Psychobiotics are defined as the organisms that can provide the mental health benefit. The possible mechanism of psychobiotics is manipulation of neurotransmitter production and neurotransmitter production by the microbes. The lactobacillus group has been reported for the potential of neurotransmitter production, especially g-aminobutyric acid (GABA) which is an important inhibitory neurotransmitter. Therefore, GABA can be used for relaxation and applied in various psychiatric disorders. The aim of this study was determination of lactic acid bacterial isolates from Pak Sian Dong in Thailand for GABA producing ability. The results found that there were 3 isolates, SF66, SF80 and SF82, which revealed the ability to produce glutamic acid decarboxylase (GAD) enzyme. The GABA were detected by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) in the bacterial culture containing 3% monosodium glutamate. The survival in gastrointestinal synthetic condition found that only SF66 isolate showed the authentic percentage of survival then this isolate was selected. From the identification, the isolate was identified as Lactiplantibacillus pentosus and was designated as L. pentosus SF66 which exhibited with the potential for further investigation and development to be psychobiotics.