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ORIGINAL RESEARCH article

Front. Nutr.

Sec. Clinical Nutrition

Volume 12 - 2025 | doi: 10.3389/fnut.2025.1562278

The association between a dietary index for the gut microbiota and frailty in older adults: emphasising the mediating role of inflammatory indicators

Provisionally accepted
Huangyi  YinHuangyi YinYue  QiuYue QiuChaomei  GanChaomei GanYubo  ZhouYubo ZhouTingting  ChenTingting ChenMin  LiangMin Liang*
  • First Affiliated Hospital, Guangxi Medical University, Nanning, China

The final, formatted version of the article will be published soon.

The dietary index for the gut microbiota (DI-GM) is a novel indicator of gut microbiome health, and its association with frailty remains unknown. Methods: We recruited participants from the 2007-2020 National Health and Nutrition Examination Survey (NHANES). Restricted cubic splines (RCSs) and multifactorial logistic regression were employed to investigate the relationship between the DI-GM and frailty. A mediation analysis was conducted to evaluate the mediating role of inflammatory markers. Stratification and sensitivity analyses were performed to evaluate the consistency of this association. Results: A total of 4,578 eligible individuals were screened, with a frailty prevalence of 35.50%. After adjusting for all of the covariates, each unit increase in the DI-GM was associated with a 6% decrease in the prevalence of frailty (OR = 0.94; 95% CI: 0.89, 0.99; P = 0.020). Furthermore, participants in the highest tertile of the DI-GM were significantly less likely to be frail than were those in the lowest tertile (OR = 0.70; 95% CI: 0.53, 0.91; P = 0.008). Mediation analysis revealed that inflammatory biomarkers significantly mediated the association between the DI-GM and frailty, with percentages of 16.47% for the neutrophil-to-lymphocyte ratio (NLR), 14.59% for the systemic inflammation response index (SIRI), and 11.13% for the systemic immune-inflammation index (SII). This negative relationship remained robust across subgroups and in the sensitivity analyses. Conclusions: An elevated DI-GM, which reflects a healthier microbiota state, was associated with a reduced prevalence of frailty. This relationship was partially mediated through inflammatory biomarkers.

Keywords: gut microbiome, Frailty, DI-GM, NHANES, Ageing

Received: 17 Jan 2025; Accepted: 26 Jun 2025.

Copyright: © 2025 Yin, Qiu, Gan, Zhou, Chen and Liang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Min Liang, First Affiliated Hospital, Guangxi Medical University, Nanning, China

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