Daily evidence update

Daily microbiome literature · 7 October 2026

Today's literature: 68 papers; 3 primary human interventions.

4 animal and in-vitro studies read, not shown.

Zinc with or without a probiotic in IBS

In a double-blind randomized trial, 84 adults with irritable bowel syndrome received zinc, zinc plus a probiotic, or placebos for 90 days. Both active groups had higher serum zinc and lower total oxidant status and oxidative stress index than placebo. No significant between-group effects were reported for serum MDA, total antioxidant capacity or SOD activity. The abstract did not identify the probiotic strain or dose, and it did not show that adding the probiotic improved outcomes beyond zinc alone.

Walnut-derived metabolites and cortical thickness

In a longitudinal MRI sub-study of 104 participants who were cognitively healthy older adults in a two-year walnut trial, increases in urolithin A, urolithin C and a glucuronide conjugate within the walnut-diet group were associated with preservation of cortical thickness. This was an association within the walnut group, not a randomized comparison of urolithin exposure; the abstract did not establish that urolithins caused the MRI differences.