Altered gut microbiome associated with metabolic-associated fatty liver disease in Chinese children

Limited studies have investigated the association between gut microbiota and metabolic dysfunction-associated fatty liver disease (MAFLD) in children and adolescents. We aimed to identify differences in gut microbiota composition and diversity between children with MAFLD and healthy counterparts.

Data were collected from a nested case-control study (October to December, 2021) of the "Huantai Childhood Cardiovascular Health Cohort Study" in Huantai County, Zibo City, China. The study included 52 children aged 5-11 years with new-onset MAFLD and 52 healthy children matched by age and sex. Stool samples were collected and analyzed using 16S rRNA gene sequencing. Shannon index and Chao index were used to assess the α diversity of gut microbiota and Principal coordinates analysis (PCoA) was performed to evaluate β diversity between the two groups. The differences in the relative abundance of gut microbiota between MAFLD group and control group were compared by the Wilcoxon rank-sum test after false discovery rate (FDR) correction. Additionally, the gut-microbial metabolic pathways were identified using the phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt).

We found that children with MAFLD had significant different gut microbiota composition and reduced α diversity compared with the control group. PCoA showed that the two groups can be significantly distinguished based on the unweighted unifrac distance algorithm. Gut microbiota at the phylum level such as Verrucomicrobia and Desulfobacterial, genus level such as Blautia, Lachnospiraceae_NK4A136_group, Coprococcus, Erysipelotrichaceae_UCG-003, UCG-002 and Akkermansia, and species level such as Bifidobacterium_longum abundances were significantly decreased in children with MAFLD compared with that in children without MAFLD. Notably, the abundance of these bacteria were found to be associated with HDL-C, SBP, DBP, WC, BMI, etc. In addition, our analysis of gut-microbial metabolic pathways identified differences in carbohydrate transport and metabolism, as well as amino acid transport and metabolism between the two groups.

Significant differences in gut microbiota composition are observed between children with and without MAFLD, which indicate that gut microbiota may be a potential contributor to the development of MAFLD in childhood.