Dietary index for gut microbiota (DIGM) and cardiometabolic, inflammatory, and gut-brain-related biomarkers in adults with obesity: a cross-sectional study.
El-Sehrawy A, Kandil I, et al. • Scientific reports • 2026
Greater adherence to the Dietary Index for Gut Microbiota (DIGM) was independently associated with a more favorable inflammatory profile, higher circulating BDNF concentrations, lower LPS and CRP levels, and lower blood pressure among adults with obesity.
Key Findings
Results
Higher DIGM scores were independently associated with lower systolic blood pressure after multivariable adjustment.
Beta coefficient: β = -0.057; 95% CI: -0.011 to -0.006
Adjusted for age, sex, BMI, smoking status, physical activity, dietary energy intake, education, occupation, marital status, and history of depression
Cross-sectional study of 637 adults with obesity aged 20-55 years recruited from clinics affiliated with Mansoura University, Egypt
Study conducted January to December 2025
Results
Higher DIGM scores were independently associated with higher HDL cholesterol concentrations after multivariable adjustment.
Beta coefficient: β = 0.100; 95% CI: 0.004 to 0.011
HDL-C was one of two cardiometabolic markers significantly associated with DIGM adherence in multivariable linear regression
Participants were categorized into tertiles according to their DIGM score for comparison analyses
Results
Higher DIGM scores were independently associated with higher circulating BDNF (brain-derived neurotrophic factor) concentrations.
Beta coefficient: β = 0.504; 95% CI: 0.295 to 0.407
This was the largest standardized beta coefficient observed among the biomarker associations
Participants in the highest DIGM tertile showed higher BDNF levels compared with lower tertiles (adjusted P < 0.001)
Results
Higher DIGM scores were independently associated with lower circulating lipopolysaccharide (LPS) concentrations.
Beta coefficient: β = -0.468; 95% CI: -0.208 to -0.146
Participants in the highest DIGM tertile showed lower circulating LPS concentrations compared with lower tertiles (adjusted P < 0.001)
LPS is a marker of gut permeability and endotoxemia
Results
Higher DIGM scores were independently associated with lower C-reactive protein (CRP) concentrations.
Beta coefficient: β = -0.048; 95% CI: -0.028 to -0.003
Participants in the highest DIGM tertile showed lower CRP concentrations compared with lower tertiles (adjusted P < 0.001)
CRP is a systemic inflammatory biomarker
Methods
The study recruited 637 adults with obesity aged 20-55 years using clinic-based recruitment and a semi-quantitative food frequency questionnaire to assess dietary intake.
Participants were recruited from clinics affiliated with Mansoura University, Egypt, through clinic-based recruitment and public advertisements
Study was conducted from January to December 2025
DIGM score was calculated based on predefined favorable and unfavorable dietary components according to the original scoring framework
Assessments included anthropometric measurements, blood pressure, glycemic indices, lipid profile, LPS, BDNF, and CRP
Background
Gut microbiota plays an important role in metabolic homeostasis and systemic inflammation, and dietary habits are major determinants of its composition and function.
The DIGM is a dietary scoring tool designed to capture dietary patterns relevant to gut microbiota composition
The study focused specifically on adults with obesity, a population characterized by altered gut microbiota and elevated cardiometabolic risk
No direct assessment of gut microbiota composition or microbial metabolites was performed in this study
What This Means
This research suggests that eating a diet that supports healthy gut bacteria — as measured by a scoring tool called the Dietary Index for Gut Microbiota (DIGM) — is linked to better heart and metabolic health markers in people with obesity. The study followed 637 Egyptian adults with obesity and found that those who ate diets with higher DIGM scores had lower blood pressure, higher levels of 'good' HDL cholesterol, lower levels of inflammation (measured by CRP), and lower levels of a toxin called LPS that leaks from the gut into the bloodstream when the gut barrier is compromised. They also had higher levels of BDNF, a protein important for brain health and linked to mood and cognition.
The associations held up even after accounting for factors like age, sex, body weight, smoking, physical activity, and other lifestyle variables, suggesting that diet quality related to gut microbiota may independently influence these health markers. The DIGM score reflects how closely someone's diet includes foods considered favorable for gut bacteria (such as fiber-rich foods) and avoids unfavorable ones, and was assessed through a detailed dietary questionnaire.
This research suggests that adopting dietary patterns that promote a healthy gut microbiome could be an important strategy for improving heart health and reducing inflammation in people with obesity, though the study's cross-sectional design means it cannot prove that the diet caused these improvements. The authors note that future studies should directly measure gut bacteria and follow participants over time to better understand how diet, gut microbiota, and health outcomes are connected.
El-Sehrawy A, Kandil I, Labib S, Abdelrahim I, Alanazi M, Maashi M, et al.. (2026). Dietary index for gut microbiota (DIGM) and cardiometabolic, inflammatory, and gut-brain-related biomarkers in adults with obesity: a cross-sectional study.. Scientific reports. https://doi.org/10.1038/s41598-026-71219-5