Table 3.

Evidence from animal experiments and human clinical trials of LAB treatment for improving mental symptoms.

Symptoms	Bacterial Strains	Subjects	Therapeutic Effects
Stress-related symptoms: anxiety, fatigue, sleep disturbance	L. gasseri CP2305	Healthy young adults	Reduced anxiety and fatigue and improved sleep quality, including shortened sleep latency and increased sleep duration [117]
Stress-related symptoms: anxiety, depression, sleep disturbance; Parkinson’s disease (PD); Alzheimer’s disease (AD)	Lpb. plantarum PS128TM	IT specialists PD patients AD mice	1. Apparently improved job and life satisfaction among IT specialists [118] 2. Lpb. plantarum PS128TM supplementation while continuously taking antiparkinsonian medicines could improve the motor ability of PD patients, inhibit the development of the disease, and improve the quality of life [119] 3. Effectively prevented damage in 3 × Tg-AD mice by ventricular injection of streptozotocin [120]
Depression disorder; Alzheimer’s disease	B. breve CCFM1025	Major depressive disorder patients AD mice	1. Significantly alleviated the psychiatric and gastrointestinal disorders of major depression disorder patients [121] 2. Significant improvement in cognitive impairment and neuroinflammation [122]

AD: Alzheimer’s disease; B. breve: Bifidobacterium breve; PD: Parkinson’s disease.