The Weissella Genus: Clinically Treatable Bacteria with Antimicrobial/Probiotic Effects on Inflammation and Cancer

Characteristic alterations of gut microbiota and serum metabolites in patients with chronic tinnitus: a multi-omics analysis

Chronic tinnitus is a central nervous system disorder. Currently, the effects of gut microbiota on tinnitus remain unexplored. To explore the connection between gut microbiota and tinnitus, we conducted 16S rRNA sequencing of fecal microbiota and serum metabolomic analysis in a cohort of 70 patients with tinnitus and 30 healthy volunteers. We used the weighted gene co-expression network method to analyze the relationship between the gut microbiota and the serum metabolites. The random forest technique was utilized to select metabolites and gut taxa to construct predictive models. A pronounced gut dysbiosis in the tinnitus group, characterized by reduced bacterial diversity, an increased Firmicutes/Bacteroidetes ratio, and some opportunistic bacteria including Aeromonas and Acinetobacter were enriched. In contrast, some beneficial gut probiotics decreased, including Lactobacillales and Lactobacillaceae. In serum metabolomic analysis, serum metabolic disturbances in tinnitus patients and these differential metabolites were enriched in pathways of neuroinflammation, neurotransmitter activity, and synaptic function. The predictive models exhibited great diagnostic performance, achieving 0.94 (95% CI: 0.85-0.98) and 0.96 (95% CI: 0.86-0.99) in the test set. Our study suggests that changes in gut microbiota could potentially influence the occurrence and chronicity of tinnitus, and exert regulatory effects through changes in serum metabolites. Overall, this research provides new perceptions into the potential role of gut microbiota and serum metabolite in the pathogenesis of tinnitus, and proposes the "gut-brain-ear" concept as a pathomechanism underlying tinnitus, with significant clinical diagnostic implications and therapeutic potential.IMPORTANCETinnitus affects millions of people worldwide. Severe cases may lead to sleep disorders, anxiety, and depression, subsequently impacting patients' lives and increasing societal healthcare expenditures. However, tinnitus mechanisms are poorly understood, and effective therapeutic interventions are currently lacking. We discovered the gut microbiota and serum metabolomics changes in patients with tinnitus, and provided the potential pathological mechanisms of dysregulated gut flora in chronic tinnitus. We proposed the innovative concept of the "gut-brain-ear axis," which underscores the exploration of gut microbiota impact on susceptibility to chronic tinnitus through serum metabolic profile modulation. We also reveal novel biomarkers associated with chronic tinnitus, offering a new conceptual framework for further investigations into the susceptibility of patients, potential treatment targets for tinnitus, and assessing patient prognosis. Subsequently, gut microbiota and serum metabolites can be used as molecular markers to assess the susceptibility and prognosis of tinnitus.Furthermore, fecal transplantation may be used to treat tinnitus.

Clinical outcomes and associated bacterial and fungal microbiota changes after high dose probiotic therapy for severe alcohol-associated hepatitis: An observational study

Alcohol-associated hepatitis (AH) is a critical condition with high mortality rates and is worsened by infections. Organ failure is strongly associated with intestinal dysbiosis. Emerging research suggests that gut microbiota modulation with probiotics can improve AH outcomes. This study investigated the clinical and microbiome effects of high-dose probiotic infusion (HDPI) compared with corticosteroid therapy (CST) and fecal microbiota transplantation (FMT) in severe AH. Patients with biopsy-proven severe-AH were enrolled from March 2019 to June 2020 and matched for age and disease severity. The patients received HDPI (n = 20), FMT (n = 16), or CST (n = 14). HDPI consists of a potent probiotic mix delivered via a nasoduodenal tube for 6 days. The primary outcome was survival at 90-days. Stool samples were subjected to 16S and 18S rRNA sequencing to assess significant bacterial and fungal taxa and their interactions at baseline and post treatment. At 90-days, survival rates were 55%, 64.3%, and 87.5% (HDPI, CST, respectively). HDPI did not beneficially impact bacterial alpha-diversity but significantly altered beta-diversity. Notably, the number of pathogenic bacteria, such as Bilophila and Roseburia increased. Fungal analysis revealed no significant changes in alpha diversity, but significant dissimilarities in beta diversity post-HDPI. New fungal genera such as Basidiomycota and Phragmoplastophyta have emerged, with significant deleterious expansion in fungal communities and damaging modifications between fungal-bacterial interactions. HDPI failed to outperform CST in improving the clinical outcomes of patients with severe AH. While HDPI influenced both bacterial and fungal microbiomes, it also led to the persistence of pathogenic communities. FMT showed superior survival outcomes, highlighting the urgent need for further controlled trials.

Evaluation of inhibitory, immunomodulatory, survival, and growth effects of host-derived Weissella confusa on Macrobrachium rosenbergii challenged with Vibrio parahaemolyticus

Macrobrachium rosenbergii is a highly valuable prawn species in aquaculture due to its current growing demand in the market. However, various bacterial diseases caused by Vibrio parahaemolyticus have been observed to induce mortality in larval, juvenile, and adult stages of M. rosenbergii. While antibiotics are commonly used to manage these diseases, they contribute to antimicrobial resistance, a global concern with serious environmental and health implications. Consequently, the scientific community is exploring host-derived beneficial microorganisms as functional feed additives, offering eco-friendly alternatives that boost shrimp and prawn immunity. The purpose of this study was to examine the effects of host-derived beneficial microorganisms from the gut of M. rosenbergii, on the inhibition, immunomodulation, survival, and growth of M. rosenbergii when exposed to V. parahaemolyticus. The result of this study showed that Weissella confusa C6, a lactic acid bacterium isolated from the gut of M. rosenbergii, significantly inhibits the growth of V. parahaemolyticus R1 as demonstrated in agar well diffusion assay and co-culture assay. Additionally, it showed immunomodulatory effects, indicated by elevated total hemocyte count (THC) and phenoloxidase (PO) activity during the bacterial challenge test. Furthermore, supplementing the diet with W. confusa led to significant improvements in M. rosenbergii, including increased survival rates, weight gain, specific growth rate, better feed conversion ratio, and reduced density of V. parahaemolyticus in the prawn's gut. Therefore, it can be considered a viable option for use as a feed supplement in prawn farming, enhancing M. rosenbergii's immune system, disease resistance, and overall health.

Two-stage solid-state fermentation to increase the nutrient value of corn processing waste and explore its efficacy as a feed protein source

Corn gluten meal-corn husk mixes (CCM) are an inexpensive and readily available agricultural by-product. This study explores a novel technique by converting CCM into high-value livestock feed protein sources through fermentation with Aspergillus niger AAX and Lactobacillus fermentum LLS, aiming to sustainably meet future global protein needs. The process of fermentation significantly altered the structural composition of high molecular weight proteins, zein, and dietary fibers. This transformation resulted in a marked elevation in the concentrations of peptides, free amino acids, and polyphenols. The acidic environment produced during fermentation prevented lipid oxidation in CCM, thereby extending its storability. After fermentation, the content of anti-nutritional factors decreased, while its antioxidant capacity increased. In vitro simulated digestion suggested that fermentation improved the digestibility of CCM protein. In vivo animal experiments showed that fermented CCM (FCCM) promoted growth and gut health in chicks. This study provides new insights into the utilization of CCM.

Resolution of Peritoneal Dialysis-Associated Peritonitis From Weissella confusa Combined Gastric Hookworm Disease: A Case Report and Literature Review

We reported a rare case of peritoneal dialysis-associated peritonitis caused by Weissella confusa. In this case, the symptoms of peritonitis were insidious and atypical, with only turbid peritoneal dialysis effluent and no fever or abdominal pain. The peritoneal dialysis effluent showed slightly elevated leukocytes (predominantly lymphocytes). Weissella confusa was confirmed through repeated peritoneal dialysis effluent cultures. Gastroscopy revealed erosive gastritis with a hookworm infection. The patient recovered after antibiotic and deworming treatments. Our report highlights the unusual and atypical symptoms, characterized by insidious onset, turbid peritoneal dialysis fluid, and an absence of typical signs such as fever or abdominal pain.

Multikingdom and functional gut microbiota markers for autism spectrum disorder

Associations between the gut microbiome and autism spectrum disorder (ASD) have been investigated although most studies have focused on the bacterial component of the microbiome. Whether gut archaea, fungi and viruses, or function of the gut microbiome, is altered in ASD is unclear. Here we performed metagenomic sequencing on faecal samples from 1,627 children (aged 1-13 years, 24.4% female) with or without ASD, with extensive phenotype data. Integrated analyses revealed that 14 archaea, 51 bacteria, 7 fungi, 18 viruses, 27 microbial genes and 12 metabolic pathways were altered in children with ASD. Machine learning using single-kingdom panels showed area under the curve (AUC) of 0.68 to 0.87 in differentiating children with ASD from those that are neurotypical. A panel of 31 multikingdom and functional markers showed a superior diagnostic accuracy with an AUC of 0.91, with comparable performance for males and females. Accuracy of the model was predominantly driven by the biosynthesis pathways of ubiquinol-7 or thiamine diphosphate, which were less abundant in children with ASD. Collectively, our findings highlight the potential application of multikingdom and functional gut microbiota markers as non-invasive diagnostic tools in ASD.

Biosynthesis, classification, properties, and applications of Weissella bacteriocins

This review aims to comprehensively chronicle the biosynthesis, classification, properties, and applications of bacteriocins produced by Weissella genus strains, particularly emphasizing their potential benefits in food preservation, human health, and animal productivity. Lactic Acid Bacteria (LAB) are a class of microorganisms well-known for their beneficial role in food fermentation, probiotics, and human health. A notable property of LAB is that they can synthesize antimicrobial peptides known as bacteriocins that exhibit antimicrobial action against both closely related and other bacteria as well. Bacteriocins produced by Weissella spp. are known to exhibit antimicrobial activity against several pathogenic bacteria including food spoilage species, making them highly invaluable for potential application in food preservation and food safety. Importantly, they provide significant health benefits to humans, including combating infections, reducing inflammation, and modulating the gut microbiota. In addition to their applications in food fermentation and probiotics, Weissella bacteriocins show promising prospects in poultry production, processing, and improving animal productivity. Future research should explore the utilization of Weissella bacteriocins in innovative food safety measures and medical applications, emphasizing their potential to combat antibiotic-resistant pathogens, enhance gut microbiota composition and function, and synergize with existing antimicrobial therapies.

Changes in the Gastrointestinal Microbiota Induced by Proton Pump Inhibitors-A Review of Findings from Experimental Trials

The use of proton pump inhibitors (PPIs) has increased considerably in many Western countries, and there is concern that numerous conditions and diseases associated with PPI use may be adverse events. The main function of gastric acid is to defend the organism against orally ingested microorganisms, and there is also concern that alterations not only in the gastric microbiome but also the downstream intestinal microbiome may increase the risk of disease or alter the course of preexisting disease. The current study is a systematic review of the available evidence from experimental trials investigating the effects of PPIs on the gastrointestinal microbiota by next-generation sequencing. Thirteen studies were identified. The effects of PPIs were seen on alterations in diversity and richness in some of the studies, while a larger proportion of the studies detected alterations at various taxonomic levels. The general finding was that PPI use caused an increase in bacteria normally found in the oral microbiota in both the upper and lower GI tract. The most consistent taxonomic alterations seemed to be increases in oral flora along the axis Streptococcaceae and Streptococcus at genus level and various Streptococcus spp., as well as Veillonellaceae, Veillonella and Haemophilus.

Characterization of Weissella Species during a 3-Year Observational Study - An Emerging Threat

Weissella species are mistaken for Lactobacillus or Leuconostoc because of their Gram-staining property and resistance to vancomycin. In this study, we aimed to evaluate the demographic pattern, presenting symptoms, risk factors, associated pathologies, and clinical outcomes in patients with Weissella infection. We also analyzed the antibiotic susceptibility pattern of the Weissella species isolated. This retrospective observational study was done from January 2021 to August 2023 in a tertiary care referral center in Uttar Pradesh. All Weissella species isolated from blood cultures or cerebrospinal fluid (CSF) samples during this period were included in the study. Twenty-four-hour growth from a positive blood culture or CSF sample was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Demographic and clinical details of the patients were extracted from the hospital information system. Kirby-Bauer disk diffusion was used for antibiotic susceptibility testing. During the 3-year study, 13 isolates of Weissella species were identified in our laboratory. Among the patients, male predominance was seen. The age range of the patients was 5-53 years. The samples were blood samples (n = 11) and CSF samples (n = 2). Of these isolates, 12 (92.3%) were identified as Weissella confusa and 1 (7.69%) was identified as Weissella viridescens. Common risk factors were anemia, prolonged hospital stay, indwelling catheter, chemotherapy, and chronic kidney disease. All the isolates in this study were sensitive to amikacin, daptomycin, amoxicillin-clavulanate, minocycline, and linezolid. Death was attributed to Weissella infection in three patients. Weissella species are opportunistic organisms that need to be identified quickly and precisely to guarantee the right course of treatment.

Weissella cibaria Relieves Gut Inflammation Caused by Escherichia coli through Inflammation Modulation and Gut Microbiota Regulation

The emergence of multi-drug-resistant (MDR) pathogens has considerably challenged the development of new drugs. Probiotics that inhibit MDR pathogens offer advantages over chemical antibiotics and drugs due to their increased safety and fewer side effects. This study reported that Weissella cibaria P-8 isolated from pickles showed excellent antibacterial activity against intestinal pathogens, particularly the antibacterial activity against MDR Escherichia coli B2 was the highest. This study showed that the survival rates of W. cibaria P-8 at pH 2.0 and 0.3% bile salt concentration were 72% and 71.56%, respectively, and it still had antibacterial activity under pepsin, trypsin, protease K, and catalase hydrolysis. Moreover, W. cibaria P-8 inhibits the expression of inflammatory factors interleukin-1β, tumor necrosis factor-α, and interleukin-6, upregulates the interleukin-10 level, and increases total antioxidant capacity and superoxide dismutase enzyme activity in serum. W. cibaria P-8 also efficiently repairs intestinal damage caused by E. coli infection. The gut microbiota analysis demonstrated that W. cibaria P-8 colonizes the intestine and increases the abundance of some beneficial intestinal microorganisms, particularly Prevotella. In conclusion, W. cibaria P-8 alleviated MDR E. coli-induced intestinal inflammation by regulating inflammatory cytokine and enzyme activity and rebalancing the gut microbiota, which could provide the foundation for subsequent clinical analyses and probiotic product development.

Effects of nano-cerium dioxide on intestinal microflora in rats by oral subchronic exposure

OBJECTIVE

To investigate intestinal toxicity in rats and the effects of Nano-cerium dioxide on intestinal flora in rats after oral sub-chronic exposure.

METHOD

Forty healthy male SD rats were randomly divided into four groups: a control group (deionized water) and three groups treated with different doses of Nano-ceria (e.g., 20 mg/kg, 100 mg/kg, and 500 mg/kg), with 10 rats in each group. The rats were given intragastric administrations (every other day) for 90 days. After the last intragastric administration, fresh fecal samples were collected by pressing the abdomen, and the animals were sacrificed. Jejunum, ileum and cecum tissues were retained for pathological analysis by Hematoxylin-eosin staining. The stool samples of rats were sequenced by the Illumina NovaSeq sequencing platform, and the sequencing results were further analyzed by QIIME2 software.

RESULTS

The histopathology results show that compared with the control group, in the middle- and high-dose groups, epithelial tissue was shed, lamina propria glandular structures were damaged or disappeared, and large numbers of inflammatory cells were distributed in the mucosa. The intestinal flora results show that there were no significant differences in the α-/β-diversities in each Nano-ceria-treated group compared with the control group (P>0.05). Compared with the control group, the intestinal pathogenic bacteria, Mucispirillum and Streptococcus increased significantly after Nano-cerium dioxide ingestion, while Weissella decreased. The abundances of Akkermansia in all Nano-ceria-treated groups were higher than those in the control group, but the abundances decreased with increasing dose. MetagenomesSeq analysis show that, compared with the control group, the abundances of S24-7, Lactobacillus and Clostridiales in all experimental groups significantly decreased.

CONCLUSIONS

The sub-chronic toxicity of Nano-cerium dioxide to rats can affect the structure and abundance of intestinal microflora, long-term exposure to high doses (>100 mg/kg) causes enteritis, but there was no significant difference in the diversity of gut microbiota. Therefore, we infer that the enteritis in rats may be associated with the relative ratios of the pathogenic bacteria and intestinal probiotics, and increased of the intestinal pathogenic bacteria can disrupted intestinal homeostasis.

Exploring the relationship between nutritional properties and structure of chestnut resistant starch constructed by extrusion with starch-proanthocyanidins interactions

Driven by the high economic value of chestnut, creating chestnut-based food with nutritional functions has become a hot spot in food industry. In this study, effect of hot-extrusion treatment (HEX) with starch-proanthocyanidins (PR) interactions (HEX-PR) on chestnut starch (CS) nutritional properties was evaluated from the perspective of structural changes. Results showed that HEX-PR promoted the formation of ordered structure of CS containing single helix, V-type crystalline structure, and starch aggregates, thus increasing the resistant starch (RS) content from 3.25 % to 12.35 %. For the nutritional evaluation, the α-amylase inhibitory activity, antioxidant activity and antiglycation activity of HEX-PR treated CS (HEX-PRS) were enhanced, and the enhancing effect became stronger as PR concentration rose. In addition, HEX-PRS increased the level of short-chain fatty acids (SCFAs), especially propionate, and meanwhile enriched beneficial intestinal bacteria especially the Bifidobacterium. Notably, correction analysis showed that the microbial community was closely related to the α-amylase inhibitory activity, antioxidant activity and antiglycation activity. Overall, this study provided an approach for improving the nutritional functions of starch, and could offer guidance for further investigations to improve the nutritional quality of chestnut starch-based foods.

The Weissella and Periweissella genera: up-to-date taxonomy, ecology, safety, biotechnological, and probiotic potential

Bacteria belonging to the genera Weissella and Periweissella are lactic acid bacteria, which emerged in the last decades for their probiotic and biotechnological potential. In 2015, an article reviewing the scientific literature till that date on the taxonomy, ecology, and biotechnological potential of the Weissella genus was published. Since then, the number of studies on this genus has increased enormously, several novel species have been discovered, the taxonomy of the genus underwent changes and new insights into the safety, and biotechnological and probiotic potential of weissellas and periweissellas could be gained. Here, we provide an updated overview (from 2015 until today) of the taxonomy, ecology, safety, biotechnological, and probiotic potential of these lactic acid bacteria.

Effect of minocycline, methyl prednisolone, or combination treatment on the colonic bacterial population in a state of colonic inflammation using the murine dextran sulfate sodium model

BACKGROUND

Several reports demonstrated anti-inflammatory properties of minocycline in various inflammatory disorders including colitis. We have experimental evidence suggesting synergistic anti-inflammatory effect of minocycline with methyl prednisolone in reducing colitis severity in mice, but if this effect is in part related to modulating the composition of colonic microbiota is still unknown.

METHODS

the effect of vehicle (V), minocycline (M), methyl prednisolone (MP), or combination (C) regimen on the composition of the microbiota of mice in a state of colon inflammation compared to untreated (UT) healthy mice was determined using 16s metagenomic sequencing, and the taxonomic and functional profiles were summarized.

RESULTS

Overall, the bacterial flora from the phylum Firmicutes followed by Bacteroidota were found to be predominant in all the samples. However, the composition of Firmicutes was decreased relatively in all the treatment groups compared to UT group. A relatively higher percentage of Actinobacteriota was observed in the samples from the C group. At the genus level, Muribaculaceae, Bacteroides, Bifidobacterium, and Lactobacillus were found to be predominant in the samples treated with both drugs (C). Whereas "Lachnospiraceae NK4A136 group" and Helicobacter in the M group, and Helicobacter in the MP group were found to be predominant. But, in the UT group, Weissella and Staphylococcus were found to be predominant. Eubacterium siraeum group, Clostridia vadinBB60 group, Erysipelatoclostridium and Anaeroplasma genera were identified to have a significant (FDR p < 0.05) differential abundance in V compared to C and UT groups. While at the species level, the abundance of Helicobacter mastomyrinus, Massiliomicrobiota timonensis and uncultured Anaeroplasma were identified as significantly low in UT, C, and M compared to V group. Functional categories related to amino acid, carbohydrate, and energy metabolism, cell motility and cell cycle control were dominated overall across all the samples. Methane metabolism was identified as an enriched pathway. For the C group, "Colitis (decrease)" was among the significant (p = 1.81E-6) associations based on the host-intrinsic taxon set.

CONCLUSION

Combination regimen of minocycline plus methyl prednisolone produces a synergistic anti-inflammatory effect which is part related to alternation in the colonic microbiota composition.

Plant miRNA bol-miR159 Regulates Gut Microbiota Composition in Mice: In Vivo Evidence of the Crosstalk between Plant miRNAs and Intestinal Microbes

New evidence reveals that bol-miR159, an miRNA rich in fruits and vegetables, cross-kingdomly functions in mammalian bodies. However, whether the miRNA could regulate gut microbiota remains unclear. Here, the effect of miR159 on mouse intestinal microbes was comprehensively examined. The results showed that supplementation of miR159 to the chow diet significantly enhanced the diversity of mouse gut microbiota without causing pathological lesions or inflammatory responses on the intestines. At the phylum level, miR159 increased the abundance of Proteobacteria and decreased the Firmicute-to-Bacteroidetes (F/B) ratio. miR159 had prebiotic-like effects on mouse gut microbiota, as it promoted the growth of the bacteria that is beneficial for maintaining gut health. The miRNA can target bacteria genes and get into the bacteria cells. The data provide direct in vivo evidence on the crosstalk between plant miRNAs and intestinal microbes, highlighting the potential for miRNA-based strategies that modulate gut microbes to improve host health.

Potential contribution of the gut microbiota to the development of portal vein thrombosis in liver cirrhosis

Background

Portal vein thrombosis (PVT) is a serious complication of liver cirrhosis (LC) and is closely related to gut homeostasis. The study aimed to investigate the composition of gut microbiota and its putative role in PVT development in LC.

Methods

33 patients with LC admitted between January 2022 and December 2022 were enrolled in this study. Based on imaging findings, they were categorized into LC without PVT (n = 21) and LC with PVT (n = 12) groups. Fecal samples were collected from each participant and underwent 16S rDNA sequencing.

Results

D-Dimer and platelet elevations were the main clinical features of LC with PVT. The alpha and beta diversity of the gut microbiota in LC with PVT group was found to be significantly higher compared to the control group. The structure of the gut microbiota was significantly different between the two groups. Based on LEfSe data, the genera Akkermansia, Eubacterium hallii group, Fusicatenibacter, and Anaerostipes were enriched in the LC with PVT, while Enterococcus, Weissella, Bacteroides, and Subdoligranulum were enriched in those of the LC subjects. Changes in microbiota structure result in significant differences in gut microbiota metabolism between the two groups. Altered levels of the microbiota genera were shown to be correlated with coagulation factor parameters. In animal experiments, the addition of Bacteroides reversed the CCl4-induced PVT.

Conclusion

Liver cirrhosis with PVT led to a disorder in the gut microbiota, which was characterized by an increase in pathogenic bacteria and a decrease in beneficial bacteria. Furthermore, modulating the gut microbiota, especially Bacteroides, may be a promising therapeutic approach to reduce the progression of PVT in LC.

Integrative analysis of microbiota and metabolomics in chromium-exposed silkworm (Bombyx mori) midguts based on 16S rDNA sequencing and LC/MS metabolomics

The gut microbiota, a complex ecosystem integral to host wellbeing, is modulated by environmental triggers, including exposure to heavy metals such as chromium. This study aims to comprehensively explore chromium-induced gut microbiota and metabolomic shifts in the quintessential lepidopteran model organism, the silkworm (Bombyx mori). The research deployed 16S rDNA sequence analysis and LC/MS metabolomics in its experimental design, encompassing a control group alongside low (12 g/kg) and high (24 g/kg) feeding chromium dosing regimens. Considerable heterogeneity in microbial diversity resulted between groups. Weissella emerged as potentially resilient to chromium stress, while elevated Propionibacterium was noted in the high chromium treatment group. Differential analysis tools LEfSe and random forest estimation identified key species like like Cupriavidus and unspecified Myxococcales, offering potential avenues for bioremediation. An examination of gut functionality revealed alterations in the KEGG pathways correlated with biosynthesis and degradation, suggesting an adaptive metabolic response to chromium-mediated stress. Further results indicated consequential fallout in the context of metabolomic alterations. These included an uptick in histidine and dihydropyrimidine levels under moderate-dose exposure and a surge of gentisic acid with high-dose chromium exposure. These are critical players in diverse biological processes ranging from energy metabolism and stress response to immune regulation and antioxidative mechanisms. Correlative analyses between bacterial abundance and metabolites mapped noteworthy relationships between marker bacterial species, such as Weissella and Pelomonas, and specific metabolites, emphasizing their roles in enzyme regulation, synaptic processes, and lipid metabolism. Probiotic bacteria showed robust correlations with metabolites implicated in stress response, lipid metabolism, and antioxidant processes. Our study reaffirms the intricate ties between gut microbiota and metabolite profiles and decodes some systemic adaptations under heavy-metal stress. It provides valuable insights into ecological and toxicological aspects of chromium exposure that can potentially influence silkworm resilience.

Weissella confusa F213 ameliorated inflammation and maintained intestinal mucosa integrity in chemically induced colitis rats

OBJECTIVE

This study was performed to investigate the potential effects of Weissella confusa F213 (WCF213) on chemically-induced colitis rats. Twelve male Wistar rats were divided into three groups: T1 (saline sterile), T2 (2.5% dextran sulfate sodium (DSS)- for 7 days), and T3 (WCF213 for 14 days, continued with 2.5% DSS for 7 days). The disease activity index (DAI) was monitored. After sacrificing the rats, the colon was collected for length measurement, local TNF-α level, HE staining for histology, and ZO-1 expression by using immunohistochemistry.

RESULTS

WCF213 administration prevented weight loss and haematochezia, maintained average colon length and alleviated the clinical symptom of colitis, such as diarrhoea, albeit statistically non-significant (p < 0.05) compared with the T2 group. The histopathology of WCF213-treated colitis rats showed better architecture and less inflammatory cell infiltration into colon tissue. WCF213 significantly maintained the expression of ZO-1 in the mucosa (p < 0.001) and markedly reduced mucosal TNF-α concentration (p < 0.001) compared with the DSS group. Hence, these findings suggested that WCF213 attenuated clinical symptoms and inflammation and maintained mucosal integrity in DSS-induced colitis in vivo.

Characterization of Functional Microorganisms in Representative Traditional Fermented Dongcai from Different Regions of China

Dongcai is loved for its delicious flavor and nutritional value. The microorganisms in Dongcai play a vital role in their flavor, quality, and safety, and the microbial communities of Dongcai vary greatly from region to region. However, it remains unknown what the predominant microorganisms are in different traditional Dongcai and how they affect its flavor. The objective of this study is to explore the microbial diversity of traditional fermented Dongcai in three representative Chinese regions (Tianjin, Sichuan, and Guangzhou) and further assess their microbial functions. The microbial diversity of fermented Dongcai in Guangdong has the lowest diversity compared to fermented Dongcai in Sichuan, which has the highest. The distribution of the main genera of fermented Dongcai varies from region to region, but Carnimonas, Staphylococcus, Pseudomonas, Sphingomonas, Burkholderia-Caballeronia-Paraburkholderia, and Rhodococcus are the dominant genera in common. In addition, halophilic bacteria (HAB, i.e., Halomonas Bacillus, Virgibacillus, etc.) and lactic acid bacteria (LAB, i.e., Weissella and Lactobacillus) are also highly abundant. Of these, Burkholderia-Caballeronia-Paraburkholderia, Rhodococcus, Sphingomonas, Ralstonia, and Chromohalobacter are dominant in the Sichuan samples. In the Tianjin samples, Lactobacillus, Weissella, Virgibacillus, Enterobacter, Klebsiella, and Pseudomonas are the most abundant. Predictions of microbial metabolic function reveal that carbohydrates, amino acids, polyketides, lipids, and other secondary metabolites are abundantly available for biosynthesis. In addition, the different flavors of the three types of Dongcai may be due to the fact that the abundance of HAB and LAB shows a significant positive correlation with the amounts of important metabolites (e.g., salt, acid, amino nitrogen, and sugar). These results contribute to our understanding of the link between the distinctive flavors of different types of Dongcai and the microorganisms they contain and will also provide a reference for the relationship between microbial communities and flavor substances in semi-fermented pickles.

Weissella confusa Causing Vancomycin-Resistant Septicemia Infection in a Pediatric Patient: A Case Report From a University Teaching Hospital in North India

Weissella confusa is a Gram-positive coccus usually found in the microbiota of humans and the environment. Different studies quote that it has caused infections in humans under unfavourable conditions. A case report causing septicemia in an 11-year-old male patient diagnosed with acute pancreatitis and having acute respiratory distress syndrome (ARDS) is presented. The patient was successfully treated with ceftazidime and a piperacillin-tazobactam combination after confirmation of bacteria by matrix-assisted laser desorption and ionisation-time of flight (MALDI-TOF-MS) and antimicrobial sensitivity testing (AST) performed as per the latest Clinical and Laboratory Standard Institute (CLSI) guidelines. The patient was discharged asymptomatically after drainage of fluid and was managed conservatively. Correct identification by the automated method is important for this species and also to find its mode of infection. Because of its similarities to other vancomycin-resistant cocci, isolates of this species might be difficult to identify, leading to drug resistance. A literature review in tabulated form is summarised.

Comparative genomics of 40 Weissella paramesenteroides strains

Weissella strains are often detected in spontaneously fermented foods. Because of their abilities to produce lactic acid and functional exopolysaccharides as well as their probiotic traits, Weissella spp. improve not only the sensorial properties but also nutritional values of the fermented food products. However, some Weissella species have been associated with human and animal diseases. In the era of vast genomic sequencing, new genomic/genome data are becoming available to the public on daily pace. Detailed genomic analyses are due to provide a full understanding of individual Weissella species. In this study, the genomes of six Weissella paramesenteroides strains were de novo sequenced. The genomes of 42 W. paramesenteroides strains were compared to discover their metabolic and functional potentials in food fermentation. Comparative genomics and metabolic pathway reconstructions revealed that W. paramesenteroides is a compact group of heterofermentative bacteria with good capacity of producing secondary metabolites and vitamin Bs. Since the strains rarely harbored plasmid DNA, they did not commonly possess the genes associated with bacteriocin production. All 42 strains were shown to bear vanT gene from the glycopeptide resistance gene cluster vanG. Yet none of the strains carried virulence genes.

Probiotics and Their Antimicrobial Effect

This Special Issue of the journal Microorganisms highlights the importance of the antimicrobial effect of probiotics [...].

Weissella and the two Janus faces of the genus

The genus Weissella belongs to the lactic acid bacteria group. It occurs naturally in foods and is a component of the human microbiome. A few Weissella species are candidate probiotics due to their potential for survival under the harsh conditions present in the gastrointestinal tract of humans and animals. Various species have also shown potential for treating and preventing periodontal disease, skin pathologies, and atopic dermatitis; some are used as starters for the fermentation of foods due to their production of exopolysaccharides; and others are used as protective cultures due to their production of weissellicin, a bacteriocin. However, a few Weissella species are opportunistic pathogens, such as W. ceti, which is the etiological agent of weissellosis, a disease in rainbow trout. Additionally, most Weissella species are intrinsically vancomycin-resistant. Thus, the Weissella genus is important from both medical and industrial points of view, and the Janus faces of this genus should be considered in any expected biotechnological applications. In this review, we present an overview of the probiotic potential and pathogenic cases of the Weissella genus reported in the literature.