“…A meta-analysis showed that the use of polyunsaturated fatty acids alleviates depressive symptoms in humans [ 191 , 192 ]. Water-soluble cellulose acetate, which is fermented by intestinal bacteria and increases the production of short-chain fatty acids and GABA in the human gut, has the potential to be a prebiotic [ 193 ]. However, in the majority of studies, prebiotics used as monopreparations did not influence the manifestation of depression symptoms in humans, unlike probiotics and synbiotics [ 76 , 88 , 136 , 138 , 158 ].…”