Objective: This study investigates the association between dietary live microbial intake and mortality among obese adults. Methods: From the 1999–2018 cycles of the U.S. National Health and Nutrition Examination Survey (NHANES), we included 22,746 adults with obesity and categorized them into three groups according to consumption of foods with medium or high microbial content (MedHi): G1 (no intake), G2 (>0 and below the median), and G3 (at or above the median). Associations with all-cause, CVD, and cancer mortality were examined using Kaplan–Meier curves and fully adjusted Cox proportional hazards models. Additionally, dose-response and sensitivity analyses were performed to further explore these relationships. Results: Over a median follow-up period of 9.67 years, a total of 3,792 deaths occurred, comprising 952 CVD-related and 866 cancer-related deaths. Compared to G1, participants in G3 had a 16% lower risk of all-cause mortality (hazard ratio [HR] = 0.84, 95% confidence interval [CI]: 0.77-0.92) and an 18% lower risk of CVD mortality (HR = 0.82, 95% CI: 0.69-0.98). However, no significant association was observed between dietary live microbial intake and cancer mortality. Dose–response modelling revealed an inverse approximately linear association between dietary live microbial intake and both all-cause and CVD mortality. Conclusions: These findings suggest that higher dietary exposure to live microbes is associated with lower risks of all-cause and CVD mortality in individuals with obesity, highlighting a potential target for obesity-oriented health policies and preventive strategies.

Objectives: Gastroesophageal reflux disease (GERD) is a common chronic digestive disorder, and diet is an important modifiable risk factor. The Dietary Index for Gut Microbiota (DI-GM) reflects dietary patterns considered favorable to the gut microbiota; however, the gut microbiome itself was not measured, and evidence on whether DI-GM is associated with GERD risk is limited. We aimed to evaluate the association between DI-GM and incident GERD and to explore potential intermediate pathways using mediation analysis and plasma proteomics. Methods: We included 133,915 UK Biobank participants free of GERD at baseline. DI-GM scores (range 0–14) were calculated from the Oxford WebQ 24-h dietary recall and grouped into four categories (0–3, 4, 5, ≥6). Incident GERD was identified from the UK Biobank first-occurrence records (ICD-10 K21). Cox proportional hazards regression was complemented by restricted cubic spline (RCS), subgroup, and Cox weighted quantile sum (WQS) analyses, counterfactual mediation analysis, integrated plasma proteomics (Olink Explore 3072), and a range of sensitivity analyses. Results: During a median follow-up of 13.6 years, 12,271 incident GERD cases occurred. In the fully adjusted model, each 1-point increase in DI-GM was associated with an approximately 4% lower hazard of GERD [hazard ratio (HR) 0.956, 95% CI 0.947–0.965; P < 0.001], and the highest DI-GM group (≥6) had a lower hazard than the lowest (0–3) (HR 0.812, 95% CI 0.774–0.851; P for trend < 0.001). RCS analysis showed a modest inverse dose–response relationship that was most apparent at higher DI-GM scores, and WQS analysis indicated that the association was driven by a few key components rather than shared equally across the index. BMI (proportion mediated 21.43%) and phenotypic age acceleration (7.53%) both significantly mediated the association (both P < 0.001). Integrated proteomic analysis identified 13 shared proteins; the nine positively associated with DI-GM and inversely associated with GERD showed exploratory enrichment in neurodevelopment- and cell-adhesion-related processes. Conclusions: Higher DI-GM was associated with a lower incidence of medically attended GERD, with mediation analysis suggesting that BMI and biological aging may partly account for this association. Exploratory proteomic analyses identified shared protein correlates, including adiposity-related and, tentatively, neurodevelopment- and cell-adhesion-related proteins; these are hypothesis-generating and require confirmation. Because the gut microbiome was not measured, the diet–microbiota link remains inferential, and these findings should be interpreted as associations rather than established mechanisms.

Immunotherapy targeting immune checkpoints such as programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) has emerged as a novel treatment option for various cancers, including colon cancer. However, immune evasion mechanisms can limit the efficacy of cancer immunotherapy. Understanding the regulatory mechanisms of PD-1/PD-L1 expression is therefore critical to enhancing immunotherapeutic outcomes. A previous study demonstrated that the adenosine A1 receptor (Adora1) regulates PD-L1 expression and tumor immune evasion in human melanoma; however, its role in colon cancer and associated immune escape remains poorly defined. To investigate this, we downregulated Adora1 expression in CT26 colon cancer cells using lentiviral transduction of Adora1-targeting shRNA. We assessed Adora1 and PD-L1 expression levels and evaluated cell proliferation in CT26 cells. In vivo, we inoculated CT26 cells into mice and monitored tumor growth, immune cell phenotypes, and T cell exhaustion within the tumors. Additionally, we evaluated T cell exhaustion in vitro by co-culturing T cells with CT26 cells. While Adora1 knockdown did not impact CT26 cell viability or proliferation in vitro, it significantly suppressed tumor growth in vivo (P<0.0001). Furthermore, Adora1 downregulation reduced T cell exhaustion (all P=0.0025) by decreasing PD-L1 expression in CT26 cells. Knockdown of Adora1 did not alter Atf3 expression but led to reduced Irf1 expression (P=0.0268), which contributed to the downregulation of PD-L1. Overall, these findings suggest that Adora1 downregulation inhibits immune escape in colon cancer by suppressing PD-L1 expression.

This study aims to evaluate the associations of Klemera-Doubal Method Biological Age Acceleration (KDM-BAA) and Phenotypic Age Acceleration (PAA) with all-cause and cause-specific mortality in U.S. adults with Cardio-Kidney-Metabolic (CKM) syndrome stages 0–3 and to establish risk prediction models. Data were obtained from 16,837 participants in NHANES 1999–2010 and 2015–2018, linked to mortality through 2019. Biological age was estimated using KDM-BA and Phenotypic Age algorithms, with residuals defining Biological Age Acceleration (BAA). Cox proportional hazards models were applied, and LASSO-Cox nomograms were developed for mortality prediction. Over a median follow-up of 11.33 years, 10.8% of the weighted population (9.75 million adults) died. After full adjustment for confounders, KDM-BAA positivity increased the risk of all-cause, CVD, and non-CVD mortality by 41%, 74%, and 31%, respectively; PAA positivity showed even larger increases – 103%, 79%, and 112%. Both metrics consistently exhibited a positive association in multiple subgroups and sensitivity analyses. The LASSO-Cox-based nomogram showed favorable discrimination (training AUCs 0.776 and 0.775 at 10 and 20 years; validation AUCs 0.765 and 0.757, respectively) and good calibration, suggesting potential clinical applicability. BAA independently predicts long-term mortality among individuals with CKM stages 0–3. PAA provides superior prognostic value, supporting the importance of monitoring biological aging to guide early intervention and improve long-term outcomes.