Studies on Lactobacillus plantarum YS2 (Yak Yogurt Lactobacillus) Exhibited an Activity to Attenuate Activated Carbon-induced Constipation in Male Kunming Mice

The present study investigated the effects of Lactobacillus plantarum YS2 (LP-YS2) that was isolated
from yak yogurt on activated carbon-induced constipation in Kunming (KM) mice. The KM mice were
orally administered LP-YS2 and reference strain Lactobacillus delbrueckii ssp. bulgaricus.
Administration of LP-YS2 [1.0 × 109 cfu/kg of body weight (BW)] promoted gastrointestinal peristalsis
and reduced the first black stool defecation time (129 min), which clearly defines attenuation of the
voiding difficulty in mice with constipation. The LP-YS2 treatment also increased the serum level of
motilin (MTL; 178.2 pg/mL), gastrin (69.4 pg/mL), acetylcholine (Ach; 30.1 pg/mL), substance P (SP;
57.6 pg/mL), and vasoactive intestinal peptide (VIP; 53.2 pg/mL) and reduced the somatostatin (SS,
32.6 pg/mL) levels compared with the L. delbrueckii ssp. bulgaricus treatment (MTL, 139.7 pg/mL;
gastrin, 43.1 pg/mL; Ach, 15.9 pg/mL; SP, 43.6 pg/mL; VIP, 32.3 pg/mL; SS, 55.1 pg/mL) and the
control (MTL, 105.3 pg/mL; gastrin, 26.7 pg/mL; Ach, 9.7 pg/mL; SP, 30.2 pg/mL; VIP, 21.0 pg/mL;
SS, 70.5 pg/mL). The LP-YS2 treatment significantly increased the colonic mRNA and protein
expression of c-Kit (CD117, cluster of differentiation 117; 2.87 times mRNA expression of the control
group), stem cell factor (30.40 times mRNA expression of the control group), and glial cell-derived
neurotrophic factor (29.97 times mRNA expression of the control group) in mice with constipation. In
addition, LP-YS2 reduced the expression of transient receptor potential vanilloid 1 (0.42 times mRNA
expression of the control group) and nitric oxide synthase (0.49 times mRNA expression of the control
group) in constipated mice. Administration of LP-YS2 reduced the first black stool defecation and
promoted gastrointestinal peristalsis in constipated mice. In addition, LP-YS2 showed greater activity
to increase the serum levels of MTL, gastrin, ACh, SP, and VIP compared with LB-treated mice. In the
same way, LP-YS2-treated mice exhibited lower levels of SS compared with LB-treated mice.
The LP-YS2-treated mice showed higher mRNA and protein expression levels of c-Kit, SCF, and
GDNF and lower levels of TRPV1 and NOS than LB-treated mice and control mice. These results
demonstrate that LP-YS2 was able to attenuate the activated carbon-induced constipation in KM
mice.