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The following is a summary of “Association between the dietary index of gut microbiota and abnormal bowel symptoms in U.S. adults: a cross-sectional study based on NHANES 2007–2010,” published in the May 2025 issue of BMC Gastroenterology by Shen et al. 

Researchers conducted a retrospective study to analyze whether the Dietary Index of Gut Microbiota (DI-GM) was linked with the risk of chronic constipation and chronic diarrhea 

They analyzed data from 7,943 patients aged 20 years and older who participated in the 2007–2010 National Health and Nutrition Examination Survey (NHANES). Weighted logistic regression, subgroup analysis, and restricted cubic spline (RCS) models were applied to evaluate the association between the DI-GM and abnormal bowel symptoms.  

The results showed that a higher DI-GM score was linked to a lower risk of abnormal bowel symptoms. Each 1-point increase in DI-GM was associated with a 12.4% reduction in constipation risk (OR = 0.876, 95% CI = 0.806–0.951, P= 0.002) and a 14.1% reduction in diarrhea risk (OR = 0.859, 95% CI = 0.789–0.936, P< 0.001). Compared with the lowest DI-GM quartile, the highest quartile had lower risks of diarrhea (OR = 0.480, 95% CI = 0.338–0.682, P< 0.001) and constipation (OR = 0.487, 95% CI = 0.340–0.696, P< 0.001). The RCS analysis showed a significant linear relationship between DI-GM and both constipation (nonlinear P= 0.686) and diarrhea (nonlinear P= 0.136).  

Investigators concluded that higher DI-GM scores were related to a lower prevalence of abnormal bowel symptoms, which may also reflect improvements in mental health outcomes such as depression, supporting the need for future longitudinal research to guide dietary approaches for gut health. 

Source: bmcgastroenterol.biomedcentral.com/articles/10.1186/s12876-025-04021-8