NLR and Intestinal Dysbiosis-Associated Inflammatory Illness: Drivers or Dampers?

Abstract

The intestinal microbiome maintains a close relationship with the host immunity. This connection fosters a health state by direct and indirect mechanisms. Direct influences occur mainly through the production of short-chain fatty acids (SCFAs), gastrointestinal hormones and precursors of bioactive molecules. Indirect mechanisms comprise the crosstalk between bacterial products and the host's innate immune system. Conversely, intestinal dysbiosis is a condition found in a large number of chronic intestinal inflammatory diseases, such as ulcerative colitis and Crohn's disease, as well as in diseases associated with low-grade inflammation, such as obesity, type 1 and 2 diabetes mellitus and cardiovascular diseases. NOD-Like receptors (NLRs) are cytoplasmic receptors expressed by adaptive and innate immune cells that form a multiprotein complex, termed the inflammasome, responsible for the release of mature interleukin (IL)-1β and IL-18. NLRs are also involved in the recognition of bacterial components and production of antimicrobial molecules that shape the gut microbiota and maintain the intestinal homeostasis. Recent novel findings show that NLRs may act as positive or negative regulators of inflammation by modulating NF-κB activation. This mini-review presents current and updated evidence on the interplay between NLRs and gut microbiota and their dual role, contributing to progression or conferring protection, in diabetes and other inflammatory diseases.

Ethanol: striking the cardiovascular system by harming the gut microbiota

“…In addition to TLRs, NOD-like receptors (NLRs) also participate in the maintenance of intestinal homeostasis and modulate the occurrence of diabetes, inflammatory bowel diseases, and colorectal cancer (67,68). NLRs are expressed in the cytosol, mainly in cells of innate and adaptive immunity, and are subdivided into the subfamilies NLRA, NLRB, NLRC, and NLRP (69).…”

Augmented Enterocyte Damage During Candida albicans and Proteus mirabilis Coinfection

“…It should be noted that the prevalence of P. mirabilis in the gut is generally low, but might increase in various inflammatory diseases ( Kanareykina et al., 1987 ; Elias-Oliveira et al., 2020 ; Zhang et al., 2021 ). If this leads to situations of significant overgrowth of both P. mirabilis and C. albicans in the same patient, remains unclear.…”

“…Due to its very low abundance (< 0.05%) in healthy gut microbiota and consequently undersampling in stool and failed detection by 16S profiling, its exact prevalence in healthy individuals is less well determined than for other Enterobacteriaceae – it is estimated to be around 3% or higher ( Muller, 1986 ; Hamilton et al., 2018 ). However, P. mirabilis has been described as part of the dysbiotic gut microbiota in ulcerative colitis, Crohn’s disease, and rheumatic arthritis ( Kanareykina et al., 1987 ; Elias-Oliveira et al., 2020 ; Zhang et al., 2021 ). Furthermore, inherent resistance to several antibiotics, such as polymyxins, tigecycline, and tetracycline, results in increased P. mirabilis abundance upon antibiotic treatment.…”

Neutrophil-to-Lymphocyte Ratio as an Indicator of Opioid-Induced Immunosuppression After Thoracoscopic Surgery: A Randomized Controlled Trial

“… 23 In recent years, some studies have investigated the potential diagnostic role of NLR in the inflammatory processes of different chronic diseases. 24 , 25 NLR is a readily available and inexpensive marker of systemic inflammation. This indicator is driven by elevated concentrations of circulating cytokines.…”