Lactiplantibacillus plantarum ELF051 Alleviates Antibiotic-Associated Diarrhea by Regulating Intestinal Inflammation and Gut Microbiota

Deciphering the pharmacological mechanisms of Shenlingbaizhu formula in antibiotic-associated diarrhea treatment: Network pharmacological analysis and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Shenlingbaizhu (SLBZ) formula, a classical traditional Chinese medicinal (TCM) formula, has been widely used for treating antibiotic-associated diarrhea (AAD). However, the underlying pharmacological mechanisms have not yet been investigated thoroughly.

AIM OF THE STUDY

To explore the remission mechanism of SLBZ in the treatment of AAD, we conducted network pharmacological analysis and experimental validation in vitro and in vivo.

MATERIALS AND METHODS

In this study, the main compounds of SLBZ were identified by ultra-high-performance liquid chromatography-mass spectroscopy (UHPLC-MS) and online databases. The targets of the active components and AAD-related targets were predicted by network pharmacology, and the potential targets of SLBZ against AAD were obtained. Then the core targets were recognized after Protein-Protein Interaction (PPI) analysis. Based on these, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analyses were conducted, and the key pathway was screened. Subsequently, molecular docking was performed using Auto Dock Vina to find the key components that played a crucial role in that pathway. Molecular dynamics simulation was performed by Gromacs software to detect the binding mode. Finally, the results were confirmed by in vitro and in vivo experiments.

RESULTS

A total of 66 active ingredients of SLBZ were detected by UHPLC-MS, and 128 active ingredients were screened out by network pharmacological analysis. Additionally, 935 drug targets and 1686 AAD-related targets were obtained. Seventy-eight intersected genes were selected as potential therapeutic targets and 19 genes were excavated as core targets. Enrichment analysis revealed PI3K-AKT signaling pathway was the key pathway in SLBZ against AAD. Topological analysis further revealed that JAK2, MTOR, TLR4, and SYK were the key targets affected by SLBZ on the PI3K-AKT pathway, and 52 components of SLBZ were associated with them. Molecular docking and dynamics simulation revealed strong binding affinities between MTOR and diosgenin. Subsequently, after SLBZ treatment, the expression levels of JAK2, MTOR, TLR4, and SYK were found significantly upregulated in the AAD model rats (p < 0.05). The cell experiment further validated the good binding ability between MTOR and diosgenin.

CONCLUSION

We demonstrate that the therapeutic effect of SLBZ on AAD was achieved in part by inhibiting the PI3K-AKT pathway.

Microorganisms and Their Importance in the Food Industry: Safety, Quality and Health Properties

Microorganisms can play an important role in food production, especially through fermentation processes [...].

Probiotics: Shaping the gut immunological responses

Probiotics are live microorganisms exerting beneficial effects on the host's health when administered in adequate amounts. Among the most popular and adequately studied probiotics are bacteria from the families Lactobacillaceae, Bifidobacteriaceae and yeasts. Most of them have been shown, both in vitro and in vivo studies of intestinal inflammation models, to provide favorable results by means of improving the gut microbiota composition, promoting the wound healing process and shaping the immunological responses. Chronic intestinal conditions, such as inflammatory bowel diseases (IBD), are characterized by an imbalance in microbiota composition, with decreased diversity, and by relapsing and persisting inflammation, which may lead to mucosal damage. Although the results of the clinical studies investigating the effect of probiotics on patients with IBD are still controversial, it is without doubt that these microorganisms and their metabolites, now named postbiotics, have a positive influence on both the host's microbiota and the immune system, and ultimately alter the topical tissue microenvironment. This influence is achieved through three axes: (1) By displacement of potential pathogens via competitive exclusion; (2) by offering protection to the host through the secretion of various defensive mediators; and (3) by supplying the host with essential nutrients. We will analyze and discuss almost all the in vitro and in vivo studies of the past 2 years dealing with the possible favorable effects of certain probiotic genus on gut immunological responses, highlighting which species are the most beneficial against intestinal inflammation.

Intestinal Flora Imbalance Induced by Antibiotic Use in Rats

Aim

This study aims to explore the effect of different doses of antibiotics on rats in order to observe alterations in their fecal microbiota, inflammatory changes in the colonic mucosa and four types of inflammatory markers in blood serum.

Methods

Our methodology involved separating 84 female Sprague Dawley rats into groups A-G, with each group consisting of 12 rats. We collected the rat feces for analysis, using a distinct medium for bacterial cultivation and counting colonies under a microscope. On the 11th and 15th days of the experiment, half of the rats from each group were euthanized and 5 mL of abdominal aortic blood and colon tissues were collected. Inflammations changes of colon were observed and assessed by pathological Hematoxylin Eosin (HE) staining. Enzyme-linked immune sorbent assay (ELISA) was adopted for detecting C-reactive protein (CRP), IL-6, IL1-β and TNF-α.

Results

Our findings revealed that the initial average weight of the rats did not differ between groups (p>0.05); but significant differences were observed between stool samples, water intake, food intake and weight (p=0.009, <0.001, 0.016 and 0.04, respectively) within two hours after the experiment. Additionally, there were notable differences among the groups in nine tested microbiota before and after weighting methods (all p<0.001). There were no difference in nine microbiota at day 1 (all p>0.05); at day 4 A/B (p=0.044), A/D (p<0.001), A/E (p=0.029); at day 8, all p<0.01, at day 11, only A/F exist significant difference (p<0.001); at day 14 only A/D has difference (p=0.045). Inflammation changes of colon were observed between groups A-G at days 11 and 15. Significant differences between all groups can be observed for CRP, IL-6, IL1-β and TNF-α (p<0.001).

Conclusion

This study suggests that antibiotics administration can disrupt the balance of bacteria in the rat gut ecosystem, resulting in an inflammatory response in their bloodstream and inducing inflammation changes of colon.

Probiotic Potential and Safety Assessment of Lactiplantibacillus plantarum cqf-43 and Whole-Genome Sequence Analysis

This study reports the whole-genome sequence of Lactiplantibacillus plantarum cqf-43 isolated from healthy sow feces. Based on genomic analysis, we performed a comprehensive safety assessment of strain cqf-43, using both in vitro and in vivo experiments, and explored its probiotic potential. The total genome length measures 3,169,201 bp, boasting a GC content of 44.59%. Through phylogenetic analyses, leveraging both 16S rRNA gene and whole-genome sequences, we confidently categorize strain cqf-43 as a member of Lactiplantibacillus. Genome annotation using Prokka unveiled a total of 3141 genes, encompassing 2990 protein-coding sequences, 71 tRNAs, 16 rRNAs, and 1 tmRNA. Functional annotations derived from COG and KEGG databases highlighted a significant abundance of genes related to metabolism, with a notable emphasis on carbohydrate utilization. The genome also revealed the presence of prophage regions and CRISPR-Cas regions while lacking virulence and toxin genes. Screening for antibiotic resistance genes via the CARD database yielded no detectable transferable resistance genes, effectively eliminating the potential for harmful gene transfer. It is worth highlighting that the virulence factors identified via the VFDB database primarily contribute to bolstering pathogen resilience in hostile environments. This characteristic is particularly advantageous for probiotics. Furthermore, the genome is devoid of menacing genes such as hemolysin, gelatinase, and biogenic amine-producing genes. Our investigation also unveiled the presence of three unannotated secondary metabolite biosynthetic gene clusters, as detected by the online tool antiSMASH, suggesting a great deal of unknown potential for this strain. Rigorous in vitro experiments confirmed tolerance of strain cqf-43 in the intestinal environment, its antimicrobial efficacy, sensitivity to antibiotics, absence of hemolysis and gelatinase activity, and its inability to produce biogenic amines. In addition, a 28-day oral toxicity test showed that the strain cqf-43 did not pose a health hazard in mice, further establishing it as a safe strain.