FIGURE 6.

Potential microbiome-gut-brain axis relationships depicted in obesity comorbid with depression and associated anxiety involving diet, fecal SCFAs, and inflammatory cytokines. The linkage between diet and mental health may rely on the mediating relationship of biomarkers such as inflammatory cytokines and gut microbial metabolites, SCFAs. For this sample population, biomarkers at 2 mo, including 2 plasma cytokines, TNF-α and IL-1RA, and 4 SCFAs, propionic, butyric, acetic, and isovaleric acids, were associated with depression and anxiety scores after 6 mo. These biomarkers at 2 mo were also associated with dietary intake markers such as animal protein at 2 mo and animal protein associated with depression at 6 mo. IL-1RA, interleukin 1 receptor agonist;.