Evaluation of the therapeutic effect and dose-effect of Bifidobacterium breve on the primary Clostridioides difficile infected mice

Harnessing probiotics capability to combat Salmonella Heidelberg and improve intestinal health in broilers

The poultry industry faces significant challenges in controlling Salmonella contamination while reducing antibiotic use, particularly with the emergence of Salmonella Heidelberg (SH) strains posing risks to food safety and public health. Probiotics, notably lactic acid bacteria (LAB) and Saccharomyces boulardii (SB) offer promising alternatives for mitigating Salmonella colonization in broilers. Understanding the efficacy of probiotics in combating SH and their impact on gut health and metabolism is crucial for improving poultry production practices and ensuring food safety standards. This study aimed to assess the inhibitory effects of LAB and SB against SH both in vitro and in vivo broilers, while also investigating their impact on fecal metabolites and caecal microbiome composition. In vitro analysis demonstrated strong inhibition of SH by certain probiotic strains, such as Lactiplantibacillus plantarum (LP) and Lacticaseibacillus acidophilus (LA), while others like SB and Lactobacillus delbrueckii (LD) did not exhibit significant inhibition. In vivo testing revealed that broilers receiving probiotics had significantly lower SH concentrations in cecal content compared to the positive control (PC) at all ages, indicating a protective effect of probiotics against SH colonization. Metagenomic analysis of cecal-content microbiota identified predominant bacterial families and genera, highlighting changes in microbiota composition with age and probiotic supplementation. Additionally, fecal metabolomics profiling showed alterations in metabolite concentrations, suggesting reduced oxidative stress, intestinal inflammation, and improved gut health in probiotic-supplemented birds. These findings underscore the potential of probiotics to mitigate SH colonization and improve broiler health while reducing reliance on antibiotics.

Potential Applications of Blautia wexlerae in the Regulation of Host Metabolism

Blautia wexlerae (B. wexlerae) is a strong candidate with the potential to become a next-generation probiotics (NGPs) and has recently been shown for the first time to exhibit potential in modulating host metabolic levels and alleviating metabolic diseases. However, the factors affecting the change in abundance of B. wexlerae and the pattern of its abundance change in the associated indications remain to be further investigated. Here, we summarize information from published studies related to B. wexlerae; analyze the effects of food source factors such as prebiotics, probiotics, low protein foods, polyphenols, vitamins, and other factors on the abundance of B. wexlerae; and explore the patterns of changes in the abundance of B. wexlerae in metabolic diseases, neurological diseases, and other diseases. At the same time, the development potential of B. wexlerae was evaluated in the direction of functional foods and special medical foods.

Environmental and Nutritional Parameters Modulating Genetic Expression for Virulence Factors of Clostridioides difficile

Clostridioides difficile infections (CDIs) continue to be a persistent healthcare concern despite newer antibiotic treatments, enhanced infection control practices, and preventive strategies focused on restoring the protective intestinal microbial barrier. Recent strides in gene sequencing research have identified many genes regulating diverse virulence factors for CDIs. These genes may be over- or under-expressed when triggered by various environmental and nutritional factors. The aims of this paper are to review the important genes involved in C. difficile pathogenesis and to identify modifiable environmental, nutritional, and other factors that may trigger the expression of these genes and thus offer new strategies to prevent CDIs.

Evaluation of Safety and Beneficial Health Effects of the Human-Milk Strain Bifidobacterium breve DSM32583: An Infant Pilot Trial

Human milk promotes the growth of bifidobacteria in the infant gut. Adding bifidobacterial species to infant formula may contribute to increasing their presence in the gut of formula-fed infants. Therefore, the safety and anti-infectious effects of Bifidobacterium breve DSM32583, a breast milk isolate, were assessed in a pilot trial involving 3-month-old infants. The infants were randomly assigned to either the probiotic (PG) or the control (CG) groups. All the infants consumed the same formula, although it was supplemented with the strain (1 × 107 cfu/g of formula) in the PG. Overall, 160 infants (80 per group) finished the intervention. Infants in CG gained more weight compared to PG (p < 0.05), but the weights for age Z-scores at 6 months were within the normal distribution for this age group. The rates of infections affecting the gastrointestinal and respiratory tracts and antibiotic therapy were significantly lower in the PG. The bifidobacterial population and the level of short-chain fatty acids were higher (p < 0.05) in the fecal samples of PG infants. No adverse events related to formula consumption were observed. In conclusion, the administration of an infant formula with B. breve DSM32583 was safe and exerted potential beneficial effects on gut health.

Evaluating the Role of Postbiotics in the Modulation of Human Oral Microbiota: A Randomized Controlled Clinical Trial

There is a lack of clinical data to support the effectiveness and safety of postbiotics in the modulation of human oral microbiota and oral health care. Here, volunteers were recruited and randomly assigned to two cohorts: a placebo group (n = 15) and a postbiotic group (n = 16). The placebo group used toothpaste that did not contain postbiotics, while the postbiotic group used toothpaste with postbiotics (3 × 1010 CFU inactivated Lactobacillus salivarius LS97, L. paracasei LC86, and L. acidophilus LA85). Saliva samples were collected at different time points and the immunoglobulin A (IgA) and short-chain fatty acid (SCFA) levels were determined, while the salivary microbiota was analyzed by 16S rRNA amplicon sequencing. The results showed that salivary IgA levels and acetic and propionic acid levels were notably higher in the postbiotic group (P < 0.05), accompanied by an increase in the level of alpha diversity of the salivary microbiota, and these indexes remained high 1 month after discontinuing the use of toothpaste with or without postbiotics. A notable decrease in the relative abundance of the unclassified_Enterobacteriaceae, Klebsiella, Escherichia, etc. in the postbiotic group was accompanied by a notable increase in Ruminofilibacter and Lactobacillus. However, both groups did not cause significant changes in the overall structure of the host salivary microbiota. In conclusion, postbiotics dramatically and consistently improved oral immunity levels and SCFA content in the host. In addition, postbiotics were able to increase the level of microbial alpha diversity and down-regulate the abundance of some harmful microbes without significantly altering the structure of the host salivary microbiota. Chinese Clinical Trial Registry (ChiCTR) ( www.chictr.org.cn ) under the registration number ChiCTR2300074088.

Strategies for applying probiotics in the antibiotic management of Clostridioides difficile infection

The vital role of probiotics in the food field has been widely recognized, and at the same time, probiotics are gradually exhibiting surprising effects in the field of nutraceuticals, especially in regulating gut inflammation and the nutritional environment. As a dietary supplement in clinical nutrition, the coadministration of probiotics with antibiotics model has been applied to prevent intestinal infections caused by Clostridioides difficile. However, the mechanism behind this "bacteria-drug combination" model remains unclear. In particular, the selection of specific probiotic strains, the order of probiotics or antibiotics, and the time interval of coadministration are key issues that need to be further explored and clarified. Here, we focus on the issues mentioned above and give reasonable opinions, mainly including: (1) probiotics are safer and more effective when they intervene after antibiotics have been used; (2) the choice of the time interval between coadministration should be based on the metabolism of antibiotics in the host, differences in probiotic strains, the baseline ecological environment of the host's intestine, and the host immune level; in addition, the selection of the coadministration regime should also take into account factors such as the antibiotic sensitivity of probiotics and dosage of probiotics; and (3) by encapsulating probiotics, combining probiotics with prebiotics, and developing next-generation probiotics (NGPs) and postbiotic formulations, we can provide a more reasonable reference for this type of "bacteria-drug combination" model, and also provide targeted guidance for the application of probiotic dietary supplements in the antibiotic management of C. difficile infection.

From the perspective of rumen microbiome and host metabolome, revealing the effects of feeding strategies on Jersey Cows on the Tibetan Plateau

Background

Previous studies have discussed the effects of grazing and house feeding on yaks during the cold season when forage is in short supply, but there is limited information on the effects of these feeding strategies on Jersey cows introduced to the Tibetan Plateau. The objective of this study was to use genomics and metabolomics analyses to examine changes in rumen microbiology and organism metabolism of Jersey cows with different feeding strategies.

Methods

We selected 12 Jersey cows with similar body conditions and kept them for 60 days under grazing (n = 6) and house-feeding (n = 6) conditions. At the end of the experiment, samples of rumen fluid and serum were collected from Jersey cows that had been fed using different feeding strategies. The samples were analyzed for rumen fermentation parameters, rumen bacterial communities, serum antioxidant and immunological indices, and serum metabolomics. The results of the study were examined to find appropriate feeding strategies for Jersey cows during the cold season on the Tibetan plateau.

Results

The results of rumen fermentation parameters showed that concentrations of acetic acid, propionic acid, and ammonia nitrogen in the house-feeding group (Group B) were significantly higher than in the grazing group (Group G) (P < 0.05). In terms of the rumen bacterial community 16S rRNA gene, the Chao1 index was significantly higher in Group G than in Group B (P = 0.038), while observed species, Shannon and Simpson indices were not significantly different from the above-mentioned groups (P > 0.05). Beta diversity analysis revealed no significant differences in the composition of the rumen microbiota between the two groups. Analysis of serum antioxidant and immune indices showed no significant differences in total antioxidant capacity between Group G and Group B (P > 0.05), while IL-6, Ig-M , and TNF-α were significantly higher in Group G than in Group B (P < 0.05). LC-MS metabolomics analysis of serum showed that a total of 149 major serum differential metabolites were found in Group G and Group B. The differential metabolites were enriched in the metabolic pathways of biosynthesis of amino acids, protein digestion and absorption, ABC transporters, aminoacyl-tRNA biosynthesis, mineral absorption, and biosynthesis of unsaturated fatty acids. These data suggest that the house-feeding strategy is more beneficial to improve the physiological state of Jersey cows on the Tibetan Plateau during the cold season when forages are in short supply.

A study on the method and effect of the construction of a humanized mouse model of fecal microbiota transplantation

The gestation period is critical for the health of the mother and fetus. Malnutrition or over nutrition during pregnancy may cause gestational diseases that can result in adverse pregnancy outcomes. Fecal microbiota transplantation (FMT) can be used to re-establish new gut microbiota to treat a variety of diseases and construct a model to investigate the nutritional health during pregnancy. Therefore, this study investigated whether human-derived gut microbiota during pregnancy could colonize the intestines of mice. Moreover, we determined the time and method of intervention for FMT. Based on this information, a humanized mouse model of FMT was constructed to simulate the human intestinal microecology during pregnancy, and serve as a useful animal model for the study of nutritional health and disease during pregnancy. Germ-free (GF) and specific pathogen free (SPF) C57BL/6J mice were selected for humanized gestational FMT and the transplantation outcomes were evaluated. The results demonstrated that the gestational intestinal microbiota colonized the intestines of mice, allowing researchers to construct a humanized mouse model of gestational FMT. The main intestinal flora of the gestational period were transplanted into GF mice, with the gestational flora being similar to the flora of GF mice after transplantation. However, antibiotics could not eliminate the original microbial flora in SPF mice, and the flora was complex and variable after FMT with little increase in abundance. Background flora had a significant impact on the outcomes assessment. The results were better in GF mice than in SPF mice, and after microbiota transplantation, a superior effect was observed on day 21 compared to days 7 and 14.

Antagonistic activity of selenium-enriched Bifidobacterium breve against Clostridioides difficile

Probiotics have the potential to be used in the prevention of Clostridioides difficile infection (CDI). In this study, selenium (Se)-enriched Bifidobacterium breve YH68-Se was obtained under optimal culture conditions with single-factor and response surface optimization. The overall environmental resistance of YH68-Se was superior to that of the parental strain YH68, mainly reflected in the substantial improvement of antioxidant activity and gastrointestinal tolerance. YH68-Se dramatically inhibited C. difficile growth, spore, biofilm, toxin production, and virulence gene expression, rapidly disrupted C. difficile cell membrane permeability and integrity, and altered the membrane proton motive force (PMF), induced a large outflow of intracellular substances and eventually caused bacterial death. The main factor inducing this process originated from the lactic acid (LD) in YH68-Se. In addition, the LD production of YH68 increased with increasing selenite concentration and was accompanied by enhanced activities of thioredoxin reductase (TrxR), glutathione peroxidase (GSH-Px), and increased concentration of autoinducer-2 (AI-2), which may be the crucial factors contributing to the outstanding probiotic properties of YH68-Se and their potent antagonism of C. difficile. KEY POINTS: • Compared with the parental strain B. breve YH68, the environmental resistance of YH68-Se was improved. • YH68-Se was able to produce more lactic acid, which suppressed the important physiological activities of C. difficile and rapidly disrupted their cell membrane structures. • Sodium selenite in the suitable concentration range gradually increases the yield of lactic acid and phenylacetic acid, increased the concentration of autoinducer-2, and enhanced the activities of antioxidant enzymes TrxR and GSH-Px in YH68.

Bioengineered Probiotics: Synthetic Biology Can Provide Live Cell Therapeutics for the Treatment of Foodborne Diseases

The rising prevalence of antibiotic resistant microbial pathogens presents an ominous health and economic challenge to modern society. The discovery and large-scale development of antibiotic drugs in previous decades was transformational, providing cheap, effective treatment for what would previously have been a lethal infection. As microbial strains resistant to many or even all antibiotic drug treatments have evolved, there is an urgent need for new drugs or antimicrobial treatments to control these pathogens. The ability to sequence and mine the genomes of an increasing number of microbial strains from previously unexplored environments has the potential to identify new natural product antibiotic biosynthesis pathways. This coupled with the power of synthetic biology to generate new production chassis, biosensors and “weaponized” live cell therapeutics may provide new means to combat the rapidly evolving threat of drug resistant microbial pathogens. This review focuses on the application of synthetic biology to construct probiotic strains that have been endowed with functionalities allowing them to identify, compete with and in some cases kill microbial pathogens as well as stimulate host immunity. Weaponized probiotics may have the greatest potential for use against pathogens that infect the gastrointestinal tract: Vibrio cholerae, Staphylococcus aureus, Clostridium perfringens and Clostridioides difficile. The potential benefits of engineered probiotics are highlighted along with the challenges that must still be met before these intriguing and exciting new therapeutic tools can be widely deployed.