Identification of the key physiological characteristics of Lactobacillus plantarum strains for ulcerative colitis alleviation

Resistant starch and tannic acid synergistically ameliorated dextran sulfate sodium-induced ulcerative colitis, particularly in the distal colon

We previously confirmed that tannic acid could delay the metabolism of resistant starch in vitro, which suggested that tannic acid might deliver resistant starch to the distal colon in vivo. Accordingly, co-supplementation of resistant starch and tannic acid might be beneficial for keeping the distal colon healthy. Thus, this study compared the effects of resistant starch, tannic acid and their mixtures on dextran sulfate sodium (DSS)-induced ulcerative colitis in mice. It was found that the mixtures had a more profound effect on ameliorating DSS-induced ulcerative colitis than resistant starch or tannic acid. In particular, the mixtures reversed the histology damage of the distal colon induced by DSS, while resistant starch or tannic acid alone did not. The mixtures also had a stronger ability to resist oxidative stress and inhibit inflammation in the distal colon. These results suggested that resistant starch and tannic acid synergistically alleviated DSS-induced ulcerative colitis, particularly in the distal colon. On the other hand, DSS decreased the production of short-chain fatty acids and induced significant microbial disorder, while the administration of resistant starch, tannic acid and their mixtures reversed the above shifts caused by DSS. In particular, the mixtures exhibited stronger prebiotic activity, as indicated by the microbial composition and production of short-chain fatty acids. Therefore, it was inferred that tannic acid delivered resistant starch to the distal colon of mice, and thus the mixtures had stronger prebiotic activity. As a result, the mixtures effectively alleviated ulcerative colitis in the whole colon.

The Lactobacillus plantarum P-8 Probiotic Microcapsule Prevents DSS-Induced Colitis through Improving Intestinal Integrity and Reducing Colonic Inflammation in Mice

Probiotics, recognized as beneficial and active microorganisms, often face challenges in maintaining their functionality under harsh conditions such as exposure to stomach acid and bile salts. In this investigation, we developed probiotic microcapsules and assessed their protective effects and underlying mechanisms in a murine model of dextran sulfate sodium (DSS)-induced colitis using male C57BL/6J mice. The administration of the probiotic microcapsules significantly mitigated body weight loss, prevented colon length shortening, decreased the disease activity index scores, and reduced histopathological scores in mice with DSS-induced colitis. Concurrently, the microencapsulated probiotics preserved intestinal barrier integrity by upregulating the expressions of tight junction proteins ZO-1 and occludin, as well as the mucus layer component MUC-2. Moreover, the treatment with probiotic microcapsules suppressed the activation of the NLRP3 inflammasome signaling pathway in the context of DSS-induced colitis. In conclusion, these findings support the utilization of probiotic microcapsules as a potential functional food ingredient to maintain the permeability of the intestinal barrier and alleviate colonic inflammation in UC.

Novel Synergistic Probiotic Intervention: Transcriptomic and Metabolomic Analysis Reveals Ameliorative Effects on Immunity, Gut Barrier, and Metabolism of Mice during Salmonella typhimurium Infection

Salmonella typhimurium (S. typhimurium), a prevalent cause of foodborne infection, induces significant changes in the host transcriptome and metabolome. The lack of therapeutics with minimal or no side effects prompts the scientific community to explore alternative therapies. This study investigates the therapeutic potential of a probiotic mixture comprising Lactobacillus acidophilus (L. acidophilus 1.3251) and Lactobacillus plantarum (L. plantarum 9513) against S. typhimurium, utilizing transcriptome and metabolomic analyses, a novel approach that has not been previously documented. Twenty-four SPF-BALB/c mice were divided into four groups: control negative group (CNG); positive control group (CPG); probiotic-supplemented non-challenged group (LAPG); and probiotic-supplemented Salmonella-challenged group (LAPST). An RNA-sequencing analysis of small intestinal (ileum) tissue revealed 2907 upregulated and 394 downregulated DEGs in the LAPST vs. CPG group. A functional analysis of DEGs highlighted their significantly altered gene ontology (GO) terms related to metabolism, gut integrity, cellular development, and immunity (p ≤ 0.05). The KEGG analysis showed that differentially expressed genes (DEGs) in the LAPST group were primarily involved in pathways related to gut integrity, immunity, and metabolism, such as MAPK, PI3K-Akt, AMPK, the tryptophan metabolism, the glycine, serine, and threonine metabolism, ECM-receptor interaction, and others. Additionally, the fecal metabolic analysis identified 1215 upregulated and 305 downregulated metabolites in the LAPST vs. CPG group, implying their involvement in KEGG pathways including bile secretion, propanoate metabolism, arginine and proline metabolism, amino acid biosynthesis, and protein digestion and absorption, which are vital for maintaining barrier integrity, immunity, and metabolism. In conclusion, these findings suggest that the administration of a probiotic mixture improves immunity, maintains gut homeostasis and barrier integrity, and enhances metabolism in Salmonella infection.

Gut microbiome-targeted therapies for Alzheimer's disease

The advent of high-throughput 'omics' technologies has improved our knowledge of gut microbiome in human health and disease, including Alzheimer's disease (AD), a neurodegenerative disorder. Frequent bidirectional communications and mutual regulation exist between the gastrointestinal tract and the central nervous system through the gut-brain axis. A large body of research has reported a close association between the gut microbiota and AD development, and restoring a healthy gut microbiota may curb or even improve AD symptoms and progression. Thus, modulation of the gut microbiota has become a novel paradigm for clinical management of AD, and emerging effort has focused on developing potential novel strategies for preventing and/or treating the disease. In this review, we provide an overview of the connection and causal relationship between gut dysbiosis and AD, the mechanisms of gut microbiota in driving AD progression, and the successes and challenges of implementing available gut microbiome-targeted therapies (including probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation) in preventive and/or therapeutic preclinical and clinical intervention studies of AD. Finally, we discuss the future directions in this field.

Intraspecific difference of Latilactobacillus sakei in inflammatory bowel diseases: Insights into potential mechanisms through comparative genomics and metabolomics analyses

Inflammatory bowel diseases (IBDs) are chronic inflammatory diseases of the gastrointestinal tract that have become a global health burden. Studies have revealed that Latilactobacillus sakei can effectively alleviate various immune diseases, including colitis, rheumatoid arthritis, and metabolic disorders. Here, we obtained 72 strains of L. sakei from 120 fermentation and fecal samples across China. In total, 16 strains from different sources were initially screened in an in vitro Caco-2 model induced by dextran sulfate sodium. Subsequently, six strains (four exhibiting effectiveness and two exhibiting ineffectiveness) were selected for further validation in an in vivo colitis mouse model. The results demonstrated that L. sakei strains exhibited varying degrees of amelioration of the colitis disease process. Notably, L. sakei CCFM1267, the most effective strain, significantly restored colon length and tight-junction protein expression, and reduced the levels of cytokines and associated inflammatory enzymes. Moreover, L. sakei CCFM1267 upregulated the abundance of Enterorhabdus, Alloprevotella, and Roseburia, leading to increased levels of acetic acid and propionic acid. Conversely, the other four strains (L. sakei QJSSZ1L4, QJSSZ4L10, QGZZYRHMT1L6, and QGZZYRHMT2L6) only exhibited a partial remission effect, while L. sakei QJSNT1L10 displayed minimal impact. Therefore, L. sakei CCFM1267 and QJSNT1L10 were selected for further exploration of the mechanisms underlying their differential mitigating effects. Comparative genomics analysis revealed significant variations between the two strains, particularly in genes associated with carbohydrate-active enzymes, such as the glycoside hydrolase family, which potentially contribute to the diverse profiles of short-chain fatty acids in vivo. Additionally, metabolome analysis demonstrated that acetylcholine and indole-3-acetic acid were the main differentiating metabolites of the two strains. Therefore, the strains of L. sakei exhibited varying degrees of effectiveness in alleviating IBD-related symptoms, and the possible reasons for these variations were attributed to discrepancies in the carbohydrate-active enzymes and metabolites among the strains.

Regulatory effect of lactulose on intestinal flora and serum metabolites in colitis mice: In vitro and in vivo evaluation

Lactulose is a common component in foods. However, the effect of lactulose on intestinal flora and overall metabolic levels remains unclear. Therefore, this study aims to explore the regulative role of lactulose on intestinal flora and serum metabolites via in vitro simulated colonic fermentation model and in vivo colitis mouse model. The results showed that lactulose significantly enriched beneficial bacteria including Dubosiella and Bifidobacterium, and reduced pathogenic bacteria such as Fusobacterium. Moreover, lactulose significantly inhibited dextran sodium sulfate-induced body weight loss, colon shortening, colonic inflammatory infiltration, and pro-inflammatory cytokines IL-6, TNF-α, IL-17, and IL-1β. Lactulose significantly affected serum metabolome in colitis mice and total 24 metabolites representing a high inter-group difference were obtained. Correlation analysis revealed that the changes in serum metabolites were closely associated with the role of intestinal flora, and thus affected phenotypic indicators. Our study provides a reference for nutritional characteristics and application scenarios of dietary lactulose.

Arecoline alleviated loperamide induced constipation by regulating gut microbes and the expression of colonic genome

This study aimed to investigate the effects of arecoline on constipation by intervening at different times to explore its preventive and therapeutic effects. Symptoms related to constipation, gut microbes, short-chain fatty acid (SCFA) content in the cecum, and gene expression in the colon were measured to examine the effect of arecoline on relieving constipation. The results showed that arecoline intervention alleviated loperamide-induced constipation, as evidenced by significantly shortened intestinal transit time, increased fecal water content, improved small bowel propulsion, and increased defecation frequency. In addition, arecoline significantly reduced the levels of gastrointestinal regulatory peptides such as somatostatin and vasoactive intestinal peptide in the serum, thereby regulating intestinal peristalsis. Histopathological analysis showed that arecoline ameliorated intestinal injury caused by constipation. Gut microbial analysis indicated that arecoline altered the taxonomic composition and levels of its metabolite SCFAs in the gut microbiota. Furthermore, the colonic transcriptome results indicated that genes expression related to intestinal diseases were significantly down-regulated by arecoline intervention. In conclusion, the results of the correlation analysis propose a possible mechanism of arecoline in alleviating constipation by modulating the gut microbes and their metabolites and regulating the gut genome.

Hermetia illucens Fermented with Lactobacillus plantarum KCCM12757P Alleviates Dextran Sodium Sulfate-Induced Colitis in Mice

Inflammatory bowel disease (IBD) can severely affect humans and animals and is difficult to treat. Black soldier fly (Hermetia illucens; Hi) larvae (BSFL) are a sustainable source of protein. However, no studies exist on the antioxidant and anti-inflammatory functions of BSFL or fermented BSFL with respect to IBD. In this study, riboflavin-producing Lactobacillus plantarum KCCM12757P was isolated from a fish farm tank, and in conjunction with hot water-extracted Hi (HeHi) (termed HeHi_Lp), was used to determine optimal fermentation conditions to increase vitamin B2 concentration. This in vivo study investigated the therapeutic effects and mechanistic role of HeHi_Lp in chronic colitis-induced murine models. Histological changes, inflammatory cytokine levels, and intestinal barrier function were explored. Gut microbial communities and gene expression in the nuclear factor (NF)-κB signaling pathway were also studied. HeHi_Lp remarkably reduced the disease activity index, inflammatory cytokine (inducible nitric oxide synthase, cyclooxygenase 2, tumor necrosis factor α, interleukin (IL-6 and IL-1β) levels, and increased body weight and colon length. HeHi_Lp administration significantly raised zonula occludens 1, occludin and claudin 1 and improved the composition of the gut microbiota and beneficial intestinal bacteria. These results suggest that HeHi_Lp can be used as a dietary supplement in pet food to alleviate colitis.

A High-Fat, High-Cholesterol Diet Promotes Intestinal Inflammation by Exacerbating Gut Microbiome Dysbiosis and Bile Acid Disorders in Cholecystectomy

Patients with post-cholecystectomy (PC) often experience adverse gastrointestinal conditions, such as PC syndrome, colorectal cancer (CRC), and non-alcoholic fatty liver disease (NAFLD), that accumulate over time. An epidemiological survey further revealed that the risk of cholecystectomy is associated with high-fat and high-cholesterol (HFHC) dietary intake. Mounting evidence suggests that cholecystectomy is associated with disrupted gut microbial homeostasis and dysregulated bile acids (BAs) metabolism. However, the effect of an HFHC diet on gastrointestinal complications after cholecystectomy has not been elucidated. Here, we aimed to investigate the effect of an HFHC diet after cholecystectomy on the gut microbiota-BA metabolic axis and elucidate the association between this alteration and the development of intestinal inflammation. In this study, a mice cholecystectomy model was established, and the levels of IL-Iβ, TNF-α, and IL-6 in the colon were increased in mice fed an HFHC diet for 6 weeks. Analysis of fecal BA metabolism showed that an HFHC diet after cholecystectomy altered the rhythm of the BA metabolism by upregulating liver CPY7A1, CYP8B1, and BSEP and ileal ASBT mRNA expression levels, resulting in increased fecal BA levels. In addition, feeding an HFHC diet after cholecystectomy caused a significant dysbiosis of the gut microbiota, which was characterized by the enrichment of the metabolic microbiota involved in BAs; the abundance of pro-inflammatory gut microbiota and related pro-inflammatory metabolite levels was also significantly higher. In contrast, the abundance of major short-chain fatty acid (SCFA)-producing bacteria significantly decreased. Overall, our study suggests that an HFHC diet after cholecystectomy promotes intestinal inflammation by exacerbating the gut microbiome and BA metabolism dysbiosis in cholecystectomy. Our study also provides useful insights into the maintenance of intestinal health after cholecystectomy through dietary or probiotic intervention strategies.

Probiotics for the treatment of ulcerative colitis: a review of experimental research from 2018 to 2022

Ulcerative colitis (UC) has become a worldwide public health problem, and the prevalence of the disease among children has been increasing. The pathogenesis of UC has not been elucidated, but dysbiosis of the gut microbiota is considered the main cause of chronic intestinal inflammation. This review focuses on the therapeutic effects of probiotics on UC and the potential mechanisms involved. In animal studies, probiotics have been shown to alleviate symptoms of UC, including weight loss, diarrhea, blood in the stool, and a shortened colon length, while also restoring intestinal microecological homeostasis, improving gut barrier function, modulating the intestinal immune response, and attenuating intestinal inflammation, thereby providing theoretical support for the development of probiotic-based microbial products as an adjunctive therapy for UC. However, the efficacy of probiotics is influenced by factors such as the bacterial strain, dose, and form. Hence, the mechanisms of action need to be investigated further. Relevant clinical trials are currently lacking, so the extension of animal experimental findings to clinical application requires a longer period of consideration for validation.

Anti-Inflammatory, Barrier Maintenance, and Gut Microbiome Modulation Effects of Saccharomyces cerevisiae QHNLD8L1 on DSS-Induced Ulcerative Colitis in Mice

The use of probiotics has been considered as a new therapy option for ulcerative colitis (UC), and yeast has recently received widespread recommendation for human health. In this study, the probiotic characteristics of four yeast strains, Saccharomyces boulardii CNCMI-745, Kluyveromyces marxianus QHBYC4L2, Saccharomyces cerevisiae QHNLD8L1, and Debaryomyces hansenii QSCLS6L3, were evaluated in vitro; their ability to ameliorate dextran sulfate sodium (DSS)-induced colitis was investigated. Among these, S. cerevisiae QHNLD8L1 protected against colitis, which was reflected by increased body weight, colon length, histological injury relief, decreased gut inflammation markers, and intestinal barrier restoration. The abundance of the pathogenic bacteria Escherichia–Shigella and Enterococcaceae in mice with colitis decreased after S. cerevisiae QHNLD8L1 treatment. Moreover, S. cerevisiae QHNLD8L1 enriched beneficial bacteria Lactobacillus, Faecalibaculum, and Butyricimonas, enhanced carbon metabolism and fatty acid biosynthesis function, and increased short chain fatty acid (SCFAs) production. Taken together, our results indicate the great potential of S. cerevisiae QHNLD8L1 supplementation for the prevention and alleviation of UC.

Preventive and synbiotic effects of the soluble dietary fiber obtained from Lentinula edodes byproducts and Lactobacillus plantarum LP90 against dextran sulfate sodium-induced colitis in mice

BACKGROUND

Soluble dietary fiber (SDF) obtained from Lentinula edodes byproducts has beneficial effects on human intestinal health. This study aimed to examine the combined preventive and ameliorative effects of a kind of synbiotic (SDF with a molecular weight of 1.58 × 10²  kDa and Lactobacillus plantarum LP90 (LP) at 1 × 10⁹  CFU kg^-1 ) on dextran sulfate sodium-induced colitis mice.

RESULTS

The results demonstrated that synbiotic treatment could alleviate weight loss, decrease the disease activity index level and cause histological amelioration. Synbiotic treatment also promoted the production of goblet cells, increased the expression of tight junction proteins, and adjusted the production of myeloperoxidase, malondialdehyde and superoxide dismutase to repair intestinal epithelial injury. Clinical symptoms were alleviated by maintaining Th17/Treg balance, increasing interleukin 10 and immunoglobulin A levels, reducing interleukin 17a and tumor necrosis factor α production, and promoting mRNA to highly express of Foxp3 and vitamin D receptors. Moreover, synbiotic treatment could upregulate butyric acid production (4.71 ± 0.46 mol g^-1 feces, P < 0.05) and diversity of intestinal microbial to maintain intestinal homeostasis.

CONCLUSION

This study suggested that the combination of LP and SDF as a synbiotic has the potential for use as a nutritional supplement to alleviate colitis. © 2022 Society of Chemical Industry.

Integrative analysis of the metabolome and transcriptome reveals the influence of Lactobacillus plantarum CCFM8610 on germ-free mice

This study describes the influence of Lactobacillus plantarum CCFM8610 on the host by employing transcriptome and untargeted metabolomics. According to the enrichment analysis, three pathways, including the complement and coagulation cascade pathway, antigen processing and presentation pathways, and protein processing in the endoplasmic reticulum pathway, were affected by L. plantarum CCFM8610 colonization. According to partial least squares-discriminant analysis, five metabolites, L-methionine, D-tryptophan, indoleacrylic acid, DL-acetylcarnitine, and L-norleucine, were identified as key metabolites in the serum. Furthermore, integrative analysis of the metabolome and transcriptome revealed connections between enriched pathways and differential metabolites, and the regulation strategy of choline by affecting gene expression was proposed. Overall, the effects of L. plantarum CCFM8610 on host health were investigated after excluding the influence of gut microbes, which provides a valuable reference for studying the potential mechanisms of the effect of probiotics on host health.

Probiotics (Lactobacillus plantarum HNU082) Supplementation Relieves Ulcerative Colitis by Affecting Intestinal Barrier Functions, Immunity-Related Gene Expression, Gut Microbiota, and Metabolic Pathways in Mice

Probiotics can effectively improve ulcerative colitis (UC), but the mechanism is still unclear. Here, shotgun metagenome and transcriptome analyses were performed to explore the therapeutic effect and the mechanism of the probiotic Lactobacillus plantarum HNU082 (Lp082) on UC. The results showed that Lp082 treatment significantly ameliorated dextran sulfate sodium (DSS)-induced UC in mice, which was manifested as increases in body weight, water intake, food intake, and colon length and decreases in disease activity index (DAI), immune organ index, inflammatory factors, and histopathological scores after Lp082 intake. An in-depth study discovered that Lp082 could improve the intestinal mucosal barrier and relieve inflammation by cooptimizing the biological barrier, chemical barrier, mechanical barrier, and immune barrier. Specifically, Lp082 rebuilt the biological barrier by regulating the intestinal microbiome and increasing the production of short-chain fatty acids (SCFAs). Lp082 improved the chemical barrier by reducing intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM) and increasing goblet cells and mucin2. Lp082 ameliorated the mechanical barrier by increasing zonula occludens-1 (ZO-1), zonula occludens-2 (ZO-2), and occludin while decreasing claudin-1 and claudin-2. Lp082 optimized the immune barrier by reducing the content of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), myeloperoxidase (MPO), and interferon-γ (IFN-γ) and increasing IL-10, transforming growth factor-β1 (TGF-β1), and TGF-β2, inhibiting the NF-κB signaling pathway. Taken together, probiotic Lp082 can play a protective role in a DSS-induced colitis mouse model by protecting the intestinal mucosal barrier, attenuating the inflammatory response, and regulating microbial imbalance. This study provides support for the development of probiotic-based microbial products as an alternative treatment strategy for UC. IMPORTANCE Many studies have focused on the therapeutic effect of probiotics on ulcerative colitis (UC), but few studies have paid attention to the mechanism of probiotics, especially the therapeutic effect. This study suggests that Lp082 has a therapeutic effect on colitis in mice. Its mechanisms of action include protecting the mucosal barrier and actively modulating the gut microbiome, modulating inflammatory pathways, and reducing neutrophil infiltration. Our study enriches the mechanism and provides a new prospect for probiotics in the treatment of colitis, helps to deepen the understanding of the intestinal mucosal barrier, and provides guidance for the future probiotic treatment of human colitis.

In vitro selection and characterization of probiotic properties in eight lactobacillus strains isolated from cocoa fermentation

Traditionally, probiotic microorganisms are isolated from human and animal intestinal microbiota. However, the demand for diversification of biofunctional products has driven the search for new sources of probiotic candidates, such as fermented foods and vegetables. The present study found that strains isolated from the fermentation of fine cocoa from southern Bahia have biotechnological potential for use as a probiotic, since they showed capacity for self-aggregation and co-aggregation, antimicrobial activity against intestinal pathogens and resistance to gastrointestinal transits. Scores of importance for each property were established in order to more accurately assess the probiotic potential of the strains. The tests carried out contemplate the criteria previously established for the selection of probiotic candidates.

Stronger gut microbiome modulatory effects by postbiotics than probiotics in a mouse colitis model

Probiotics are increasingly used as adjunctive therapy to manage gastrointestinal diseases, such as ulcerative colitis. However, probiotic use has posed some safety concerns. Thus, postbiotics are proposed as alternatives to probiotics in clinical applications. However, no study has directly compared the clinical benefits of probiotics and postbiotics. This study compared the beneficial effect of postbiotics and probiotics derived from the strain, Bifidobacterium adolescentis B8598, in a dextran sulfate sodium (DSS)-induced experimental colitis mouse model. Four groups of mice (n = 7 per group) were included in this work: Control (received water plus saline), DSS (received DSS without postbiotic/probiotic), Postbiotic (received DSS plus postbiotic), and Probiotic (received DSS plus probiotic). Our results showed that intragastric administration of both probiotic and postbiotic ameliorated colitis, reflected by decreased histology scores in Postbiotic and Probiotic groups compared with DSS group (P < 0.05). The fecal microbiota alpha diversity was not significantly affected by DSS-, postbiotic, or probiotic treatment. However, the postbiotic treatment showed stronger effects on modulating the fecal microbiota beta diversity, composition, and metagenomic potential than the probiotic treatment. Overall, our findings suggested that probiotics and postbiotics had similar ability to improve disease phenotype but had distinct ability to regulate the gut microbiota and metabolic pathways in the context of ulcerative colitis. In view of the smaller safety concern of postbiotics compared with probiotics and its stronger modulatory effect on the host gut microbiota, we propose that postbiotics are to be considered for use as next-generation biotherapeutics in managing ulcerative colitis or even other diseases.

In vivo evidence of the prevents DSS-induced colitis of Lactiplantibacillus plantarum L15

Ulcerative colitis (UC) is challenging to treat and severely impacts patients and families. A previous study reported immunomodulatory and reduction of pro-inflammatory properties for the Lactiplantibacillus plantarum L15. This study aimed to analyze the preventive properties and mechanistic actions in an in vivo colitis model. The histopathological alteration, inflammation cytokines, and intestinal barrier function were analyzed. Subsequently, the cecal gut microbiota contents and products from different groups were detected. Finally, gene expressions related to the NF-κB signaling process were evaluated. L. plantarum L15 significantly decreased disease activity index (DAI), myeloperoxidase activity (MPO), pro-inflammatory cytokine (TNF-α, IL-1β, and IL-6) level, and increased weight change, colon length, and production of inflammation-suppressing cytokines. Furthermore, this strain supplementation substantially increased ZO-1, Occludin, and Claudin-1, and MUC2 mRNA expression levels with a corresponding decrease in serum lipopolysaccharide and D-lactic acid contents. In addition, L. plantarum L15 improved gut microbiota composition and increased short-chain fatty acid (SCFAs) in the colon content, which significantly reduced the transfer of NF-κB p65 to the nucleus. Our findings provide a theoretical basis for L. plantarum L15 as a preventive candidate for UC.

Screening and Probiotic Potential Evaluation of Bacteriocin-Producing Lactiplantibacillus plantarum In Vitro

Probiotics are gaining attention due to their functions of regulating the intestinal barrier and promoting human health. The production of bacteriocins is one of the important factors for probiotics to exert beneficial properties. This study aimed to screen bacteriocin-producing Lactiplantibacillus plantarum and evaluate the probiotic potential in vitro. It was found that L. plantarum Q7, L. plantarum F3-2 and L. plantarum YRL45 could produce bacteriocins and inhibit common intestinal pathogens. These three strains had probiotic potential with tolerance to the gastrointestinal environmental and colonization in the gut, and exhibited various degrees of anti-inflammatory activity and tight junction function in the intestinal barrier. Particularly, L. plantarum YRL45 could significantly (p < 0.05) reduce the increase in nitric oxide (NO), prostaglandin E2 (PGE2), necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) induced by lipopolysaccharide (LPS), thereby easing inflammatory response. L. plantarum F3-2 could remarkably (p < 0.05) up-regulate the expression levels of ZO-1, Occludin and Claudin-1 in intestinal epithelial injured cells, which was conducive to protecting the intestinal barrier. These findings provided fundamental information about the probiotic properties of bacteriocin-producing L. plantarum, which suggested that L. plantarum Q7, L. plantarum F3-2 and L. plantarum YRL45 had the potential to be used as novel probiotic strains.

Lactiplantibacillus plantarum-12 Alleviates Inflammation and Colon Cancer Symptoms in AOM/DSS-Treated Mice through Modulating the Intestinal Microbiome and Metabolome

In our previous research, Lactiplantibacillus plantarum-12 alleviated inflammation in dextran sodium sulfate (DSS)-induced mice by regulating intestinal microbiota and preventing colon shortening (p < 0.05). The purpose of the present study was to evaluate whether L. plantarum-12 could ameliorate the colon cancer symptoms of azoxymethane (AOM)/DSS-treated C57BL/6 mice. The results showed that L. plantarum-12 alleviated colonic shortening (from 7.43 ± 0.15 to 8.23 ± 0.25) and weight loss (from 25.92 ± 0.21 to 27.75 ± 0.88) in AOM/DSS-treated mice. L. plantarum-12 oral administration down-regulated pro-inflammatory factors TNF-α (from 350.41 ± 15.80 to 247.72 ± 21.91), IL-8 (from 322.19 ± 11.83 to 226.08 ± 22.06), and IL-1β (111.43 ± 8.14 to 56.90 ± 2.70) levels and up-regulated anti-inflammatory factor IL-10 (from 126.08 ± 24.92 to 275.89 ± 21.87) level of AOM/DSS-treated mice. L. plantarum-12 oral administration restored the intestinal microbiota dysbiosis of the AOM/DSS treated mice by up-regulating beneficial Muribaculaceae, Lactobacillaceae, and Bifidobacteriaceae levels and down-regulating pathogenic Proteobacteria, Desulfovibrionaceae, and Erysipelotrichaceae levels. As a result, the fecal metabolites of the AOM/DSS-treated mice were altered, including xanthosine, uridine, 3,4-methylenesebacic acid, 3-hydroxytetradecanedioic acid, 4-hydroxyhexanoylglycine, beta-leucine, and glycitein, by L. plantarum-12 oral administration. Furthermore, L. plantarum-12 oral administration significantly ameliorated the colon injury of the AOM/DSS-treated mice by enhancing colonic tight junction protein level and promoting tumor cells death via down-regulating PCNA (proliferating cell nuclear antigen) and up-regulating pro-apoptotic Bax. (p < 0.05). Taken together, L. plantarum-12 oral administration could ameliorate the colon cancer burden and inflammation of AOM-DSS-treated C57BL/6 mice through regulating the intestinal microbiota, manipulating fecal metabolites, enhancing colon barrier function, and inhibiting NF-κB signaling. These results suggest that L. plantarum-12 might be an excellent probiotic candidate for the prevention of colon cancer.

Advancement of Traditional Chinese Medicine in Regulation of Intestinal Flora: Mechanism-based Role in Disease Management

Intestinal microecology is the largest and most complex human microecology. The intestinal microflora plays an important role in human health. Imbalance of intestinal microflora contributes to the occurrence and development of many diseases. Recently, the treatment of human diseases by regulating intestinal microflora has become a research topic of interest. Traditional Chinese medicine considers the whole human body as the central concept in disease treatment strategies. It advocates maintaining the coordination and balance of the functions of various organs and systems of the human body, including the intestinal microflora. Traditional Chinese medicine improves the metabolism and immune function of the human body by regulating the intestinal microflora. The intestinal microflora could trigger pharmacological activity or reduce toxicity of drugs through regulating metabolism, which enables traditional Chinese medicine formulations to exert their best therapeutic effects. This review summarized the relationship between the intestinal microflora and digestive system, tumors, and other diseases. Furthermore, the role of traditional Chinese medicine in the treatment of tumors, and other diseases is discussed. The relationship among traditional Chinese medicine and the common intestinal microflora, pathogenesis of human diseases, and effective intervention methods were elaborated. In addition, we explored the research progress of traditional Chinese medicine in the treatment of various human diseases by regulating intestinal microflora to provide new treatment concepts. There is a close relationship between traditional Chinese medicine and the intestinal microflora. Traditional Chinese medicine formulations contribute to maintain the natural balance of the intestinal tract and the intestinal microflora to achieve treatment effects. This paper summarizes the mechanism of action of traditional Chinese medicine formulations in regulating the intestinal microflora in the prevention and treatment of various diseases. Furthermore, it summarizes information on the application of the interaction between traditional Chinese medicine preparations and the regulation of intestinal microflora in the treatment of common human diseases. Intestinal microflora plays a key role in traditional Chinese medicine in maintaining the natural balance of physiology and metabolism of human body. It will provide a theoretical basis for the traditional Chinese medicine preparations in the prevention and treatment of common human diseases, and simulate future research on this aspect.

A Mixture of Lactobacillus fermentum HFY06 and Arabinoxylan Ameliorates Dextran Sulfate Sodium-Induced Acute Ulcerative Colitis in Mice

Objective

Colitis is one of the main gastrointestinal diseases threatening human health.

Materials and Methods

In this study, a synbiotic composed of arabinoxylan (AX) and Lactobacillus fermentum HFY06 was tested to determine its ability to relieve dextran sulfate sodium (DSS)-induced colitis.

Results

The experimental results showed that the synergistic effect of AX and L. fermentum HFY06 alleviated the weight loss of DSS-mediated colitis mice and lowered the disease activity index (DAI) score. Determination of biochemical indicators found that the synbiotic composed of AX and L. fermentum HFY06 increased the body’s antioxidant capacity and reduced inflammation. The histopathological examination results showed that the colonic crypts of the mice in the model group were disordered, goblet cells were lost, and the mucous membrane was severely damaged. However, the combination of AX and L. fermentum HFY06 can significantly reverse the histopathological changes in the colon mediated by DSS. The gene expression of colon tissue was further determined, and the results showed that the synergistic effect of AX and L. fermentum HFY06 inhibited the activation of the NF-κB signaling pathway, downregulated the mRNA expression levels of nuclear factor-κB-p65 (NF-κBp65), upregulated the mRNA expression of NF-κB inhibitor-α (IκB-α), inhibited the release of cytokines tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX-2), and exerted anti-colitis effects.

Conclusion

This study shows that the synbiotic composed of AX and L. fermentum HFY06 has the potential to prevent and treat colitis.

Latest developments in food-grade delivery systems for probiotics: A systematic review

Tremendous progress in the inseparable relationships between probiotics and human health has enabled advances in probiotic functional foods. To ensure the vitality of sensitive probiotics against multiple harsh conditions, rising food-grade delivery systems for probiotics have been developed. This review gives a summary of recently reported delivery vehicles for probiotics, analyzes their respective merits and drawbacks and makes comparisons among them. Subsequently, the applications and future prospects are discussed. According to the types of encapsulating probiotics, food-grade delivery systems for probiotics can be classified into "silkworm cocoons" and "spider webs", which are put forward in this paper. The former, which surrounds the inner probiotics with the outer protective layers, includes particles, emulsions, beads, hybrid electrospun nanofibers and microcapsules. While hydrogels and bigels belong to the latter, which protects probiotics with the aid of network structures. The future prospects include preferable viability and stability of probiotics, co-delivery systems, targeted gut release of probiotics, delivery of multiple strains, more scientific experimental verification and more diversified food products, which will enlighten further studies on delivering probiotics for human health. Taken together, delivery vehicles for probiotics are-or will soon be-in the field of food science, with further applications under development.

Akkermansia muciniphila Exerts Strain-Specific Effects on DSS-Induced Ulcerative Colitis in Mice

Akkermansia muciniphila is a commensal bacterium of the gut mucus layer. Although both in vitro and in vivo data have shown that A. muciniphila strains exhibit strain-specific modulation of gut functions, its ability to moderate immunity to ulcerative colitis have not been verified. We selected three isolated human A. muciniphila strains (FSDLZ39M14, FSDLZ36M5 and FSDLZ20M4) and the A. muciniphila type strain ATCC BAA-835 to examine the effects of different A. muciniphila strains on dextran sulfate sodium-induced colitis. All of the A. muciniphila strains were cultured anaerobically in brain heart infusion medium supplemented with 0.25% type II mucin from porcine stomach. To create animal models, colitis was established in C57BL/6 mice which randomly divided into six groups with 10 mice in each group by adding 3% dextran sulfate sodium to drinking water for 7 days. A. muciniphila strains were orally administered to the mice at a dose of 1 × 10⁹ CFU. Only A. muciniphila FSDLZ36M5 exerted significant protection against ulcerative colitis (UC) by increasing the colon length, restoring body weight, decreasing gut permeability and promoting anti-inflammatory cytokine expression. However, the other strains (FSDLZ39M14, ATCC BAA-835 and FSDLZ20M4) failed to provide these effects. Notably, A. muciniphila FSDLZ20M4 showed a tendency to exacerbate inflammation according to several indicators. Gut microbiota sequencing showed that A. muciniphila FSDLZ36M5 supplementation recovered the gut microbiota of mice to a similar state to that of the control group. A comparative genomic analysis demonstrated that the positive effects of A. muciniphila FSDLZ36M5 compared with the FSDLZ20M4 strain may be associated with specific functional genes that are involved in immune defense mechanisms and protein synthesis. Our results verify the efficacy of A. muciniphila in improving UC and provide gene targets for the efficient and rapid screening of A. muciniphila strains with UC-alleviating effects.

The roles of different Bacteroides fragilis strains in protecting against DSS-induced ulcerative colitis and related functional genes

The role of supplementation with different Bacteroides fragilis (B. fragilis) strains in alleviating ulcerative colitis (UC) is unclear due to the controversial results from animal experiments. In this study, three B. fragilis strains were evaluated for their ability to alleviate dextran sulfate sodium (DSS)-induced UC in C57BL/6J mice. We analyzed the anti-inflammatory effects of different B. fragilis strains and the changes they caused in the intestinal microbiota composition, intestinal epithelial permeability, cytokine concentrations, protein expression of nuclear factor kappa-B (NF-κB) and the underlying specific genes. The results showed that when orally administered, the different B. fragilis strains exerted different effects on the assessed parameters of the mice. The results of real-time quantitative polymerase chain reaction and immunofluorescence staining showed that the supplementation of B. fragilis FSHCM14E1, but not FJSWX11BF, enhanced the expression of the tight-junction proteins ZO-1, occludin and claudin-1. Western blot analysis showed that the anti-inflammatory effects of B. fragilis FSHCM14E1 were related to the NF-κB pathway. Genomic analysis suggested that the anti-inflammatory effects of FSHCM14E1 may be mediated through specific genes associated with defense mechanisms and the secretion of SCFAs. Overall, this study indicates the therapeutic potential of B. fragilis FSHCM14E1 for the prevention of UC.

Lactobacillus ruminis Alleviates DSS-Induced Colitis by Inflammatory Cytokines and Gut Microbiota Modulation

Lactobacillus ruminis can stimulate the immune response in vitro, but previous studies were only carried out in vitro and the anti-inflammatory effects of L. ruminis needs more in vivo evidences. In this study, the immune regulation and potential mechanisms of L. ruminis was investigated in DSS-induced colitis mice. L. ruminis FXJWS27L3 and L. ruminis FXJSW17L1 relieved the symptoms of colitis, including inhibition of colon shortening and colon tissue damage. L. ruminis FXJWS27L3 significantly reduced the pro-inflammatory cytokines IL-1β, TNF-α, and IL-17, while L. ruminis FXJSW17L1 significantly increased short chain fatty acids in mice feces. Moreover, L. ruminis FXJWS27L3 and L. ruminis FXJSW17L1 treatments significantly increased the gut microbiota diversity and balance the intestine microbiota profiles, which improved the imbalance of intestine microbiota composition to a certain extent. The results showed that L. ruminis can alleviate DSS-induced colitis, which possibly was related to promoting the expression of pro-inflammatory cytokines, up-regulating SCFAs and restoring the imbalance of gut microbiota.

Evidence from comparative genomic analyses indicating that Lactobacillus-mediated irritable bowel syndrome alleviation is mediated by conjugated linoleic acid synthesis

Irritable bowel syndrome (IBS) is a chronic intestinal disorder accompanied by low-grade inflammation, visceral hypersensitivity, and gut microbiota dysbiosis. Several studies have indicated that Lactobacillus supplementation can help to alleviate IBS symptoms and that these effects are strain-specific. Therefore, this study aimed to investigate the key physiological characteristics and functional genes contributing to the IBS-alleviating effects of Lactobacillus. An IBS model was established by subjecting C57BL/6 mice to Citrobacter rodentium ingestion and water avoidance stress. Lactobacillus strains with different physiological characteristics were administered to mice intragastrically for 4 weeks (5 × 109 CFU/0.2 mL per mouse per day). Indicators of colonic inflammation, visceral hypersensitivity, and gut microbiota were also evaluated. Finally, differences in functional genes between Lactobacillus strains were analyzed by a comparative genomic analysis, and the relationships between the physiological characteristics, functional genes, and IBS-alleviating effects of the strains were quantified using correlation analysis. Among the eight tested Lactobacillus strains, only Lactobacillus plantarum CCFM8610 significantly inhibited the expression of IL-1β, IL-6, PAR-2, and mast cell tryptase. L. plantarum CCFM8610 also significantly increased the intestinal barrier function, inhibited visceral hypersensitivity symptoms, and modulated the gut microbiota diversity and composition. The correlation analysis of factors associated with the IBS-alleviating effects of Lactobacillus revealed the ability to synthesize conjugated linoleic acid as the most strongly associated physiological characteristic and COG1028-related genes as the most strongly associated functional genes. In conclusion, these findings can facilitate the rapid screening of Lactobacillus strains with IBS-alleviating effects and lay a foundation for studies of the related mechanisms.

Identification of the key characteristics of Bifidobacterium longum strains for the alleviation of ulcerative colitis

Bifidobacterium longum (B. longum) species are widely used to prevent and treat ulcerative colitis (UC). In this study, phylogenetic and pan-genomic characterization of 122 B. longum strains was performed on the basis of 936 core genes; among these, four strains from different branches of the phylogenetic tree were selected for an evaluation of anti-inflammatory and immune modulatory activities in a DSS-induced colitis mouse model. Among the tested B. longum strains (B. longum FBJ20M1, B. longum FGDLZ8M1, B. longum FGSZY16M3, and B. longum FJSWXJ2M1), B. longum FGDLZ8M1 was found to most effectively alleviate colitis by reducing the expression of pro-inflammatory cytokines, restoring the colon length, and maintaining the mucosal integrity. The anti-inflammatory mechanisms of B. longum FGDLZ8M1 were related to the inhibition of NF-κB signaling. Genomic analysis indicated that these protective effects of B. longum FGDLZ8M1 may be related to specific genes associated with carbohydrate transport and metabolism and defense mechanisms (e.g., tolerance to bile salts and acids). Correlation analysis indicated that gastrointestinal transit tolerance was the most strongly associated factor. Our findings may contribute to the rapid screening of lactic acid bacterial strains with UC-alleviating effects.

Grape seed proanthocyanidin extract ameliorates dextran sulfate sodium-induced colitis through intestinal barrier improvement, oxidative stress reduction, and inflammatory cytokines and gut microbiota modulation

It is widely believed that grape seed proanthocyanidin extract (GSPE) exerts antioxidant and anti-inflammatory effects. Dietary supplementation with GSPE has been reported to alleviate colitis signs in mice, but the mechanisms involved require further exploration. The present study investigated how the oral administration of GSPE ameliorates colitis signs and reduces colitis-associated inflammation. C57BL/6 mice were treated with GSPE for 21 days. During the final 7 days of treatment, the mice were administered dextran sulfate sodium (DSS) dissolved in drinking water to induce experimental colitis. We found that GSPE treatment improved DSS-induced colitis, which was evidenced by decreases in disease activity index (DAI) scores, pathological scores, and oxidative stress and increases in zonula occludens-1 (ZO-1), occludin, and claudin-1 mRNA levels of colon tissue. Notably, the proinflammatory cytokines TNF-α and IL-1β were significantly downregulated as a result of GSPE treatment in colon tissues. GSPE treatment also reduced NLR family pyrin domain-containing 3 (NLRP3) inflammasome mRNA levels of colon tissue. Furthermore, an analysis of 16S rRNA sequences showed that GSPE rebalanced the DSS-damaged gut microbiota, including reducing Bacteroidetes, Dubosiella, and Veillonella, increasing Verrucomicrobia and Akkermansia, and elevating the Firmicutes to Bacteroidetes ratio. In conclusion, GSPE supplementation alleviates DSS-induced colitis by modulating inflammatory cytokines and oxidation stress, maintaining the intestinal barrier, and improving the microbial community. These results indicate that GSPE might be a new dietary strategy for the treatment of ulcerative colitis.

Anti-Adhesion Effects of Lactobacillus Strains on Caco-2 Cells Against Escherichia Coli and Their Application in Ameliorating the Symptoms of Dextran Sulfate Sodium-Induced Colitis in Mice

The beneficial effects of probiotics on ameliorating ulcerative colitis (UC) have attracted much attention in recent years. Nevertheless, the number of these identified probiotics is still limited. In addition, the adhesion abilities of probiotics are considered to be a key determinant for probiotic efficacy. However, the relationship between the adhesion abilities of probiotics and their role in ameliorating UC has been poorly studied to date. This study measured the adhesion abilities of four Lactobacillus strains to Caco-2 cells and their anti-adhesion effects on Caco-2 cells against pathogenic bacteria, as well as their application in ameliorating the symptoms of dextran sulfate sodium-induced UC, and further illustrated the relationship between these two potential probiotic properties of probiotics and their beneficial effects on UC. Results suggested that the adhesion abilities of the four tested Lactobacillus strains exists highly strain-specific and the mechanisms of their anti-adhesion effect on Caco-2 cells against Escherichia coli may be different. Moreover, all these strains had promising effects on ameliorating UC by reducing inflammatory response and improving the intestinal mucosal barrier function, as well as promoting the production of SCFAs. In conclusion, the four tested Lactobacillus strains can be considered as alternative dietary supplements in alleviating UC. In addition, it could be concluded that there is no significant correlation between the adhesion abilities of probiotics and their role in ameliorating UC, which further illustrated that the adhesion properties of probiotics in vitro may not be suitable as the key criterion for screening potential strains with UC-alleviating effects.

Lactobacillus plantarum L15 Alleviates Colitis by Inhibiting LPS-Mediated NF-κB Activation and Ameliorates DSS-Induced Gut Microbiota Dysbiosis

Previous studies have suggested that the Lactobacillus plantarum bacteria strain could be effective in ulcerative colitis (UC) management. However, its effects are strain-specific and the related mechanisms for its attenuating effects on UC remain unclear. This study aimed to elucidate the underlying mechanisms for the protective effect of L. plantarum on UC. Firstly, 15 L. plantarum strains were screened for potential probiotic characteristics with good tolerance to simulated human gastrointestinal transit and adhesion. Secondly, the inflammatory response of selected strains to the Caco-2 cells induced by lipopolysaccharide (LPS) was measured. Finally, an in vivo mouse model induced by dextran sulfate sodium (DSS) was used to assess the beneficial effects and likely action mechanisms the successfully screened in vitro strain, L. plantarum L15. In vitro results showed that L. plantarum L15 possessed the highest gastrointestinal transit tolerance, adhesion and reduction of pro-inflammatory abilities compared to the other screened strains. In vivo, high dose of L. plantarum L15 supplementation increased the body weight, colon length and anti-inflammatory cytokine production. Pro-inflammatory cytokine production, disease activity index (DAI) levels and myeloperoxidase (MPO) parameters decreased using this strain. In addition, L. plantarum L15 alleviated the histopathological changes in colon, modulated the gut microbiota, and decreased LPS secretion. The activities of this strain down-regulated the expression of TLR4 and MyD88 genes as well as genes associated with NF-κB signaling pathway. Our findings present L. plantarum L15 as a new probiotic, with promising application for UC management.

Leuconostoc pseudomesenteroides improves microbiota dysbiosis and liver metabolism imbalance and ameliorates the correlation between dihydroceramide and strains of Firmicutes and Proteobacteria in high fat diet obese mice

Leuconostoc pseudomesenteroides is widely isolated from fermented foods; however, the underlying molecular mechanism behind its anti-obesity function has rarely been studied. This study aims to explore the role of alterations in gut microbes and liver metabolites mediated by Leuconostoc pseudomesenteroides (Tu) in obese mice for a period of 8 weeks through UPLC/Q-TOF-MS and 16S rRNA sequencing. Our results showed that Tu administration at a dosage of 1 × 10⁹ CFU per day per mouse effectively attenuated the weight of mice, significantly reduced serum lipids, and markedly improved fecal lipid output. Tu also ameliorated the lipid profiles in the liver and epididymal fat tissues, and restored intestinal disorder caused by a high-fat diet. Moreover, glycerophospholipid metabolism in the liver was altered by increased dihydroceramide levels. Surprisingly, the correlation between dihydroceramide and strains of Firmicutes and Proteobacteria was found for the first time. Collectively, these findings highlight that Tu could be a potential dietary supplement for weight control.

Bifidobacterium longum subsp. longum Remodeled Roseburia and Phosphatidylserine Levels and Ameliorated Intestinal Disorders and liver Metabolic Abnormalities Induced by High-Fat Diet

Bifidobacterium longum is considered as a potential supplement in antiobesity treatment; however, the underlying molecular mechanism has rarely been studied. To understand the contributions of B. longum subsp. longum (BL21) in the prevention of obesity, we investigated alterations in the liver metabonomic phenotype and gut microbiota by ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and 16S ribosomal RNA gene sequencing in C57BL/6J male mice orally administered with BL21 for 8 weeks [high-fat diet (HFD)]. BL21 at 1 × 109 CFU·day-1 per mouse reduced the weight of mice by 16.9% relative to that of the mice fed with HFD and significantly lowered the serum levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol. BL21 also ameliorated fat vacuolization in liver cells and epididymal fat accumulation. BL21 also lowered the Firmicutes/Bacteroidetes ratio, regulated liver remodeling in glycerophospholipids, and alleviated the levels of d-tryptophan. A positive correlation between the butyrate-producing strain Roseburia and the cell membrane component phosphatidylserine was found for the first time. Thus, BL21 can potentially prevent mice from being obese by rebalancing the gut microbiota and glycerophospholipid metabolism. BL21 can be a promising dietary supplement for weight control.

Synbiotic supplementation containing Bifidobacterium infantis and xylooligosaccharides alleviates dextran sulfate sodium-induced ulcerative colitis

Synbiotics (Bifidobacterium infantis + xylooligosaccharides) had the strongest efficacy on colitis through inhibiting inflammation and oxidative stress and protecting epithelial integrity.