Heat inactivation partially preserved barrier and immunomodulatory effects of Lactobacillus gasseri LA806 in an in vitro model of bovine mastitis

OPTIMIZATION OF EXPERIMENTAL MODEL SYSTEMS FOR EVALUATING RECIPROCAL INFLUENCE OF BIFIDOBACTERIUM ANIMALIS AND HUMAN BREAST CANCER CELLS IN VITRO

BACKGROUND

The development of human breast cancer (BC) is known to be closely related to disturbances in the mammary gland microbiota. Bacteria of the genus Bifidobacterium are an important component of normal breast microbiota and exert antitumor activity. The molecular-biological mechanisms of interaction between BC cells and microbiota members remain poorly studied yet. The aim of this study was to develop and optimize an experimental model system for the co-cultivation of BC cells with Bifidobacterium animalis in vitro.

MATERIALS AND METHODS

Human ВС cells of the MCF-7, T47D, and MDA-MB-231 lines, as well as live and heat-inactivated bacteria of Bifidobacterium animalis subsp. lactis (B. animalis) were used as research objects. The growth kinetics and viability of B. animalis in the presence of different ВС cell lines and without them were determined by both the turbidimetry method and seeding on an elective nutrient medium. Glucose consumption and lactate production by bifidobacteria were assessed by biochemical methods. The viability of BC cells was determined by a standard colorimetric method.

RESULTS

The growth kinetics of B. animalis in the complete DMEM nutrient medium showed standard patterns. The indicators of glucose consumption and lactate production of B. animalis confirm its physiological metabolic activity under the growth conditions. The presence of BC cells in the model system did not affect the duration of the growth phases of the B. animalis cells' population but contributed to the increase in their counts. A significant decrease in the number of live BC cells of all studied lines was observed only after 48 h of co-cultivation with live B. animalis. To achieve similar suppression of the BC cell viability, 10-30-fold higher counts of heatinactivated bacteria were required compared to live ones.

CONCLUSIONS

The optimal conditions for co-cultivation of human BC cells and living B. animalis cells in vitro have been identified.

Beyond probiotics: Exploring the potential of postbiotics and parabiotics in veterinary medicine

Postbiotics and parabiotics (PP) are emerging fields of study in animal nutrition, preventive veterinary medicine, and animal production. Postbiotics are bioactive compounds produced by beneficial microorganisms during the fermentation of a substrate, while parabiotics are inactivated beneficial microbial cells, either intact or broken. Unlike probiotics, which are live microorganisms, PP are produced from a fermentation process without live cells and show significant advantages in promoting animal health owing to their distinctive stability, safety, and functional diversity. PP have numerous beneficial effects on animal health, such as enhancing growth performance, improving the immune system and microbiota of the gastrointestinal tract, aiding ulcer healing, and preventing pathogenic microorganisms from colonizing in the skin. Moreover, PP have been identified as a potential alternative to traditional antibiotics in veterinary medicine due to their ability to improve animal health without the risk of antimicrobial resistance. This review comprehensively explores the current research and applications of PP in veterinary medicine. We aimed to thoroughly examine the mechanisms of action, benefits, and potential applications of PP in various species, emphasizing their use specifically in livestock and poultry. Additionally, we discuss the various routes of administration to animals, including feed, drinking water, and topical use. This review also presents in-depth information on the methodology behind the preparation of PP, outlining the criteria employed to select appropriate microorganisms, and highlighting the challenges commonly associated with PP utilization in veterinary medicine.

Two human milk-like synthetic bacterial communities displayed contrasted impacts on barrier and immune responses in an intestinal quadricellular model

The human milk (HM) microbiota, a highly diverse microbial ecosystem, is thought to contribute to the health benefits associated with breast-feeding, notably through its impact on infant gut microbiota. Our objective was to further explore the role of HM bacteria on gut homeostasis through a "disassembly/reassembly" strategy. HM strains covering the diversity of HM cultivable microbiota were first characterized individually and then assembled in synthetic bacterial communities (SynComs) using two human cellular models, peripheral blood mononuclear cells and a quadricellular model mimicking intestinal epithelium. Selected HM bacteria displayed a large range of immunomodulatory properties and had variable effects on epithelial barrier, allowing their classification in functional groups. This multispecies characterization of HM bacteria showed no clear association between taxonomy and HM bacteria impacts on epithelial immune and barrier functions, revealing the entirety and complexity of HM bacteria potential. More importantly, the assembly of HM strains into two SynComs of similar taxonomic composition but with strains exhibiting distinct individual properties, resulted in contrasting impacts on the epithelium. These impacts of SynComs partially diverged from the predicted ones based on individual bacteria. Overall, our results indicate that the functional properties of the HM bacterial community rather than the taxonomic composition itself could play a crucial role in intestinal homeostasis of infants.

Veillonella parvula promotes the proliferation of lung adenocarcinoma through the nucleotide oligomerization domain 2/cellular communication network factor 4/nuclear factor kappa B pathway

Enrichment of Veillonella parvula in the lung microbiota is strongly associated with non-small cell lung cancer (NSCLC) and induces the progression of lung adenocarcinoma in vivo, but its actual role and mechanism remain unexplored. This study analyzed the correlation between NSCLC and V. parvula abundance based on 16 s rRNA sequencing results. The effects of V. parvula on the progression of lung adenocarcinoma were observed in vivo and in vitro using a C57 bl/6j mouse tumor-bearing model, a bacterial cell co-culture model, combined with transcriptome sequencing, and a TCGA database to explore and validate the growth promotion of lung adenocarcinoma by V. parvula and its molecular mechanism. 16 s rRNA sequencing revealed that V. parvula was significantly enriched in lung adenocarcinoma. In vivo, V. parvula promoted the growth of lung adenocarcinoma in mice by suppressing the infiltration of tumor-associated T lymphocytes and peripheral T lymphocytes. It showed a higher affinity for lung adenocarcinoma in vitro and promoted lung adenocarcinoma cell proliferation through adhesion or intracellular invasion. Further analysis of differential gene expression and KEGG enrichment by transcriptome sequencing revealed that V. parvula induced CCN4 expression and activated NOD-like receptor and NF-κB signaling pathway in lung adenocarcinoma cells. Further analysis clarified that V. parvula promoted activation of the NF-κB pathway via Nod2/CCN4 signaling, which promoted lung adenocarcinoma cell proliferation. Thus, V. parvula mediates activation of the Nod2/CCN4/NF-κB signaling pathway to promote non-small cell lung adenocarcinoma progression, thereby providing a potential target for diagnosing and treating lung adenocarcinoma.

Lactobacillus gasseri LA806 Supplementation in Patients with Irritable Bowel Syndrome: A Multicenter Study

The potential benefits of Lactobacillus gasseri LA806 in IBS were previously identified in a comprehensive preclinical research program. The purpose of this multicenter study was to explore in real-life conditions changes in IBS symptoms and quality of life in patients receiving a 4-week supplementation with L. gasseri LA806. Altogether 119 patients meeting Rome IV criteria for IBS were included, of whom 118 received the supplement. The majority of patients (71.8% (95% CI 63.6−79.9%)) manifested a ≥30% decrease in abdominal pain at 4 weeks, the mean abdominal pain score diminishing by 54.2% (from 5.3 ± 2.2 to 2.2 ± 2.4, p < 0.0001). A statistically significant decrease in abdominal pain was seen as early as the first week. A decrease of ≥30% in both abdominal pain score and global IBS symptom score was attained in 61.5% of patients (95% CI 51.7−71.2%). The mean IBS-SSS score fell by 152 ± 112 points (p = 0.001), with symptoms being attenuated in 85% of patients (CGI-I). Supplementation led to a 10-fold decrease in the number of patients reporting severe IBS symptoms. The concomitant intake of antidiarrheals, antispasmodics and analgesics decreased and quality of life scores significantly improved. These preliminary results warrant confirmation by a randomized, placebo-controlled study that this study will allow a better design.

Immunomodulatory Effects of Probiotics: A Novel Preventive Approach for the Control of Bovine Mastitis

Bovine mastitis (BM) is one of the most common diseases of dairy cattle, causing economic and welfare problems in dairy farming worldwide. Because of the predominant bacterial etiology, the treatment of BM is mostly based on antibiotics. However, the antimicrobial resistance (AMR), treatment effectiveness, and the cost of mastitis at farm level are linked to limitations in the antibiotic therapy. These scenarios have prompted the quest for new preventive options, probiotics being one interesting alternative. This review article sought to provide an overview of the recent advances in the use of probiotics for the prevention and treatment of BM. The cellular and molecular interactions of beneficial microbes with mammary gland (MG) cells and the impact of these interactions in the immune responses to infections are revised. While most research has demonstrated that some probiotics strains can suppress mammary pathogens by competitive exclusion or the production of antimicrobial compounds, recent evidence suggest that other probiotic strains have a remarkable ability to modulate the response of MG to Toll-like receptor (TLR)-mediated inflammation. Immunomodulatory probiotics or immunobiotics can modulate the expression of negative regulators of TLR signaling in the MG epithelium, regulating the expression of pro-inflammatory cytokines and chemokines induced upon pathogen challenge. The scientific evidence revised here indicates that immunobiotics can have a beneficial role in MG immunobiology and therefore they can be used as a preventive strategy for the management of BM and AMR, the enhancement of animal and human health, and the improvement of dairy cow milk production.

Impact of Probiotics on Dairy Production Efficiency

There has been growing interest on probiotics to enhance weight gain and disease resistance in young calves and to improve the milk yield in lactating animals by reducing the negative energy balance during the peak lactation period. While it has been well established that probiotics modulate the microbial community composition in the gastrointestinal tract, and a probiotic-mediated homeostasis in the rumen could improve feed conversation competence, volatile fatty acid production and nitrogen flow that enhances the milk composition as well as milk production, detailed changes on the molecular and metabolic level prompted by probiotic feed additives are still not understood. Moreover, as living biotherapeutic agents, probiotics have the potential to directly change the gene expression profile of animals by activating the signalling cascade in the host cells. Various direct and indirect components of probiotic approaches to improve the productivity of dairy animals are discussed in this review.

Emulsion-Based Postbiotic Formulation Is Comparable to Viable Cells in Eliciting a Localized Immune Response in Dairy Cows With Chronic Mastitis

Bovine mastitis is a disease with a multi-etiological nature, defined as an infection and inflammation of the udder. Mastitis represents a significant ongoing concern in the dairy industry, leading to substantial losses in profits and revenue for farmers worldwide. The predominant causes of bovine mastitis include the pathogens Staphylococcus aureus, Streptococcus dysgalactiae, Streptococcus uberis, and Escherichia coli. Antibiotic administration is currently the main treatment option for mastitis. However, there is a pressing need for alternative therapies to treat and prevent the disease, especially with the emergence of antibiotic-resistant, mastitis-causing pathogens, resulting in antibiotic treatment failure. One such example is live bio-therapeutics (also known as probiotics), such as Lactococcus lactis DPC3147. The efficacy of this live bio-therapeutic has been demonstrated in several previous trials by our group. The most recent of these trials showed that an emulsion-based formulation of this strain was as effective as a commercial antibiotic formulation in treating sub-clinical and clinical cases of bovine mastitis. Here, we report the results of a follow-up field trial, in which we sought to gain insight into the mechanism of action of such live bio-therapeutics, focussing on chronic mastitis cases. We treated 28 cows with chronic mastitis with two separate emulsion-based formulations containing either viable L. lactis DPC3147 cells (15 cows) or heat-killed L. lactis DPC3147 cells (13 cows). We then evaluated the efficacies of the two formulations (two treatment groups) in terms of stimulating a localized immune response (quantified by measuring IL-8 concentrations in milk collected from udders affected by mastitis) and efficacies in terms of cure rates (quantified by reductions in somatic cell counts and absence of pathogens). We demonstrate that the presence of heat-inactivated bacteria (a postbiotic) was as effective as the live bio-therapeutic in eliciting a localized immune response in cows with chronic mastitis. The response to heat-killed cells (postbiotic) reported herein could have beneficial implications for farmers with regard to prolonging the shelf life of such emulsion-based formulations containing heat-killed cells of L. lactis DPC3147 for curing cows with mastitis.

ADDAGMA: A Database for Domestic Animal Gut Microbiome Atlas

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We curated all publicly available high-throughput sequencing data on gut microbiomes for four domestic animal species.

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We compiled data for multiple levels of microbial taxa and classified the associated animal phenotypes in detail.

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Exhibiting the dynamic changes of animal gut microbes under different conditions.

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We developed a user-friendly website for browsing, searching, and displaying dynamic changes in animal gut microbes under different conditions.

Animal gut microbiomes play important roles in the health, diseases, and production of animal hosts. The volume of animal gut metagenomic data, including both 16S amplicon and metagenomic sequencing data, has been increasing exponentially in recent years, making it increasingly difficult for researchers to query, retrieve, and reanalyze experimental data and explore new hypotheses. We designed a database called the domestic animal gut microbiome atlas (ADDAGMA) to house all publicly available, high-throughput sequencing data for the gut microbiome in domestic animals. ADDAGMA enhances the availability and accessibility of the rapidly growing body of metagenomic data. We annotated microbial and metadata from four domestic animals (cattle, horse, pig, and chicken) from 356 published papers to construct a comprehensive database that is equipped with browse and search functions, enabling users to make customized, complicated, biologically relevant queries. Users can quickly and accurately obtain experimental information on sample types, conditions, and sequencing platforms, and experimental results including microbial relative abundances, microbial taxon-associated host phenotype, and P-values for gut microbes of interest. The current version of ADDAGMA includes 290,422 quantification events (changes in abundance) for 3215 microbial taxa associated with 48 phenotypes. ADDAGMA presently covers gut microbiota sequencing data from pig, cattle, horse, and chicken, but will be expanded to include other domestic animals. ADDAGMA is freely available at (http://addagma.omicsbio.info/).

Probiotics and Postbiotics as Substitutes of Antibiotics in Farm Animals: A Review

Simple Summary

Breeders are searching for methods to protect farming animals against diseases caused by pathogenic bacteria. The easiest way to fight bacteria is to use antibiotics. Unfortunately, their abuse results in the presence of bacteria resistant to the most commonly used antibiotics in the environment. The restrictions on the use of antibiotics have forced the search for natural and safe ways to protect animals. It has been shown that the use of probiotics based on lactic acid bacteria may have a positive effect on the growth and use of feed by broilers, on the stabilization of the intestinal microbiota of chickens and pigs, and in the prevention of mastitis in dairy cows. The use of probiotics (live, nonpathogenic microorganisms) and postbiotics (inanimate bacteria, cell components or post-fermentation by-products) reduces the occurrence of pathogens in large-scale farms.

Abstract

Since 2006, the use of growth-promoting antibiotics has been banned throughout the European Union. To meet the expectations of livestock farmers, various studies have been carried out with the use of lactic acid bacteria. Scientists are trying to obtain the antimicrobial effect against the most common pathogens in large-scale farms. Supplementing the diet of broilers with probiotics (live, nonpathogenic microorganisms) stabilized the intestinal microbiota, which improved the results of body weight gain (BWG) and feed intake (FI). The positive effect of probiotics based on lactic acid bacteria has been shown to prevent the occurrence of diarrhea during piglet weaning. The antagonistic activity of postbiotics (inanimate bacteria, cell components, or post-fermentation by-products) from post-culture media after lactobacilli cultures has been proven on Staphylococcus aureus—the pathogen most often responsible for causing mastitis among dairy cows. The article aims to present the latest research examining the antagonistic effect of lactic acid bacteria on the most common pathogens in broilers, piglets, pigs, and cow farms.

Live and ultrasound-inactivated Lacticaseibacillus casei modulate the intestinal microbiota and improve biochemical and cardiovascular parameters in male rats fed a high-fat diet

This study aimed to evaluate the effects of ingestion of live (9 log CFU mL-1) and ultrasound-inactivated (paraprobiotic, 20 kHz, 40 min) Lacticaseibacillus casei 01 cells for 28 days on healthy parameters (biochemical and cardiovascular) and intestinal microbiota (amplicon sequencing of 16S ribosomal RNA) of rats fed a high-fat diet. Twenty-four male Wistar rats were divided into four groups of six animals: CTL (standard diet), HFD (high-fat diet), HFD-LC (high-fat diet and live L. casei), and HFD-ILC (high-fat diet and inactivated L. casei). The administration of live and ultrasound-inactivated L. casei prevented the increase (p < 0.05) in cholesterol levels (total and LDL) and controlled the insulin resistance in rats fed a high-fat diet. Furthermore, it promoted a modulation of the intestinal microbial composition by increasing (p < 0.05) beneficial bacteria (Lachnospiraceae and Ruminoccocaceae) and decreasing (p < 0.05) harmful bacteria (Clostridiaceae, Enterobacteriaceae, and Helicobacteriacea), attenuating the effects promoted by the HFD ingestion. Only live cells could increase (p < 0.05) the HDL-cholesterol, while only inactivated cells caused attenuation (p < 0.05) of the blood pressure. Results show beneficial effects of live and inactivated L. casei 01 and indicate that ultrasound inactivation produces a paraprobiotic with similar or improved health properties compared to live cells.