- The gut microbiome (GM) in patients with melanoma may be negatively influenced by probiotics and could be targeted by dietary manipulation.
Why this matters
- A favorable GM signature is associated with anti-programmed cell death 1 (anti-PD-1) therapy in melanoma, but it is unclear how diet and probiotic use influence this relationship.
- An analysis of data from 113 patients with melanoma who prospectively provided pretreatment stool samples and completed a National Cancer Institute lifestyle diet questionnaire.
- Stool samples were subjected to 16S rRNA sequencing, and GM alpha- and beta-diversity (AD and BD, respectively, associated with response and nonresponse to anti-PD-1 therapy) was compared.
- Response to anti-PD-1 therapy was defined per RECIST criteria.
- Funding: Melanoma Research Alliance, MD Anderson, Mulva Research Fund, Adelson Medical Research Foundation.
- Reported probiotic use (42%) was associated with lower AD (P=.05) and poorer response to anti-PD-1 therapy (OR 0.36 [95% CI, 0.10-1.31]).
- Patients with a high-fiber diet had higher odds of response (OR 4.78 [95% CI, 1.1-20.3]).
- Higher intake of whole grains, fruits, vegetables, and fiber correlated positively with proresponse bacterial populations, while higher intake of red and processed meats and added sugars negatively correlated.
- Self-reported data, small study, not all results statistically significant, correlative design, referral center population.