Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Microbiol.

Sec. Microorganisms in Vertebrate Digestive Systems

Volume 16 - 2025 | doi: 10.3389/fmicb.2025.1683885

This article is part of the Research TopicThe Role of Gut Microbes and Their Metabolites in Metabolic Diseases: Mechanisms and Therapeutic TargetsView all 20 articles

Distinct Gut Microbial Species, but Not Phylum-to-Genus Composition, Associate with Insulin Resistance: A Unique Perspective from the Kazakh Population

Provisionally accepted
  • 1Gerontology Center, Medical Center Hospital of the President's Affairs Administration of the Republic of Kazakhstan, Astana, Kazakhstan
  • 2Corporate fund "Institute for Innovational and Profilaxy Medicine, Astana, Kazakhstan
  • 3Department of Surgery No. 2, West Kazakhstan Medical University, Aktobe, Kazakhstan
  • 4Department of Natural Sciences, West Kazakhstan Marat Ospanov Medical University, Aktobe, Kazakhstan

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

Objectives: Links between gut microbiota and insulin resistance (IR) vary across populations. We profiled the fecal microbiota of Kazakh adults to test whether community composition associates with IR at broad (phylum→genus) and species levels. Methods: In a cross-sectional case control study (N=200; IR = 183, controls = 17), TyG indexed IR status. 16S rRNA sequencing (two primer pools; nine hypervariable regions) characterized taxa. After CSS normalization, we compared presence/absence across groups (χ²) and modeled species with univariate and multivariable logistic regressions, using absence of each species as the predictor. Results: High-level composition did not differ between IR and controls (phylum, class, family, genus; all p>0.05). In contrast, several species differed. In univariate models, absence of Actinomyces odontolyticus (OR = 25.55, p=0.010), Bifidobacterium kashiwanohense (OR = 12.69, p=0.015), Lactobacillus sp. (OR = 5.71, p=0.020), and Streptococcus lactarius (OR = 6.27, p=0.044) associated with higher IR odds, suggesting protection when present; whereas absence of Alistipes onderdonkii (OR = 0.30, p=0.044) and Prevotella copri (OR = 0.19, p=0.003) associated with lower IR odds, suggesting risk when present. In multivariable models, these signals persisted: absence of P. copri (OR = 0.146, p=0.003) and Roseburia inulinivorans (OR = 0.143, p=0.011) predicted lower IR odds (risk alignment), while absence of Lactobacillus sp. (OR = 8.29, p=0.016) and Coprococcus catus (OR = 7.04, p=0.004) predicted higher IR odds (protective alignment). Conclusion: In this Kazakh cohort, no broad compositional signal emerged, but species-specific associations were strong and bidirectional. Findings highlight population-specificity and identify candidate species associated with IR that may serve as hypothesis-generating targets for future validation. Any attempt to modulate these taxa for insulin resistance is unproven and requires function-resolved, diet-measured longitudinal studies and randomized trials before clinical application. The IR:control imbalance (183:17) increases uncertainty for low-prevalence taxa; species-level findings are hypothesis-generating and require validation in a more balanced design. Because 16S rRNA profiling does not measure gene functions or metabolites, these species–IR associations are hypothesis-generating and warrant validation using shotgun metagenomics and metabolomics.

Keywords: Insulin Resistance, Gut Microbiota, 16S ribosomal RNA sequencing, Kazakhstan, bacterium

Received: 11 Aug 2025; Accepted: 23 Sep 2025.

Copyright: © 2025 Abildinova, Benberin, Vochshenkova, Mussin, Afshar and Tamadon. 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:
Alireza Afshar, alireza.af2017@gmail.com
Amin Tamadon, amintamaddon@yahoo.com

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.