Towards a better understanding of Lactobacillus rhamnosus GG--host interactions

LGG promotes activation of intestinal ILC3 through TLR2 receptor and inhibits salmonella typhimurium infection in mice

Salmonella is a foodborne pathogen that causes disruption of intestinal mucosal immunity, leading to acute gastroenteritis in the host. In this study, we found that Salmonella Typhimurium (STM) infection of the intestinal tract of mice led to a significant increase in the proportion of Lacticaseibacillus, while the secretion of IL-22 from type 3 innate lymphoid cells (ILC3) increased significantly. Feeding Lacticaseibacillus rhamnosus GG (LGG) effectively alleviated the infection of STM in the mouse intestines. TLR2-/- mice experiments found that TLR2-expressing dendritic cells (DCs) are crucial for LGG's activation of ILC3. Subsequent in vitro experiments showed that heat-killed LGG (HK-LGG) could promote DCs to secrete IL-23, which in turn further promotes the activation of ILC3 and the secretion of IL-22. Finally, organoid experiments further verified that IL-22 secreted by ILC3 can enhance the intestinal mucosal immune barrier and inhibit STM infection. This study demonstrates that oral administration of LGG is a potential method for inhibiting STM infection.

Impact of synbiotics on disease activity in systemic lupus erythematosus: Results from a randomized clinical trial

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects various organs in the body. In SLE, inflammatory cytokines play a crucial role in initiating and sustaining the inflammatory process. Synbiotics may help modulate these inflammatory cytokines. This randomized, double-blind, placebo-controlled clinical trial aimed to assess the impact of synbiotics intervention on interleukin-17A (IL-17A) levels, disease activity, and inflammatory factors in patients with SLE. Fifty SLE patients were randomly assigned to receive either standard therapy plus synbiotics (consisting of Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus salivarius, Lactobacillus reuteri, Bifidobacterium lactis, Bifidobacterium longum, Bifidobacterium bifidum, and the prebiotic fructooligosaccharides) or standard therapy alone for 2 months. The results demonstrated a significant reduction in both protein and mRNA levels of IL-17A, as well as in the Systemic Lupus Erythematosus Disease Activity Index 2000 score, within the synbiotics group after the intervention compared to baseline. In contrast, the placebo group did not experience significant changes in IL-17A levels or disease activity. Synbiotic supplementation shows potential as an adjunctive therapeutic approach for SLE management; however, further research is needed to elucidate its underlying mechanisms. PRACTICAL APPLICATION: This study explores the use of synbiotics as a supplementary treatment for systemic lupus erythematosus, which is typically managed with immunosuppressive therapies.

Genomic insights and functional evaluation of Lacticaseibacillus paracasei EG005: a promising probiotic with enhanced antioxidant activity

Introduction

Probiotics, such as Lacticaseibacillus paracasei EG005, are gaining attention for their health benefits, particularly in reducing oxidative stress. The goal of this study was to reinforce the antioxidant capacity of EG005, along with comprehensive genomic analysis, with a focus on assessing superoxide dismutase (SOD) activity, acid resistance and bile tolerance, and safety.

Methods

EG005 was screened for SOD activity and change of SOD activity was tested under various pH conditions. Its survival rates were assessed in acidic (pH 2.5) and bile salt (0.3%) conditions and the antibiotic MIC test and hemolysis test were performed to evaluate safety. Genetic analyses including functional identification and phylogenetic tree construction were performed. The SOD overexpression system was constructed using Ptuf, Pldh1, Plhd2, and Pldh3 strong promoters.

Results

EG005 demonstrated higher SOD activity compared to Lacticaseibacillus rhamnosus GG, with optimal activity at pH 7.0. It showed significant acid and bile tolerance, with survival rates recovering to 100% after 3 h in acidic conditions. Phylogenetic analysis confirmed that EG005 is closely related to other L. paracasei strains with ANI values above 98%. Overexpression of SOD using the Ptuf promoter resulted in a two-fold increase in activity compared to the controls. Additionally, EG005 exhibited no hemolytic activity and showed antibiotic susceptibility within safe limits.

Discussion

Our findings highlight EG005's potential as a probiotic with robust antioxidant activity and high tolerance to gastrointestinal conditions. Its unique genetic profile and enhanced SOD activity through strong promoter support its application in probiotic therapies and functional foods. Further research should be investigated to find the in vivo effects of EG005 on gut health and oxidative stress reduction. In addition, attB and attP-based recombination, combined with CRISPR-Cas9 technologies, could offer a more stable alternative for long-term sodA gene expression in commercial and medical applications.

Oral delivery of sodium alginate/chitosan bilayer microgels loaded with Lactobacillus rhamnosus GG for targeted therapy of ulcerative colitis

Probiotics regulate intestinal flora balance and enhance the intestinal barrier, which is useful in preventing and treating colitis. However, they have strict storage requirements. In addition, they degrade in a strongly acidic environment, resulting in a significant decrease in their activity when used as microbial agents. Lactobacillus rhamnosus GG (LGG) was loaded into acid-resistant and colon-targeting double-layer microgels. The inner layer consists of guar gum (GG) and low methoxyl pectin (LMP), which can achieve retention and degradation in the colon. To achieve colon localization, the outer layer was composed of chitosan (CS) and sodium alginate (SA). The formulation demonstrated favorable bio-responses across various pH conditions in vitro and sustained release of LGG in the colon lesions. Bare LGG survival decreased by 52.2 % in simulated gastric juice (pH 1.2) for 2 h, whereas that of encapsulated LGG decreased by 18.5 %. In the DSS-induced inflammatory model, LGG-loaded microgel significantly alleviated UC symptoms in mice and reduced inflammatory factor levels in the colon. Encapsulation of LGG improved its stability in acidic conditions, thus increasing its content at the colon lesions and reducing pathogenic bacteria. These findings provide an experimental basis and a technical reference for developing and applying probiotic microgel preparations.

Identification and characterization of Lacticaseibacillus rhamnosus HP-B1083-derived β-glucuronidase and its application for baicalin biotransformation

Baicalein, showing higher bioavailability and stronger pharmacological activity, can be obtained via a β-glucuronidase (GUS)-catalyzed transformation of baicalein 7-O-β-D-glucuronide (baicalin). Recently, we have found that the fermentation broth of Lacticaseibacillus rhamnosus HP-B1083 can efficiently convert baicalin to baicalein. In this study, the L. rhamnosus HP-B1083-derived enzyme involved in baicalin biotransformation was identified and characterized. First, the LruidA gene, encoding the responsible enzyme, was cloned and sequenced. Sequence analysis revealed that the deduced enzyme (designated as LrUidA) belonged to the glycosyl hydrolase family 2. The recombinant LrUidA was expressed and purified for characterization. LrUidA had a molecular weight of 70 kDa, with an optimal temperature of 50 °C and pH 4.5. Although LrUidA was susceptible to temperature, it possessed a relative pH stability. Its Michaelis-Menten constant, maximum reaction velocity and catalytic constant values were 9.710 mM, 13.08 mM/min/mg, and 14.95 s-1, respectively. Site-directed mutagenesis experiment results demonstrated that the enzyme reaction uses side chains of E509 and E415 to hydrolyze the glycosidic bond of baicalin and involves three negatively charged residues, E450, D451, and D452, respectively. Surprisingly, biotransformation was performed under optimized reaction conditions by incubating the purified enzyme with 0.1 % baicalin for 4 h, resulting in a considerable conversion ratio of 99 %. Altogether, our findings provide insights into the properties of L. rhamnosus HP-B1083-derived enzyme and expand our understanding regarding using GUS for the industrial production of baicalein.

Mechanisms of action of Lactobacillus spp. in the treatment of oral candidiasis

Candida albicans is often associated with oral candidiasis, and drug-resistance profiles have contributed to an increase in morbidity and mortality. It is known that Lactobacillus spp. acts by competing for adhesion to the epithelium, absorption of nutrients and modulation of the human microbiota. Therefore, they are important to assist in the host's microbiological balance and reduce the growth of Candida spp. Until now, there have been no reports in the literature of reviews correlating to the use of Lactobacillus spp. in the treatment of oral candidiasis. Thus, this review aims to highlight the mechanisms of action of Lactobacillus spp. and methods that can be used in the treatment of oral candidiasis. This is a study carried out through the databases PubMed Central and Scientific Electronic Library Online, using the following keywords: Oral Candidiasis and Lactobacillus. Original articles about oral candidiasis were included, with both in vitro and in vivo analyses, and published from 2012 to 2022. Lactobacillus rhamnosus was the most common microorganism used in the experiments against Candida, acting mainly in the reduction of biofilm, filamentation, and competing for adhesion sites of Candida spp. Among in vivo studies, most researchers used immunosuppressed mouse modelsof Candida infection. The studies showed that Lactobacillus has a great potential as a probiotic, acting mainly in the prevention and treatment of mucosal diseases. Thus, the use of Lactobacillus may be a good strategy for the treatment of oral candidiasis.

Colonic long-term retention and colonization of probiotics by double-layer chitosan/tannic acid coating and microsphere embedding for treatment of ulcerative colitis and radiation enteritis

Oral probiotics can alleviate enteric inflammations but their rapid transit through the gut limits their retention and colonization in the colon. Here, a novel strategy integrating the bacterial double-layer coating and hydrogel microsphere embedding techniques was used to highly enhance the colonic retention and colonization efficiency of Lactobacillus rhamnosus GG (LGG). LGG was coated by the double layers of chitosan (CS) and tannic acid (TA), and then embedded in calcium alginate (CA) hydrogel microspheres to form LGG@CT@CA. The microspheres resisted gastric liquids, improving LGG safe transit through the stomach to reach the colon. LGG@CT rapidly released in the colon due to the good swelling of hydrogel microspheres. More importantly, LGG exhibited long-term retention up to 7 days in the colon, and colonized the deep site of the colonic mucosa. LGG@CT@CA had a high therapeutic efficiency of ulcer colitis with the long colon and the low intestinal permeability of colonic tissues. LGG@CT@CA also alleviated the small intestinal damage induced by irradiation and the survival rates were improved. The mechanisms included local ROS decrease, IL-10 increase, and ferroptosis reduction in the small intestine. The oral colon-targeted system holds promise for oral probiotic therapy by the long-term retention and colonization in the colon.

Microbiome contributions to pain: a review of the preclinical literature

ABSTRACT

Over the past 2 decades, the microbiome has received increasing attention for the role that it plays in health and disease. Historically, the gut microbiome was of particular interest to pain scientists studying nociplastic visceral pain conditions given the anatomical juxtaposition of these microorganisms and the neuroimmune networks that drive pain in such diseases. More recently, microbiomes both inside and across the surface of the body have been recognized for driving sensory symptoms in a broader set of diseases. Microbiomes have never been a more popular topic in pain research, but to date, there has not been a systematic review of the preclinical microbiome pain literature. In this article, we identified all animal studies in which both the microbiome was manipulated and pain behaviors were measured. Our analysis included 303 unique experiments across 97 articles. Microbiome manipulation methods and behavioral outcomes were recorded for each experiment so that field-wide trends could be quantified and reported. This review specifically details the animal species, injury models, behavior measures, and microbiome manipulations used in preclinical pain research. From this analysis, we were also able to conclude how manipulations of the microbiome alter pain thresholds in naïve animals and persistent pain intensity and duration in cutaneous and visceral pain models. This review summarizes by identifying existing gaps in the literature and providing recommendations for how to best plan, implement, and interpret data collected in preclinical microbiome pain experiments.

The global population stru cture of Lacticaseibacillus rhamnosus and its application to an investigation of a rare case of infective endocarditis

BACKGROUND

Lacticaseibacillus (formerly Lactobacillus) rhamnosus is widely used in probiotics or food supplements to promote microbiome health and may also be part of the normal microbiota of the human gastrointestinal tract. However, it rarely also causes invasive or severe infections in patients. It has been postulated that these infections may originate from probiotics or from endogenous commensal reservoirs. In this report, we examine the population structure of Lacticaseibacillus rhamnosus and investigate the utility of using bacterial genomics to identify the source of invasive Lacticaseibacillus infections.

METHODS

Core genome phylogenetic analysis was performed on 602 L. rhamnosus genome sequences from the National Center for Biotechnology public database. This information was then used along with newly generated sequences of L. rhamnosus isolates from yogurt to investigate a fatal case of L. rhamnosus endocarditis.

RESULTS

Phylogenetic analysis demonstrated substantial genetic overlap of L. rhamnosus isolates cultured from food, probiotics, infected patients, and colonized individuals. This was applied to a patient who had both consumed yogurt and developed L. rhamnosus endocarditis to attempt to identify the source of his infection. The sequence of the isolate from the patient's bloodstream differed at only one nucleotide position from one of the yogurt isolates. Both isolates belonged to a clade, identified here as clade YC, composed of mostly gastrointestinal isolates from healthy individuals, some of which also differed by only a single nucleotide change from the patient's isolate.

CONCLUSIONS

As illustrated by this case, whole genome sequencing may be insufficient to reliably determine the source of invasive infections caused by L. rhamnosus.

Contribution of Surface Adhesins of Lacticaseibacillus paracasei S-NB to Its Intestinal Adhesion and Colonization

The intestinal retention and persistence of lactic acid bacteria (LAB) are strain-specific and affected by the bacterial surface components. However, the contribution of surface adhesins of LAB to intestinal adhesion and colonization remains unclear. In the present study, seven gene knockout mutants (genes related to surface adhesin synthesis) of Lacticaseibacillus paracasei S-NB were derived based on the Cre-lox-based recombination system. Results showed that the capsule layer appeared thinner in the cell wall of S-NBΔ7576, S-NBΔdlt, and S-NBΔsrtA mutants when compared with the wild-type (WT) S-NB. The effects of S-NB_7576 (wzd and wze genes, responsible for capsular polysaccharide synthesis) and S-NB_srtA (sortase A) mutation on the hydrophobicity, surface charge, and adhesion ability seem to vary strongly among seven mutant strains. In vivo colonization experiments showed a decrease in the colonization numbers of S-NBΔ7576 and S-NBΔsrtA in both the ileal and colon lumen from 2 to 8 days when compared with those of the WT S-NB. In conclusion, the synthesis of capsular polysaccharides and the transport of surface proteins are closely related to the adhesion ability and intestinal colonization of L. paracasei S-NB.

Lacticaseibacillus rhamnosus GG alleviates sleep deprivation-induced intestinal barrier dysfunction and neuroinflammation in mice

Consuming probiotic products is a solution that people are willing to choose to augment health. As a global health hazard, sleep deprivation (SD) can cause both physical and mental diseases. The present study investigated the protective effects of Lacticaseibacillus rhamnosus GG (LGG), a widely used probiotic, on a SD mouse model. Here, it has been shown that SD induced intestinal damage in mice, while LGG supplementation attenuated disruption of the intestinal barrier and enhanced the antioxidant capacity. Microbiome analysis revealed that SD caused dysbiosis in the gut microbiota, characterized by increased levels of Clostridium XlVa, Alistipes, and Desulfovibrio, as well as decreased levels of Ruminococcus, which were partially ameliorated by LGG. Moreover, SD resulted in elevated pro-inflammatory cytokine concentrations in both the intestine and the brain, while LGG provided protection in both organs. LGG supplementation significantly improved locomotor activity in SD mice. Although heat-killed LGG showed some protective effects in SD mice, its overall efficacy was inferior to that of live LGG. In terms of mechanism, it was found that AG1478, an inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, could diminish the protective effects of LGG. In conclusion, LGG demonstrated the ability to alleviate SD-induced intestinal barrier dysfunction through EGFR activation and alleviate neuroinflammation.

Missing microbes in infants and children in the COVID-19 pandemic: a study of 1,126 participants in Beijing, China

The COVID-19 pandemic has caused many fatalities worldwide and continues to affect the health of the recovered patients in the form of long-COVID. In this study, we compared the gut microbiome of uninfected infants and children before the pandemic began (BEFORE cohort, n=906) to that of after the pandemic (AFTER cohort, n=220) to examine the potential impact of social distancing and life habit changes on infant/children gut microbiome. Based on 16S rRNA sequencing, we found a significant change in microbiome composition after the pandemic, with Bacteroides enterotype increasing to 35.45% from 30.46% before the pandemic. qPCR quantification indicated that the bacterial loads of seven keystone taxa decreased by 91.69%-19.58%. Quantitative microbiome profiling, used to enhance the resolution in detecting microbiome differences, revealed a greater explained variance of pandemic on microbiome compared to gender, as well as a significant decrease in bacterial loads in 15 of the 20 major genera. The random forest age-predictor indicated the gut microbiomes were less mature in the after-pandemic cohort than in the before-pandemic cohort in the children group (3-12 years old) and had features of a significantly younger age (average of 1.86 years). Lastly, body weight and height were significantly lower in the after-pandemic cohort than in the before-pandemic cohort in infants (<1 year of age), which was associated with a decrease in bacterial loads in the fecal microbiome.

Beneficial Effect of Synbiotic Combination of Limosilactobacillus fermentum FS-10, Lactiplantibacillus plantarum Lp1-IC and Short-Chain Fructooligosaccharides in Colitis Murine Model

Therapies targeting gut microbiota are being extensively researched for colitis patients. In this study, we have tested the efficacy of indigenously isolated strains Lactiplantibacillus plantarum Lp1-IC and Limosilactobacillus fermentum FS-10 and their combination with short-chain fructooligosaccharides (sc-FOS) in mice models of DSS-induced colitis. For a desired efficacy, a synbiotic should be very meticulously formulated with the right choice of prebiotic and probiotic. Therefore, the ability of lactobacilli to utilize scFOS for growth was first tested by culturing the strains in a specially designed minimal media supplemented with scFOS as carbon source. The bacteria utilized scFOS and produced metabolites such as acetate and lactate. Thereafter, the in vitro anti-inflammatory effect was tested on markers such as TNF-alpha (TNF-α), nitric oxide and IL-10 in human monocyte (THP-1) and mouse macrophage (Raw 264.7) cell lines. The in vivo efficacy was studied in mice model of DSS-induced colitis, and the effect on the systemic and localized inflammatory markers was assessed in serum and colon tissue samples respectively. Administration of DSS elicited predominant clinical signs of weight loss, diarrhoea, faecal occult blood, increase in inflammatory markers and extensive damage of colon tissue. These symptoms were significantly reversed in all the treatment groups; however, the combination of lactobacilli and scFOS performed better than the individual ingredients. The study highlights the potential of the indigenous lactobacilli strains, scFOS and their combination for management of gut inflammation in colitis patients.

Probiotic Lactobacillus rhamnosus GG improves insulin sensitivity and offspring survival via modulation of gut microbiota and serum metabolite in a sow model

BACKGROUND

Sows commonly experience insulin resistance in late gestation and lactation, causing lower feed intake and milk production, which can lead to higher mortality rates in newborn piglets. The probiotic Lactobacillus rhamnosus GG (LGG) is known to improve insulin resistance. However, whether supplementing LGG can improve insulin sensitivity in sows and enhance lactation performance, particularly the early survival of offspring remains unclear. Hence, we explored the effects and mechanisms of supplementing LGG during late gestation and lactation on sow insulin sensitivity, lactation performance, and offspring survival. In total, 20 sows were randomly allocated to an LGG (n = 10) and control group (n = 10).

RESULTS

In sows, LGG supplementation significantly improved insulin sensitivity during late gestation and lactation, increased feed intake, milk production and colostrum lactose levels in early lactation, and enhanced newborn piglet survival. Moreover, LGG treatment significantly reshaped the gut microbiota in sows, notably increasing microbiota diversity and enriching the relative abundance of insulin sensitivity-associated probiotics such as Lactobacillus, Bifidobacterium, and Bacteroides. Serum metabolite and amino acid profiling in late-gestation sows also revealed decreased branched-chain amino acid and kynurenine serum levels following LGG supplementation. Further analyses highlighted a correlation between mitigated insulin resistance in late pregnancy and lactation by LGG and gut microbiota reshaping and changes in serum amino acid metabolism. Furthermore, maternal LGG enhanced immunity in newborn piglets, reduced inflammation, and facilitated the establishment of a gut microbiota.

CONCLUSIONS

We provide the first evidence that LGG mitigates insulin resistance in sows and enhances offspring survival by modulating the gut microbiota and amino acid metabolism.

Community metabolic modeling of host-microbiota interactions through multi-objective optimization

The human gut microbiota comprises various microorganisms engaged in intricate interactions among themselves and with the host, affecting its health. While advancements in omics technologies have led to the inference of clear associations between microbiome composition and health conditions, we usually lack a causal and mechanistic understanding of these associations. For modeling mechanisms driving the interactions, we simulated the organism's metabolism using in silico genome-scale metabolic models (GEMs). We used multi-objective optimization to predict and explain metabolic interactions among gut microbes and an intestinal epithelial cell. We developed a score integrating model simulation results to predict the type (competition, neutralism, mutualism) and quantify the interaction between several organisms. This framework uncovered a potential cross-feeding for choline, explaining the predicted mutualism between Lactobacillus rhamnosus GG and the epithelial cell. Finally, we analyzed a five-organism ecosystem, revealing that a minimal microbiota can favor the epithelial cell's maintenance.

Black Goji Berry (Lycium ruthenicum) Juice Fermented with Lactobacillus rhamnosus GG Enhances Inhibitory Activity against Dipeptidyl Peptidase-IV and Key Steps of Lipid Digestion and Absorption

With the global increase in hyperglycemia and hyperlipidemia, there is an urgent need to explore dietary interventions targeting the inhibition of dipeptidyl peptidase-IV (DPP-IV) and lipid digestion and absorption. This study investigated how Lactobacillus rhamnosus GG (LGG) affects various aspects of black goji berry (BGB) (Lycium ruthenicum Murr.) juice, including changes in physicochemical and functional properties, as well as microbiological and sensory attributes. Throughout the fermentation process with 2.5-10% (w/v) BGB, significantly improved probiotic viability, lactic acid production, and decreased sugar content. While total flavonoids increase, anthocyanins decrease, with no discernible change in antioxidant activities. Metabolite profiling reveals elevated phenolic compounds post-fermentation. Regarding the inhibition of lipid digestion and absorption, fermented BGB exhibits improved bile acid binding, and disrupted cholesterol micellization by approximately threefold compared to non-fermented BGB, while also increasing pancreatic lipase inhibitory activity. Furthermore, a decrease in cholesterol uptake was observed in Caco-2 cells treated with fermented BGB (0.5 mg/mL), with a maximum reduction of 16.94%. Fermented BGB also shows more potent DPP-IV inhibition. Sensory attributes are significantly improved in fermented BGB samples. These findings highlight the potential of BGB as a bioactive resource and a promising non-dairy carrier for LGG, enhancing its anti-hyperglycemic and anti-hyperlipidemic properties.

Bad to the bone? - Genomic analysis of Enterococcus isolates from diverse environments reveals that most are safe and display potential as food fermentation microorganisms

Enterococci comprise a group of lactic acid bacteria (LAB) with considerable potential to serve as food fermentation microorganisms. Unfortunately, enterococci have received a lot of negative attention, due to the occurrence of pathogenic and multidrug resistant strains. In this study, we used genomics to select safe candidates among the forty-four studied enterococcal isolates. The genomes of the forty-four strains were fully sequenced and assessed for presence of virulence and antibiotic resistance genes. Nineteen isolates belonging to the species Enterococcus lactis, Enterococcus faecium, Enterococcus durans, and Enterococcus thailandicus, were deemed safe from the genome analysis. The presence of secondary metabolite gene clusters for bacteriocins was assessed, and twelve candidates were found to secrete antimicrobial compounds effective against Listeria monocytogenes isolated from cheese and Staphylococcus aureus. Physiological characterization revealed nineteen industrial potentials; all strains grew well at 42 °C and acidified 1.5 hours faster than their mesophilic counterpart Lactococcus lactis, with which they share metabolism and flavor forming ability. We conclude that a large fraction of the examined enterococci were safe and could serve as excellent food fermentation microorganisms with inherent bioprotective abilities.

From growth promotion to intestinal inflammation alleviation: Unraveling the potential role of Lactobacillus rhamnosus GCC-3 in juvenile grass carp (Ctenopharyngodon idella)

Lactobacillus rhamnosus is a probiotic, which not only promotes the growth of animals, but also has anti-inflammatory effects. However, the mechanism by which Lactobacillus rhamnosus regulates intestinal immunity is not well comprehended. Hence, the study aimed to research how Lactobacillus rhamnosus affects the intestinal immunity using juvenile grass carp (Ctenopharyngodon idella) as a model. We selected 1800 juvenile grass carp for testing. They were divided into six treatments and fed with six gradients of Lactobacillus rhamnosus GCC-3 (0.0, 0.5, 1.0, 1.5, 2.0, 2.5 g/kg) for 70 days. Enteritis was subsequently induced with dextroside sodium sulfate. Results indicated that dietary Lactobacillus rhamnosus GCC-3 addition improved growth performance. Meanwhile, appropriate levels of Lactobacillus rhamnosus GCC-3 alleviated excessive inflammatory response by down-regulating the expression of TLR4 and NOD receptors, up-regulating the expression of TOR, and then down-regulating the expression of NF-κB. Additionally, appropriate Lactobacillus rhamnosus GCC-3 improved intestinal immunity by reducing pyroptosis triggered by NLRP3 inflammasome and mediated by GSDME. Furthermore, 16 S rRNA sequencing showing appropriate levels of Lactobacillus rhamnosus GCC-3 increased Lactobacillus and Bifidobacterium abundance and decreased Aeromonas abundance. These results suggest that Lactobacillus rhamnosus GCC-3 can alleviate intestinal inflammation through down-regulating NF-κB and up-regulating TOR signaling pathways, as well as by inhibiting pyroptosis.

Development and study of the functional properties of marshmallow enriched with bee (Apis mellifera) honey and encapsulated probiotics (Lactobacillus rhamnosus)

Consumer demand for healthier confectionery products has prompted the confectionery industry to create products that are reduced in sugar content and supplemented with vitamins, antioxidants or biological elements beneficial to health. The aim of this study was to develop marshmallows enriched with Apis mellifera honey and Lactobacillus rhamnosus and to evaluate the effect of honey concentration and gelatin bloom degrees on marshmallow properties. A completely randomized design with a factorial structure was applied with different honey concentrations (0, 50 and 75%) and at different gelatin bloom degrees (265, 300 and 315 bloom degrees); moreover, the physicochemical properties, total phenol content and antioxidant activity of the marshmallow were studied, as well as the viability of the probiotic. The physicochemical properties of the marshmallows were found to be adequate and showed good stability over time. The concentration of honey and gelatin bloom degrees did not significantly affect probiotic viability. The density of the marshmallows decreased as the percentage of honey increased. Additionally, the pH was lower at higher honey concentrations. The marshmallow with 75% honey and 265 bloom degrees had a higher °Brix value. The honey treatments exhibited higher levels of total antioxidant activity and total phenolic compounds than the sugar-only marshmallows. However, the bloom degrees did not have a significant impact on the antioxidant activity and total phenolic compound content. Although the probiotics did not reach the minimum viability needed, their use as paraprobiotics can be considered.

Self-Assembling Sulfated Lactobacillus Exopolysaccharide Nanoparticles as Adjuvants for SARS-CoV-2 Subunit Vaccine Elicit Potent Humoral and Cellular Immune Responses

Coronavirus disease 2019 (COVID-19) has caused a global pandemic since its onset in 2019, and the development of effective vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to induce potent and long-lasting immunity remains a priority. Herein, we prepared two Lactobacillus exopolysaccharide (EPS) nanoparticle adjuvants (NPs 7-4 and NPs 8-2) that were constructed by using sulfation-modified EPS and quaternization-modified chitosan. These two NPs displayed a spherical morphology with sizes of 39 and 47 nm. Furthermore, the zeta potentials of NPs 7-4 and NPs 8-2 were 50.40 and 44.40 mV, respectively. In vitro assays demonstrated that NPs could effectively adsorb antigenic proteins and exhibited a sustained release effect. Mouse immunization tests showed that the NPs induced the expression of cytokines and chemokines at the injection site and promoted the uptake of antigenic proteins by macrophages. Mechanically, the NPs upregulated the expression of pattern recognition receptors (toll-like receptors and nod-like receptors) and activated the immune response of T cells and the production of neutralizing antibodies. In addition, the NP adjuvants had favorable immune-enhancing effects in cats, which are of great significance for controlling the trans-host transmission and re-endemicity of SARS-CoV-2. Overall, we demonstrated that NP-adjuvanted SARS-CoV-2 receptor binding domain proteins could induce robust specific humoral and cellular immunity.

Molecular Mechanisms of Lacticaseibacillus rhamnosus, LGG® Probiotic Function

To advance probiotic research, a comprehensive understanding of bacterial interactions with human physiology at the molecular and cellular levels is fundamental. Lacticaseibacillus rhamnosus LGG® is a bacterial strain that has long been recognized for its beneficial effects on human health. Probiotic effector molecules derived from LGG®, including secreted proteins, surface-anchored proteins, polysaccharides, and lipoteichoic acids, which interact with host physiological processes have been identified. In vitro and animal studies have revealed that specific LGG® effector molecules stimulate epithelial cell survival, preserve intestinal barrier integrity, reduce oxidative stress, mitigate excessive mucosal inflammation, enhance IgA secretion, and provide long-term protection through epigenetic imprinting. Pili on the cell surface of LGG® promote adhesion to the intestinal mucosa and ensure close contact to host cells. Extracellular vesicles produced by LGG® recapitulate many of these effects through their cargo of effector molecules. Collectively, the effector molecules of LGG® exert a significant influence on both the gut mucosa and immune system, which promotes intestinal homeostasis and immune tolerance.

Orally Administered Lactobacillus rhamnosus CY12 Alleviates DSS-Induced Colitis in Mice by Restoring the Intestinal Barrier and Inhibiting the TLR4-MyD88-NF-κB Pathway via Intestinal Microbiota Modulation

Oral ingestion of probiotics is a promising approach to relieving inflammatory disease through regulating the gut microbiota. A newly discovered strain, Lactobacillus rhamnosus CY12 (LCY12), obtained from cattle-yak milk, displayed numerous probiotic properties. These included enhanced viability in low pH and bile environments, adhesion capabilities, and potent antimicrobial effects. The research aimed to explore the beneficial impacts of the novel LCY12 strain on colitis in mice induced by dextran sulfate sodium (DSS) and to elucidate the underlying molecular mechanisms. The results of the study showed that administration of LCY12 effectively helped to reduce the negative effects of DSS-induced body weight loss, disease activity index score, colon length shortening, loss of goblet cells, and overall histopathological scores in the intestines. Simultaneously, LCY12 administration significantly alleviated intestinal inflammation and safeguarded intestinal barrier integrity by enhancing IL-10 levels, while dampening IL-6, IL-1β, and TNF-α production. Additionally, LCY12 boosted the presence of tight junction proteins. Furthermore, LCY12 hindered the TLR4/MyD88/NF-κB signaling pathway by downregulating TLR4 and MyD88 expression, inactivating phosphorylated IκBα, and preventing translocation of NF-κB p65 from the cytoplasm to the nucleus. The LCY12 also increased specific intestinal microbial communities and short-chain fatty acid (SCFA) production. Altogether, LCY12 oral administration alleviated colitis induced with DSS in mice by improving intestinal barrier function and regulating inflammatory cytokines, SCFA production, and intestinal microbiota.

Lactobacillus rhamnosus GG triggers intestinal epithelium injury in zebrafish revealing host dependent beneficial effects

Lactobacillus rhamnosus GG (LGG), the well-characterized human-derived probiotic strain, possesses excellent properties in the maintenance of intestinal homeostasis, immunoregulation and defense against gastrointestinal pathogens in mammals. Here, we demonstrate that the SpaC pilin of LGG causes intestinal epithelium injury by inducing cell pyroptosis and gut microbial dysbiosis in zebrafish. Dietary SpaC activates Caspase-3-GSDMEa pathways in the intestinal epithelium, promotes intestinal pyroptosis and increases lipopolysaccharide (LPS)-producing gut microbes in zebrafish. The increased LPS subsequently activates Gaspy2-GSDMEb pyroptosis pathway. Further analysis reveals the Caspase-3-GSDMEa pyroptosis is initiated by the species-specific recognition of SpaC by TLR4ba, which accounts for the species-specificity of the SpaC-inducing intestinal pyroptosis in zebrafish. The observed pyroptosis-driven gut injury and microbial dysbiosis by LGG in zebrafish suggest that host-specific beneficial/harmful mechanisms are critical safety issues when applying probiotics derived from other host species and need more attention.

Protective effects of Lactobacillus on heat stress-induced intestinal injury in finisher broilers by regulating gut microbiota and stimulating epithelial development

Heat stress (HS) is a critical challenge in broilers due to the high metabolic rate and lack of sweat glands. Results from this study show that implementing a cyclic chronic HS (34 °C for 7 h/d) to finisher broilers decreased the diversity of cecal microbiota and impaired intestinal barrier, resulting in gut leak and decreased body weight (both P < 0.05). These alterations might be related to inflammatory outbursts and the retarded proliferation of intestinal epithelial cells (IECs) according to the transcriptome analysis. Considering the potential beneficial properties of Lactobacillus on intestinal development and function, the protective effects of Lactobacillus rhamnosus (L. rhamnosus) on the intestine were investigated under HS conditions in this study. Orally supplemented L. rhamnosus improved the composition of cecal microbiota and upregulated the transcription of tight junction proteins in both duodenum and jejunum, with a consequent suppression in intestinal gene expressions of pro-inflammatory cytokines and facilitation in digestive capability. Meanwhile, the jejunal villus height of the birds that received L. rhamnosus was significantly higher compared with those treated with the broth (P < 0.05). The expression abundances of genes related to IECs proliferation and differentiation were increased by L. rhamnosus, along with upregulated mRNA levels of Wnt3a and β-catenin in jejunum. In addition, L. rhamnosus attenuated enterocyte apoptosis as indicated by decreased caspase-3 and caspase-9 gene expressions. The results indicated that oral administration with L. rhamnosus mitigated HS-induced dysfunction by promoting intestinal development and epithelial maturation in broilers and that the effects of L. rhamnosus might be dependent of Wnt/β-catenin signaling.

Analysis of the gut microbiome in sled dogs reveals glucosamine- and activity-related effects on gut microbial composition

The composition of the microbiome influences many aspects of physiology and health, and can be altered by environmental factors, including diet and activity. Glucosamine is a dietary supplement often administered to address arthritic symptoms in humans, dogs, and other mammals. To investigate how gut microbial composition varies with glucosamine supplementation, we performed 16S rRNA sequence analysis of fecal samples from 24 Alaskan and Inuit huskies and used mixed effects models to investigate associations with activity, age, and additional factors. Glucosamine ingestion, age, activity, sex, and diet were correlated with differences in alpha-diversity, with diversity decreasing in dogs consuming glucosamine. Beta-diversity analysis revealed clustering of dogs based on glucosamine supplementation status. Glucosamine supplementation and exercise-related activity were associated with greater inter-individual pairwise distances. At the family level, Lactobacillaceae and Anaerovoracaceae relative abundances were lower in supplemented dogs when activity was accounted for. At the genus level, Eubacterium [brachy], Sellimonus, Parvibacter, and an unclassified genus belonging to the same family as Parvibacter (Eggerthellaceae) all were lower in supplemented dogs, but only significantly so post-activity. Our findings suggest that glucosamine supplementation alters microbiome composition in sled dogs, particularly in the context of exercise-related activity.

In vitro adhesion and anti-inflammatory properties of Limosilactobacillus fermentum FS-10 isolated from infant fecal sample

In this study, seven strains of Limosilactobacillus fermentum were isolated from an infant fecal sample and characterized using in vitro studies. Lactobacillus rhamnosus GG was used as a comparison because it is a well-documented commercial probiotic. The isolates were tested for attributes such as acid and phenol tolerance, bile salt hydrolase (BSH) activity, and antibiotic sensitivity. One isolate, L. fermentum FS-10, displayed enhanced cell surface hydrophobicity (> 85%) and mucin adhesion. Mucin-binding helps colonization in the gut. The immunomodulatory property of L. fermentum FS-10 was evaluated by determining the modulation of pro- and anti-inflammatory factors such as tumor necrosis factor-alpha (TNF-α), interleukin (IL)-10, and nitric oxide (NO) in human acute monocytic leukemia (THP-1) cells under inflammatory conditions induced by lipopolysaccharide (LPS). L. fermentum FS-10 potently downregulated the expression of TNF-α and nitric oxide and upregulated IL-10 levels, indicating an anti-inflammatory response. Safety assessment of the strain revealed the absence of genes for virulence factors, toxin production, and antibiotic resistance, potentiating application as a probiotic strain.

Identification and quantification of viable Lacticaseibacillus rhamnosus in probiotics using validated PMA-qPCR method

The identification and quantification of viable bacteria at the species/strain level in compound probiotic products is challenging now. Molecular biology methods, e.g., propidium monoazide (PMA) combination with qPCR, have gained prominence for targeted viable cell counts. This study endeavors to establish a robust PMA-qPCR method for viable Lacticaseibacillus rhamnosus detection and systematically validated key metrics encompassing relative trueness, accuracy, limit of quantification, linear, and range. The inclusivity and exclusivity notably underscored high specificity of the primers for L. rhamnosus, which allowed accurate identification of the target bacteria. Furthermore, the conditions employed for PMA treatment were fully verified by 24 different L. rhamnosus including type strain, commercial strains, etc., confirming its effective discrimination between live and dead bacteria. A standard curve constructed by type strain could apply to commercial strains to convert qPCR Cq values to viable cell numbers. The established PMA-qPCR method was applied to 46 samples including pure cultures, probiotics as food ingredients, and compound probiotic products. Noteworthy is the congruity observed between measured and theoretical values within a 95% confidence interval of the upper and lower limits of agreement, demonstrating the relative trueness of this method. Moreover, accurate results were obtained when viable L. rhamnosus ranging from 103 to 108 CFU/mL. The comprehensive appraisal of PMA-qPCR performances provides potential industrial applications of this new technology in quality control and supervision of probiotic products.

Research Progress for Probiotics Regulating Intestinal Flora to Improve Functional Dyspepsia: A Review

Functional dyspepsia (FD) is a common functional gastrointestinal disorder. The pathophysiology remains poorly understood; however, alterations in the small intestinal microbiome have been observed. Current treatments for FD with drugs are limited, and there are certain safety problems. A class of active probiotic bacteria can control gastrointestinal homeostasis, nutritional digestion and absorption, and the energy balance when taken in certain dosages. Probiotics play many roles in maintaining intestinal microecological balance, improving the intestinal barrier function, and regulating the immune response. The presence and composition of intestinal microorganisms play a vital role in the onset and progression of FD and serve as a critical factor for both regulation and potential intervention regarding the management of this condition. Thus, there are potential advantages to alleviating FD by regulating the intestinal flora using probiotics, targeting intestinal microorganisms. This review summarizes the research progress of probiotics regarding improving FD by regulating intestinal flora and provides a reference basis for probiotics to improve FD.

pH-dependent pressure-sensitive colonic capsules for the delivery of aqueous bacterial suspensions

Microbiome-based therapies hold great promise for treating various diseases, but the efficient delivery of live bacteria to the colon remains a challenge. Furthermore, current oral formulations, such as lyophilized bacterial capsules or tablets, are produced using processes that can decrease bacterial viability. Consequently, high dosages are required to achieve efficacy. Herein, we report the design of pressure-sensitive colonic capsules for the encapsulation and delivery of aqueous suspensions of live bacteria. The capsules consisted of 2 functional thin-films (hydrophobic and enteric) of ethyl cellulose and Eudragit S100 dip-coated onto hydroxypropyl methylcellulose molds. The capsules could be loaded with aqueous media and provide protection against acidic fluids and, to some extent, oxygen diffusion, suggesting their potential suitability for delivering anaerobic bacterial strains. Disintegration and mechanical studies indicated that the capsules could withstand transit through the stomach and upper/proximal small intestinal segments and rupture in the ileum/colon. In vitro studies showed that bacterial cells (anaerobic and aerobic commensals) remained highly viable (74-98%) after encapsulation and exposure to the simulated GI tract conditions. In vivo studies with a beagle dog model revealed that 67% of the capsules opened after 3.5 h, indicating content release in the distal gastrointestinal tract. These data demonstrate that live aqueous bacterial suspensions comprised of both aerobic and anaerobic commensals can be encapsulated and in the future might be efficiently delivered to the distal gastrointestinal tract, suggesting the practical applications of these capsules in microbiome-based therapies.

Prebiotic Cellulose-Pullulan Matrix as a "Vehicle" for Probiotic Biofilm Delivery to the Host Large Intestine

This study describes the development of a new combined polysaccharide-matrix-based technology for the immobilization of Lactobacillus rhamnosus GG (LGG) bacteria in biofilm form. The new composition allows for delivering the bacteria to the digestive tract in a manner that improves their robustness compared with planktonic cells and released biofilm cells. Granules consisting of a polysaccharide matrix with probiotic biofilms (PMPB) with high cell density (>9 log CFU/g) were obtained by immobilization in the optimized nutrient medium. Successful probiotic loading was confirmed by fluorescence microscopy and scanning electron microscopy. The developed prebiotic polysaccharide matrix significantly enhanced LGG viability under acidic (pH 2.0) and bile salt (0.3%) stress conditions. Enzymatic extract of feces, mimicking colon fluid in terms of cellulase activity, was used to evaluate the intestinal release of probiotics. PMPB granules showed the ability to gradually release a large number of viable LGG cells in the model colon fluid. In vivo, the oral administration of PMPB granules in rats resulted in the successful release of probiotics in the colon environment. The biofilm-forming incubation method of immobilization on a complex polysaccharide matrix tested in this study has shown high efficacy and promising potential for the development of innovative biotechnologies.

Limosilactobacillus reuteri inhibits the acid tolerance response in oral bacteria

Probiotic bacteria show promising results in prevention of the biofilm-mediated disease caries, but the mechanisms are not fully understood. The acid tolerance response (ATR) allows biofilm bacteria to survive and metabolize at low pH resulting from microbial carbohydrate fermentation. We have studied the effect of probiotic strains: Limosilactobacillus reuteri and Lacticaseibacillus rhamnosus on ATR induction in common oral bacteria. Communities of L. reuteri ATCC PTA5289 and Streptoccus gordonii, Streptococcus oralis, Streptococcus mutans or Actinomyces naeslundii in the initial stages of biofilm formation were exposed to pH 5.5 to allow ATR induction, followed by a low pH challenge. Acid tolerance was evaluated as viable cells after staining with LIVE/DEAD®BacLight™. The presence of L. reuteri ATCC PTA5289 caused a significant reduction in acid tolerance in all strains except S. oralis. When S. mutans was used as a model organism to study the effects of additional probiotic strains (L. reuteri SD2112, L. reuteri DSM17938 or L. rhamnosus GG) as well as L. reuteri ATCC PTA5289 supernatant on ATR development, neither the other probiotic strains nor supernatants showed any effect. The presence of L. reuteri ATCC PTA5289 during ATR induction led to down-regulation of three key genes involved in tolerance of acid stress (luxS, brpA and ldh) in Streptococci. These data suggest that live cells of probiotic L. reuteri ATCC PTA5289 can interfere with ATR development in common oral bacteria and specific strains of L. reuteri may thus have a role in caries prevention by inhibiting development of an acid-tolerant biofilm microbiota.

Mechanism Insights of Antibacterial Surfaces Coated with Dead Probiotics

To understand the antimicrobial effect of surfaces fabricated with dead probiotics, we prepared surfaces decorated with dead probiotics Lactobacillus rhamnosus GG (LGG) with varied inactivation methods and explored their inhibitory interactions with Pseudomonas aeruginosa (PAO1). By combining several techniques, i.e., digital holographic microscopy (DHM), atomic force microscopy (AFM), RNA sequencing, and metabolomic analysis, we studied the three-dimensional (3D) swimming behaviors, surface adhesion, biofilm formation, and adaptive responses of PAO1 near such surfaces. The results show that planktonic PAO1 decreases their flick and reverse motions by downregulating the chemotaxis pathway and accelerates with less accumulation near dead LGG surfaces by upregulating the flagellar assembly pathway and decreasing cyclic adenosine monophosphate. Distinct from live siblings, the surfaces decorated with dead LGG show a significant reduction in adhesion strength with PAO1 and inhibit biofilm formation with more downregulated genes in the Pseudomonas quinolone signal and biofilm formation pathway. We demonstrate that the antibacterial ability of such surfaces stems from the gradually released lysate from the dead LGG that is unfavorable to PAO1 in close proximity. The releasing rate and order depend on the cell membrane integrity, which closely relates to the inactivation methods.

Lactobacillus rhamnosus Attenuates Cisplatin-Induced Intestinal Mucositis in Mice via Modulating the Gut Microbiota and Improving Intestinal Inflammation

Lactobacillus rhamnosus (LBS) is a well-documented probiotic strain in oncology and has a pivotal role in clinical applications. Here, we have investigated the protective effect of Lactobacillus rhamnosus on intestinal mucositis induced by cisplatin (CP) and explored the underlying mechanisms targeting inflammatory proteins, as well as the histological changes in the intestinal tissue of mice, in addition, the bacterial strains that may be related to the health-enhancing properties. BALB/c mice were pre-treated with or without LBS via oral gavage, followed by mucositis induction with cisplatin. Our results revealed that the LBS-treated groups significantly attenuated proinflammatory cytokine levels (IL-1β, IL-6, and TNF-α) compared to the CP group. Furthermore, LBS mitigated the damaged tight junction integrity caused by CP via up-regulating the levels of claudin, occludin, ZO-1, and mucin-2 protein (MUC-2). Finally, the 16S rRNA fecal microbiome genomic analysis showed that LBS administration enhanced the growth of beneficial bacteria, i.e., Firmicutes and Lachnospiraceae, while the relative abundance of the opportunistic bacteria Bacteroides and Proteobacteria decreased. Collectively, LBS was found to beneficially modulate microbial composition structure and functions and enrich the ecological diversity in the gut.

Infection and inflammation stimulate expansion of a CD74+ Paneth cell subset to regulate disease progression

Paneth cells (PCs), a specialized secretory cell type in the small intestine, are increasingly recognized as having an essential role in host responses to microbiome and environmental stresses. Whether and how commensal and pathogenic microbes modify PC composition to modulate inflammation remain unclear. Using newly developed PC-reporter mice under conventional and gnotobiotic conditions, we determined PC transcriptomic heterogeneity in response to commensal and invasive microbes at single cell level. Infection expands the pool of CD74+ PCs, whose number correlates with auto or allogeneic inflammatory disease progressions in mice. Similar correlation was found in human inflammatory disease tissues. Infection-stimulated cytokines increase production of reactive oxygen species (ROS) and expression of a PC-specific mucosal pentraxin (Mptx2) in activated PCs. A PC-specific ablation of MyD88 reduced CD74+ PC population, thus ameliorating pathogen-induced systemic disease. A similar phenotype was also observed in mice lacking Mptx2. Thus, infection stimulates expansion of a PC subset that influences disease progression.

Postbiotic Preparation of Lacticaseibacillus rhamnosus GG against Diarrhea and Oxidative Stress Induced by Spike Protein of SARS-CoV-2 in Human Enterocytes

The Spike protein of SARS-CoV-2 acts as an enterotoxin able to induce chloride secretion and production of reactive oxygen species (ROS), involved in diarrhea pathogenesis. L. rhamnosus GG (LGG) is recommended in pediatric acute gastroenteritis guidelines as a therapy independent of infectious etiology. We tested a postbiotic preparation of LGG (mLGG) in an in vitro model of COVID-associated diarrhea. Caco-2 cell monolayers mounted in Ussing chambers were exposed to Spike protein, and electrical parameters of secretory effect (Isc and TEER) were recorded in the Ussing chambers system. Oxidative stress was analyzed by measuring ROS production (DCFH-DA), GSH levels (DNTB), and lipid peroxidation (TBARS). Experiments were repeated after mLGG pretreatment of cells. The Isc increase induced by Spike was consistent with the secretory diarrhea pattern, which was dependent on oxidative stress defined by a 2-fold increase in ROS production and lipid peroxidation and variation in glutathione levels. mLGG pretreatment significantly reduced the secretory effect (p = 0.002) and oxidative stress, namely ROS (p < 0.001), lipid peroxidation (p < 0.001), and glutathione level changes (p < 0.001). LGG counteracts Spike-induced diarrhea by inhibiting the enterotoxic effect and oxidative stress. The LGG efficacy in the form of a postbiotic depends on metabolites secreted in the medium with antioxidant properties similar to NAC. Because SARS-CoV-2 is an enteric pathogen, the efficacy of LGG independent of etiology in the treatment of acute gastroenteritis is confirmed by our data.

The Biochemical, Microbiological, Antioxidant and Sensory Characterization of Fermented Skimmed Milk Drinks Supplemented with Probiotics Lacticaseibacillus casei and Lacticaseibacillus rhamnosus

A variety of foods fermented with lactic acid bacteria (LAB) serve as dietary staples in many countries. The incorporation of health-promoting probiotics into fermented milk products can have profound effects on human health. Considering the health benefits of Yakult, the current study was undertaken to develop an enriched Yakult-like fermented skimmed milk drink by the addition of two probiotic strains, namely Lacticaseibacillus casei (Lc) and Lacticaseibacillus rhamnosus (Lr). The prepared drinks were compared in terms of various parameters, including their physicochemical properties, proximate chemical composition, mineral estimation, microbial viable count, antioxidant activity, and sensory evaluation. Each strain was employed at five different concentrations, including 1% (T1), 1.5% (T2), 2% (T3), 2.5% (T4), and 3% (T5). The prepared Yakult samples were stored at 4 °C and analyzed on days 0, 7, 14, 21, and 28 to evaluate biochemical changes. The findings revealed that the concentration of the starter culture had a significant (p ≤ 0.05) impact on the pH value and moisture and protein contents, but had no marked impact on the fat or ash content of the developed product. With the Lc strain, Yakult's moisture content ranged from 84.25 ± 0.09 to 85.65 ± 0.13%, whereas with the Lr strain, it was from 84.24 ± 0.08 to 88.75 ± 0.13%. Protein levels reached their highest values with T5 (3% concentration). The acidity of all treatments increased significantly due to fermentation and, subsequently, pH showed a downward trend (p ≤ 0.05). The total soluble solids (TSS) content decreased during storage with Lc as compared to Lr, but the presence of carbohydrates had no appreciable impact. The drink with Lc exhibited a more uniform texture and smaller pore size than Yakult with Lr. Except for the iron values, which showed an increasing trend, the contents of other minerals decreased in increasing order of the added probiotic concentration used: 1% (T1), 1.5% (T2), 2% (T3), 2.5% (T4), and 3% (T5). The highest lactobacilli viable count of 8.69 ± 0.43 colony-forming units (CFU)/mL was observed with the T1 Lr-containing drink at the end of the storage period. Regarding the storage stability of the drink, the highest value for DPPH (88.75 ± 0.13%) was found with the T1 Lc drink on day 15, while the highest values for FRAP (4.86 ± 2.80 mmol Fe2+/L), TPC (5.97 ± 0.29 mg GAE/mL), and TFC (3.59 ± 0.17 mg GAE/mL) were found with the T5 Lr drink on day 28 of storage. However, the maximum value for ABTS (3.59 ± 0.17%) was noted with the T5 Lr drink on the first day of storage. The results of this study prove that Lc and Lr can be used in dairy-based fermented products and stored at refrigerated temperatures.

Effect and safety of probiotics for treating urticaria: A systematic review and meta-analysis

BACKGROUND

To assess the effect and safety of probiotics for treating urticaria.

METHODS

Randomized controlled trial (RCT) papers on the probiotics treatment published before May 2019 were retrieved from various databases like PubMed, EMbase, MEDLINE (Ovid), SCI-Hub, Springer, ClinicalKey, VIP, and CNKI. The treatment plan that we include are oral administration of single probiotic, multiple probiotics, and the combination of probiotics and antihistamines. Meta-analysis of the data was performed by RevMan 5.3 software.

RESULTS

A total of nine RCT papers were included: four papers for oral administration of single probiotic, three papers for oral administration of multiple probiotics, and two papers for oral administration of a probiotic combined with antihistamines. The results of meta-analysis showed that the therapeutic effect of the probiotic group was significantly higher than the control group (placebo or antihistamines) (RR = 1.09, 95% CI: 1.03-1.16, p = 0.006). And compared with the placebo group, the therapeutic effect of single probiotic group was significantly improved (RR = 1.11, 95% CI: 1.01-1.21, p = 0.03). Regarding therapeutic effect, there was no statistically significant difference between the multiple probiotics group and placebo group (RR = 1.00, 95% CI: 0.94 ~ 1.07, p = 0.91); the therapeutic effect of single probiotic combined antihistamine group was significantly higher than the antihistamine group (RR = 1.13, 95% CI: 1.07-1.19, p < 0.0001). Regarding the incidence of adverse reactions, there was no significant difference between the probiotic group and the control group (p = 0.46).

CONCLUSION

The treatment plan of oral administration of probiotics has significant therapeutic effects on urticaria, but the therapeutic effects of the administration of multiple probiotics and the safety of probiotic therapy are still not yet obvious. Some large-scale, multi-centered RCT studies are needed in the future for clarification.

Metabolic inputs in the probiotic bacterium Lacticaseibacillus rhamnosus contribute to cell-wall remodeling and increased fitness

Lacticaseibacillus rhamnosus GG (LGG) is a Gram-positive beneficial bacterium that resides in the human intestinal tract and belongs to the family of lactic acid bacteria (LAB). This bacterium is a widely used probiotic and was suggested to provide numerous benefits for human health. However, as in most LAB strains, the molecular mechanisms that mediate the competitiveness of probiotics under different diets remain unknown. Fermentation is a fundamental process in LAB, allowing the oxidation of simple carbohydrates (e.g., glucose, mannose) for energy production under oxygen limitation, as in the human gut. Our results indicate that fermentation reshapes the metabolome, volatilome, and proteome architecture of LGG. Furthermore, fermentation alters cell envelope remodeling and peptidoglycan biosynthesis, which leads to altered cell wall thickness, aggregation properties, and cell wall composition. In addition, fermentable sugars induced the secretion of known and novel metabolites and proteins targeting the enteric pathogens Enterococcus faecalis and Salmonella enterica Serovar Typhimurium. Overall, our results link simple carbohydrates with cell wall remodeling, aggregation to host tissues, and biofilm formation in probiotic strains and connect them with the production of broad-spectrum antimicrobial effectors.

Lactiplantibacillus plantarum LPJZ-658 Improves Non-Alcoholic Steatohepatitis by Modulating Bile Acid Metabolism and Gut Microbiota in Mice

Non-alcoholic steatohepatitis (NASH) is one of the most prevalent diseases worldwide; it is characterized by hepatic lipid accumulation, inflammation, and progressive fibrosis. Here, a Western diet combined with low-dose weekly carbon tetrachloride was fed to C57BL/6J mice for 12 weeks to build a NASH model to investigate the attenuating effects and possible mechanisms of Lactiplantibacillus plantarum LPJZ-658. Hepatic pathology, lipid profiles, and gene expression were assessed. The metabolomic profiling of the serum was performed. The composition structure of gut microbiota was profiled using 16s rRNA sequencing. The results show that LPJZ-658 treatment significantly attenuated liver injury, steatosis, fibrosis, and inflammation in NASH mice. Metabolic pathway analysis revealed that several pathways, such as purine metabolism, glycerophospholipid metabolism, linoleic acid metabolism, and primary bile acid biosynthesis, were associated with NASH. Notably, we found that treatment with LPJZ-658 regulated the levels of bile acids (BAs) in the serum. Moreover, LPJZ-658 restored NASH-induced gut microbiota dysbiosis. The correlation analysis deduced obvious interactions between BAs and gut microbiota. The current study indicates that LPJZ-658 supplementation protects against NASH progression, which is accompanied by alternating BA metabolic and modulating gut microbiota.

Beneficial Effects of Lactobacilli Species on Intestinal Homeostasis in Low-Grade Inflammation and Stress Rodent Models and Their Implication in the Modulation of the Adhesive Junctional Complex

Intestinal barrier integrity is essential in order to maintain the homeostasis of mucosal functions and efficient defensive reactions against chemical and microbial challenges. An impairment of the intestinal barrier has been observed in several chronic diseases. The gut microbiota and its impact on intestinal homeostasis is well described and numerous studies suggest the ability of some probiotic strains to protect the intestinal epithelial integrity and host homeostasis. In this work, we aimed to assess the beneficial effects of three Lactobacillus strains (Lacticaseibacillus rhamnosus LR04, Lacticaseibacillus casei LC03, and Lactiplantibacillus plantarum CNCM I-4459) and their mechanism of action in low-grade inflammation or neonatal maternal separation models in mice. We compared the impact of these strains to that of the well-known probiotic Lacticaseibacillus rhamnosus GG. Our results demonstrated that the three strains have the potential to restore the barrier functions by (i) increasing mucus production, (ii) restoring normal permeability, and (iii) modulating colonic hypersensitivity. Moreover, gene expression analysis of junctional proteins revealed the implication of Claudin 2 and Cingulin in the mechanisms that underlie the interactions between the strains and the host. Taken together, our data suggest that LR04, CNCM I-4459, and LC03 restore the functions of an impaired intestinal barrier.

Evaluation of anti-biofilm activity of Lactobacillus rhamnosus GG and Nisin on the expression of aap, ica-A and ica-D as biofilm-associated genes of Staphylococcus epidermidis

Background and Objectives

In the present study, the anti-biofilm activity of Lactobacillus rhamnosus GG and Nisin was investigated on biofilm-forming abilities of Staphylococcus epidermidis strains and the expression of the biofilm-associated genes.

Materials and Methods

In this study, the standard strain of L. rhamnosus GG (ATCC 53103) and Nisin were used to assess their anti-microbial and anti-biofilm effects on S. epidermidis (RP62A).

Results

The MIC and MBC analysis showed that Nisin at 256 μg/mL and 512 μg/mL, and L. rhamnosus GG at 1×107 CFU/mL and 1×108 CFU/mL have anti-microbial activity compared to the negative control respectively. L. rhamnosus GG bacteria and Nisin inhibited the biofilm formation of S. epidermidis based on optical density of at 570 nm (P <0.001). The relative mRNA expression of aap, icaA, and icaD genes was significantly reduced compared to the negative control after treating S. epidermidis with sub-MIC of Nisin (0.44, 0.25 and 0.6 fold, respectively) (P>0.05). In addition, the relative expression of aap and icaA genes, but not icaD (P>0.05), was significantly lower than the negative control (0.62 and 0.7 fold, respectively) (P>0.05), after exposure to the sub MIC of L. rhamnosus GG.

Conclusion

Nisin and L. rhamnosus GG exhibit potent activity against biofilm-forming abilities of S. epidermidis and these agents could be utilized as an anti-biofilm agents against S. epidermidis infections.

Bifidobacterium longum BORI inhibits pain behavior and chondrocyte death, and attenuates osteoarthritis progression

Osteoarthritis (OA), the most common form of arthritis, is characterized by pain and cartilage damage; it usually exhibits gradual development. However, the pathogenesis of OA remains unclear. This study was undertaken to improve the understanding and treatment of OA. OA was induced in 7-week-old Wistar rats by intra-articular injection of monosodium iodoacetate (MIA); subsequently, the rats underwent oral administration of Bifidobacterium longum BORI (B. BORI). The effects of B. BORI were examined in chondrocytes and an MIA-induced OA rat model. In the rats, B. BORI-mediated effects on pain severity, cartilage destruction, and inflammation were recorded. Additional effects on mRNA and cytokine secretion were analyzed by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Paw withdrawal threshold, paw withdrawal latency, and weight-bearing assessments revealed that pain severity in MIA-induced OA rats was decreased after B. BORI treatment. Histopathology analyses and three-dimensional surface renderings of rat femurs from micro-computed tomography images revealed cartilage protection and cartilage loss inhibition effects in B. BORI-treated OA rats. Immunohistochemical analyses of inflammatory cytokines and catabolic markers (e.g., matrix metalloproteinases) showed that the expression levels of both were reduced in tissue from B. BORI-treated OA rats. Furthermore, B. BORI treatment decreased the expression levels of the inflammatory cytokine monocyte chemoattractant protein-1 and inflammatory gene factors (e.g., inflammatory cell death markers) in chondrocytes. The findings indicate that oral administration of B. BORI has therapeutic potential in terms of reducing pain, progression, and inflammation in OA.

Probiotic-loaded calcium alginate/fucoidan hydrogels for promoting oral ulcer healing

Probiotics are beneficial bacteria located in the oral cavity which exhibit antimicrobial properties and contribute to the regulation of immune function and the modulation of tissue repair. Fucoidan (FD), a marine prebiotic, may further enhance the ability of probiotics to promote ulcer healing. However, neither FD nor probiotics are attached to the oral cavity and neither are well-suited for oral ulcer healing owing to the wet and highly dynamic environment. In this study, probiotic-loaded calcium alginate/fucoidan composite hydrogels were developed for use as bioactive oral ulcer patches. The well-shaped hydrogels exhibited remarkable wet-tissue adhesion, suitable swelling and mechanical properties, sustained probiotic release, and excellent storage durability. Moreover, in vitro biological assays demonstrated that the composite hydrogel exhibited excellent cyto/hemocompatibility and antimicrobial effects. Importantly, compared to commercial oral ulcer patches, bioactive hydrogels show superior therapeutic capability for promoting ulcer healing in vivo by enhancing cell migration, inducing epithelial formation and orderly collagen fiber deposition, as well as facilitating neovascularization. These results demonstrate that this novel composite hydrogel patch demonstrates great potential for the treatment of oral ulcerations.

Lacticaseibacillus rhamnosus Strain GG (LGG) Regulate Gut Microbial Metabolites, an In Vitro Study Using Three Mature Human Gut Microbial Cultures in a Simulator of Human Intestinal Microbial Ecosystem (SHIME)

In the present research, we investigated changes in the gut metabolome that occurred in response to the administration of the Laticaseibacillus rhamnosus strain GG (LGG). The probiotics were added to the ascending colon region of mature microbial communities established in a human intestinal microbial ecosystem simulator. Shotgun metagenomic sequencing and metabolome analysis suggested that the changes in microbial community composition corresponded with changes to metabolic output, and we can infer linkages between some metabolites and microorganisms. The in vitro method permits a spatially-resolved view of metabolic transformations under human physiological conditions. By this method, we found that tryptophan and tyrosine were mainly produced in the ascending colon region, while their derivatives were detected in the transverse and descending regions, revealing sequential amino acid metabolic pathways along with the colonic tract. The addition of LGG appeared to promote the production of indole propionic acid, which is positively associated with human health. Furthermore, the microbial community responsible for the production of indole propionic acid may be broader than is currently known.

Safety and Potential Role of Lactobacillus rhamnosus GG Administration as Monotherapy in Ulcerative Colitis Patients with Mild-Moderate Clinical Activity

Probiotics are microorganisms that confer benefits to the host, and, for this reason, they have been proposed in several pathologic states. Specifically, probiotic bacteria have been investigated as a therapeutic option in ulcerative colitis (UC) patients, but clinical results are dishomogeneous. In particular, many probiotic species with different therapeutic schemes have been proposed, but no study has investigated probiotics in monotherapy in adequate trials for the induction of remission. Lactobacillus rhamnosus GG (LGG) is the more intensively studied probiotic and it has ideal characteristics for utilization in UC patients. The aim of the present study is to investigate the clinical efficacy and safety of LGG administration in an open trial, delivered in monotherapy at two different doses, in UC patients with mild-moderate disease. The UC patients with mild-moderate disease activity (Partial Mayo score ≥ 2) despite treatment with oral mesalamine were included. The patients stopped oral mesalamine and were followed up for one month, then were randomized to receive LGG supplement at dose of 1.2 or 2.4 × 10¹⁰ CFU/day for one month. At the end of the study, the clinical activity was evaluated and compared to that at the study entrance (efficacy). Adverse events were recorded (safety). The primary end-point was clinical improvement (reduction in the Partial Mayo score) and no serious adverse events, while the secondary end-points were the evaluation of different efficacies and safeties between the two doses of LGG. The patients with disease flares dropped out of the study and went back to standard therapy. The efficacy data were analyzed in an intention-to-treat (ITT) and per-protocol (PP) analysis. Out of the 76 patients included in the study, 75 started the probiotic therapy (n = 38 and 37 per group). In the ITT analysis, 32/76 (42%) responded to treatment, 21/76 (28%) remained stable, and 23/76 (30%) had a worsening of their clinical condition; 55 (72%) completed the treatment and were analyzed in a PP analysis: 32/55 (58%) had a clinical response, 21 (38%) remained stable, and 2 (4%) had a light worsening of their clinical condition (p < 0.0001). Overall, 37% of the patients had a disease remission. No severe adverse event was recorded, and only one patient stopped therapy due to obstinate constipation. No difference in the clinical efficacy and safety has been recorded between groups treated with different doses of LGG. The present prospective clinical trial demonstrates, for the first time, that LGG in monotherapy is safe and effective for the induction of remission in UC patients with mild-moderate disease activity (ClinicalTrials.gov identifier: NCT04102852).

Identification and Characterization of Probiotic Lactiplantibacillus plantarum BI-59.1 Isolated from tejuino and Its Capacity to Produce Biofilms

Tejuino is a popular and traditional beverage consumed in north and western of Mexico, due to its biological properties, it is considered a natural source of probiotics. Nevertheless, few studies have been performed on Tejuino microbiota. In this work, the probiotic potential of the tejuino isolated Lactiplantibacillus plantarum BI-59.1 strain was investigated. Its effectiveness was compared with a commercial Lactobacillus spp and identified by 16S rDNA sequence homology. Lactiplantibacillus plantarum BI-59.1 strain showed probiotic properties, i.e., production of antimicrobial compounds (lactic acid and presence of plantaricin A gene), inhibition of entero-pathogens by planktonic cells and metabolites (Salmonella enterica serovar Typhimurium inhibition to HT29-MTX adhesion), biofilm formation, bacterial adhesion (HT29-MTX, 3.96 CFU/cell), and tolerance to stimulated gastrointestinal conditions (tolerance to pH 3 and bile salts). The strain was gamma hemolytic, susceptible to most antibiotics and negative for gelatinase production; thus, the Lactiplantibacillus. plantarum BI-59.1 strain is suitable for its use as a probiotic for nutraceutical or pharmaceutical formulations.

3D printing of microencapsulated Lactobacillus rhamnosus for oral delivery

3D Printing is an innovative technology within the pharma and food industries that allows the design and manufacturing of novel delivery systems. Orally safe delivery of probiotics to the gastrointestinal tract faces several challenges regarding bacterial viability, in addition to comply with commercial and regulatory standpoints. Lactobacillus rhamnosus CNCM I-4036 (Lr) was microencapsulated in generally recognised as safe (GRAS) proteins, and then assessed for robocasting 3D printing. Microparticles (MP-Lr) were developed and characterised, prior to being 3D printed with pharmaceutical excipients. MP-Lr showed a size of 12.3 ± 4.1 µm and a non-uniform wrinkled surface determined by Scanning Electron Microscopy (SEM). Bacterial quantification by plate counting accounted for 8.68 ±0.6 CFU/g of live bacteria encapsulated within. Formulations were able to keep the bacterial dose constant upon contact with gastric and intestinal pH. Printlets consisted in oval-shape formulations (15 mm × 8 mm × 3.2 mm) of ca. 370 mg of total weight, with a uniform surface. After the 3D printing process, bacterial viability remained even as MP-Lr protected bacteria alongside the process (log reduction of 0.52, p>0.05) in comparison with non-encapsulated probiotic (log reduction of 3.05). Moreover, microparticle size was not altered during the 3D printing process. We confirmed the success of this technology for developing an orally safe formulation, GRAS category, of microencapsulated Lr for gastrointestinal vehiculation.

Ameliorating effect of probiotic on nonalcoholic fatty liver disease and lipolytic gene expression in rabbits

Nonalcoholic fatty liver disease (NAFLD) is a condition that affects about 24% of people worldwide. Increased liver fat, inflammation, and, in the most severe cases, cell death are all characteristics of NAFLD. However, NAFLD pathogenesis and therapy are still not clear enough. Thus, this study aimed to determine the effect of a high-cholesterol diet (HCD) inducing NAFLD on lipolytic gene expression, liver function, lipid profile, and antioxidant enzymes in rabbits and the modulatory effects of probiotic Lactobacillus acidophilus (L. acidophilus) on it. A total of 45 male New Zealand white rabbits, eight weeks old, were randomly divided into three groups of three replicates (5 rabbits/replicate). Rabbits in group I were given a basal diet; rabbits in group II were given a high-cholesterol diet that caused NAFLD; and rabbits in group III were given a high-cholesterol diet as well as probiotics in water for 8 weeks. The results showed that a high-cholesterol diet caused hepatic vacuolation and upregulated the genes for lipoprotein lipase (LPL), hepatic lipase (HL), and cholesteryl ester transfer protein (CETP). Downregulated low-density lipoprotein receptor (LDLr) gene, increased liver enzymes [alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH)], cholesterol, triglycerides (TG), low-density lipoprotein (LDL), glucose, and total bilirubin. On the other hand, it decreased high-density lipoprotein (HDL), total protein, albumin, and liver antioxidants [glutathione peroxidase (GPx), catalase (CAT), reduced glutathione (GSH), and superoxide dismutase (SOD)]. Supplementing with probiotics helped to return all parameters to normal levels. In conclusion, probiotic supplementation, especially L. acidophilus, protected against NAFLD, and restored lipolytic gene expression, liver functions, and antioxidants to normal levels.

Over-production of exopolysaccharide by Lacticaseibacillus rhamnosus CNCM I-3690 strain cutbacks its beneficial effect on the host

Most lactobacilli produce extracellular polysaccharides that are considered to contribute to the probiotic effect of many strains. Lacticaseibacillus rhamnosus CNCM I-3690 is an anti-inflammatory strain able to counterbalance gut barrier dysfunction. In this study ten spontaneous variants of CNCM I-3690 with different EPS-production were generated and characterized by their ropy phenotype, the quantification of the secreted EPS and genetic analysis. Amongst them, two were further analysed in vitro and in vivo: an EPS over-producer (7292) and a low-producer derivative of 7292 (7358, with similar EPS levels than the wild type (WT) strain). Our results showed that 7292 does not have anti-inflammatory profile in vitro, and lost the capacity to adhere to the colonic epithelial cells as well as the protective effect on the permeability. Finally, 7292 lost the protective effects of the WT strain in a murine model of gut dysfunction. Notably, strain 7292 was unable to stimulate goblet cell mucus production and colonic IL-10 production, all key features for the beneficial effect of the WT strain. Furthermore, transcriptome analysis of colonic samples from 7292-treated mice showed a down-regulation of anti-inflammatory genes. Altogether, our results point out that the increase of EPS production in CNCM I-3690 impairs its protective effects and highlight the importance of the correct EPS synthesis for the beneficial effects of this strain.

Ampicillin exacerbates acetaminophen-induced acute liver injury by inducing intestinal microbiota imbalance and butyrate reduction

BACKGROUND AND AIMS

Antibiotics (ATBx) and acetaminophen (APAP) are widely used worldwide. APAP is the most common cause of acute liver injury (ALI) and might be used in combination with ATBx in clinics. However, the impact of ATBx on APAP-induced ALI has rarely been studied.

METHODS

First, we compared the effects of seven ATBx on APAP-induced ALI. Then, we analysed faecal, serum and liver samples to investigate the impact of the gut microbiota on this process. Finally, we assessed the role of short-chain fatty acids in this process.

RESULTS

In this work, we found that the ALI was significantly aggravated in the mice treated with ampicillin (Amp) instead of other ATBx. Amp exposure reduced the diversity and altered the composition of gut microbiota. The altered gut microbiota aggravated APAP-induced ALF, which was proven by faecal microbiota transplantation from ATBx-treated mice. Metagenomic analysis showed a significantly decreased Lactobacillus abundance in Amp-treated mice. Gavage with Lactobacillus, especially Lactobacillus rhamnosus, significantly reversed the severer ALF induced by APAP and Amp. Moreover, Lactobacillus supplementation increased butyrate-producing clostridia and lowered butyrate levels in Amp-treated mice. In accordance, butyrate supplementation could also alleviate Amp-aggravated ALI. In addition, inhibition of nuclear factor erythroid 2-related factor 2 counteracted the protective effect of butyrate on aggravated ALI induced by Amp and APAP.

CONCLUSION

Together, this study revealed a potential health impact of Amp that may exacerbate liver damage when co-exposed to excess APAP.