The causality between gut microbiome and anorexia nervosa: a Mendelian randomization analysis

Abstract

Background and aimNutrient production by intestinal microbiota corresponds to regulate appetite while gut microbial composition was influenced by diet ingestion. However, the causal relationship between gut microbial taxa and anorexia nervosa (AN) remains unclear. Mendelian Randomization (MR) is a novel research method that effectively eliminates the interference of confounding factors and allows for the exploration of the direct causal effects between exposure and outcome. This study employs MR to explore the causal effect between AN and specific gut microbiome.MethodsLarge-scale Genome Wide Association Study (GWAS) data of AN and 211 gut microbes were obtained from the IEU open GWAS project and Mibiogen Consortium. Two-sample MR was performed to determine the causal relationship between gut microbiota and AN. Furthermore, a bi-directional MR analysis was to examine the direction of the causal relations. The Bonferroni correction test was used to adjust potential correlations among microbial taxa.ResultIn forward MR analysis, 10specific gut microbial taxa have an impact on the occurrence of AN (the p value of IVW <0.05). The high abundance of Genus Eubacteriumnodatumgroup ID: 11297 (OR:0.78, 95% CI:0.62–0.98, p = 0.035) and Class Melainabacteria ID: 1589 (OR:0.72, 95% CI:0.51–0.99, p = 0.045) may be considered protective factors for AN. But after Bonferroni correction, only Class Actinobacteria ID:419 (OR:1.53, 95% CI:1.19–1.96, p = 0.00089) remained significantly associated and high abundance of Class Actinobacteria ID:419 considered as a risk factor for AN. In the reverse MR analysis, AN influences 8 gut microbial taxa with none-statistically significant associations after adjustment.ConclusionWe identified a significant correlation between AN and 18 microbial taxa which have not been previously reported. Among them, 10 kinds of gut bacteria may affect the occurrence of AN, and the status of AN would affect 8 kinds of gut bacteria. After correction, the Class Actinobacteria ID:419 continued to exert an influence on AN.

Anorexia nervosa and bulimia nervosa: a Mendelian randomization study of gut microbiota

“…In a previously published MR analysis, Actinobacteria , Bilophila , Holdemania , Lactobacillus , Ruminococcaceae UCG009 , and two unknown gut microbes were identified as risk factors for the development of AN, which is very different from our conclusions ( Xia et al, 2023 ). Interestingly, the results are highly similar to those of our BN study.…”

The Role of the Gut Microbiota in Anorexia Nervosa in Children and Adults—Systematic Review

“…Their findings indicate that certain microbial taxa, including Actinibacteria , Bilophila , Holdemania , Lactobacillus , and Ruminococcaceae , function as risk factors for the occurrence of AN, while others such as Eubacteriumnodatum and Melaina bacteria act as protective factors. Furthermore, the investigation into the impact of AN on the gut microbiome revealed that the abundance of Alphaproteobacteria , Coriobacteriaceae , Christensenellaceae , and Anaerostipes species is influenced by the presence of AN [ 58 ].…”

Association of mental disorders with sepsis: a bidirectional Mendelian randomization study

“…According to a previous longitudinal study, individuals with AN possess substantially great abundances of Alistipes, Clostridiales, Christensenellaceae, and Ruminococcaceae and a lower abundance of Faecalibacterium, Agathobacter, Bacteroides, Blautia, and Lachnospira (84). A recent MR study revealed that AN was associated with increased levels of gut microbiome, including Alphaproteobacteria, Christensenellaceae, and Coriobacteriia (103). Variations in the gut microbiome make a person more prone to sepsis because they promote the growth of harmful bacteria in the gastrointestinal tract and trigger a robust proinflammatory response in the immune system (85).…”