Akikazu Takada was born in Japan, 1935. After graduation from Keio University School of Medicine and finishing his post-graduate studies, he worked at Roswell Park Memorial Institute NY, USA. He then took a professorship at Hamamatsu University School of Medicine. In thrombosis studies, he found the SK potentiator that enhances plasminogen activation by streptokinase. Using simultaneous analyses of plasma fatty acids, he indicated that plasma levels of trans-fatty acids of old men were far higher in the US than Japanese men. By using simultaneous LC/MS analyses of plasma levels of tryptophan metabolites, he recently found that plasma levels of serotonin, kynurenine, or 5-HIAA were higher in patients of mono- and bipolar depression, which is significantly different from observations reported before. In view of recent reports that plasma tryptophan metabolites are mainly produced by microbiota, he is now working on the relationships between microbiota and depression or autism.