IL1B and major depressive disorder: Furthermore, the combined use of probiotics (Bifidobacterium and Lactobacillus) has been found to decrease the incidence of post-stroke depression and lower serum inflammatory markers, such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and interleukin-1 beta (IL-1β) (Wang et al., 2023b).