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The American Journal of Clinical Nutrition

Elsevier BV

Preprints posted in the last 7 days, ranked by how well they match The American Journal of Clinical Nutrition's content profile, based on 19 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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A variance QTL approach to uncover gene-fish oil supplement interaction loci for 14 circulating unsaturated fatty acid traits

Ihejirika, S. A.; Stephen, E.; Ye, K.

2026-04-20 genetic and genomic medicine 10.64898/2026.04.13.26350791 medRxiv
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Gene-environment interactions (GEI) contribute to circulating polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid (MUFA) profiles. GEI may partly explain differences in trait variance across genotype groups. To identify GEI for circulating unsaturated fatty acids, we adopted a two-stage strategy. First, we detected quantitative trait loci associated with trait variance (vQTLs). Second, we tested these vQTLs for interaction with fish oil supplements (FOS). We performed genome-wide vQTL screens for 14 plasma PUFA and MUFA phenotypes in a UK Biobank subset of 200,478 participants. At the genome-wide significance threshold (p < 5.0 x 10-8), we identified 172 vQTL-trait pairs across all 14 traits, and 16 of these vQTLs had no marginal genetic effect on the corresponding trait. We found 46 non-overlapping loci across all phenotypes, with an average of 12 vQTLs per trait. Omega-6% and PUFA% had the most independent vQTLs (N = 24) while DHA% and Omega-3% had the least (N = 1 and 2, respectively). For each of the 172 vQTL-trait pairs, we tested the interaction effect of the vQTL with FOS on the corresponding trait. We found six significant interaction signals in DHA, DHA%, Omega-3, Omega-3%, LA, and Omega-6/Omega-3 ratio around the FADS1/2, ZPR1, and SUGP1/TM6SF2 genes. Our results provide a comprehensive resource of vQTLs and gene-FOS interactions shaping the circulating levels of unsaturated fatty acids.

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Post-Diarrheal Nutritional Trajectories Among Malnourished Children: A Clustering and Multinomial Modelling Approach

Ogwel, B.; Awuor, A. O.; Onyando, B. O.; Ochieng, R.; Hossain, M. J.; Conteh, B.; Mujahid, W.; Shaheen, F.; Munthali, V.; Malemia, T.; Tapia, M.; Keita, A. M.; Nasrin, D.; Kosek, M. N.; Qadri, F.; Kotloff, K. L.; Pavlinac, P. B.; McQuade, E. T. R.

2026-04-21 nutrition 10.64898/2026.04.20.26351264 medRxiv
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Although the co-occurrence of diarrhea and malnutrition is well documented, research has largely focused on the acute management of diarrheal illness. Despite its importance, longitudinal evidence characterizing post-diarrheal recovery trajectories is sparse. We sought to characterize post-diarrheal nutritional recovery trajectories among children aged 6-35 months who were malnourished at enrollment using data from the Enterics for Global Health (EFGH) Shigella Surveillance study (2022-2024). EFGH enrolled children aged 6-35 months presenting with medically-attended diarrhea and followed them at 4 weeks and 3 months post-enrollment. This analysis included children with baseline wasting, stunting, or underweight (z-score < -2) and complete anthropometric follow-up. Latent class mixed-effects models were used to identify distinct post-diarrheal growth trajectories based on changes in anthropometric z-scores over time. Multinomial modified Poisson regression models examined associations between baseline factors and trajectory membership. Among 9,480 enrolled children, 16.5% (n=1,561) were wasted, 22.7% (n=2,155) stunted, and 21.0% (n=1,994) underweight at baseline. Wasting showed greater recovery potential (80.8%) compared with stunting (38.5%) and underweight (40.3%). Recovery was shaped by factors across multiple levels. Clinical severity markers ( prolonged diarrhea, dehydration, and hypoxemia) increased the risk of nutritional failure. Age also influenced outcomes: infants were more likely to worsen, whereas older toddlers more often experienced stagnation. Interventions including exclusive breastfeeding, oral rehydration therapy, appropriate antibiotics, and zinc supplementation, improved outcomes, while unimproved sanitation undermined recovery. These findings highlight the need for integrated strategies combining infection control, nutritional rehabilitation, and water, sanitation, and hygiene interventions tailored to the childrens developmental stage. Key MessagesO_LIPost-diarrheal nutritional recovery is highly heterogeneous, with wasting showing the greatest potential for improvement, while stunting and underweight often result in persistent growth stagnation. C_LIO_LIBaseline anthropometric deficits alone are insufficient to predict recovery, highlighting the need for dynamic monitoring and individualized management. C_LIO_LIInfants are particularly vulnerable to acute nutritional deterioration, while older toddlers frequently experience growth stagnation. C_LIO_LIModifiable protective factors including exclusive breastfeeding, ORS, zinc, and appropriate antibiotics, improved outcomes, whereas poor sanitation undermined recovery. C_LIO_LIIntegrated strategies, tailored to a childs developmental stage, combining clinical care, nutrition, and environmental interventions are critical to support sustained child growth and development. C_LI

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Meal Timing Patterns and Associations with Fat Mass in Adolescents

Decker, J. E.; Morales, K. H.; Chen, P.-W.; Master, L.; Kwon, M.; Jansen, E. C.; Zemel, B. S.; Mitchell, J. A.

2026-04-23 nutrition 10.64898/2026.04.22.26351498 medRxiv
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Background: The timing of energy intake could be important in the development of obesity. However, most observational evidence stems from adults, anthropometric defined obesity outcomes, single meal timing phenotyping, and traditional regression modeling. Objective: We aimed to describe meal timing patterns in adolescents and determine if they associated with fat mass by modeling the median and all other percentiles of the frequency distribution. Methods: We analyzed data from the Sleep and Growth Study 2 (S-Grow2, N=286, 12-13y). Participants completed 3-day 24-hour dietary recalls and time stamped eating occasions were used to define 8 meal timing traits, with aide from self-reported wake and bed timing. Principal component analysis (PCA) identified multi-dimensional meal timing patterns. Fat mass index (FMI) was estimated using dual energy X-ray absorptiometry. Quantile regression assessed if there were associations between meal timing traits and FMI across the entire FMI frequency distribution. Results: The typical first and last eating occasions were 8:00am (40 minutes after waking) and 8:00pm (2.7 hours before sleep), respectively, thus the eating period typically lasted 11.5 hours per day. The typical eating period midpoint was 2:15pm, and the timing when 50% of energy intake was consumed typically occurred at 3:15pm. PCA revealed three meal timing patterns: 1) Delayed Start, Condensed Eating Period (43% of variance; shorter eating period and delayed timing of first eating); 2) Late, Sleep Proximal Eating (30% of variance; later timing of last eating and extended eating period), and 3) Later Energy Intake (10% of variance; delayed energy intake midpoint). Higher scores for the Delayed Start, Condensed Eating Period pattern associated with higher body mass index and FMI at the upper tails of their distributions. Conclusions: Distinct multidimensional meal timing patterns emerged in early adolescence, with the delayed start, condensed eating period pattern potentially associated with higher adiposity.

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Konjac Glucomannan Improves Body Composition and Reduced Blood Cholesterol, Inflammation, and Cardiovascular Risk in Adults with Excess Weight: A Triple-Blind, Placebo-Controlled Randomized Clinical Trial

Escobar, J. S.; Corrales-Agudelo, V.; Ortega-Sierra, O. L.; Villota-Salazar, N. A.; Rivera, D. A.; Pulgarin-Zapata, I. C.; Hernandez-Londono, M.; Lara-Guzman, O. J.; Sierra, J. A.; Alvarez-Quintero, R.; Polanco, J. P.; Munoz-Durango, K.

2026-04-20 nutrition 10.64898/2026.04.18.26351176 medRxiv
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Obesity and related cardiometabolic diseases pose significant global health challenges. Konjac glucomannan, a soluble dietary fiber, has shown promise in managing these conditions. However, rigorous studies are necessary to establish its benefits on human health. We designed a parallel-arm, triple-blind, placebo-controlled RCT to test the effects of glucomannan (3 g/day, 12 weeks) on body weight and composition, lipid profile, glucose metabolism, inflammation, adipokines, intestinal permeability, gut microbiota, and fecal metabolites in 40 adults. Participants were randomly assigned to either the glucomannan or placebo group, with both groups adhering to personalized hypocaloric diets and moderate physical activity. Outcomes were analyzed as intention-to-treat using linear mixed-effect models. Irrespective of the treatment, our intervention reduced body weight (mean: -2.39 kg; 95% CI: -3.38, -1.40), BMI (-0.83 kg/m2; -1.15, -0.52), and waist (-2.70 cm; -3.87, -1.53). Glucomannan promoted additional benefits not obtained with the placebo, reducing body fat measured by DEXA (body fat%: -2.16%; -3.04, -1.28; VAT: -20.0 cm2; - 29.2, -10.8; FMI: -0.98 kg/m2; -1.34, -0.62), LDL (-14.1 mg/dL; -23.4, -4.9), and the atherogenic index (-0.50; -0.80, -0.21). It also diminished the Framingham score of 10-year risk of coronary heart disease (-0.370; -0.625, -0.115), C reactive protein (-1.01 mg/L; -2.18, 0.15), leptin (-2.06 ng/mL; -4.48, 0.365), and leptin/adiponectin (-0.282; -0.603, 0.040). The two treatments had similar intakes, physical activity, and adherence to the intervention. There were no adverse effects. This intervention fostered health benefits in a population at high risk of cardiometabolic diseases. Konjac glucomannan was an effective co-adjuvant for further reducing risk factors.

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Biobank-scale survey of gene-diet interactions informs precision nutrition polygenic scores

Di Scipio, M.; Man, A.; Lali, R.; Wu, J.; Le, A.; Franks, P. W.; Pare, G.

2026-04-20 genetic and genomic medicine 10.64898/2026.04.13.26350340 medRxiv
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Genome-guided dietary advice is a goal of precision nutrition. However, the contribution of gene-diet interactions (GxDs) to disease risk remains unclear, hindering the identification of diet-outcome pairs more likely amenable to genetic-based recommendations. We thus implemented a two-step approach: first, we comprehensively assessed the contributions of genome-wide GxDs to cardiometabolic outcomes across a broad array of dietary exposures in UK Biobank participants (N = 141,144 to 325,989). Second, we selected the 20 significant diet-outcome pairs from the 713 pairs tested (p < 7.0 x 10-5) and derived GxD polygenic scores. In an independent sample, all scores were nominally associated with their corresponding outcomes, with 12 of 20 polygenic scores Bonferroni significant (p < 0.0025). Further analyses revealed GxD polygenic scores were associated with clinical outcomes such as incident gout, suggesting translational potential. Altogether, these results showcase the promise of GxD scores to inform precision nutrition.

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Impact of a Community Based Positive Deviance Hearth Intervention on Feeding Practices Among Malnourished Children Aged 6-59 Months in Bomet County Kenya

Koskei, G.; Karanja, S.; Ndugu, Z. W.; Anino, C. O.

2026-04-23 nutrition 10.64898/2026.04.18.26351171 medRxiv
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Child undernutrition remains a major public health challenge in Kenya. Suboptimal feeding practices contribute significantly to persistent underweight and stunting. This study evaluated the effect of a community-based Positive Deviance Hearth (PDH) intervention on feeding practices among children aged 6-59 months in Sub County within a County of study. The study adopted a two-group pretest-posttest randomized experimental study design conducted for six months period, among 84 caregiver-child pairs in intervention and control groups. A multi-stage sampling was employed to identify study settings and participants. Structured and pretested questionnaires, 24-hour food recall questionnaires and meal diversity questionnaires were used for data collection at pre-intervention and post-intervention periods. Data was analyzed using R software v.4.5.2. The differences between intervention and control groups at baseline and endline were assessed using difference-in-difference analysis, relevantly summarized using adjusted DID estimates, 95% confidence intervals and p-values, with p<0.05 considered significant. The PDH intervention significantly improved feeding practices among children 6-59 months. Meal frequency increased for 9-23 months (DiD = +1.4; 95% CI: 1.2-1.7; p = 0.034) and 24 months and above (DiD = +1.2; 95% CI: 1.1-1.5; p = 0.017), and dietary diversity rose (DiD = +1.3; 95% CI: 1.1-1.9; p < 0.001). Nutrient-dense food consumption improved, including legumes (DiD = +32.6%; p < 0.001) and animal-source foods (DiD = +35.4%; p < 0.001). Energy and protein intake increased across all age groups (p < 0.05), and micronutrients iron, vitamin A, vitamin C also rose significantly (p < 0.05). The PDH intervention substantially improved caregiver feeding practices, increased dietary diversity, and enhanced macro- and micronutrient intake, demonstrating its effectiveness as a scalable, community-driven strategy for sustainably improving child nutrition in high-burden settings.

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Effect mechanisms of different malaria chemoprevention regimens in pregnancy on infant growth outcomes: causal mediation analysis of a randomized controlled trial

Nguyen, A. T.; Nankabirwa, J. I.; Kakuru, A.; Roh, M. E.; Aguti, M.; Adrama, H.; Kizza, J.; Olwoch, P.; Kamya, M. R.; Dorsey, G.; Jagannathan, P.; Benjamin-Chung, J.

2026-04-25 public and global health 10.64898/2026.04.17.26351121 medRxiv
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Introduction: Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) has become less effective at preventing malaria due to rising parasite resistance. IPTp with dihydroartemisinin-piperaquine (DP) alone or in combination with SP (DP+SP) dramatically lowers the risk of malaria in pregnancy compared to SP but is associated with lower birthweight and early life wasting. We estimated the effect of IPTp-DP, DP+SP, and SP on infant growth outcomes and assessed possible treatment mechanisms through a causal mediation analysis. Methods: We used infant follow-up data (N=761) from a trial (NCT04336189) that randomized pregnant women to receive monthly IPTp-DP, SP, or DP+SP. We compared weight-for-length (WLZ) and length-for-age (LAZ) z-scores between treatment arms. We assessed possible mediation through pregnancy, birth, and infancy factors using interventional indirect effect models. Results: Compared to IPTp-SP, IPTp-DP+SP decreased mean WLZ by 0.18 [95% confidence interval (CI) -0.03, 0.39] between 1-3 months and 0.28 (95% CI 0.07, 0.49) between 4-6 months, with the largest differences among primigravidae. Lower risk of active placental malaria in IPTp-DP+SP helped reduce differences in mean WLZ vs IPTp-SP (+0.06, 95% CI 0.02, 0.10). The IPTp-DP+SP arm had up to 0.28 lower mean LAZ between 7-13 months compared to IPTp-DP, particularly among children who were wasted between 0-6 months; low birthweight had a persistent, mediating effect on linear growth. Conclusion: Adverse birth outcomes contributed to early growth faltering among children born to mothers receiving IPTp-DP+SP vs IPTp-SP, but the prevention of placental malaria partially counteracted the negative effects of IPTp-DP+SP on ponderal growth.

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Dietary Sodium Restriction Reprograms Gut Microbial Fermentation and Reduces Host Energy Harvest

Cornman-Homonoff, J.; Rajendran, K. M.; Kolandaivelu, S.; Coon, S. D.; Kupec, J. T.; Wang, L.; Hu, G.; Jala, V. R.; Sandle, G. I.; Rajendran, V. M.

2026-04-21 microbiology 10.64898/2026.04.20.719706 medRxiv
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Diet is a major determinant of gut microbiome structure and function, yet the role of dietary electrolytes--particularly sodium--remains poorly defined. Here, we identify dietary sodium availability as a key regulator of gut microbial fermentation and host energy harvest. Using a controlled sodium-sufficient versus sodium-deprived dietary intervention in rats, we integrated shotgun metagenomic sequencing, functional pathway analysis, targeted short-chain fatty acid (SCFA) quantification, and host physiological phenotyping. Sodium deprivation induced a coordinated restructuring of the gut microbiome, characterized by depletion of classical saccharolytic Firmicutes, including multiple Lactobacillus species, and enrichment of stress-tolerant, metabolically flexible taxa. Functional profiling revealed a shift away from growth-associated metabolic programs toward stress-adaptive and nutrient-scavenging pathways. Consistent with these changes, fecal concentrations of key SCFAs--including acetate, butyrate, hexanoate, and valerate--were significantly reduced, indicating impaired microbial fermentative capacity. These microbiome-level alterations translated into measurable host phenotypes, including reduced cecal mass and attenuated weight gain, consistent with decreased microbial energy harvest. Together, these findings establish a functional link between luminal sodium availability, microbial metabolic efficiency, and host energy balance, extending the framework of diet-microbiome interactions beyond macronutrients to include dietary electrolytes. This work identifies sodium as a previously underappreciated ecological constraint shaping gut microbial metabolism and suggests that modulation of dietary sodium intake may influence host metabolic outcomes through microbiome-mediated mechanisms.

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Preconception metabolic-bariatric surgery and child health outcomes: Identification and cohort profile of the POSIT study protocol

Purnell, J. Q.; Getahun, D.; Vesco, K. K.; Qiu, S.; Shi, J. M.; Wong, C. P.; Koppolu, P.; Im, T. M.; Oshiro, C. E.; Boone-Heinonen, J.

2026-04-24 obstetrics and gynecology 10.64898/2026.04.22.26351521 medRxiv
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Preconception weight loss by metabolic-bariatric surgery (MBS) improves maternal-fetal outcomes, but little is known about its impact on offspring growth and health. The preconception bariatric surgery and child health outcomes (POSIT) study aims to estimate the effects of maternal MBS-induced preconception weight loss on infant and childhood body size, growth, and related outcomes. This report presents the methods used to construct the POSIT cohort and its baseline characteristics. This retrospective cohort study sampled members from a United States healthcare system aged 18 and older with a singleton, live birth to create three study groups: 1) a treatment group including women who underwent preconception MBS and subsequently became pregnant (n=1,374); 2) a control group matched to the MBS pre-surgery body mass index (BMI) (pre-surgery controls, n=13,740); and 3) a second control group matched to the MBS post-surgical, pre-pregnancy BMI (pre-pregnancy controls, n=13,740). MBS and pre-surgery BMI controls showed slight imbalances in that pre-surgery BMI controls were on average ~6 months younger, had 0.6 lower BMI (44.5 kg/m2) at the time of their pregnancy and were more likely to have become pregnant in earlier years than the MBS group prior to surgery. MBS and pre-pregnancy controls had comparable age (mean {+/-} SD 33 {+/-} 5 years), pre-pregnancy BMI (33 {+/-} 6 kg/m2), and year of delivery. Following matching, the MBS group had similar socioeconomic and health disparities as the pre-surgery control group, and both were worse than pre-pregnancy control group. Pregestational maternal comorbidity index improved after MBS and matched the pre-pregnancy controls. Upon extraction of offspring growth patterns and mediation analyses of maternal weight loss and metabolic responses to MBS, study findings will investigate effects of preconception weight loss by MBS on short- and long-term child health outcomes. Results will guide future studies focusing on improving maternal preconception weight and maternal-fetal outcomes.

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Weight Trajectories and Cancer Risk: A Pooled Cohort Study

Nilsson, A.; da Silva, M.; Le, H. T.; Haggstrom, C.; Wahlstrom, J.; Michaelsson, K.; Trolle Lagerros, Y.; Sandin, S.; Magnusson, P. K.; Fritz, J.; Stocks, T.

2026-04-24 epidemiology 10.64898/2026.04.23.26351553 medRxiv
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Excess body weight has been associated with increased cancer risk, but the role of weight change across adulthood remains unclear. We examined body weight trajectories from ages 17 to 60 and their associations with site-specific cancer incidence. Data were based on the ODDS study, a pooled, nationwide cohort study in Sweden, with data on weight spanning 1911 to 2020, and cancer follow-up through 2023. Weight trajectories were estimated with linear mixed effects models in individuals with at least three weight measurements. Cox regressions estimated hazard ratios for associations between weight trajectories and established and potentially obesity-related cancers. Fifth versus first quintile of weight change was associated with many cancers, most strongly with esophageal adenocarcinoma in men (HR 2.25; 95% CI 1.66-3.04), liver cancer in men (HR 2.67; 95% CI 2.15-3.33), endometrial cancer in women (HR 3.78; 95% CI 3.09-4.61), and pituitary tumors in both sexes (men: HR 3.13 [95% CI 2.13-4.61]; women: HR 2.13 [95% CI 1.41-3.22]). Associations varied by sex and age. Heavier weight at age 17 years and earlier obesity onset were also associated with higher cancer incidence. These findings highlight the importance of a life-course approach to weight management and support sex- and age-targeted cancer prevention strategies.

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Diet Explains Significant Variance in Oral Microbial Community Structure

Xie, Y.; Bi, M.; Gu, W.; Li, Y.; Roccuzzo, A.; Rosier, B. T.; Tonetti, M.

2026-04-25 dentistry and oral medicine 10.64898/2026.04.24.26351661 medRxiv
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Diet is an important ecological modulator of the oral microbiome, yet population-level evidence on a broader spectrum of food components remains limited. This cross-sectional study investigated associations among dietary intake, oral rinse microbiome, and oral disease conditions in a nationally representative sample of United States adults from the National Health and Nutrition Examination Survey. A total of 3,254 participants with oral rinse microbiome sequencing data were included, with oral conditions classified as oral health, caries-only, periodontitis-only, or co-existing disease. Dietary intake was assessed using 24-hour dietary recalls and summarized as dietary indices and energy-adjusted food components. Associations between diet and the oral microbiome were evaluated using community-level analyses, regression models, mediation analyses, and unsupervised clustering, while accounting for oral conditions. This study found that dietary intake, as a combined variable set, explained 3.6% of the variance in oral rinse microbial community structure; this was comparable to oral disease status or smoking and larger than sociodemographic factors. Healthier dietary profiles, including higher health-associated dietary index scores and greater vegetable and fruit intake, were associated with taxa commonly linked to oral health (e.g., Neisseria, Cardiobacterium and Lautropia). In contrast, added sugars, alcoholic drinks, cured meat, potatoes, dairy products, and higher dietary inflammatory index scores showed opposite association patterns. Mediation analyses suggested that coordinated microbial groups may partly link dietary exposures with oral disease outcomes, particularly for vegetables and added sugars. Additionally, three population-level dietary patterns were identified, among which the plant-rich pattern was associated with more favorable oral health and microbial profiles enriched in nitrate-reducing commensals, including Neisseria and Haemophilus. Overall, dietary intake was associated with oral microbiota composition and oral health conditions, supporting ecological influences of dietary components beyond sugar on oral bacteria and dental diseases. Longitudinal studies are needed to clarify the direction and causality of these relationships.

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Menopause in the All of Us Research Program: A Descriptive Summary of Electronic Health Record and Survey Response across Sociodemographic Characteristics

Staples, J. W.; White, S. L.; Giacalone, A.; Pozdeyev, N.; Sammel, M. D.; Stranger, B. E.; Valencia, C. I.; Santoro, N.; Hendricks, A. E.

2026-04-25 sexual and reproductive health 10.64898/2026.04.17.26351129 medRxiv
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Objective. Menopause is a significant physiological transition with implications for health outcomes (e.g., cardiometabolic), yet gaps remain in understanding the menopause transition, including how menopause timing and type influence health outcomes. Large-scale cohort studies in midlife (age~40-60) females, including the All of Us Research Program (AoURP), provide opportunities to study menopause across diverse populations and data modalities. We characterized menopause-related data in AoURP, focusing on age distributions and concordance between EHR diagnosis codes and self-reported survey responses. Methods. We analyzed menopause-related survey, EHR diagnostic code, and genomic data among ~396,000 participants in AoURP with female sex. We summarized menopause data across modalities, overlap between survey, EHR, and genomic data, and age distributions overall and across sociodemographic characteristics. Results. Among ~396,000 females, surveys captured ~193,000 menopause observations, nearly seven times more than structured EHR diagnoses (~28,000), suggesting under- ascertainement in EHR data. Nearly all females (~99%) with an EHR menopause diagnosis also reported menopause in the survey. Approximately 22,000 participants had intersected EHR, survey, and genomic menopause-related data. Survey-based age patterns matched expectations, with participants <40 years predominantly reporting pre-menopausal status and those >60 years predominantly reporting post-menopausal status. A small subset (N{approx}1,700; 4%) (age>70 years) reported no menopause, suggesting response or recall bias. EHR menopause codes were concentrated after age>45 years, with a notable spike at age 65. Modest differences in survey-based menopause age distributions were observed by sociodemographic characteristics (e.g., race, ancestry). Conclusions. These findings inform sampling strategies, power calculations, phenotype definition, and study design for menopause research using AoURP.

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A systematic review and meta-analysis of the efficacy and safety of pharmacological treatments for obesity in adults: 2026 Update

Ciudin Mihai, A.; Baker, J. L.; Belancic, A.; Busetto, L.; Dicker, D.; Fabryova, L.; Fruhbeck, G.; Goossens, G. H.; Gordon, J.; Monami, M.; Sbraccia, P.; Martinez Tellez, B.; Yumuk, V.; McGowan, B.

2026-04-24 endocrinology 10.64898/2026.04.19.26351196 medRxiv
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This updated systematic review and network meta-analysis evaluated the efficacy and safety of obesity management medications (OMMs) in terms of reducing body weight and obesity related complications. Medline and Embase were searched up to 21 November 2025 for randomized controlled trials comparing OMMs versus placebo or active comparators in adults. The primary endpoint was percentage total body weight loss (TBWL%) at the end of the study. Secondary endpoints were TBWL% at 1, 2 and 3 years, anthropometric, metabolic, mental health and quality of life outcomes, cardiovascular morbidity and mortality, remission of obesity related complications, serious adverse events and all cause mortality. Sixty six RCTs (66 comparisons) were identified: orlistat (22), semaglutide (18), liraglutide (11), tirzepatide (8), naltrexone/bupropion (5) and phentermine/topiramate (2), enrolling 63,909 patients (34,861 and 29,048 with active compound and placebo, respectively). All OMMs showed significantly greater TBWL% versus placebo; tirzepatide and semaglutide exceeded 10% TBWL and showed the most favourable glycaemic effects. Semaglutide reduced major adverse cardiovascular events and all cause mortality. In dedicated complication specific trials, semaglutide and tirzepatide showed benefit on heart failure related outcomes; tirzepatide was associated with improved obstructive sleep apnoea syndrome and semaglutide with knee osteoarthritis pain remission. Tirzepatide and semaglutide were associated with improvements in metabolic dysfunction-associated steatohepatitis remission, and semaglutide with improvement in liver fibrosis. No OMMs were associated with an increased risk of serious adverse events. These updated results reinforce the need to individualize OMMs selection according to weight loss efficacy, complication profile and safety.

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Localized prebiotic nitrate supplementation formula remodels oral biofilm metabolism and reduces gingival inflammation: a randomized placebo-controlled trial

Yi, B.; Kim, H. Y.; Sotka, W.; Estey, R.; Green, S. J.; Shiau, H.

2026-04-23 dentistry and oral medicine 10.64898/2026.04.22.26351516 medRxiv
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Gingival inflammation is associated with dysbiotic oral biofilms characterized by reduced nitrate-reducing capacity and diminished nitric oxide (NO) bioavailability. While dietary nitrate has been shown to influence oral microbial activity, the effects of sustained, localized nitrate delivery on oral biofilm ecology and gingival inflammation remain incompletely defined. In this randomized, double-blind, placebo-controlled trial, 30 adults with gingival bleeding were assigned to receive localized prebiotic nitrate (~0.989 mmol per dose) or placebo for 21 days. The primary outcome was mean bleeding on probing (mBOP). Secondary outcomes included modified Gingival Index (mGI), Quigley-Hein plaque index (QHPI), salivary nitrite (as a proxy for NO bioavailability), oral pH, and microbiome composition assessed by 16S rRNA gene sequencing. Prebiotic nitrate supplementation formulation delivered in a slow-release chewing gum significantly reduced mBOP (25.7% to 15.3%; p = 0.0002) compared to placebo chewing gum. Salivary nitrite levels and oral pH increased, indicating enhanced nitrate metabolism. Microbiome analysis demonstrated enrichment of nitrate-reducing taxa, including Rothia mucilaginosa and Neisseria spp., and a relative reduction in inflammation-associated genera such as Prevotella and Porphyromonas. Localized prebiotic nitrate formula delivered in a functional chewing gum was associated with reduced gingival inflammation and shifts in oral microbiome composition consistent with enhanced nitrate-reducing capacity critical in nitric oxide formation. These findings support a role for biofilm-directed nutritional modulation as a non-antimicrobial approach for managing gingival inflammation and improving nitric oxide bioavailability.

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Dietary emulsifiers and host inflammation synergistically drive genomic evolution of Crohn disease-associated E. coli toward enhanced pathogenicity

Rytter, H.; Chevarin, C.; Martin, L.; Bruder, E.; Denizot, J.; Tenaillon, O.; Espeli, o.; Birer, A.; Viennois, E.; Barnich, N.; Chassaing, B.

2026-04-20 microbiology 10.64898/2026.04.20.719593 medRxiv
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Background and AimsThe rising incidence of Crohns disease (CD) in Westernized countries has been linked to changes in diet and increased consumption of food additives, yet the mechanisms by which these factors fuel intestinal inflammation remain unclear. Adherent-invasive Escherichia coli (AIEC), a pathobiont involved in CD pathogenesis, lacks a clear genetic hallmark but exhibits intestinal colonization and virulence traits, raising questions about the evolutionary forces promoting its emergence among select individuals. Here, we investigated how chronic exposure to two common dietary emulsifiers, carboxymethylcellulose (CMC) and polysorbate 80 (P80), along with host inflammation, drives AIEC genomic evolution and pathogenic potential. MethodsWild-type and Il10-deficient mice were monocolonized with AIEC and chronically exposed to CMC, P80, or water. Bacterial isolates were collected and analyzed for genomic diversification, mutations, and phenotype both in vitro and in vivo. ResultsEmulsifiers accelerated AIEC genomic diversification and selected for mutations linked to increased motility, invasion, and pro-inflammatory activity. Moreover, dietary emulsifier-evolved strains displayed a marked fitness advantage in vivo, outcompeting their counterparts in murine hosts, with the greatest advantage observed when evolution occurred under inflammatory conditions. Notably, evolutionary pathways and phenotypic outcomes were shaped by both emulsifier and the hosts inflammatory status, highlighting synergy between diet and host genetics in fostering pro-inflammatory pathobionts. ConclusionThese findings provide an evolutionary framework connecting modern dietary habits to the emergence of pathogenic AIEC strains, and underscore the importance of dietary interventions in individuals at risk for inflammatory bowel disease.

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Diminished sex hormone levels influence the risk of skewed X chromosome inactivation

Roberts, A. L.; Osterdahl, M. F.; Sahoo, A.; Pickles, J.; Franklin-Cheung, C.; Wadge, S.; Mohamoud, N. A.; Morea, A.; Amar, A.; Morris, D. L.; Vyse, T. J.; Steves, C. J.; Small, K. S.

2026-04-22 genetic and genomic medicine 10.64898/2026.04.20.26351303 medRxiv
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BackgroundX chromosome inactivation (XCI) is the mechanism which randomly silences one X chromosome to equalise gene expression between 46, XX females and 46, XY males. Though XCI is expected to result in a random pattern of mosaicism across tissues, some females display a significantly unbalanced ratio in immune cells, termed XCI-skew, in which [&ge;]75% of cells have the same X inactivated. XCI-skew is associated with adverse health outcomes and its prevalence increases with age - particularly after midlife - yet the specific risk factors have yet to be identified. The menopausal transition, which is driven by profound shifts in sex hormone levels, has significant impact on chronic disease risk yet the molecular and cellular effects are incompletely understood. We hypothesised that the menopausal transition may impact XCI-skew. MethodsUsing XCI data measured in blood-derived DNA from 1,395 females from the TwinsUK population cohort, along with questionnaires, genetic data, and sex hormone measures, we carried out a cross-sectional study to assess the impact of the menopausal transition and sex hormones on XCI-skew. ResultsWe demonstrate that early menopause (<45yrs) is associated with increased risk of XCI-skew. In subset analyses across those who had a surgically induced or natural menopause, we find the association restricted to those who underwent a surgical menopause. We next identify a low polygenic score (PGS) for testosterone levels is significantly associated with XCI-skew, which we replicate in an independent dataset (n=149), while a PGS for age at natural menopause is not associated. Finally, using longitudinal measures across two time points spanning [~]18 years we show XCI-skew is a stable cellular phenotype that typically increases over time. DiscussionThese data represent the first environmental and genetic risk factors of XCI-skew, both of which implicate endogenous sex hormone levels, particularly testosterone. We propose XCI-skew may have clinical relevance in postmenopausal females.

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Proteomic Insights into Lp(a) Cardiovascular Mechanisms: A Mendelian Randomization Study

Tomasi, J.; Xu, H.; Zhang, L.; Carey, C. E.; Schoenberger, M.; Yates, D. P.; Casas, J.

2026-04-22 genetic and genomic medicine 10.64898/2026.04.20.26351299 medRxiv
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Background: Elevated lipoprotein(a) [Lp(a)] is a known risk factor for several cardiovascular-related diseases established from multiple genetic and observational studies. However, the underlying mechanisms mediating the effects of Lp(a) levels on cardiovascular disease risk and major adverse cardiovascular events (MACE) are unclear. The aim of this study was to identify proteins downstream of Lp(a) using mendelian randomization (MR) - a genetic causal inference approach. Methods: A two-sample MR was performed by initially identifying Lp(a) genetic instruments based on data from genome wide association studies (GWAS) of Lp(a) blood concentrations. These instruments were then tested for association with proteins from proteomic pQTL data (Olink from UK Biobank, 2940 proteins and SomaScan from deCODE, 4907 proteins). Results: A total of 521 proteins associated with Lp(a) were identified. Using pathway enrichment analysis, the following MACE-relevant pathways were identified comprising a total of 91 Lp(a) downstream proteins: oxidized phospholipid-related, chemotaxis of immune cells and endothelial cell activation, pro-inflammatory monocyte activation, neutrophil activity, coagulation, and lipid metabolism. Conclusion: The results suggest that the influence of Lp(a) treatments is primarily through modifying inflammation rather than lipid-lowering, thus providing insight into the mechanistic framework which mediates the effects of elevated Lp(a) on atherosclerotic cardiovascular disease.

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Racioethnic Disparities in Risk of Cardiometabolic Risk Factors and Cardiovascular Disease among Women Treated for Breast Cancer: The Pathways Heart Study

Yao, S.; Zimbalist, A.; Sheng, H.; Fiorica, P.; Cheng, R.; Medicino, L.; Omilian, A.; Zhu, Q.; Roh, J.; Laurent, C.; Lee, V.; Ergas, I.; Iribarren, C.; Rana, J.; Nguyen-Huynh, M.; Rillamas-Sun, E.; Hershman, D.; Ambrosone, C.; Kushi, L.; Greenlee, H.; Kwan, M.

2026-04-24 epidemiology 10.64898/2026.04.23.26351612 medRxiv
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Background: Few studies have examined racioethnic disparities in cardiovascular disease (CVD) in women after breast cancer treatment, who are at higher risk due to cardiotoxic cancer treatment. Methods: Based on the Pathways Heart Study of women with a history of breast cancer, this analysis examines the association between cardiometabolic risk factors (hypertension, diabetes, and dyslipidemia) and CVD events with self-reported race and ethnicity, as well as genetic similarity. Multivariable logistic and Cox proportional hazards regression models were used to test race and ethnicity and genetic similarity with prevalent and incident cardiometabolic risk factors and CVD events. Results: Of the 4,071 patients in this analysis, non-Hispanic Black (NHB), Asian, and Hispanic women were more likely to have prevalent and incident diabetes than non-Hispanic White (NHW) women. Analysis of genetic similarity revealed results consistent with self-reported race and ethnicity. For CVD risk, NHB women were more likely to develop heart failure and cardiomyopathy than NHW women. In contrast, Hispanic women were at lower risk of any incident CVD, serious CVD, arrhythmia, heart failure or cardiomyopathy, and ischemic heart disease, which was consistent with the associations found with Native American ancestry. Conclusions: This is the largest multi-ethnic study of disparities in CVD health in breast cancer survivors, demonstrating corroborating findings between self-reported race and ethnicity and genetic similarity. The results highlight disparities in cardiometabolic risk factors and CVD among breast cancer survivors that warrant more research and clinical attention in these distinct, high-risk populations.

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Impact of Azithromycin Administration at Hospital Discharge on Antimicrobial Resistance and Enteropathogen Carriage 3 Months Following Treatment

Mogeni, P.; Ochieng, J. B.; Kariuki, K.; Rwigi, D.; Atlas, H. E.; Tickell, K. D.; Aluoch, L. R.; Sonye, C.; Apondi, E.; Ambila, L.; Diakhate, M. M.; Singa, B. O.; Liu, J.; Platts-Mills, J. A.; Saidi, Q.; Denno, D. M.; Fang, F. C.; Walson, J. L.; Houpt, E. R.; Pavlinac, P. B.

2026-04-20 epidemiology 10.64898/2026.04.17.26351054 medRxiv
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BackgroundThe Toto Bora trial tested whether a course of azithromycin reduced rates of re-hospitalization or death in the 6 months following hospitalization among Kenyan children. We hypothesized that azithromycin would reduce enteric bacteria and increase carriage of macrolide resistance in the subsequent 3 months. MethodsKenyan children (1-59 months) hospitalized and subsequently discharged for non-traumatic conditions provided fecal samples before and 3 months after randomization to a 5-day course of azithromycin or placebo. Quantitative PCR identified enteropathogens and AMR-conferring genes in fecal samples. Generalized estimating equations assessed the impact of the randomization arm on pathogen and resistance gene detection, accounting for baseline presence and site. ResultsAmong 1,393 baseline stools, 12.4% had at least one bacterial enteropathogen, 94.7% had at least one macrolide-resistance gene, and 92.6% had at least one beta-lactamase-resistance gene identified. At month 3, children randomized to azithromycin had a 6.1% higher likelihood of carrying a macrolide resistance gene compared to placebo (adjusted prevalence ratio [aPR], 1.06; 95% CI, 1.04-1.08; P<0.001). Specifically, azithromycin randomization was associated with a higher relative prevalence of erm(B) (aPR, 1.09 [95% CI, 1.04-1.15]; P=0.001), erm(C) (aPR, 1.23 [95% CI, 1.14-1.31]; P<0.001), msr(A) (aPR, 1.14 [95% CI, 1.04-1.25]; P=0.007), and msr(D) (aPR, 1.07 [95% CI, 1.03-1.11]; P=0.001). There was no difference in overall bacterial pathogen prevalence (18.9% vs 17.3%) between randomization arms, but a slightly lower proportion of children had Shigella after randomization in the azithromycin arm (3% vs. 5%, aPR, 0.79 [95% CI, 0.62, 1.01]; P=0.063). InterpretationAzithromycin at hospital discharge was associated with higher carriage of macrolide-resistance-conferring genes in the post-discharge period compared with placebo, without significant declines in enteric pathogen carriage other than modest changes to Shigella. The potential benefits and risks of empiric azithromycin need to be considered, as children are increasingly exposed to this broad-spectrum antibiotic.

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Novel Genetic Risk Loci for Pancreatic Ductal Adenocarcinoma Identified in a Genome-wide Study of African Ancestry Individuals

Vergara, C.; Ni, Z.; Zhong, J.; McKean, D.; Connelly, K. E.; Antwi, S. O.; Arslan, A. A.; Bracci, P. M.; Du, M.; Gallinger, S.; Genkinger, J.; Haiman, C. A.; Hassan, M.; Hung, R. J.; Huff, C.; Kooperberg, C.; Kastrinos, F.; LeMarchand, L.; Lee, W.; Lynch, S. M.; Moore, S. C.; Oberg, A. L.; Park, M. A.; Permuth, J. B.; Risch, H. A.; Scheet, P.; Schwartz, A.; Shu, X.-O.; Stolzenberg-Solomon, R. Z.; Wolpin, B. M.; Zheng, W.; Albanes, D.; Andreotti, G.; Bamlet, W. R.; Beane-Freeman, L.; Berndt, S. I.; Brennan, P.; Buring, J. E.; Cabrera-Castro, N.; Campa, D.; Canzian, F.; Chanock, S. J.; Chen, Y.;

2026-04-22 genetic and genomic medicine 10.64898/2026.04.21.26351329 medRxiv
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Pancreatic cancer disproportionately affects Black individuals in the United States, but they have limited representation in genetic studies of pancreatic ductal adenocarcinoma (PDAC). To address this gap, we performed admixture mapping and genome-wide association analysis (GWAS) in genetically inferred African ancestry individuals (1,030 cases and 889 controls). Admixture mapping identified three regions with a significantly higher proportion of African ancestry in cases compared to controls (5q33.3, 10p1, 22q12.3). GWAS identified a genome-wide significant association at 5p15.33 (CLPTM1L, rs383009:T>C, T Allele Frequency=0.51, OR:1.45, P value=1.24x10-8), a locus previously associated with PDAC. Known loci at 5p15.33, 7q32.3, 8q24.21 and 7q25.1 also replicated (P value <0.01). Multi-ancestral fine-mapping identified two potential causal SNPs (rs3830069 and rs2735940) at 5p15.33. Collectively these findings identified novel PDAC risk loci and expanded our understanding of this deadly cancer in underrepresented populations, emphasizing the multifactorial nature of PDAC risk including inherited genetic and non-genetic factors. Statement of SignificanceTo understand how genetic variation contributes to PDAC risk in Black people in North American, we studied individuals of genetically-inferred African ancestry. We identified novel risk loci and differences in the contribution of known loci. This demonstrates that ancestry-informed genetic analyses improve our understanding of PDAC risk and enhances discovery.