Psychotropic effects of Lactobacillus plantarum PS128 in early life-stressed and naïve adult mice.
Liu YW, Liu WH, Wu CC, Juan YC, Wu YC, Tsai HP, Wang Sabrina*, Tsai YChieh*. (2016) Psychotropic effects of Lactobacillus plantarum PS128 in early life-stressed and naïve adult mice. Brain Res. 1631:1-12.
Ingestion of specific probiotics, namely “psychobiotics”, produces psychotropic effects on
behavior and affects the hypothalamic–pituitary–adrenal axis and neurochemicals in the
brain. We examined the psychotropic effects of a potential psychobiotic bacterium,
Lactobacillus plantarum strain PS128 (PS128), on mice subjected to early life stress (ELS)
and on naïve adult mice. Behavioral tests revealed that chronic ingestion of PS128
increased the locomotor activities in both ELS and naïve adult mice in the open field test.
In the elevated plus maze, PS128 significantly reduced the anxiety-like behaviors in naïve
adult mice but not in the ELS mice; whereas the depression-like behaviors were reduced in
ELS mice but not in naïve mice in forced swimming test and sucrose preference test. PS128 administration also reduced ELS-induced elevation of serum corticosterone under both
basal and stressed states but had no effect on naïve mice. In addition, PS128 reduced
inflammatory cytokine levels and increased anti-inflammatory cytokine level in the serum
of ELS mice. Furthermore, the dopamine level in the prefrontal cortex (PFC) was
significantly increased in PS128 treated ELS and naïve adult mice whereas serotonin (5-
HT) level was increased only in the naïve adult mice. These results suggest that chronic
ingestion of PS128 could ameliorate anxiety- and depression-like behaviors and modulate
neurochemicals related to affective disorders. Thus PS128 shows psychotropic properties
and has great potential for improving stress-related symptoms.