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Abstract Background In clinical practice, anthropometric measures other than BMI are rarely assessed yet may be more predictive of cardiovascular (CV) risk. We analyzed the placebo group of the REWIND CV Outcomes Trial to compare several anthropometric measures as baseline risk factors for cardiovascular disease (CVD)-related outcomes in participants with type 2 diabetes (T2D). Methods Data from the REWIND trial placebo group (N = 4952) were analyzed. All participants had T2D, age ≥ 50 years, had either a previous CV event or CV risk factors, and a BMI of ≥ 23 kg/m2. Cox proportional hazard models were used to investigate if BMI, waist-to-hip ratio (WHR), and waist circumference (WC) were significant risk factors for major adverse CV events (MACE)-3, CVD-related mortality, all-cause mortality, and heart failure (HF) requiring hospitalization. Models were adjusted for age, sex, and additional baseline factors selected by LASSO method. Results are presented for one standard deviation increase of the respective anthropometric factor. Results Participants in the placebo group experienced 663 MACE-3 events, 346 CVD-related deaths, 592 all-cause deaths, and 226 events of HF requiring hospitalization during the median follow-up of 5.4 years. WHR and WC, but not BMI, were identified as independent risk factors of MACE-3 (hazard ratio [HR] for WHR: 1.11 [95% CI 1.03 to 1.21]; p = 0.009; HR for WC: 1.12 [95% CI 1.02 to 1.22]; p = 0.012). WC adjusted for hip circumference (HC) showed the strongest association with MACE-3 compared to WHR, WC, or BMI unadjusted for each other (HR: 1.26 [95% CI 1.09 to 1.46]; p = 0.002). Results for CVD-related mortality and all-cause mortality were similar. WC and BMI were risk factors for HF requiring hospitalization, but not WHR or WC adjusted for HC (HR for WC: 1.34 [95% CI 1.16 to 1.54]; p

In healthy hosts the gut microbiota is restricted to gut tissues by several barriers some of which require MyD88-dependent innate immune sensor pathways. Nevertheless, some gut taxa have been reported to disseminate to systemic tissues. However, the extent to which this normally occurs during homeostasis in healthy organisms is still unknown. In this study, we recovered viable gut bacteria from systemic tissues of healthy wild type (WT) and MyD88−/− mice. Shotgun metagenomic-sequencing revealed a marked increase in the relative abundance of L. johnsonii in intestinal tissues of MyD88−/− mice compared to WT mice. Lactobacillus johnsonii was detected most frequently from multiple systemic tissues and at higher levels in MyD88−/− mice compared to WT mice. Viable L. johnsonii strains were recovered from different cell types sorted from intestinal and systemic tissues of WT and MyD88−/− mice. L. johnsonii could persist in dendritic cells and may represent murine immunomodulatory endosymbionts.

Exopolysaccharide (EPS) is a bacterial extracellular carbohydrate moiety which has been associated with immunomodulatory activity and host protective effects of several gut commensal bacteria. Bifidobacterium breve are early colonizers of the human gastrointestinal tract (GIT) but the role of EPS in mediating their effects on the host has not been investigated for many strains. Here, we characterized EPS production by a panel of human B. breve isolates and investigated the effect of EPS status on host immune responses using human and murine cell culture-based assay systems. We report that B. breve EPS production is heterogenous across strains and that immune responses in human THP-1 monocytes are strain-specific, but not EPS status-specific. Using wild type and isogenic EPS deficient mutants of B. breve strains UCC2003 and JCM7017 we show that EPS had strain-specific divergent effects on cytokine responses from murine bone marrow derived macrophages (BMDMs) and dendritic cells (BMDCs). The B. breve UCC2003 EPS negative (EPS–) strain increased expression of cytokine genes (Tnfa, Il6, Il12a, and Il23a) relative to untreated BMDCs and BMDCs treated with wild type strain. B. breve UCC2003 and JCM7017 EPS– strains increased expression of dendritic cell (DC) activation and maturation marker genes (Cd80, Cd83, and Cd86) relative to untreated BMDCs. Consistent with this, BMDCs co-cultured with B. breve UCC2003 and JCM7017 EPS– strains engineered to express OVA antigen activated OVA-specific OT-II CD4+ T-cells in a co-culture antigen-presentation assay while EPS proficient strains did not. Collectively, these data indicate that B. breve EPS proficient strains use EPS to prevent maturation of DCs and activation of antigen specific CD4+ T cells responses to B. breve. This study identifies a new immunomodulatory role for B. breve EPS and suggests it may be important for immune evasion of adaptive immunity by B. breve and contribute to host-microbe mutualism.

Interactions between the intestinal microbiota, immune system and nervous system are essential for homeostasis in the gut. Inflammasomes contribute to innate immunity and brain–gut interactions, but their role in microbiota–neuro–immune interactions is not clear. Therefore, we investigated the effect of the inflammasome on visceral pain and local and systemic neuroimmune responses after antibiotic-induced changes to the microbiota. Wild-type (WT) and caspase-1/11 deficient (Casp1 KO) mice were orally treated for 2 weeks with an antibiotic cocktail (Abx, Bacitracin A and Neomycin), followed by quantification of representative fecal commensals (by qPCR), cecal short chain fatty acids (by HPLC), pathways implicated in the gut–neuro-immune axis (by RT-qPCR, immunofluorescence staining, and flow cytometry) in addition to capsaicin-induced visceral pain responses. Abx-treatment in WT-mice resulted in an increase in colonic macrophages, central neuro-immune interactions, colonic inflammasome and nociceptive receptor gene expression and a reduction in capsaicin-induced visceral pain. In contrast, these responses were attenuated in Abx-treated Casp1 KO mice. Collectively, the data indicate an important role for the inflammasome pathway in functional and inflammatory gastrointestinal conditions where pain and alterations in microbiota composition are prominent.