Recent research suggests that fruit and vegetable intake is inversely associated with mood states and depression. Although the mechanism is not known, increased gut fermentation is suspected as changes in gut tryptophan metabolism was noted in these trials. Tryptophan is the precursor to serotonin, the neurotransmitter associated with improved mood state, but other metabolites of tryptophan have been associated with mental wellbeing as well. The main ingredient of vinegar, acetic acid, is the most common metabolite produced during gut fermentation of dietary fiber (mainly from fruits and vegetables) and can also be expected to influence the gut microbiome. It has been reported that vinegar ingestion is linked to a change in tryptophan metabolism in healthy adults consuming vinegar daily for 8 weeks. This study will explore the impact of vinegar ingestion on mood states.
