Synbiotic Supplementation to Reduce Anxiety Symptoms in Female Breast Cancer Survivors and/or Their Female Relatives

Cancer survivors experience more rapid declines in health-related quality of life which include physical and psychological comorbidities, the latter of which may be subclinical and often overlooked by primary care providers. Recently, the gut-brain axis (GBA) has been identified as a therapeutic target to improve host health. The GBA is greatly influenced by the composition of the gut microbiome, as microbial metabolites directly influence the central nervous system. Thus, prebiotics, probiotics, and synbiotics (a combination of pre- and probiotics) have emerged as a possible approach to treating anxiety symptoms. Preclinical studies suggest efficacy of synbiotics, while pre- and probiotics have only been studied in isolation in humans.

This is a double-blind, placebo-controlled clinical trial in which female breast cancer survivors and/or their female relatives experiencing moderate to severe anxiety symptoms will be randomized to daily consumption of the synbiotic supplement or placebo. The previously validated Generalized Anxiety Disorder-7 (GAD-7) will be used to assess anxiety symptom severity at study screening and at each time point. The primary outcome of this study is feasibility, measured by accrual, adherence, retention, and adverse effects. Secondary outcomes relate to reduction of anxiety symptoms and other physiological changes. No study has investigated the mediating effects of gut microbiota and inflammatory markers on the ability of synbiotics to reduce anxiety symptoms. Thus, at each timepoint, phlebotomy will be conducted to determine serum levels of inflammatory cytokines and stool samples will be collected to determine alpha- and beta-diversity of the fecal microbiome as well as relative abundance of target genera. Hypothesis: this placebo-controlled study will be feasible and synbiotic treatment will result in a significant reduction in anxiety symptoms and inflammatory markers, which may be moderated by changes in the microbiome.