4) and gut microbiota changes were found. These observations highlight the importance of lifestyle intervention in the modulation of gut microbiota and the management of metabolic syndrome and its hepatic manifestations.