Interaction between mucus layer and gut microbiota in non-alcoholic fatty liver disease: Soil and seeds

Abstract

The intestinal mucus layer is a barrier that separates intestinal contents and epithelial cells, as well as acts as the "mucus layersoil" for intestinal flora adhesion and colonization. Its structural and functional integrity is crucial to human health. Intestinal mucus is regulated by factors such as diet, living habits, hormones, neurotransmitters, cytokines, and intestinal flora. The mucus layer's thickness, viscosity, porosity, growth rate, and glycosylation status affect the structure of the gut flora colonized on it. The interaction between "mucus layer-soil" and "gut bacteria-seed" is an important factor leading to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Probiotics, prebiotics, fecal microbiota transplantation (FMT), and wash microbial transplantation are efficient methods for managing NAFLD, but their long-term efficacy is poor. FMT is focused on achieving the goal of treating diseases by enhancing the "gut bacteria-seed". However, a lack of effective repair and management of the "mucus layer-soil" may be a reason why "seeds" cannot be well colonized and grow in the host gut, as the thinning and destruction of the "mucus layer-soil" is an early symptom of NAFLD. This review summarizes the existing correlation between intestinal mucus and gut microbiota, as well as the pathogenesis of NAFLD, and proposes a new perspective that "mucus layersoil" restoration combined with "gut bacteria-seed" FMT may be one of the most effective future strategies for enhancing the long-term efficacy of NAFLD treatment.

Genetically Predicted Causal Effects of Gut Microbiota and Gut Metabolites on Digestive Tract Cancer: A Two-Sample Mendelian Randomization Analysis

“…The gut microbiota performs complex metabolic activities, generating various metabolites that can have both harmful and beneficial effects [57,58]. These metabolites play a significant role in the interactions between colorectal cancer cells and the gut microbiota.…”

Bacteroides and NAFLD: pathophysiology and therapy

“…The study by You et al (2023) further demonstrated that a metabolite called N-acetyl-D-glucosamine (GlcNAc), induced by B. vulgatus , had a mucin-stimulating effect, effectively reversing the decline of Akkermansia in mice fed a HFD. Additionally, B. vulgatus serves as a provider of nutrients, supplying microbiota-accessible carbohydrates, such as mucin glycans, to maintain microbial homeostasis, particularly with Lactobacilli and Bifidobacteria , which play a crucial role in the mucus integrity, indirectly reinforcing the cooperative network with Akkermansia ( You et al, 2023 ; Zhang et al, 2023 ). Therefore, it can be inferred that the therapeutic effects of Bacteroides in NAFLD are partially mediated by increasing the abundance of beneficial flora in the gut.…”