Understanding the physiological functions of the host xenobiotic-sensing nuclear receptors PXR and CAR on the gut microbiome using genetically modified mice

Pharmacological activation of the xenobiotic-sensing nuclear receptors pregnane X receptor (PXR) and constitutive androstane receptor (CAR) is well-known to increase drug metabolism and reduce inflammation. Little is known regarding their physiological functions on the gut microbiome. In this study, we discovered bivalent hormetic functions of PXR/CAR modulating the richness of the gut microbiome using genetically engineered mice. The absence of PXR or CAR increased microbial richness, and absence of both receptors synergistically increased microbial richness. PXR and CAR deficiency increased the pro-inflammatory bacteria Helicobacteraceae and Helicobacter. Deficiency in both PXR and CAR increased the relative abundance of Lactobacillus, which has bile salt hydrolase activity, corresponding to decreased primary taurine-conjugated bile acids (BAs) in feces, which may lead to higher internal burden of taurine and unconjugated BAs, both of which are linked to inflammation, oxidative stress, and cytotoxicity. The basal effect of PXR/CAR on the gut microbiome was distinct from pharmacological and toxicological activation of these receptors. Common PXR/CAR-targeted bacteria were identified, the majority of which were suppressed by these receptors. hPXR-TG mice had a distinct microbial profile as compared to wild-type mice. This study is the first to unveil the basal functions of PXR and CAR on the gut microbiome.

Effect of physical therapy on neuromuscular control dysfunction for chronic ankle instability: a systematic review / 中国康复理论与实践

@#Objective To identify the effectiveness of physical therapy on neuromuscular control dysfunction of chronic ankle instability (CAI). Methods CAI physiotherapy-related systematic reviews, meta-analysis, randomized controlled studies and case-controlled studies were systematically searched in PubMed, Web of Science, Cochrane, PEDro, EBSCO and CNKI from October 1st, 2010 to October 1st, 2020. After quality assessment, the research evidence regarding certain intervention was then graded according to the Oxford Center for Evidence-based Medicine. Results A total of 20 articles were included. Intervention based on unstable plane exercise training could significantly improve lower limb balance control ability (Ⅰ A) and muscle strength (Ⅱ A) for CAI patients. The efficiency of exercise-based intervention could be further raised (Ⅱ C) with the aid of external equipment, but either the benefits in muscle reaction (Ⅲ C) or proprioception (Ⅱ D) was limited. Six sessions or more of manual therapy could be used to enhance the balance ability of the lower limbs (Ⅱ B), while taping failed to provide improvements in ankle proprioception in short period or immediately (Ⅰ A). Conclusion Unstable plane training-based therapeutic exercise and manual therapy could effectively enhance the neuromuscular control with high-quality evidence supporting, which can be primary interventions for CAI patients. Meanwhile, taping and other external devices could be used as adjunct methods to improve the efficiency of physiotherapy program, while there is currently no evidence to support the application of modality treatment in neuromuscular control of CAI.