The interplay between host cellular and gut microbial metabolism in NAFLD development and prevention

In Vitro Probiotic Properties of Bifidobacterium animalis subsp. lactis SF and Its Alleviating Effect on Non-Alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease with many influencing factors. With the increasing role of the gut–liver axis in various liver diseases, research on the prevention and treatment of NAFLD with probiotics is increasing. In the present study, a Bifidobacterium animalis subsp. strain, B. lactis SF, was isolated from the feces of healthy infants and characterized by sequencing of the 16S rDNA. A systematic probiotic evaluation was carried out, and a diet-induced mouse model was constructed to study the effect and mechanism of B. lactis SF on diet-induced NAFLD. Results show that B. lactis SF has excellent gastrointestinal fluid tolerance and intestinal colonization, and strong antibacterial and antioxidant capabilities. In vivo, B. lactis SF modulated intestinal flora, restored the intestinal barrier, and inhibited LPS entrance into the portal circulation, which subsequently inhibited the TLR4/NF-κB and modulated the PI3K-Akt/AMPK signaling pathway, attenuated the inflammatory response, and reduced lipid accumulation. In addition, B. lactis SF attenuated oxidative stress and further alleviated autophagy, resulting in an ameliorative effect on NAFLD. Therefore, our study provides a new dietary method for the treatment of NAFLD.

Analyzing the synergistic adverse effects of BPA and its substitute, BHPF, on ulcerative colitis through comparative metabolomics

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that causes long-term inflammation and ulcers in the colon and rectum. Approximately 3 million adults were diagnosed with IBD in the US in 2015, and its incidence rate is estimated to increase by 4-6 times in 2030. Industrial pollutants are largely responsible for this significant increase in UC cases. Several epidemiological and animal studies have demonstrated the correlation between pollutants and gastrointestinal diseases, but detailed molecular mechanisms responsible for adverse effects of environmental pollutants on UC are still unknown. In the present study, we used a dextran sulfate sodium (DSS)-induced colitis mouse model, comparative metabolomics analysis, and systematic bioinformatics analysis to delineate the synergistic adverse effects of bisphenol A (BPA) and its substitute fluorene-9-bisphenol (BHPF) on UC. Subsequently, a significant alteration in gut metabolites was observed by the BPA and BHPF treatments. Furthermore, the bioinformatics analysis indicated deregulation of sugar and fatty acid metabolisms in the DSS-induced colitis model by the BPA and BHPF treatments, respectively. Additionally, both the treatments induced an inflammatory response in the model. Particularly, some DSS-deregulated metabolites, which play important roles in gut inflammation, were synergistically induced or reduced by the BPA and BHPF treatments. To the best knowledge of the authors, the synergistic adverse effects of the BPA and BHPF treatments on UC were demonstrated for the first time through gut metabolism alterations. Therefore, the present study provides novel insights in the role of environmental pollutants, such as BPA and BHPF, in UC development.

Gut microbes in gastrointestinal cancers

Gut microbes (GMs), dominated by bacteria, play important roles in many physiological processes. The structures and functions of GMs are closely related to human health, the occurrence and development of diseases and the rapid recovery of the body. Gastrointestinal cancers are the major diseases affecting human health worldwide. With the development of metagenomic technology and the wide application of new generation sequencing technology, a large number of studies suggest that complex GMs are related to the occurrence and development of gastrointestinal cancers. Fecal microbiota transplantation (FMT) and probiotics can treat and prevent the occurrence of gastrointestinal cancers. This article reviews the latest research progress of microbes in gastrointestinal cancers from the perspectives of the correlation, the influence mechanism and the application, so as to provide new directions for the prevention, early diagnosis and treatment of gastrointestinal cancers.