TUESDAY, April 28, 2026 (HealthDay News) -- The combination of stress and nighttime eating increases the likelihood of abnormal bowel habits, according to a study presented at Digestive Disease Week 2026, held from May 2 to 5 in Chicago.
Harika Dadigiri, M.D., from New York Medical College at Saint Mary's in Passaic, New Jersey, and colleagues used data from 11,149 participants in the National Health and Nutrition Examination Survey (NHANES; 2005 to 2010) and 4,157 from the American Gut Project to evaluate whether late-night eating amplifies allostatic load on bowel function and alters gut microbiome diversity. Gut microbiota was evaluated using 16S rRNA gene sequencing, focusing on Alpha diversity (Shannon index) and specific taxa abundance.
The researchers found that a high allostatic load score (≥5) was linked to a higher likelihood of abnormal bowel habits (constipation or diarrhea; odds ratio [OR], 1.32) using the NHANES data. Among individuals with both high stress and late-night eating habits, a synergistic pattern was seen, with the highest prevalence of abnormal bowel habits (39.3 percent) compared with a low-stress/normal-eating baseline (23.2 percent), yielding a 1.7-fold absolute risk increase. The "High Stress + Poor Diet" phenotype was strongly validated using American Gut Project data, showing 2.5-fold increased odds of abnormal bowel function (OR, 2.50). This high-risk group also showed significantly lower gut microbial diversity versus healthy controls (Shannon index, −0.18; Cohen's d = 0.19).
"It's not just what you eat, but when you eat it," Dadigiri said in a statement. "And when we're already under stress, that timing may deliver a 'double hit' to gut health."
