Inhibitory Effect of Lactiplantibacillus plantarun HFY11 on Compound Diphenoxylate-Induced Constipation in Mice

<i>Lactiplantibacillus plantarun</i> HFY11 (LP-HFY11) is a newly discovered microbial strain. This study was the first to investigate the preventive effect of LP-HFY11 on compound diphenoxylate induced constipation in mice by measuring intestinal contents, serum, and small intestinal tissue indexes. In mice suffering from constipation, LP-HFY11 could prevent the reduction in fecal weight, particle count, and water content. The constipated mice that ingested a high LP-HFY11 dose (LP-HFY11H) expelled the first black stool faster than the model group and the drug lactulose-treated group, but they were slower than the normal group. Furthermore, the small intestine in the LP-HFY11H group had a greater propulsion rate of activated charcoal than that in the model and lactulose groups, but the propulsion rate was still lower than that in the normal group. According to hematoxylin-eosin (H&E) staining, LP-HFY11H was more effective than lactulose at reducing intestinal villi breaking and constipation-induced harm to the small intestine. Simultaneously, compared with the model group, the LP-HFY11H group had markedly increased serum levels of motilin (MTL), endothelin-1 (ET-1), vasoactive intestinal peptide (VIP), and acetylcholinesterase (AchE). Transient receptor potential vanilloid 1 (TRPV1) expression was only higher than in the normal group, but the mRNA expression of c-Kit, stem cell factor (SCF), and glial cell line-derived neurotrophic factor (GDNF) was all higher in the small intestine in the LP-HFY11H group than in the model and lactulose groups, according to the results of quantitative polymerase chain reaction (qPCR) experiments. Analysis of microbial mRNA in the small intestinal contents of the constipated mice further validated the capacity of LP-HFY11 to decrease the abundance of <i>Firmicutes</i> and increase the abundance of <i>Bacteroidetes</i>, <i>Bifidobacteria</i>, and <i>Lactobacillus</i>. This revealed that LP-HFY11, which produced better results than the drug lactulose, can control the gut microbiota of constipated mice and successfully cure constipation. LP-HFY11 has the potential to be used as a probiotic in the treatment of constipation. It has good application prospects in the food industry and biopharma.