Interaction between gut microbiota and toll-like receptor: from immunity to metabolism

Abstract

The human gut contains trillions of commensal bacteria, and similar to pathogenic bacteria, the gut microbes and their products can be recognized by toll-like receptors (TLRs). It is well acknowledged that the interaction between gut microbiota and the local TLRs help to maintain the homeostasis of intestinal immunity. High-fat intake or obesity can weaken gut integrity leading to the penetration of gut microbiota or their bacterial products into the circulation, leading to the activation of TLRs on immune cells and subsequently low-grade systemic inflammation in host. Metabolic cells including hepatocytes and adipocytes also express TLRs. Although they are able to produce and secrete inflammatory molecules, the effectiveness remains low compared with the immune cells embedded in the liver and adipose tissue. The interaction of TLRs in these metabolic cells or organs with gut microbiota remains unclear, but a few studies have suggested that the functions of these TLRs are related to metabolism. Alteration of the gut microbiota is associated with body weight change and adiposity in human, and the interaction between the commensal gut microbiota and TLRs may possibly involve both metabolic and immunological regulation. In this review, we will summarize the current findings on the relationship between TLRs and gut microbiota with a focus on metabolic regulation and discuss how such interaction participates in host metabolism.

Integrating gut microbiota immaturity and disease‐discriminatory taxa to diagnose the initiation and severity of shrimp disease

“…This may partly explain why shrimp diseases generally occur in later development stage, as in this study and previous report (Xiong et al ., ). It is hypothesized that low rank hosts are able to relocate the energy to balance external pressure (Yiu et al ., ), which in turn reduce the host selection (e.g., deterministic processes) on alien bacterial species. These findings collectively show that the mechanisms that govern gut microbial community assembly are largely dependent on the shrimp development stage, mirroring what has been observed in fishes (Burns et al ., ; Yan et al ., ).…”

TLR‐2, TLR‐4 and MyD88 genes expression in renal transplant acute and chronic rejections

“…Therefore, a crucial step to authenticate these genes probable validity as predicting biomarkers is to distinguish over/under‐expressing patients from normal ones. Moreover, environmental factors such as combination of intestinal microbiota have been demonstrated to influence these genes expression in local and general scales (Valentini et al, ; Wang, Devkota, et al, ; Yiu, Dorweiler, & Woo, ).…”

The microbiome in health and disease: a new role of microbes in molecular medicine

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