Related Experiment Video

Updated: Jun 19, 2026

Oral Biofilm Sampling for Microbiome Analysis in Healthy Children
10:42

Oral Biofilm Sampling for Microbiome Analysis in Healthy Children

Published on: December 31, 2017

Association between oral microbiome alpha and beta diversity and MASLD risk: a large-scale, population-based

Zeru Liu1,2, Yizhi Mao3, Lei Zhang1,2

  • 1Hunan Provincial Key Laboratory of Traditional Chinese Medicine Diagnostics, Hunan University of Chinese Medicine, Changsha, Hunan, China.

Frontiers in Cellular and Infection Microbiology
|June 18, 2026
PubMed
Abstract

Insights

Lower oral microbial diversity is linked to a higher risk of metabolic dysfunction-associated steatotic liver disease (MASLD). A healthy oral microbiome may protect liver health, but smoking and obesity can diminish this effect.

Area of Science:

  • Microbiome research
  • Liver disease pathogenesis
  • Oral health and systemic disease

Background:

  • Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent global liver condition.
  • The oral-gut-liver axis theory proposes oral microbiota influence liver health, but population data is scarce.

Purpose of the Study:

  • To investigate the association between oral microbial diversity and MASLD in a U.S. adult population.
  • To determine if oral microbiome composition is an independent risk factor for MASLD.

Main Methods:

  • Analysis of 2,759 U.S. adults from NHANES (2009-2012).
  • MASLD defined by Fatty Liver Index score ≥ 30.
  • Oral rinse samples analyzed for microbial diversity (16S rRNA sequencing).
  • Multivariable logistic regression adjusted for covariates.

Main Results:

  • Individuals with MASLD exhibited significantly lower oral microbial richness and diversity.
  • Each increase in oral microbial diversity correlated with reduced MASLD risk (up to 65% lower risk in the highest diversity group).
  • Oral microbiome differences were distinct between MASLD and non-MASLD groups, independent of weight and diabetes.

Conclusions:

  • Lower oral microbial diversity is independently associated with increased MASLD risk.
  • A diverse oral microbiome plays a protective role in liver health.
  • Smoking and increased body weight may attenuate the protective effects of oral microbial diversity.
Keywords:
NHANEScross-sectional studygut-liver axismetabolic dysfunction-associated steatotic liver diseaseoral microbiome diversity

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