NFKB1 and depressive disorder: No results showing improvement in patients’ mood after 4-week treatment;The findings indicate that patients with a four-week probiotic intake showed decreasing IL-6 gene expression levels while the placebo group showed increased gene expression levels of IL-6. This result confirms the positive effects of multispecies probiotics on mild inflammation in depressive disorders. However, on a univariate level no significant effects were found in TNF-α, nor NFKB1