Probiotics: determinants of survival and growth in the gut

Microencapsulation of Probiotics for Enhanced Stability and Health Benefits in Dairy Functional Foods: A Focus on Pasta Filata Cheese

Probiotics provide significant health benefits, but their viability is often compromised during production, storage, and passage through the gastrointestinal tract. These challenges hinder their effective incorporation into functional applications, particularly in dairy functional foods, in which factors such as acidity, oxygen exposure, and storage conditions negatively impact cell survival. The focus was on functional dairy foods, particularly on pasta filata cheeses. Indeed, the use of probiotics in pasta filata cheeses presents significant challenges due to the specific manufacturing processes, which encompass the application of high temperatures and other harsh conditions. These factors can adversely affect the viability and availability of probiotic microorganisms. However, microencapsulation has emerged as a promising solution, offering a protective barrier that enhances probiotic stability, improves survival rates, and facilitates targeted release in the gastrointestinal environment. This review examines the pivotal role of microencapsulation in stabilising probiotics for functional applications, emphasising its relevance in high-value food systems. Functional applications, including foods designed to offer essential nutritional benefits and promote host health, play a crucial role in disease prevention and immune system support, reducing the risk of infections and other physiological impairments. Key microencapsulation technologies are analysed, focusing on their benefits, limitations, and challenges related to scalability and industrial implementation. Additionally, this review discusses strategies to optimise formulations, ensure the sensory quality of final products, and explore future opportunities for expanding innovative applications that align with growing consumer demand for health-promoting solutions.

Gut microbiome and Alzheimer's disease: What we know and what remains to be explored

With advancement in human microbiome research, an increasing number of scientific evidences have endorsed the key role of gut microbiota in the pathogenesis of Alzheimer disease. Microbiome dysbiosis, characterized by altered diversity and composition, as well as rise of pathobionts influence not only various gut disorder but also central nervous system disorders such as AD. On the basis of accumulated evidences of past few years now it is quite clear that the gut microbiota can control the functions of the central nervous system (CNS) through the gut-brain axis, which provides a new prospective into the interactions between the gut and brain. The main focus of this review is on the molecular mechanism of the crosstalk between the gut microbiota and the brain through the gut-brain axis, and on the onset and development of neurological disorders triggered by the dysbiosis of gut microbiota. Due to microbiota dysbiosis the permeability of the gut and blood brain barrier is increased which may mediate or affect AD. Along with this, bacterial population of the gut microbiota can secrete amyloid proteins and lipopolysaccharides in a large quantity which may create a disturbance in the signaling pathways and the formation of proinflammatory cytokines associated with the pathogenesis of AD. These topics are followed by a critical analysis of potential intervention strategies targeting gut microbiota dysbiosis, including the use of probiotics, prebiotics, metabolites, diets and fecal microbiota transplantation. The main purpose of this review includes the summarization and discussion on the recent finding that may explain the role of the gut microbiota in the development of AD. Understanding of these fundamental mechanisms may provide a new insight into the novel therapeutic strategies for AD.

Comparative genome analysis of microbial strains marketed for probiotic interventions: an extension of the Integrated Probiotic Database

Background: Members of the Bifidobacterium genus and lactobacilli are the most commonly used probiotics to promote human health. In this context, genome-based in silico analyses have been demonstrated as a fast and reliable tool for identifying and characterizing health-promoting activities imputed to probiotics. Methods: This study is an extension of the Integrated Probiotic Database (IPDB) previously created on probiotics of the genus Bifidobacterium, facilitating a comprehensive understanding of the genetic characteristics that contribute to the diverse spectrum of beneficial effects of probiotics. The strains integrated into this new version of the IPDB, such as various lactobacilli and strains belonging to the species Streptococcus thermophilus (S. thermophilus) and Heyndrickxia coagulans (H. coagulans) (formerly Bacillus coagulans), were selected based on the labels of probiotic formulations currently on the market and using the bacterial strains whose genome had already been sequenced. On these bacterial strains, comparative genome analyses were performed, mainly focusing on genetic factors that confer structural, functional, and chemical characteristics predicted to be involved in microbe-host and microbe-microbe interactions. Results: Our investigations revealed marked inter- and intra-species variations in the genetic makeup associated with the biosynthesis of external structures and bioactive metabolites putatively associated with microbe- and host-microbe interactions. Conclusion: Although genetic differences need to be confirmed as functional or phenotypic differences before any probiotic intervention, we believe that considering these divergences will aid in improving effective and personalized probiotic-based interventions.

Relationship of Salmonella Typhimurium 14028 strain and its dam and seqA mutants with gut microbiota dysbiosis in rats

Introduction. Disruptions in gut microbiota, known as dysbiosis, have been increasingly linked to pathogenic infections, with Salmonella Typhimurium being a notable contributor to these disturbances.Hypothesis. We hypothesize that the S. Typhimurium 14028 WT strain induces significant dysbiosis in the rat gut microbiota and that the dam and seqA genes play crucial roles in this process.Aim. In this study, it was aimed at investigating the dysbiotic activity of the S. Typhimurium 14028 WT strain on the rat gut microbiota and the roles of dam and seqA genes on this activity.Method. Changes in the rat gut microbiota were determined by examining the anal swap samples taken from the experimental groups of these animals using 16S rRNA high-throughput sequencing technology.Results. In the experimental groups, the dominant phyla were determined to be Firmicutes and Bacteroidetes (P<0.05). However, while the rate of Bacteroidetes was significantly reduced in those treated with the WT and seqA mutants, no significant difference was observed in the dam mutant compared to the control group (P<0.05). In all experimental animals, the dominant species was determined to be Prevotella copri, regardless of the experiment time and application. The analysis results of the samples taken on the third day from the rat groups infected with the S. Typhimurium 14028 WT strain (W2) presented the most striking data of this study.Conclusion. Through distance analysis, we demonstrated that a successful Salmonella infection completely changes the composition of the microbiota, dramatically reduces species diversity and richness in the microbiota and encourages the growth of opportunistic pathogens.

Exploring the Underlying Mechanisms of Preventive Treatment Related to Dietary Factors for Gastric Diseases

Gastric diseases have emerged as one of the main chronic diseases in humans, leading to considerable health, social, and economic burdens. As a result, using food or "food and medicinal homologous substances" has become an effective strategy to prevent gastric diseases. Diet may play a crucial role in the prevention and mitigation of gastric diseases, particularly long-term and regular intake of specific dietary components that have a protective effect on the stomach. These key components, extracted from food, include polysaccharides, alkaloids, terpenoids, polyphenols, peptides, probiotics, etc. The related mechanisms involve regulating gastric acid secretion, protecting gastric mucosa, increasing the release of gastric defense factors, decreasing the level of inflammatory factors, inhibiting Helicobacter pylori infection, producing antioxidant effects or reducing oxidative damage, preventing gastric oxidative stress by inhibiting lipid peroxides, activating Nrf2 signaling pathway, and inhibiting NF-κB, TLR4, and NOS/NO signaling pathways.

Hepatic Symbiotic Bacterium L. reuteri FLRE5K1 Inhibits the Development and Progression of Hepatocellular Carcinoma via Activating the IFN-γ/CXCL10/CXCR3 Pathway

Symbiotic bacteria participate in the formation of the structure and function of the tissues and organs in which they live, and play an essential role in maintaining the balance between health and disease. Lactobacillus reuteri FLRE5K1 was isolated from the liver of healthy mice and proved to be a probiotic with anti-melanoma activity in previous studies. The relationship between hepatic symbiotic probiotics and hepatocellular carcinoma (HCC) has not been reported yet. In the present study, L. reuteri FLRE5K1 was initially confirmed to successfully enter the liver after being administered by gavage, and the efficacy of probiotic feeding on HCC and its potential mechanism of inhibiting tumor progression were investigated by an orthotopic liver cancer model established. The results showed that L. reuteri FLRE5K1 significantly reduced the tumor formation rate and inhibited tumor growth in mice. From the perspective of mechanism, activation of the IFN-γ/CXCL10/CXCR3 pathway, as well as its positive feedback on the secretion of IFN-γ, induced the polarization of Th0 cell to Th1 cells and inhibited the differentiation of Tregs, which played a key role in the inhibitory effect of L. reuteri FLRE5K1 on the development and progression of HCC.

Impact of Pediococcus pentosaceus YF01 on the exercise capacity of mice through the regulation of oxidative stress and alteration of gut microbiota

Using treadmill training, this study replicated human exercise conditions and triggered exercise-induced fatigue in mice to examine the potential of Pediococcus pentosaceus YF01 in delaying this fatigue by regulating oxidative stress and its impact on the exercise capacity and gut microbiota of mice. The exercise capacity of mice was tested by conducting exhaustion tests, determining histopathological changes in mouse tissues, detecting the levels of serum biochemical markers, and evaluating the mRNA expression levels of relevant genes. YF01 prolonged the exhaustion time of mice, increased the serum levels of oxidative stress-related markers T-AOC, CAT, and GSH, as well as GLU and LA levels in the mice. YF01 decreased the levels of hepatic-related markers AST and ALT, as well as exercise-related markers LDH, BUN, UA, and CRE in the mice. YF01 upregulated the mRNA expression of MyHc I, SIRT1, and PGC in muscle tissues, as well as SOD1, SOD2, and CAT in both liver and muscle tissues. YF01 also downregulated the mRNA expression of MyHc IIa, MyHc IIb, and MyHc IIx in muscle tissues. Furthermore, YF01 increased the abundance of beneficial bacteria such as Lactobacillus and Lachnospiraceae in the gut microbiota of mice. In conclusion, P. pentosaceus YF01 may affect the exercise capacity of mice by modulating oxidative stress levels, thereby offering novel ideas for developing of sports science and human health.

Fabrication of dry S/O/W microcapsule and its probiotic protection against different stresses

BACKGROUND

Encapsulation is commonly used to protect probiotics against harsh stresses. Thus, the fabrication of microcapsules with special structure is critical. In this work, microcapsules with the structure of S/O/W (solid-in-oil-in-water) emulsion were prepared for probiotics, with butterfat containing probiotics as the inner core and with whey protein isolate fibrils (WPIF) and antioxidants (epigallocatechin gallate, EGCG; glutathione, GSH) as the outer shell.

RESULTS

Based on the high viscosity and good emulsifying ability of WPIF, dry well-dispersed microcapsules were successfully prepared via the stabilization of the butterfat emulsion during freeze-drying with 30-50 g L-1 WPIF. WPIF, WPIF + EGCG, and WPIF + GSH microcapsules with 50 g L-1 WPIF protected probiotics very well against different stresses and exhibited similar inactivation results, indicating that EGCG and GSH exerted neither harm or protection on probiotics. This significantly reduced the harmful effects of antioxidants on probiotics. Almost all the probiotics survived after pasteurization, which was critical for the use of probiotics in other foods. The inactivation values of probiotics in microcapsules were around 1 log in simulated gastric juice (SGJ), about 0.5 log in simulated intestinal juice (SIJ), and around 1 log after 40 days of ambient storage.

CONCLUSION

Dry S/O/W microcapsule, with butterfat containing probiotics as the inner core and WPIF as the outer shell, significantly increased the resistance of probiotics to harsh environments. This work proposed a preparation method of dry S/O/W microcapsule with core/shell structure, which could be used in the encapsulation of probiotics and other bioactive ingredients.

Evaluation of probiotic properties of a Brevibacillus laterosporus strain

Brevibacillus laterosporus is a strain of probiotic bacteria that has been widely used in pest control, cash crop, and other production areas. However, few studies have been conducted on its use as a feed additive in animals. Therefore, the probiotic potential of B. laterosporus PBC01 was evaluated by characterizing hydrophobicity, auto-aggregation activity, bile salt and simulated gastrointestinal fluid tolerance, bienzymatic, and antibacterial activity. Antibiotic susceptibility, hemolysis assays, and supplemental feeding of mice were also performed to evaluate safety features. Our results showed that B. laterosporus PBC01 had moderate hydrophobicity, high auto-agglutination ability. Meanwhile, B. laterosporus PBC01 had good tolerance to bile salt and simulated gastrointestinal fluid. It had the ability to secrete protease, cellulase, and to inhibit various pathogens. In addition, B. laterosporus PBC01 was sensitive to many antibiotics, and did not produce hemolysin. In the safety assessment of mice, it did not cause any deaths, nor did it affect the cell components of blood, antioxidant capacity, and reproductive health. The study indicated the great probiotic characteristics and safety of B. laterosporus PBC01. This may provide a theoretical basis for the clinical application and development of probiotic-based feed additives.

Galacto-oligosaccharide preconditioning improves metabolic activity and engraftment of Limosilactobacillus reuteri and stimulates osteoblastogenesis ex vivo

A probiotic-related benefit for the host is inherently linked to metabolic activity and integration in the gut ecosystem. To facilitate these, probiotics are often combined with specific prebiotics in a synbiotic formulation. Here, we propose an approach for improving probiotic metabolic activity and engraftment. By cultivating the probiotic strain in the presence of a specific prebiotic (preconditioning), the bacterial enzymatic machinery is geared towards prebiotic consumption. Today, it is not known if preconditioning constitutes an advantage for the synbiotic concept. Therefore, we assessed the effects galacto-oligosaccharide (GOS) addition and preconditioning on GOS of Limosilactobacillus reuteri DSM 17938 on ex vivo colonic metabolic profiles, microbial community dynamics, and osteoblastogenesis. We show that adding GOS and preconditioning L. reuteri DSM 17938 act on different scales, yet both increase ex vivo short-chain fatty acid (SCFA) production and engraftment within the microbial community. Furthermore, preconditioned supernatants or SCFA cocktails mirroring these profiles decrease the migration speed of MC3T3-E1 osteoblasts, increase several osteogenic differentiation markers, and stimulate bone mineralization. Thus, our results demonstrate that preconditioning of L. reuteri with GOS may represent an incremental advantage for synbiotics by optimizing metabolite production, microbial engraftment, microbiome profile, and increased osteoblastogenesis.

Dietary Bacillus spp. supplementation to both sow and progenies improved post-weaning growth rate, gut function, and reduce the pro-inflammatory cytokine production in weaners challenged with Escherichia coli K88

BACKGROUND

The use of probiotics (PRO) in late gestation sow and their impact on progenies' performance during the post-weaning stage has received more attention from the researchers recently. This study aimed to analyze the effect of probiotic mixture (Bacillus subtilis and Bacillus licheniformis) on both sow and offspring's performance.

METHODS

First experiment (Exp.1) was conducted from the 100th day of gestation through to post-weaning. A total of twenty sows and their litters were assigned to one of two dietary treatments, Control (CON) based diet and PRO- CON+ 0.05% probiotic mixture. Dietary treatments were arranged in a split-plot pattern with sow and weaner treatment (CON and PRO diet) as the main and sub plot. Exp.2. E. coli challenge study was carried out two weeks after weaning with 40 piglets. Dietary treatments remained same while all pigs were orally administered with a 1.5 ml suspension of 1010 CFU of K88 strain of E. coli per ml.

RESULT

PRO group sow showed significantly decreased backfat thickness difference and body weight difference after farrowing and at the end of weaning d21. The nutrient digestibility of PRO group sows was significantly higher at the end of weaning. Moreover, piglets born from PRO group sow showed higher weaning weight and tend to increase average daily gain at the end of d21. The addition of mixed probiotic in sow and weaner diet had suppressed the production of TNF-α and interleukin-6 in E. coli challenged pigs. The phyla Firmicutes and Bacteroidetes in E. coli -challenged pigs were highly abundant while, the relative abundance of clostridium_sensu_stricto_1 at genus level was significantly reduced by the inclusion of probiotic in both the sow and weaner diet. Also, taxonomic distribution analysis showed significantly lower prevalence of Clostridium and Brachyspira and higher prevalence of Lactobacilli in E. coli-challenged pigs that were born from PRO group sow and fed CON and PRO weaner diet.

CONCLUSION

This study reveals that the inclusion of 0.05% mixed probiotics (Bacillus spp.) to both sow and their progenies diet would be more beneficial to enhance the post-weaning growth rate, gut health, and immune status of E. coli challenged pigs.

Prolonged delays in human microbiota transmission after a controlled antibiotic perturbation

Humans constantly encounter new microbes, but few become long-term residents of the adult gut microbiome. Classical theories predict that colonization is determined by the availability of open niches, but it remains unclear whether other ecological barriers limit commensal colonization in natural settings. To disentangle these effects, we used a controlled perturbation with the antibiotic ciprofloxacin to investigate the dynamics of gut microbiome transmission in 22 households of healthy, cohabiting adults. Colonization was rare in three-quarters of antibiotic-taking subjects, whose resident strains rapidly recovered in the week after antibiotics ended. In contrast, the remaining antibiotic-taking subjects exhibited lasting responses, with extensive species losses and transient expansions of potential opportunistic pathogens. These subjects experienced elevated rates of commensal colonization, but only after long delays: many new colonizers underwent sudden, correlated expansions months after the antibiotic perturbation. Furthermore, strains that had previously transmitted between cohabiting partners rarely recolonized after antibiotic disruptions, showing that colonization displays substantial historical contingency. This work demonstrates that there remain substantial ecological barriers to colonization even after major microbiome disruptions, suggesting that dispersal interactions and priority effects limit the pace of community change.

Probiotic Characteristics of Streptococcus thermophilus and Lactobacillus bulgaricus as Influenced by New Food Sources

The current research aimed to evaluate the potential effects of Solanum mammosum, Dioon mejiae, and Amanita caesarea on Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus survival and performance after exposure to different harsh conditions such as bile, acid, gastric juice, and lysozyme to mimic the digestive system from mouth to the intestine. Probiotic protease activity was observed to evaluate the proteolytic system. Probiotics were cultured in a broth mixed with plant material, and after incubation, the results were compared to the control sample. Therefore, plant material's total phenolic compound, total carotenoid compound, antioxidant activity, sugar profile, and acid profile were obtained to discuss their impact on the survival of probiotics. The results indicate that Amanita caesarea negatively affected probiotic survival in the bile tolerance test and positively affected Lactobacillus bulgaricus in the protease activity test. Otherwise, the other plant material did not change the results significantly (p > 0.05) compared to the control in different tests. Consequently, Solanum mammosum and Dioon mejiae had no significant effects (p > 0.05) in increasing probiotic survival.

Probiotic Properties and Safety Evaluation of Lactobacillus plantarum HY7718 with Superior Storage Stability Isolated from Fermented Squid

The aim of this study was to identify new potential probiotics with improved storage stability and to evaluate their efficacy and safety. Sixty lactic acid bacteria strains were isolated from Korean traditional fermented foods, and their survival was tested under extreme conditions. Lactobacillus plantarum HY7718 (HY7718) showed the greatest stability during storage. HY7718 also showed a stable growth curve under industrial conditions. Whole genome sequencing revealed that the HY7718 genome comprises 3.26 Mbp, with 44.5% G + C content, and 3056 annotated Protein-coding DNA sequences (CDSs). HY7718 adhered to intestinal epithelial cells and was tolerant to gastric fluids. Additionally, HY7718 exhibited no hemolytic activity and was not resistant to antibiotics, confirming that it has probiotic properties and is safe for consumption. Additionally, we evaluated its effects on intestinal health using TNF-induced Caco-2 cells. HY7718 restored the expression of tight junction proteins such as zonular occludens (ZO-1, ZO-2), occludin (OCLN), and claudins (CLDN1, CLDN4), and regulated the expression of myosin light-chain kinase (MLCK), Elk-1, and nuclear factor kappa B subunit 1 (NFKB1). Moreover, HY7718 reduced the secretion of proinflammatory cytokines such as interleukin-6 (IL-6) and IL-8, as well as reducing the levels of peroxide-induced reactive oxygen species. In conclusion, HY7718 has probiotic properties, is safe, is stable under extreme storage conditions, and exerts positive effects on intestinal cells. These results suggest that L. plantarum HY7718 is a potential probiotic for use as a functional supplement in the food industry.

Gut Microbiome and Dietar Considerations

The gut microbiome represents a complex microbial ecosystem that exerts direct and indirect effects on other organ systems and contributes to both health and disease. It is sensitive to various stimuli such as childhood immunity, medications, diet, stressors, and sleep. Modulating the gut microbiome can prevent and even treat certain disease states. Although no definitive guidelines exist to support a healthy microbiome, there are several evidence-based interventions proved to improve gut health and reduce the risk for numerous chronic diseases.

The Rationale for Sulforaphane Favourably Influencing Gut Homeostasis and Gut-Organ Dysfunction: A Clinician's Hypothesis

Given the increasing scientific, clinical and consumer interest in highly prevalent functional gastrointestinal disorders, appropriate therapeutic strategies are needed to address the many aspects of digestive dysfunction. Accumulating evidence for the crucifer-derived bioactive molecule sulforaphane in upstream cellular defence mechanisms highlights its potential as a therapeutic candidate in targeting functional gastrointestinal conditions, as well as systemic disorders. This article catalogues the evolution of and rationale for a hypothesis that multifunctional sulforaphane can be utilised as the initial step in restoring the ecology of the gut ecosystem; it can do this primarily by targeting the functions of intestinal epithelial cells. A growing body of work has identified the colonocyte as the driver of dysbiosis, such that targeting gut epithelial function could provide an alternative to targeting the microbes themselves for the remediation of microbial dysbiosis. The hypothesis discussed herein has evolved over several years and is supported by case studies showing the application of sulforaphane in gastrointestinal disorders, related food intolerance, and several systemic conditions. To the best of our knowledge, this is the first time the effects of sulforaphane have been reported in a clinical environment, with several of its key properties within the gut ecosystem appearing to be related to its nutrigenomic effects on gene expression.

Effects of Probiotic Supplementation on Exercise and the Underlying Mechanisms

Long-term, high-intensity exercise can trigger stress response pathways in multiple organs, including the heart and lungs, gastrointestinal tract, skeletal muscle, and neuroendocrine system, thus affecting their material and energy metabolism, immunity, oxidative stress, and endocrine function, and reducing exercise function. As a natural, safe, and convenient nutritional supplement, probiotics have been a hot research topic in the field of biomedical health in recent years. Numerous studies have shown that probiotic supplementation improves the health of the body through the gut-brain axis and the gut-muscle axis, and probiotic supplementation may also improve the stress response and motor function of the body. This paper reviews the progress of research on the role of probiotic supplementation in material and energy metabolism, intestinal barrier function, immunity, oxidative stress, neuroendocrine function, and the health status of the body, as well as the underlying mechanisms.

Short-chain fatty acids ameliorate spinal cord injury recovery by regulating the balance of regulatory T cells and effector IL-17+ γδ T cells

Spinal cord injury (SCI) causes motor, sensory, and autonomic dysfunctions. The gut microbiome has an important role in SCI, while short-chain fatty acids (SCFAs) are one of the main bioactive mediators of microbiota. In the present study, we explored the effects of oral administration of exogenous SCFAs on the recovery of locomotor function and tissue repair in SCI. Allen's method was utilized to establish an SCI model in Sprague-Dawley (SD) rats. The animals received water containing a mixture of 150 mmol/L SCFAs after SCI. After 21 d of treatment, the Basso, Beattie, and Bresnahan (BBB) score increased, the regularity index improved, and the base of support (BOS) value declined. Spinal cord tissue inflammatory infiltration was alleviated, the spinal cord necrosis cavity was reduced, and the numbers of motor neurons and Nissl bodies were elevated. Enzyme-linked immunosorbent assay (ELISA), real-time quantitative polymerase chain reaction (qPCR), and immunohistochemistry assay revealed that the expression of interleukin (IL)‍-10 increased and that of IL-17 decreased in the spinal cord. SCFAs promoted gut homeostasis, induced intestinal T cells to shift toward an anti-inflammatory phenotype, and promoted regulatory T (Treg) cells to secrete IL-10, affecting Treg cells and IL-17+ γδ T cells in the spinal cord. Furthermore, we observed that Treg cells migrated from the gut to the spinal cord region after SCI. The above findings confirm that SCFAs can regulate Treg cells in the gut and affect the balance of Treg and IL-17+ γδ T cells in the spinal cord, which inhibits the inflammatory response and promotes the motor function in SCI rats. Our findings suggest that there is a relationship among gut, spinal cord, and immune cells, and the "gut-spinal cord-immune" axis may be one of the mechanisms regulating neural repair after SCI.

Inhibition of Listeria monocytogenes Growth, Adherence and Invasion in Caco-2 Cells by Potential Probiotic Lactic Acid Bacteria Isolated from Fecal Samples of Healthy Neonates

Lactic acid bacteria (LAB) isolated from healthy humans may prove an effective tool against pathogen growth, adherence and invasion in intestinal epithelial cells. This study aimed to evaluate the antilisterial properties of LAB isolated from fecal samples of healthy neonates. Forty-five LAB strains were tested for their antimicrobial activity against ten Listeria monocytogenes strains with spot-on-lawn and agar-well diffusion assays, and ten lactobacilli strains were further assessed for their inhibitory effect against adherence and invasion of Caco-2 cells by L. monocytogenes EGDe. Inhibition was estimated in competition, exclusion or displacement assays, where lactobacilli and L. monocytogenes were added to Caco-2 monolayers simultaneously or 1 h apart from each other. Inhibition of L. monocytogenes growth was only displayed with the spot-on-lawn assay; cell-free supernatants of lactobacilli were not effective against the pathogen. Lactobacillus (L.) paragasseri LDD-C1 and L. crispatus LCR-A21 were able to adhere to Caco-2 cells at significantly higher levels than the reference strain L. rhamnosus GG. The adherence of L. monocytogenes to Caco-2 cells was reduced by 20.8% to 62.1% and invasion by 33.5% to 63.1% during competition, which was more effective compared to the exclusion and displacement assays. These findings demonstrate that lactobacilli isolated from neonatal feces could be considered a good candidate against L. monocytogenes.

Probiotic Properties of Chicken-Derived Highly Adherent Lactic Acid Bacteria and Inhibition of Enteropathogenic Bacteria in Caco-2 Cells

Lactic acid bacteria (LAB) as probiotic candidates have various beneficial functions, such as regulating gut microbiota, inhibiting intestinal pathogens, and improving gut immunity. The colonization of the intestine is a prerequisite for probiotic function. Therefore, it is necessary to screen the highly adherent LAB. In this study, the cell surface properties, such as hydrophobicity, auto-aggregation, co-aggregation, and adhesion abilities of the six chicken-derived LAB to Caco-2 cells were investigated. All six strains showed different hydrophobicity (21.18-95.27%), auto-aggregation (13.61-30.17%), co-aggregation with Escherichia coli ATCC 25922 (10.23-36.23%), and Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311 (11.71-39.35%), and adhesion to Caco-2 cells (8.57-26.37%). Pediococcus pentosaceus 2-5 and Lactobacillus reuteri L-3 were identified as the strains with strong adhesion abilities (26.37% and 21.57%, respectively). Moreover, these strains could survive in a gastric acid environment at pH 2, 3, and 4 for 3 h and in a bile salt environment at 0.1%, 0.2%, and 0.3% (w/v) concentration for 6 h. Furthermore, the cell-free supernatant of P. pentosaceus 2-5 and L. reuteri L-3 inhibited the growth of enteropathogenic bacteria and the strains inhibited the adhesion of these pathogens to Caco-2 cells. In this study, these results suggested that P. pentosaceus 2-5 and L. reuteri L-3, isolated from chicken intestines might be good probiotic candidates to be used as feed additives or delivery vehicles of biologically active substances.

Genomic and Phenotypic Evaluation of Potential Probiotic Pediococcus Strains with Hypocholesterolemic Effect Isolated from Traditional Fermented Food

The use of probiotic microorganisms in food with the aim to confer health benefits to the host is one of the most critical roles of functional foods. Many pediococci bacteria frequently related to the meat environment, have technological properties, and are therefore commercially used as starter in the production of fermented meat products, such as different types of sausages. In this study, different lactic acid bacteria were isolated, identified to the species level, and then evaluated for their safety and functionality as possible probiotics. Different properties, such as resistance to simulated human gastrointestinal conditions, antimicrobial activity, and cholesterol-lowering effects, have been studied. Finally, the complete genome of one strain, namely P. acidilactici IRZ12B, which showed interesting features as a promising probiotic candidate, was sequenced and further studied. The results revealed that IRZ12B possesses interesting probiotic properties, particularly cholesterol-lowering capability and antimicrobial activity. In silico analysis evidenced the absence of plasmids, transmissible antibiotic resistance genes, and virulence factors. We also detected a bacteriocin encoding gene and a cholesterol assimilation-related protein. The phenotypical and genomic outcomes described in this study make P. acidilactici IRZ12B a very interesting cholesterol-lowering potential probiotic strain to be considered for the development of novel non-dairy-based functional foods.

Mesoporous silica nanoparticle-encapsulated Bifidobacterium attenuates brain Aβ burden and improves olfactory dysfunction of APP/PS1 mice by nasal delivery

BACKGROUND

Dysbiosis or imbalance of gut microbiota in Alzheimer's disease (AD) affects the production of short-chain fatty acids (SCFAs), whereas exogenous SCFAs supplementation exacerbates brain Aβ burden in APP/PS1 mice. Bifidobacterium is the main producer of SCFAs in the gut flora, but oral administration of Bifidobacterium is ineffective due to strong acids and bile salts in the gastrointestinal tract. Therefore, regulating the levels of SCFAs in the gut is of great significance for AD treatment.

METHODS

We investigated the feasibility of intranasal delivery of MSNs-Bifidobacterium (MSNs-Bi) to the gut and their effect on behavior and brain pathology in APP/PS1 mice.

RESULTS

Mesoporous silica nanospheres (MSNs) were efficiently immobilized on the surface of Bifidobacterium. After intranasal administration, fluorescence imaging of MSNs-Bi in the abdominal cavity and gastrointestinal tract revealed that intranasally delivered MSNs-Bi could be transported through the brain to the peripheral intestine. Intranasal administration of MSNs-Bi not only inhibited intestinal inflammation and reduced brain Aβ burden but also improved olfactory sensitivity in APP/PS1 mice.

CONCLUSIONS

These findings suggested that restoring the balance of the gut microbiome contributes to ameliorating cognitive impairment in AD, and that intranasal administration of MSNs-Bi may be an effective therapeutic strategy for the prevention of AD and intestinal disease.

A Multi-Strain Probiotic Formulation Improves Intestinal Barrier Function by the Modulation of Tight and Adherent Junction Proteins

In healthy individuals, tight junction proteins (TJPs) maintain the integrity of the intestinal barrier. Dysbiosis and increased intestinal permeability are observed in several diseases, such as inflammatory bowel disease. Many studies highlight the role of probiotics in preventing intestinal barrier dysfunction. The present study aims to investigate the effects of a commercially available probiotic formulation of L. rhamnosus LR 32, B. lactis BL 04, and B. longum BB 536 (Serobioma, Bromatech s.r.l., Milan, Italy) on TJPs and the integrity of the intestinal epithelial barrier, and the ability of this formulation to prevent lipopolysaccharide-induced, inflammation-associated damage. An in vitro model of the intestinal barrier was developed using a Caco-2 cell monolayer. The mRNA expression levels of the TJ genes were analyzed using real-time PCR. Changes in the amounts of proteins were assessed with Western blotting. The effect of Serobioma on the intestinal epithelial barrier function was assessed using transepithelial electrical resistance (TEER) measurements. The probiotic formulation tested in this study modulates the expression of TJPs and prevents inflammatory damage. Our findings provide new insights into the mechanisms by which probiotics are able to prevent damage to the gut epithelial barrier.

Effect of a bacteriocin-producing Streptococcus salivarius on the pathogen Fusobacterium nucleatum in a model of the human distal colon

The gut microbiome is a vast reservoir of microbes, some of which produce antimicrobial peptides called bacteriocins that may inhibit specific bacteria associated with disease. Fusobacterium nucleatum is an emerging human bacterial pathogen associated with gastrointestinal diseases including colorectal cancer (CRC). In this study, fecal samples of healthy donors were screened for potential bacteriocin-producing probiotics with antimicrobial activity against F. nucleatum. A novel isolate, designated as Streptococcus salivarius DPC6993 demonstrated a narrow-spectrum of antimicrobial activity against F. nucleatum in vitro. In silico analysis of the S. salivarius DPC6993 genome revealed the presence of genes involved in the production of the bacteriocins salivaricin A5 and salivaricin B. After 6 h in a colon fermentation model, there was a significant drop in the number of F. nucleatum in samples that had been simultaneously inoculated with S. salivarius DPC6993 + F. nucleatum DSM15643 compared to those inoculated with F. nucleatum DSM15643 alone (mean ± SD: 9243.3 ± 3408.4 vs 29688.9 ± 4993.9 copies/μl). Furthermore, 16S rRNA amplicon analysis revealed a significant difference in the mean relative abundances of Fusobacterium between samples inoculated with both S. salivarius DPC6993 and F. nucleatum DSM15643 (0.05%) and F. nucleatum DSM15643 only (0.32%). Diversity analysis indicated minimal impact exerted by S. salivarius DPC6993 on the surrounding microbiota. Overall, this study highlights the ability of a natural gut bacterium to target a bacterial pathogen associated with CRC. The specific targeting of CRC-associated pathogens by biotherapeutics may ultimately reduce the risk of CRC development and positively impact CRC outcomes.

Probiotic potential of GABA-producing lactobacilli isolated from Uruguayan artisanal cheese starter cultures

AIMS

In this study, we sought to identify and characterize a collection of 101 lactobacilli strains isolated from natural whey starters used in Uruguayan artisan cheese production, based on their capacity to produce gamma-aminobutyric acid (GABA) and their probiotic potential.

METHODS AND RESULTS

The probiotic potential was assessed using low pH and bile salt resistance assays; bacterial adhesion to intestinal mucus was also evaluated. Selected strains were then identified by 16S sequencing, and their GABA-producing potential was confirmed and quantified using a UHPLC-MS system. Twenty-five strains were identified and characterized as GABA-producing lactobacilli belonging to the phylogenetical groups Lactiplantibacillus (n = 19) and Lacticaseibacillus (n = 6). Fifteen strains of the Lactiplantibacillus group showed a significantly higher GABA production than the rest. They showed the predicted ability to survive the passage through the gastrointestinal tract, according to the in vitro assays.

CONCLUSIONS

A set of promising candidate strains was identified as potential probiotics with action on the gut-brain axis. Further studies are needed to assess their possible effects on behaviour using in vivo assay.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows the potential of strains isolated from local natural whey starters as probiotics and for biotechnological use in functional GABA-enriched foods formulation.

A diagnostically challenging case of pyelonephritis caused by Lactobacillus

Extracellular polysaccharides produced by Lactobacillus have been shown to stimulate the immune system, suppress reactivity to allergens, and protect from infections; these properties underlie the use of Lactobacillus in probiotic formulations and in the prevention and treatment of urinary tract infections. However, Lactobacillus can be independently isolated at high numbers from sites of infection and has been rarely considered as the causative agent of infections in immunocompromised individuals. We herein report the case of a 46-year-old female patient who developed pyelonephritis due to Lactobacillus following total thyroidectomy for papillary thyroid cancer. The patient also had to fast due to postoperative vocal cord paralysis and received steroid treatment. As illustrated in the clinical course of our patient, Lactobacillus can be overlooked as a contaminant in culture samples and should be suspected as the etiology of infection especially in patients with weakened immune responses. We suggest that the detection of Lactobacillus in culture these patients might be an indication to initiate appropriate antibiotic treatment without delay.

role of Lactobacillus casei on some physiological and biochemical parameters in male laboratory rats infection with salmonellosis

This research was conducted to isolation and diagnosis of Salmonella typhimurium that caused child diarrhea infections, whom attend in Salah-Adin Teaching Hospital in Tikrit. and determine the susceptibility of isolates against some antibiotics, also, determine the Lactobacillus casei as probiotics which, isolation and identification from fermented dairy samples collected from different local in Salah-Adin governorate markets, then assay the effect of orally dosage of probiotics on some physiological and biological parameters in rats that infected with Salmonella typhimurium isolate. Salmonella typhimurium were appeared at 15 isolates from child diarrhea infections samples and the Lb. casei isolates from fermented dairy products, then identified according to morphological, microscopic, cultural and biochemical characterizes, then selective the probiotics isolate from Lb. casei which depended according to their ability to grow in pH 2 and able to tolerance growth at 0.3% bile salts, furthermore their ability to adhesion with intestine mucus surface at 43.8%.

Hydrolyzation of snail (Achatina fulica) meat with rice water as novel probiotic supplements for animal feed

Background and Aim: Snail meat and digestive tract hydrolyzate fermented with a consortium of preserved rice water microorganisms could serve as new sources of probiotics. Microorganisms from the examined feed supplement were isolated, identified, and characterized for resistance at low pH and with bile salts. The study aimed to determine the potential hydrolysate of the snail meat and digestive tract as a novel probiotic supplement for animal feed at various pH values and Oxgall. Materials and Methods: The submerged fermentation method was conducted for 21 days to examine the novel probiotic that originated from snail microorganisms in the hydrolyzed liquid fermented by finely ground snail meat and the digestive tract. The microorganisms in the hydrolyzate were isolated by a spread plate method, while the potential of the probiotic hydrolyzate was tested for resistance to pH values of 2, 2.5, 3, and 4, as well as resistance to bile salts at Oxgall concentrations of 0.2%, 0.3%, 0.5%, 1%, and 2%. Results: The hydrolyzate profile of snail meat and digestive tract contained five isolates of lactic acid bacteria that could serve as potential probiotics. Conclusion: The application of fermentation technology using a consortium of preserved rice water microorganisms can convert snail meat and the digestive tract into novel probiotic products that could be utilized in feed supplements.

Role of probiotics in ruminant nutrition as natural modulators of health and productivity of animals in tropical countries: an overview

Given the ever-growing population in the developing countries located in the tropics of Asia, Africa, South America, and the Caribbean, the demand for products of animal origin has increased. Probiotics have proven to be a substantial substitute for antibiotics used in the animal diet and thus gained popularity. Probiotics are live and non-pathogenic microbes commercially utilized as modulators of gut microflora, hence exerting advantageous effects on the health and productivity of animals in tropical countries. Probiotics are mainly derived from a few bacterial (Lactobacillus, Enterococcus, Streptococcus, Propionibacterium, and Prevotella bryantii) and yeast (Saccharomyces and Aspergillus) species. Numerous studies in tropical animals revealed that probiotic supplementation in a ruminant diet improves the growth of beneficial rumen microbes, thus enhancing nutrient intake and digestibility, milk production, and reproductive and feed efficiency, along with immunomodulation. Furthermore, probiotic applications have proven to minimize adverse environmental consequences, including reduced methane emissions from ruminants' anaerobic fermentation of tropical feedstuffs. However, obtained results were inconsistent due to sources of probiotics, probiotic stability during storage and feeding, dose, feeding frequency, and animal factors including age, health, and nutritional status of the host. Furthermore, the mechanism of action of probiotics by which they exhibit beneficial effects is still not clear. Thus, more definitive research is needed to select the most effective strains of probiotics and their cost-benefit analysis. In this review article, we have briefly explained the impact of feeding probiotics on nutrient intake, digestibility, reproduction, growth efficiency, productivity, and health status of tropical ruminant animals.

Solutions in microbiome engineering: prioritizing barriers to organism establishment

Microbiome engineering is increasingly being employed as a solution to challenges in health, agriculture, and climate. Often manipulation involves inoculation of new microbes designed to improve function into a preexisting microbial community. Despite, increased efforts in microbiome engineering inoculants frequently fail to establish and/or confer long-lasting modifications on ecosystem function. We posit that one underlying cause of these shortfalls is the failure to consider barriers to organism establishment. This is a key challenge and focus of macroecology research, specifically invasion biology and restoration ecology. We adopt a framework from invasion biology that summarizes establishment barriers in three categories: (1) propagule pressure, (2) environmental filtering, and (3) biotic interactions factors. We suggest that biotic interactions is the most neglected factor in microbiome engineering research, and we recommend a number of actions to accelerate engineering solutions.

In vitro probiotic and safety attributes of Bacillus spp. isolated from beebread, honey samples and digestive tract of honeybees Apis mellifera

Bacillus species isolated from honeybee Apis mellifera gut, honey and bee bread samples were characterized for their in vitro probiotic and safety attributes. Alpha and γ haemolytic cultures were tested for their antibiotic resistance, antibacterial spectrum, acid and bile tolerance, adhesion ability (auto-aggregation, co-aggregation and hydrophobicity) and phenol tolerance. Safety criteria included evaluation of virulence genes and cytotoxicity percentages. Bacillus isolates inhibited both Gram-positive and Gram-negative pathogens including Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis and Streptococcus mutans, while none could inhibit Listeria monocytogenes. Among the isolates, Bacillus subtilis ZH05, ZB03 and ZG025 showed resistance to most of the tested antibiotics and were considered unsafe. B. subtilis (4) and B. licheniformis (1) tolerated acidic pH and bile conditions, never the less were more tolerant in simulated intestinal conditions vis-a-vis gastric conditions. In 0·5% phenol concentrations, B. licheniformis ZH02 showed highest growth, while, B. subtilis ZG029 demonstrated highest auto-aggregation (65 ± 4·6) and hydrophobicity (23 ± 3·6) percentages (P < 0·05). The isolates lacked virulence genes (hblA, hblC, hblD, nhe, cytK and ces), and their cytotoxic percentage on Caco-2 cell lines was ˂15%. Overall, honeybees appear to be a good source of Bacillus species exhibiting typical in vitro probiotic properties, which could be of commercial interest.

Chewing differences in consumers affect the digestion and colonic fermentation outcomes: In vitro studies

It is important to understand variability in consumer chewing behavior for designing food products that deliver desired functionalities for target consumer segments. In this study, we selected 29 participants, representing...

Leveraging diet to engineer the gut microbiome

Autoimmune diseases, including inflammatory bowel disease, multiple sclerosis and rheumatoid arthritis, have distinct clinical presentations but share underlying patterns of gut microbiome perturbation and intestinal barrier dysfunction. Their potentially common microbial drivers advocate for treatment strategies aimed at restoring appropriate microbiome function, but individual variation in host factors makes a uniform approach unlikely. In this Perspective, we consolidate knowledge on diet-microbiome interactions in local inflammation, gut microbiota imbalance and host immune dysregulation. By understanding and incorporating the effects of individual dietary components on microbial metabolic output and host physiology, we examine the potential for diet-based therapies for autoimmune disease prevention and treatment. We also discuss tools targeting the gut microbiome, such as faecal microbiota transplantation, probiotics and orthogonal niche engineering, which could be optimized using custom dietary interventions. These approaches highlight paths towards leveraging diet for precise engineering of the gut microbiome at a time of increasing autoimmune disease.

Effects of L. plantarum HY7715 on the Gut Microbial Community and Riboflavin Production in a Three-Stage Semi-Continuous Simulated Gut System

Probiotics should be well established in the gut, passing through the digestive tract with a high degree of viability, and produce metabolites that improve the gut environment by interacting with the gut microbiome. Our previous study revealed that the Lactiplantibacillus plantarum HY7715 strain shows good bile acid resistance and a riboflavin production capacity. To confirm the interaction between HY7715 and gut microbiome, we performed a metabolite and microbiome study using a simulated gut system (SGS) that mimics the intestinal environment. Changes in the microbiome were confirmed and compared with L. plantarum NCDO1752 as the control. After 14 days, the HY7715 treatment group showed a relatively high butyrate content compared to the control group, which showed increased acetate and propionate concentrations. Moreover, the riboflavin content was higher in the HY7715 treatment group, whereas the NCDO1752 treatment group produced only small amounts of riboflavin during the treatment period and showed a tendency to decrease during the washout stage; however, the HY7715 group produced riboflavin continuously in the ascending colon during the washout period. A correlation analysis of the genus that increased as the content of riboflavin increased revealed butyrate-producing microorganisms, such as Blautia and Flavonifractor. In conclusion, treatment with L. plantarum HY7715 induced the production and maintenance of riboflavin and the enrichment of the intestinal microbiome

Evaluation of Microbiome Alterations Following Consumption of BIOHM, a Novel Probiotic

Gastrointestinal microbiome dysbiosis may result in harmful effects on the host, including those caused by inflammatory bowel diseases (IBD). The novel probiotic BIOHM, consisting of Bifidobacterium breve, Saccharomyces boulardii, Lactobacillus acidophilus, L. rhamnosus, and amylase, was developed to rebalance the bacterial–fungal gut microbiome, with the goal of reducing inflammation and maintaining a healthy gut population. To test the effect of BIOHM on human subjects, we enrolled a cohort of 49 volunteers in collaboration with the Fermentation Festival group (Santa Barbara, CA, USA). The profiles of gut bacterial and fungal communities were assessed via stool samples collected at baseline and following 4 weeks of once-a-day BIOHM consumption. Mycobiome analysis following probiotic consumption revealed an increase in Ascomycota levels in enrolled individuals and a reduction in Zygomycota levels (p value < 0.01). No statistically significant difference in Basidiomycota was detected between pre- and post-BIOHM samples and control abundance profiles (p > 0.05). BIOHM consumption led to a significant reduction in the abundance of Candida genus in tested subjects (p value < 0.013), while the abundance of C. albicans also trended lower than before BIOHM use, albeit not reaching statistical significance. A reduction in the abundance of Firmicutes at the phylum level was observed following BIOHM use, which approached levels reported for control individuals reported in the Human Microbiome Project data. The preliminary results from this clinical study suggest that BIOHM is capable of significantly rebalancing the bacteriome and mycobiome in the gut of healthy individuals, suggesting that further trials examining the utility of the BIOHM probiotic in individuals with gastrointestinal symptoms, where dysbiosis is considered a source driving pathogenesis, are warranted.

Effects of probiotics on bone mineral density and bone turnover: A systematic review

Probiotic supplements have been shown to improve bone health in animal models, although it remains uncertain whether these beneficial effects extend to humans. We undertook a systematic review of the literature to determine the effects of probiotic interventions on skeletal outcomes in postmenopausal women. MEDLINE, EMBASE, CENTRAL, and the Cochrane Database of Systematic Reviews were searched from inception to October 2020 for controlled trials comparing the effects of probiotic-containing supplements with placebo on bone mineral density (BMD) or bone turnover markers. Risk of bias was assessed using the Cochrane Risk of Bias 2 Tool. Of 338 records identified, six randomized, placebo-controlled trials (n = 632) were eligible for inclusion. All studies assessed postmenopausal women for durations of 6-12 months; three were considered to be at high risk of bias. Four studies examined Lactobacillus-containing probiotics, one assessed a proprietary blend of lactic acid bacteria, and one evaluated Bacillus subtilis. Effects of probiotic interventions on BMD were inconsistent, with the majority of studies demonstrating no benefit at the spine or hip. Probiotic effects on bone turnover markers were similarly heterogeneous. High quality studies are needed to determine whether probiotic interventions have a role in maintaining bone health in humans.

Efficacy of Lactobacillus fermentum Isolated from the Vagina of a Healthy Woman against Carbapenem-Resistant Klebsiella Infections In Vivo

Carbapenem-resistant Enterobacteriaceae (CRE) that produce Klebsiella pneumoniae carbapenemase are increasingly reported worldwide and have become more and more resistant to nearly all antibiotics during the past decade. The emergence of K. pneumoniae strains with decreased susceptibility to carbapenems, which are used as a last resort treatment option, is a significant threat to hospitalized patients worldwide as K. pneumoniae infection is responsible for a high mortality rate in the elderly and immunodeficient individuals. This study used Lactobacillus fermentum as a candidate probiotic for treating CRE-related infections and investigated its effectiveness. We treated mice with L. fermentum originating from the vaginal fluid of a healthy Korean woman and evaluated the Lactobacilli's efficacy in preventive, treatment, non-establishment, and colonization mouse model experiments. Compared to the control, pre-treatment with L. fermentum significantly reduced body weight loss in the mouse models, and all mice survived until the end of the study. The oral administration of L. fermentum after carbapenemresistant Klebsiella (CRK) infection decreased mortality and illness severity during a 2-week observation period and showed that it affects other strains of CRK bacteria. Also, the number of Klebsiella bacteria was decreased to below 5.5 log₁₀ CFU/ml following oral administration of L. fermentum in the colonization model. These findings demonstrate L. fermentum's antibacterial activity and its potential to treat CRE infection in the future.

Microbial Therapeutics in Neurocognitive and Psychiatric Disorders

Microbial therapeutics, which include gut biotics and fecal transplantation, are interventions designed to improve the gut microbiome. Gut biotics can be considered as the administration of direct microbial populations. The delivery of this can be done through live microbial flora, certain food like fiber, microbial products (metabolites and elements) obtained through the fermentation of food products, or as genetically engineered substances, that may have therapeutic benefit on different health disorders. Dietary intervention and pharmacological supplements with gut biotics aim at correcting disruption of the gut microbiota by repopulating with beneficial microorganism leading to decrease in gut permeability, inflammation, and alteration in metabolic activities, through a variety of mechanisms of action. Our understanding of the pharmacokinetics of microbial therapeutics has improved with in vitro models, sampling techniques in the gut, and tools for the reliable identification of gut biotics. Evidence from human studies points out that prebiotics, probiotics and synbiotics have the potential for treating and preventing mental health disorders, whereas with paraprobiotics, proteobiotics and postbiotics, the research is limited at this point. Some animal studies point out that gut biotics can be used with conventional treatments for a synergistic effect on mental health disorders. If future research shows that there is a possibility of synergistic effect of psychotropic medications with gut biotics, then a gut biotic or nutritional prescription can be given along with psychotropics. Even though the overall safety of gut biotics seems to be good, caution is needed to watch for any known and unknown side effects as well as the need for risk benefit analysis with certain vulnerable populations. Future research is needed before wide spread use of natural and genetically engineered gut biotics. Regulatory framework for gut biotics needs to be optimized. Holistic understanding of gut dysbiosis, along with life style factors, by health care providers is necessary for the better management of these conditions. In conclusion, microbial therapeutics are a new psychotherapeutic approach which offer some hope in certain conditions like dementia and depression. Future of microbial therapeutics will be driven by well-done randomized controlled trials and longitudinal research, as well as by replication studies in human subjects.

Potential prebiotic properties of exopolysaccharides produced by a novel Lactobacillus strain, Lactobacillus pentosus YY-112

Exopolysaccharides (EPSs) derived from Lactobacilli have important physiological effects and are commonly used as new prebiotics. We identified and studied a new Lactobacillus strain, YY-112, isolated from waxberry (Myrica rubra). This strain, identified as Lactobacillus pentosus, tolerates acids, bile salts, and artificial digestive fluids. The EPS derived from this strain weighed 5.9 × 10⁴ Da and contained glucose, mannose, glucosamine, galactose, and rhamnose at 62.69 : 85.85 : 2.46 : 2.92 : 1.00 molar ratios. We found that the EPS from this strain increased the ratio of Bacteroidetes to Firmicutes and decreased the relative abundance of Proteobacteria, especially Escherichia-Shigella, when added to a simulated gastrointestinal system in vitro. After analysing the short-chain fatty acids, we found that this EPS promoted the production of acetic acid, propionic acid, and butyric acid, and reduced the ratio of acetic acid to propionic acid. We conclude that Lactobacillus pentosus YY-112 is a potential probiotic strain with EPS that is beneficial for the intestinal microbiota and short-chain fatty acid production.

An adaptable and non-invasive method for tracking Bifidobacterium animalis subspecies lactis 420 in the mouse gut

Probiotic strains from the Bifidobacterium or Lactobacillus genera improve health outcomes in models of metabolic and cardiovascular disease. Yet, underlying mechanisms governing these improved health outcomes are rooted in the interaction of gut microbiota, intestinal interface, and probiotic strain. Central to defining the underlying mechanisms governing these improved health outcomes is the development of adaptable and non-invasive tools to study probiotic localization and colonization within the host gut microbiome. The objective of this study was to test labeling and tracking efficacy of Bifidobacterium animalis subspecies lactis 420 (B420) using a common clinical imaging agent, indocyanine green (ICG). ICG was an effective in situ labeling agent visualized in either intact mouse or excised gastrointestinal (GI) tract at different time intervals. Quantitative PCR was used to validate ICG visualization of B420, which also demonstrated that B420 transit time matched normal murine GI motility (~8 hours). Contrary to previous thoughts, B420 did not colonize any region of the GI tract whether following a single bolus or daily administration for up to 10 days. We conclude that ICG may provide a useful tool to visualize and track probiotic species such as B420 without implementing complex molecular and genetic tools. Proof-of-concept studies indicate that B420 did not colonize and establish residency align the murine GI tract.

Transcriptomic Analysis of Pediococcus pentosaceus Reveals Carbohydrate Metabolic Dynamics Under Lactic Acid Stress

Stress physiology of lactic acid bacteria (LAB) is crucial to their ecological fitness and applicational implications. As a self-imposed stress, lactic acid is the major final metabolic product of LAB and its accumulation can be detrimental to bacterial cells. However, the relationship between LAB carbohydrate metabolism, the primary energy supplying bioactivities, and lactic acid stress responses is not fully understood. Pediococcus pentosaceus has been recognized as an important cell factory and demonstrated probiotic activities. This study investigated behavior of P. pentosaceus under lactic and acetic acid stresses, particularly with supplementations of metabolizable carbohydrates. Lactic and acetic acid retain similar growth stagnation effect, and both resulted in cell death in P. pentosaceus. All metabolizable carbohydrates improved bacterial survival compared to lactic acid control, while xylooligosaccharides (XOS) exerted the highest viability protective efficacy, 0.82 log CFU/mL higher population survived than other carbohydrates after 30 h of incubation. RNA-seq pipeline showcased the intensive global transcriptional responses of P. pentosaceus to lactic acid, which caused significant regulations (more than 2 Log2 fold) of 16.5% of total mRNA coding genes. Glucose mainly led to gene suppressions (83 genes) while XOS led to gene up-regulations (19 genes) under lactic acid stress. RT-qPCR study found that RNA polymerase-centered transcriptional regulation is the primary regulatory approach in evaluated culture conditions. The synergy between lactic acid stress and carbohydrate metabolism should be attentively contemplated in future studies and applications.

Probiotic Supplementation and Micronutrient Status in Healthy Subjects: A Systematic Review of Clinical Trials

Micronutrient deficiencies are a worldwide public health concern. Emerging evidence supports the ability of probiotics to enhance micronutrient status, which could aid in the prevention of non-communicable disease-associated malnutrition. This systematic review evaluated evidence of the efficacy of probiotic supplementation to improve micronutrient status in healthy subjects. The authors searched for published English language peer-reviewed journal articles in PubMed, Scopus, Embase, and Google Scholar databases from inception to July 2020 using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of eligible studies was assessed using the Revised Cochrane Risk-of-Bias tool (RoB)2 and Risk of Bias in Non-Randomized Studies of Interventions tool (ROBINS-I tool). Fourteen original studies out of 2790 met the inclusion criteria. The results indicated that, despite varying degrees of efficacy, the intake of certain probiotics in healthy subjects was associated with a positive impact on the status of certain micronutrients (vitamin B12, calcium, folate, iron and zinc). A limitation was that studies were widely heterogeneous in terms of participant age, probiotic strain, species, dosage, intervention duration, and form of administration. Additional clinical trials are warranted to determine the most effective strains of probiotics, doses and durations of interventions.

Fermentation products of Danshen relieved dextran sulfate sodium-induced experimental ulcerative colitis in mice

With the increased incidence and recognition, ulcerative colitis (UC) has become a global public health problem in the world. Although many immunosuppressant and biological drugs have been used for UC treatment, the cure rate is still very low. It is necessary to find some safe and long-term used medicine for UC cure. Recently, the Chinese traditional herb Danshen has been investigated in the treatment of UC. However, it is a limitation of Danshen that many of the active components in Danshen are not easily absorbed by the human body. Probiotics could convert macromolecules into smaller molecules to facilitate absorption. Thus, Lactobacillus rhamnosus (F-B4-1) and Bacillus subtillis Natto (F-A7-1) were screened to ferment Danshen in this study. The fermented Danshen products were gavaged in the dextran sulfate sodium (DSS)-induced UC model mice. Danshen had better results to attenuate symptoms of DSS-induced UC after fermented with F-B4-1 and F-A7-1. Loss of body weight and disease activity index (DAI) were reduced. The abnormally short colon lengths and colonic damage were recovered. And fermented Danshen had the better inhibitory effect than Danshen itself on pro-inflammatory cytokine expression during DSS-induced UC. The results indicated that compared with Danshen, fermented Danshen relieved DSS-induced UC in mice more effectively. Danshen fermented by probiotics might be an effective treatment to UC in clinic stage in the future.

Comparative evaluation for thermostability and gastrointestinal survival of probiotic Bacillus coagulans MTCC 5856

Thermal stability (D-value and pasteurization) and gastric acid resistance of spore forming and nonspore forming probiotic strains were evaluated in this study. Bacillus coagulans MTCC 5856 spores showed highest thermal resistance (D-value 35.71 at 90 °C) when compared with other Bacillus strains and Lactobacillus species. B. coagulans strains exhibited significantly higher resistance to simulated gastric juice (pH 1.3, 1.5, and 2.0) compared to Lactobacillus strains. It also showed high resistance to cooking conditions of chapati (whole wheat flour-based flatbread) (88.94% viability) and wheat noodles (and 94.56% viability), suggesting remarkable thermal resistance during food processing. Furthermore, B. coagulans MTCC 5856 retained 73% viability after microwave cooking conditions (300 s, at 260 °C) and 98.52% in milk and juice at pasteurization temperature (420 min, at 72 °C). Thus, B. coagulans MTCC 5856 clearly demonstrated excellent resistance to gastric acid and high temperature (90 °C), thereby suggesting its extended application in functional foods (milk, fruit juices, chapati, and wheat noodles) wherein high temperature processing is involved.