Gut microbiota dysbiosis promotes coronary heart disease comorbid with depression through lipopolysaccharides and Toll-like receptor 4Original paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWho was studied?
A rat model of CHD and depression was established using a high-fat diet and chronic unpredictable mild stress and verified by electrocardiogram, behavioral assessments, and cardiac marker analysis. Fecal microbiota transplantation (FMT) was performed by transferring microbiota from diseased rats to healthy rats (FMT-Disease group); the fecal microbiota of the rats from the FMT-Disease and FMT-Normal groups were compared. The TLR4 inhibitor TAK-242 was administered, creating the Disease + TAK-242 and FMT-Disease-TAK-242 groups. Gut microbiota composition was analyzed using 16 S rRNA high-throughput sequencing; LPS levels were measured using enzyme-linked immunosorbent assay. Polymerase chain reaction and western blotting were used to detect the expression of genes and proteins related to the TLR4/MYD88/NF-κB pathway in the heart and hippocampus, respectively.
What were the most important findings?
We confirmed that in the FMT-Disease group, the gut microbiota of diseased rats altered the gut microbial composition of healthy rats in terms of β-diversity, α-diversity, and community structure. Notably, LPS levels in the serum of FMT-Disease rats were elevated, thereby activating the TLR4/MYD88/NF-κB inflammatory pathway and increasing susceptibility to CHD comorbid with depression. Additionally, after receiving fecal microbiota from healthy rats, the Disease group showed a restoration of gut microbiota balance, improvement in general condition, and normalization of pathological, biochemical, and inflammatory indicators, indicating a suppressive effect on the progression of CHD with depression.
What are the greatest implications of this study?
Our findings further clarify the interrelationship between gut microbiota and CHD comorbid with depression, enhancing our understanding of its pathogenesis. Moreover, we propose a potential novel therapeutic strategy that focuses on modulating gut microbiota composition to block the TLR4/MYD88/NF-κB inflammatory pathway.