Exploring the Dose–Effect Relationship of Bifidobacterium longum in Relieving Loperamide Hydrochloride-Induced Constipation in Rats through Colon-Released Capsules

Abstract

Constipation is a common disease affecting humans. Bifidobacterium longum is reportedly effective in relieving constipation. Current studies generally focus on the dose–response relationship of oral doses; however, the dose–effect relationship of B. longum in the colon, which is the primary site where B. longum exerts constipation-relieving effects, to treat constipation has not been studied. Herein, three strains of B. longum (FGSZY6M4, FJSWXJ10M2, and FSDJN6M3) were packaged in colon-released capsules to explore the dose–effect relationship in the colon. For each strain, three groups of capsules (104, 106, and 108 CFU/capsule, respectively) and one group of free probiotics (108 CFU/mL) were used to explore the colonic dose effect of B. longum. The results showed that the three strains of B. longum improved fecal water content and promoted intestinal motility by regulating gastrointestinal peptide (MTL, GAS, and VIP), aquaporin-3, and 5-hydroxytryptamine levels while promoting gastrointestinal motility and relieving constipation by regulating the intestinal flora composition of constipated rats and changing their metabolite content (short-chain fatty acids). Among the three free bacterial solution groups (108 CFU/mL), FGSZY6M4 was the most effective in relieving constipation caused by loperamide hydrochloride in rats. The optimal effective dose of each strain was 6M4 (104 CFU/day), 10M2 (106 CFU/day), and S3 (108 CFU/day) of the colon-released capsules. Therefore, for some effective strains, the dose of oral probiotics can be reduced by colon-released capsules, and constipation can be relieved without administering a great number of bacterial solutions. Therefore, investigating the most effective dose of B. longum at the colon site can help to improve the efficiency of relieving constipation.

Effect of Probiotics in Stress-Associated Constipation Model in Zebrafish (Danio rerio) Larvae

“…These results support previous studies showing that probiotics improved the intestinal barrier function and regulated the intestinal fluid balance [38]. In a rat model of loperamide-induced constipation, probiotic administration increased the fecal water content and intestinal motility by modulating gastrointestinal peptides such as motilin, vasoactive intestinal peptide (VIP), and AQP3 [39].…”

Effect of Probiotic Dose Escalation on Gut Microbiota and Clinical Outcomes in Preterm Infants—A Systematic Review

“…Zhou et al investigated the dosedependent effects of B. longum in relieving loperamide hydrochloride-induced constipation in rats using colon-released probiotic capsules. The three-strain B. longum showed a better ability to control gastrointestinal peptides at a low dose (2.1 ± 0.1 × 10 4 ) compared with high (9 ± 0.1 × 10 8 ) and medium (9.8 ± 0.2 × 10 6 ) doses [41]. High-dose Bifidobacterium also improved intestinal motility by improving dysbiosis, SCFA levels, and upregulating the expression of serotonin receptors.…”

Qi Lang formula relieves constipation via targeting SCF/c-kit signaling pathway: An integrated study of network pharmacology and experimental validation

“…Neurotransmitters are closely related to intestinal motility [ 22 ]. The serum levels of AChE, MTL, SP, GAS, VIP and 5-HT were measured respectively.…”