An introduction of the role of probiotics in human infections and autoimmune diseases

Bifidobacterium longum and Chlorella sorokiniana Improve the IFN Type I-Mediated Antiviral Response in Rotavirus-Infected Cells

Probiotics are effective to treat or prevent gastrointestinal infections, and microalgae have demonstrated important health-promoting effects and in some cases function as prebiotics. In this regard, the anti-rotavirus effect of Bifidobacterium longum and Chlorella sorokiniana by reducing viral infectivity is well known. However, their effect on immune response against rotavirus has not yet been investigated. Therefore, the aim of this study was to determine the role of Bifidobacterium longum and/or Chlorella sorokiniana in influencing an IFN type I-mediated antiviral response in rotavirus-infected cells. In pre-infection experiments, HT-29 cells were treated with B. longum and C. sorokiniana alone or in combination, followed by rotavirus infection, whereas in post-infection assays, HT-29 cells were treated after infection. The cells' mRNA was then purified to determine the relative expression level of IFN-α, IFN-β, and precursors of interferons such as RIG-I, IRF-3, and IRF-5 by qPCR. We showed that combination of B. longum and C. sorokiniana significantly increased IFN-α levels in pre-infection and IFN-β in post-infection assays, as compared with individual effects. Results indicate that B. longum, C. sorokiniana, or their combination improve cellular antiviral immune response.

Effect of Probiotics Lactobacillus acidophilus and Lacticaseibacillus rhamnosus on Antibacterial Response Gene Transcription of Human Peripheral Monocytes

Periodontitis and related systemic inflammatory diseases are characterized by imbalanced ratio between pro- and anti-inflammatory factors. Probiotics may control inflammation by altering the inflammatory phenotype of defense cells. We aimed to evaluate the gene transcription of the antibacterial response of monocytes to exposure to probiotic lactobacilli. CD14 + monocytes were obtained by positive selection from peripheral blood mononuclear cells from healthy donors (5 × 10⁴ CD14 + /mL) and cultured with probiotic strains of Lacticaseibacillus rhamnosus (LR-32) and Lactobacillus acidophilus (LA-5) at a 1:10 multiplicity of infection in 24-well plates for 12 h. The gene expression analysis was performed by RT-qPCR using the Kit RT² human antibacterial response, and in the supernatant, the cytokines were determined by ELISA. Tukey's post hoc test following an ANOVA with a p value of 5% was used for statistical analysis. Both probiotic strains increased the levels of cytokines TNF-α and CXCL-8 in the supernatant compared to the control of non-challenged cells (p < 0.05), but for IL-1Β and IL-6, this effect was observed only for LA-5 (p < 0.05). The fold-regulation values for the following genes for LA-5 and LR-32 were, respectively, IL-12B (431.94 and 33.30), IL-1Β (76.73 and 17.14), TNF-α (94.63 and 2.49), CXCL-8 (89.59 and 4.18), and TLR-2 (49.68 and 3.40). Likewise, most of the other genes evaluated showed greater expression for LA-5 compared to LR-32 (p < 0.05). The positive regulation of inflammatory factors such as IL-1β promoted by L. acidophilus LA-5 may increase the antibacterial activity of innate defense in periodontal tissues. However, this property may be deleterious by increasing inflammatory response.

Characterization of the oral microbiome and gut microbiome of dental caries and extrinsic black stain in preschool children

Introduction

A lower prevalence of dental caries (hereafter termed “caries”) has been observed in children with dental extrinsic black stain (EBS).

Methods

We investigated the epidemiologic characterization of EBS and explored the possible role of the oral microbiome (OM) and gut microbiome (GM) in EBS formation and caries prevention. In an epidemiologic survey, 2,675 children aged 3–6 years were included. Thirty-eight of these children (7 children had both caries and EBS, 10 had EBS only, 11 had caries only, and 10 were healthy children) were recruited for 16S rRNA sequencing and collection of samples of supragingival plaque and feces. Collected plaque samples were divided into four groups: BCP (EBS+, caries+), BP (EBS+, caries−), CP (EBS−, caries+), and P (EBS−, caries−). Fecal samples were also divided into four groups: BCF (EBS+, caries+), BF (EBS+, caries−), CF (EBS−, caries+), and F (EBS−, caries−).

Results

EBS was observed in 12.10% of this population. Children with EBS had a significantly reduced prevalence of caries and a lower mean value of decayed–missing–filled teeth (dmft; p &lt; 0.01). According to analyses of dental plaque, the P group had the most complex microbiome. The BCP group exhibited greater operational taxonomic unit (OTU) richness but a reduced evenness compared with the BP group, and the CP group showed greater OTU richness than the BP group. At the genus level, higher abundance of Actinomyces and Cardiobacterium species was observed in the BCP group. Higher abundance of Lautropia and Pesudopropionibacteriumin species was observed in the BP group compared with P and CP groups, respectively (p &lt; 0.05). Veillonella species were significantly more common in P and CP groups than in BP groups, whereas Porphyromonas and Fusobacterium species were more common in the CP group (p &lt; 0.05). With regard to the GM, the CF group exhibited greater OTU diversity than the BF group. The GM in the BCF group exhibited the most complex relationships across all fecal groups. GM groups could be distinguished by various unique biomarkers, such as Escherichia and Shigella species in the BCF group, Agathobacter and Ruminococcus species in the CF group, Lactobacillus species in the BF group, and Roseburia species in the F group. Our results suggest that EBS is a possible protective factor against early-childhood caries. Dental plaque and the GM may be relevant to EBS in primary dentition.

A systematic review on selection characterization and implementation of probiotics in human health

Probiotics are live bacteria found in food that assist the body's defence mechanisms against pathogens by reconciling the gut microbiota. Probiotics are believed to aid with gut health, the immune system, and brain function, among other factors. They've furthermore been shown to help with constipation, high blood pressure, and skin issues. The global probiotics market has been incrementally growing in recent years, as consumers' demand for healthy diets and wellness has continued to increase. This has prompted the food industry to develop new probiotic-containing food products, as well as researchers to explore their specific characteristics and impacts on human health. Although most probiotics are fastidious microorganisms that are nutritionally demanding and sensitive to environmental conditions, they become less viable as they are processed and stored. In this review we studied the current literature on the fundamental idea of probiotic bacteria, their medical benefits, and their selection, characterization, and implementations.

Graphical Abstract

Effect of Probiotic Lactobacillus plantarum on Streptococcus mutans and Candida albicans Clinical Isolates from Children with Early Childhood Caries

Probiotics interfere with pathogenic microorganisms or reinstate the natural microbiome. Streptococcus mutans and Candida albicans are well-known emerging pathogenic bacteria/fungi for dental caries. In this study, three probiotic Lactobacilli strains (Lactobacillus plantarum 8014, L. plantarum 14917, and Lactobacillus salivarius 11741) were tested on S. mutans and C. albicans clinical isolates using a multispecies biofilm model simulating clinical cariogenic conditions. The ten pairs of clinical isolates of S. mutans and C. albicans were obtained from children with severe early childhood caries. Our study findings show a remarkable inhibitory effect of L. plantarum 14917 on S. mutans and C. albicans clinical isolates, resulting in significantly reduced growth of S. mutans and C. albicans, a compromised biofilm structure with a significantly smaller microbial and extracellular matrix and a less virulent microcolony structure. FurTre, plantaricin, an antimicrobial peptide produced by L. plantarum, inhibited the growth of S. mutans and C. albicans. The mechanistic assessment indicated that L. plantarum 14917 had a positive inhibitory impact on the expression of S. mutans and C. albicans virulence genes and virulent structure, such as C. albicans hypha formation. Future utilization of L. plantarum 14917 and/or its antimicrobial peptide plantaricin could lead to a new paradigm shift in dental caries prevention.

A comprehensive review of the application of probiotics and postbiotics in oral health

Oral diseases are among the most common diseases around the world that people usually suffer from during their lifetime. Tooth decay is a multifactorial disease, and the composition of oral microbiota is a critical factor in its development. Also, Streptococcus mutans is considered the most important caries-causing species. It is expected that probiotics, as they adjust the intestinal microbiota and reduce the number of pathogenic bacteria in the human intestine, can exert their health-giving effects, especially the anti-pathogenic effect, in the oral cavity, which is part of the human gastrointestinal tract. Therefore, numerous in vitro and in vivo studies have been conducted on the role of probiotics in the prevention of tooth decay. In this review, while investigating the effect of different strains of probiotics Lactobacillus and Bifidobacteria on oral diseases, including dental caries, candida yeast infections, periodontal diseases, and halitosis, we have also discussed postbiotics as novel non-living biological compounds derived from probiotics.

Exploring the regulatory mechanism of osteoporosis based on intestinal flora: A review

Osteoporosis is 1 of the common diseases of bone metabolism in clinic. With the aging of the population in China, osteoporosis is becoming more and more serious, and it has become 1 of the major public health problems. However, traditional therapies, such as calcium therapy and estrogen therapy, can cause serious adverse effects and damage to the body when ingested over a long period of time. Therefore, there is an urgent need to explore alternative therapies with less side effects in clinical practice. Intestinal flora is a hot topic of research in recent years. It has been studied in inflammatory bowel disease, diabetes, depression and so on. Recently, intestinal flora has received increasing attention in the pathways regulating bone metabolism. This paper contains a review of recent studies related to osteoporosis and gut flora in terms of its metabolites, immune, endocrine, and brain-gut axis pathways. The strong association between intestinal flora and bone metabolism suggests, to some extent, that intestinal flora can be a potential target for osteoporosis prevention and treatment, providing new ideas and therapies for the prevention and treatment of osteoporosis.

Effect of a Short-Term Intervention with Lactobacillus salivarius Probiotic on Early Childhood Caries-An Open Label Randomized Controlled Trial

ECC is a significant therapeutic and social problem and a global burden on public health. The aim of this clinical trial was to test whether a 2-week daily consumption of chewing tablets containing thermally inactivated L. salivarius reduces the 12-month caries increment compared to the control group. The investigation was a single-center, randomized, controlled open-label, blinded end-point evaluation trial in two parallel groups. At baseline, 140 generally healthy children between 3 and 6 years of age with or without ECC were randomly assigned to the probiotic test group (n = 70) or to the treatment as the usual control group (n = 70). The primary outcome measure was the 1-year increment in caries incidence and prevalence. Secondary endpoints assessed were the initial, cavitated and obvious dentinal caries increment as well as the measurement of dental plaque accumulation, as an indicator of the ECC risk. Data were collected through the clinical assessment of the children's caries (dmft and ICDAS II) and oral hygiene status (DI-S of OHI-S index). Caries incidence and prevalence were statistically significantly lower in the probiotic group versus the control group (p < 0.001 and p = 0.0075). The initial and final mean OHI-S scores in the probiotic group did not show any significant differences. In conclusion, the regular short-term intake of probiotics may reduce caries development. Our findings suggest that self-administered probiotic therapy may provide a good complement to increase the effectiveness of individual preventive home care in preschool children. This is the first clinical study evaluating the effect of a short-term probiotic intervention on reducing early childhood caries with 12 months of follow-up.

Anticandidal and Antibiofilm Effect of Synbiotics including Probiotics and Inulin-Type Fructans

Background: There is great interest in the search for new alternatives to antimicrobial drugs, and the use of synbiotics is a promising approach to this problem. This study evaluated the growth inhibition and antibiofilm activity of the short-chain fatty acids produced by Lacticaseibacillus rhamnosus and Pediococcus acidilactici in combination with inulin-type fructans against Candida albicans. Methods: The growth inhibition of Candida was evaluated using microdilution analysis in 96-well microtiter plates; different concentrations of cell-free supernatants of Lacticaseibacillus rhamnosus and Pediococcus acidilactici were exposed to Candida albicans. The antibiofilm assessment was carried out using the crystal violet staining assay. The short-chain fatty acids were analyzed by gas chromatography. Results: The clinically isolated Candida albicans interacted with supernatants from Lacticaseibacillus rhamnosus and Pediococcus acidilactici and showed significant growth inhibition and antibiofilm formation versus the controls. Lactate and acetic acid were elevated in the supernatants. The results suggest that the supernatants obtained from the synbiotic combinations of Lacticaseibacillus rhamnosus and Pediococcus acidilactici with inulin-type fructans can inhibit the growth and biofilm formation against a clinically isolated Candida albicans strain. Conclusions: These results suggest that synbiotic formulations could be a promising alternative to antifungal drugs in candidiasis therapy.

The Evaluation of the Effects of Two Probiotic Strains on the Oral Ecosystem: A Randomized Clinical Trial

Introduction

In the current study, we evaluated the effectiveness of two well-defined probiotic strains, Lactobacillus paracasei LPc-G110 (CCTCC M 2013691) and Lactobacillus plantarum GOS42 (DSM 32131), during an experimental gingivitis challenge. The primary objective was to evaluate clinically the effectiveness of lozenges containing one of the two oral probiotic strains, compared with placebo lozenges, on the gingival bleeding (bleeding on marginal probing; BOMP change) after a two-week experimental gingivitis period. The secondary objectives were to assess the effects of the test products on gingival health (Modified Gingival Index; MGI), dental plaque accumulation and fluorescence, and the dynamics of immunological and microbiological aspects after the wash-in phase, followed by a two-week period refraining from oral hygiene and a two-week wash-out phase.

Methods

This single-center challenge intervention study was a triple-blind randomized placebo-controlled clinical trial with three parallel groups. The full study population consisted of 117 healthy 18-55 years old human volunteers. Subjects were instructed to use one lozenge, 3 times daily after each meal, containing either L. plantarum, L. paracasei, or lozenges without probiotics (placebo group). After a 2-week wash-in period, the subjects were requested to refrain from any form of oral hygiene for 2 weeks.

Results

There were no differences in the primary outcome (BOMP change) among the groups. However, gingival health (MGI) in individuals from the groups exposed to the test products recovered better from experimental gingivitis than the individuals in the placebo group (p = 0.021, one-way ANOVA). The two test products inhibited pro-inflammatory cytokine IL-1ß production, measured in saliva, during the experimental gingivitis period. Both test strains significantly reduced bacterial DNA in tongue samples and L. paracasei strain showed stronger microbiome-modulating potential than the L. plantarum strain.

Conclusions

The two tested lozenges with the L. paracasei or L. plantarum strains did show potential for beneficial effects for the oral health of the host during experimental gingivitis to the oral ecosystem.

Interactions between Blastocystis subtype ST4 and gut microbiota in vitro

BACKGROUND

Blastocystis ST4 is a common protistan parasite of the gastrointestinal tract of humans and a wide range of animals. While it has been suggested that colonization with ST4 is associated with healthy gut microbiota, how ST4 influences the gut microbiota remains poorly studied. This study aimed to examine the interactions between ST4 and several intestinal bacteria using in vitro co-culture systems, and to further investigate the mechanism of interaction and its effect on the epithelial barrier integrity of HT-29 cells.

METHODS

Seven intestinal bacteria Bacteroides fragilis, Bifidobacterium longum, Bacillus subtilis, Bacteroides vulgatus, Escherichia coli, Enterococcus faecalis, and Lactobacillus brevis were co-cultured with Blastocystis ST4 in vitro. Flow cytometry and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) were used to determine the role of reactive oxygen species (ROS) and bacteria oxidoreductase genes, respectively, in response to Blastocystis co-incubation. Transepithelial electrical resistance (TEER) and flux assays were performed to assess the effect of microbiota representatives on the integrity of the intestinal epithelial barrier.

RESULTS

Co-incubation with Blastocystis ST4 showed a beneficial influence on most intestinal bacteria, while ST4 significantly inhibited the growth of B. vulgatus, a common pathogen in the genus Bacteroides. The decrease in B. vulgatus when co-incubated with Blastocystis ST4 was associated with high levels of ROS and the upregulation of oxidative stress-related genes. Furthermore, co-incubation with Blastocystis ST4 was able to protect the intestinal epithelial barrier from damage by B. vulgatus.

CONCLUSIONS

This study demonstrated, for the first time, that Blastocystis ST4 has beneficial effects on intestinal commensal bacteria in vitro, and can inhibit the growth of pathogenic B. vulgatus. Combined with previous microbiome research on ST4, our data suggest that ST4 may be a beneficial commensal.

Evidence and possible mechanisms of probiotics in the management of type 1 diabetes mellitus

Abstract

Type 1 diabetes mellitus (T1DM) is one of the most common chronic immune-mediated diseases. The prevalence is worldwide especially among children and young adults. The destruction of the pancreatic β-cells due to some abnormalities in the immune system characterizes T1DM. Considering the high burden of the disease and its impact on human health, researchers have made great efforts during the last decades; investigating the disease pathogenesis and discovering new strategies for its management. Fortunately, probiotics have been found as potential remedies for T1DM. This review aims to explore the potentialities of probiotics in managing T1DM and its complications. Based on the outcomes of human and animal studies carried out from 2016 to 2021, the review hopes to assess the effectiveness of probiotics in the prevention and treatment of T1DM and its complications. We first tried to explain the disease's pathogenesis, and highlighted the possible mechanisms involved in these potentialities of probiotics. We concluded that, probiotics can be used as possible therapeutic tools for the management of T1DM. Possible mechanisms of action of probiotics include; the modulation of the gut microbiota, the regulation of inflammation-related cytokines, the production of short chain fatty acids (SCFAs), and the regulation of GLP-1. However, we recommend further studies especially human trials should be carried out to investigate these potentialities of probiotics.

Highlights

• T1DM is highly prevalent worldwide, causing high morbidity and mortality especially among children and young adults• Gut microbiota plays a significant role in the pathogenesis of T1DM via an interconnection with the immune system• Probiotics can be used as possible therapeutic tools for the management of T1DM• Possible mechanisms of action of probiotics include the modulation of the gut microbiota, the regulation of inflammation-related cytokines, the production of SCFAs, and the regulation of GLP-1.

The Neglected Gut Microbiome: Fungi, Protozoa, and Bacteriophages in Inflammatory Bowel Disease

The gut microbiome has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Studies suggest that the IBD gut microbiome is less diverse than that of the unaffected population, a phenomenon often referred to as dysbiosis. However, these studies have heavily focused on bacteria, while other intestinal microorganisms-fungi, protozoa, and bacteriophages-have been neglected. Of the nonbacterial microbes that have been studied in relation to IBD, most are thought to be pathogens, although there is evidence that some of these species may instead be harmless commensals. In this review, we discuss the nonbacterial gut microbiome of IBD, highlighting the current biases, limitations, and outstanding questions that can be addressed with high-throughput DNA sequencing methods. Further, we highlight the importance of studying nonbacterial microorganisms alongside bacteria for a comprehensive view of the whole IBD biome and to provide a more precise definition of dysbiosis in patients. With the rise in popularity of microbiome-altering therapies for the treatment of IBD, such as fecal microbiota transplantation, it is important that we address these knowledge gaps to ensure safe and effective treatment of patients.

The critical role of gut microbiota in obesity

Obesity is a global epidemic characterized by energy disequilibrium, metabolic disorder, fat mass development, and chronic low-grade inflammation, which significantly affects the health state of individuals of all ages and strains the socioeconomic system. The prevalence of obesity is rising at alarming rates and its etiology involves complicated interplay of diet, genetic, and environmental factors. The gut microbiota, as an important constituent of environmental factors, has been confirmed to correlate with the onset and progression of obesity. However, the specific relationship between obesity and the gut microbiota, and its associated mechanisms, have not been fully elucidated. In this review, we have summarized that the microbial diversity was significantly decreased and the Firmicutes/Bacteroidetes ratio was significantly increased in obesity. The altered gut microbiota and associated metabolites contributed to the progression of the disease by disrupting energy homeostasis, promoting lipid synthesis and storage, modulating central appetite and feeding behavior, as well as triggering chronic inflammation, and that the intentional manipulation of gut microbiota held promise as novel therapies for obesity, including probiotics, prebiotics, and fecal microbiota transplantation.

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.

Nutritional and Health Potential of Probiotics: A Review

Several products consist of probiotics that are available in markets, and their potential uses are growing day by day, mainly because some strains of probiotics promote the health of gut microbiota, especially Furmicutes and Bacteroidetes, and may prevent certain gastrointestinal tract (GIT) problems. Some common diseases are inversely linked with the consumption of probiotics, i.e., obesity, type 2 diabetes, autism, osteoporosis, and some immunological disorders, for which the disease progression gets delayed. In addition to disease mitigating properties, these microbes also improve oral, nutritional, and intestinal health, followed by a robust defensive mechanism against particular gut pathogens, specifically by antimicrobial substances and peptides producing probiotics (AMPs). All these positive attributes of probiotics depend upon the type of microbial strains dispensed. Lactic acid bacteria (LAB) and Bifidobacteria are the most common microbes used, but many other microbes are available, and their use depends upon origin and health-promoting properties. This review article focuses on the most common probiotics, their health benefits, and the alleviating mechanisms against chronic kidney diseases (CKD), type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), and obesity.

Effectiveness and safety of Bifidobacterium in preventing dental caries: a systematic review and meta-analysis

OBJECTIVES

The effectiveness and safety of Bifidobacterium in dental caries prevention are controversial. Thus, we performed this systematic review and meta-analysis to explore the preventive value of Bifidobacterium.

METHODS

Eligible studies were identified from several databases, including PubMed, the Cochrane Library, Embase, Web of Science, and Scopus. Hand searches were also conducted in relevant bibliographies. We then extracted and pooled standardized mean difference (SMD) and risk ratio (RR) to analyze the anti-caries effect of Bifidobacterium with Stata 16.0 software. If the data obtained was not suitable for meta-analysis, qualitative descriptions were performed.

RESULTS

Compared with the placebo control group, there was no statistically significant reduction in Streptococcus mutans and Lactobacilli counts in saliva in the test group. Also, there were no significant differences in Streptococcus mutans and Lactobacillus counts in dental plaque and no significant difference in caries incidence in deciduous teeth. There was no significant difference in the incidence of adverse events between the Bifidobacterium and control groups.

CONCLUSIONS

Available evidence demonstrates that Bifidobacterium is neither effective in reducing Streptococcus mutans and Lactobacillus counts in the saliva or dental plaque nor in reducing the occurrence of caries in deciduous teeth. Evaluation of its safety requires further investigations. Therefore, Bifidobacterium is not a competent probiotic candidate to prevent dental caries.

Prevalence and associated risk factors of intestinal parasitic infections among Egyptian patients with inflammatory bowel disease

The global prevalence of inflammatory bowel disease (IBD) is continuously rising, however, a little is known concerning intestinal parasitic infections (IPIs) and (IBD). We aimed to evaluate the prevalence of IPIs among IBD patients, through a case-control study and also, to correlate the positive cases to the socio-demographic risk factors of IPIs among the study groups. A 1-year case-control study included patients with IBD (n=125) and healthy controls (n=125). The fecal samples were examined with the classical parasitological methods for intestinal parasites. Also, in-vitro culture (for Blastocystis sp.) and Immuno-chromatography technique (for Cryptosporidium / Giardia /Entamoeba) were done. IBD patients had significant higher positivity rate of IPIs compared to healthy controls (Adjusted OR= 9.60, 95% CI: 4.51-20.41, P = 0.0001), with Blastocystis sp., Entamoeba dispar/ histolytica and Cryptosporidium sp. being highly significant in IBD patients. In addition to IBD, living in rural area, with low socio-economic stander, and consumed raw/contaminated food and age group > 50 years old were significant risk factors for IPIs. In conclusion, our results support a possible link between IPIs and IBD.

Alleviation of halitosis by use of probiotics and their protective mechanisms in the oral cavity

Regarding the relation of halitosis with oral infections and its effects on social relations between humans, the present study investigated the positive effects of probiotics on prevention or treatment of halitosis. The causative agents of halitosis are volatile sulphur compounds (VSCs), and halitosis is divided into oral and non-oral types according to the source of the VSCs. H2S and CH3SH are two main halitosis metabolites-produced following the degradation of proteins by bacteria in the mouth-however, CH3SCH3 has a non-oral origin, and is a blood neutral molecule. Just as much as halitosis is important in medicine, its psychological aspects are also considered, which can even lead to suicide. Today, the use of probiotics as a new therapeutic in many roles is in progress. Most probiotics are used for the treatment of gastrointestinal tract disorders, but various studies on the alleviation of halitosis by use of probiotics have reported satisfactory results. The genera Lactobacillus, Streptococcus and Weissella are among the most useful probiotics for the prevention or treatment of halitosis in the oral cavity.

Novel lactotransferrin-derived synthetic peptides suppress cariogenic bacteria in vitro and arrest dental caries in vivo: [Novel lactotransferrin-derived anticaries peptides]

Objectives: The aim of the study was to design and synthesise novel lactotransferrin-derived antimicrobial peptides (AMPs) with enhanced antibacterial activity against cariogenic bacteria. Methods: We obtained the LF-1 (WKLLRKAWKLLRKA) and LF-2 (GKLIWKLLRKAWKLLRKA) AMPs, based on the N-terminal functional sequence of lactotransferrin, and characterised their physicochemical properties and secondary structure. Their antibacterial activity against caries-associated bacteria was evaluated using bacterial susceptibility and time-killing assays, as well as transmission electron microscopy (TEM). The antibiofilm activity against Streptococcus mutans biofilms was determined using biofilm susceptibility assays and confocal laser scanning microscopy (CLSM). A rodent model of dental caries was adopted to evaluate their anticaries effectiveness in vivo. Results: Both peptides possessed an α-helical structure with excellent amphipathicity. LF-1 was effective against S. mutans and Actinomyces species, whereas LF-2 showed more potent antibacterial activity than LF-1 against a broader spectrum of tested strains. Both peptides inhibited the formation of S. mutans biofilm starting at 8 μmol/L and exerted effective eradication of S. mutans in preformed biofilms. Both peptides exhibited satisfactory biocompatibility and exerted significant anticaries effects in a rodent model. Conclusion s: Both lactotransferrin-derived peptides displayed strong antimicrobial activity against cariogenic bacteria and S. mutans biofilm in vitro and effectively inhibited dental caries in vivo.

Effects of compound deer bone extract on osteoporosis model mice and intestinal microflora

The preventive and therapeutic mechanisms of CDBE on osteoporosis were studied by observing the serum bone-related biochemical indicators, bone trabecular micro-structure and intestinal flora in ovariectomized osteoporosis model mice, in order to provide a scientific theoretical basis for the further study on the effect of CDBE on osteoporosis, and the prevention and treatment of osteoporosis with clinical traditional Chinese medicines. The components in CDBE were detected by UHPLC-MS. A mouse osteoporosis model was established by the bilateral ovariectomy in female ICR mice. The biochemical indicators related to osteoporosis were detected, the right proximal tibia was scanned by Micro-CT, the intestinal microflora in the colon contents were examined, and the changes of microflora were taken as the main target to evaluate the effect of CDBE on the intestinal microflora in the model mice. A total of 16 compounds were obtained by the combined application of UHPLC-MS. CDBE could significantly increase the contents of E2, Ca²⁺ , CT, HyP, OCN, FOXP3, P1NP and CTX-II, in the model mice. CDBE could significantly improve the trabecular micro-structure, Tb.N, Tb.Sp, SMI and Conn.D. CDBE could make the intestinal flora of osteoporosis model mice tend to healthy mice in species and quantity. CDBE can improve the symptoms of postmenopausal osteoporosis in mice, with a positive effect on the intestinal flora of postmenopausal mice. Its mechanism of regulating the symptoms of osteoporosis may be related to the regulation of bone-related biochemical indicators in the serum of mice. PRACTICAL APPLICATIONS: This research has a positive impact on the development of functional food with anti-osteoporosis in the future.

Lack of effect of Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12 on beta-cell function in children with newly diagnosed type 1 diabetes: a randomised controlled trial

INTRODUCTION

The gut microbiota may be relevant in the development of type 1 diabetes (T1D). We examined the effects of Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12 on beta-cell function in children with newly diagnosed T1D.

RESEARCH DESIGN AND METHODS

Children aged 8-17 years with newly (within 60 days) diagnosed T1D were enrolled in a double-blind, randomised controlled trial in which they received L. rhamnosus GG and B. lactis Bb12 at a dose of 10⁹ colony-forming units or placebo, orally, once daily, for 6 months. The follow-up was for 12 months. The primary outcome measure was the area under the curve (AUC) of the C-peptide level during 2-hour responses to a mixed meal.

RESULTS

Ninety-six children were randomised (probiotics, n=48; placebo n=48; median age 12.3 years). Eighty-eight (92%) completed the 6-month intervention, and 87 (91%) completed the follow-up at 12 months. There was no significant difference between the study groups for the AUC of the C-peptide level. For the secondary outcomes at 6 months, there were no differences between the study groups. At 12 months, with one exception, there also were no significant differences between the groups. Compared with the placebo group, there was a significantly increased number of subjects with thyroid autoimmunity in the probiotic group. However, at baseline, there was also a higher frequency of thyroid autoimmunity in the probiotic group. There were no cases of severe hypoglycemia or ketoacidosis in any of the groups. No adverse events related to the study products were reported.

CONCLUSIONS

L. rhamnosus GG and B. lactis Bb12, as administered in this study, had no significant effect in maintaining the residual pancreatic beta-cell function in children with newly diagnosed T1D. It remains unclear which probiotics, if any, alone or in combination, are potentially the most useful for management of T1D.

TRIAL REGISTRATION NUMBER

NCT03032354.

New insights into the interactions between Blastocystis, the gut microbiota, and host immunity

The human gut microbiota is a diverse and complex ecosystem that is involved in beneficial physiological functions as well as disease pathogenesis. Blastocystis is a common protistan parasite and is increasingly recognized as an important component of the gut microbiota. The correlations between Blastocystis and other communities of intestinal microbiota have been investigated, and, to a lesser extent, the role of this parasite in maintaining the host immunological homeostasis. Despite recent studies suggesting that Blastocystis decreases the abundance of beneficial bacteria, most reports indicate that Blastocystis is a common component of the healthy gut microbiome. This review covers recent finding on the potential interactions between Blastocystis and the gut microbiota communities and its roles in regulating host immune responses.

A Probiotic Lactobacillus gasseri Alleviates Escherichia coli-Induced Cognitive Impairment and Depression in Mice by Regulating IL-1β Expression and Gut Microbiota

Excessive expression of interleukin (IL)-1β in the brain causes depression and cognitive dysfunction. Herein, we investigated the effect of Lactobacillus gasseri NK109, which suppressed IL-1β expression in activated macrophages, on Escherichia coli K1-induced cognitive impairment and depression in mice. Germ-free and specific pathogen-free mice with neuropsychiatric disorders were prepared by oral gavage of K1. NK109 alleviated K1-induced cognition-impaired and depressive behaviors, decreased the expression of IL-1β and populations of NF-κB⁺/Iba1⁺ and IL-1R⁺ cells, and increased the K1-suppressed population of BDNF⁺/NeuN⁺ cells in the hippocampus. However, its effects were partially attenuated by celiac vagotomy. NK109 treatment mitigated K1-induced colitis and gut dysbiosis. Tyndallized NK109, even if lysed, alleviated cognitive impairment and depression. In conclusion, NK109 alleviated neuropsychiatric disorders and colitis by modulating IL-1β expression, gut microbiota, and vagus nerve-mediated gut-brain signaling.

Effects of Antibiotic Treatment on Gut Microbiota and How to Overcome Its Negative Impacts on Human Health

The need for new antimicrobial therapies is evident, especially to reduce antimicrobial resistance and minimize deleterious effects on gut microbiota. However, although diverse studies discuss the adverse effects of broad-spectrum antibiotics on the microbiome ecology, targeted interventions that could solve this problem have often been overlooked. The impact of antibiotics on gut microbiota homeostasis is alarming, compromising its microbial community and leading to changes in host health. Recent studies have shown that these impacts can be transient or permanent, causing irreversible damage to gut microbiota. The responses to and changes in the gut microbial community arising from antibiotic treatment are related to its duration, the number of doses, antibiotic class, host age, genetic susceptibility, and lifestyle. In contrast, each individual's native microbiota can also affect the response to treatment as well as respond differently to antibiotic treatment. In this context, the current challenge is to promote the growth of potentially beneficial microorganisms and to reduce the proportion of microorganisms that cause dysbiosis, thus contributing to an improvement in the patient's health. An essential requirement for the development of novel antibiotics will be personalized medicinal strategies that recognize a patient's intestinal and biochemical individuality. Thus, this Review will address a new perspective on antimicrobial therapies through pathogen-selective antibiotics that minimize the impacts on human health due to changes in the gut microbiota from the use of antibiotics.

Bifidobacterium animalis ssp. Lactis 420 Mitigates Autoimmune Hepatitis Through Regulating Intestinal Barrier and Liver Immune Cells

Autoimmune hepatitis (AIH) is an immune-mediated inflammatory liver disease of uncertain cause. Accumulating evidence shows that gut microbiota and intestinal barrier play significant roles in AIH thus the gut–liver axis has important clinical significance as a potential therapeutic target. In the present study, we found that Bifidobacterium animalis ssp. lactis 420 (B420) significantly alleviated S100-induced experimental autoimmune hepatitis (EAH) and modulated the gut microbiota composition. While the analysis of clinical specimens revealed that the fecal SCFA quantities were decreased in AIH patients, and B420 increased the cecal SCFA quantities in EAH mice. Remarkably, B420 application improved intestinal barrier function through upregulation of tight junction proteins in both vitro and vivo experiments. Moreover, B420 decreased the serum endotoxin level and suppressed the RIP3 signaling pathway of liver macrophages in EAH mice thus regulated the proliferation of Th17 cells. Nevertheless, the inhibition effect of B420 on RIP3 signaling pathway was blunted in vitro studies. Together, our results showed that early intervention with B420 contributed to improve the liver immune homeostasis and liver injury in EAH mice, which might be partly due to the protection of intestinal barrier. Our study suggested the potential efficacy of probiotics application against AIH and the promising therapeutic strategies targeting gut–liver axis for AIH.

Probiotics in Medicine: A Long Debate

During the last years probiotics gained the attention of clinicians for their use in the prevention and treatment of multiple diseases. Probiotics main mechanisms of action include enhanced mucosal barrier function, direct antagonism with pathogens, inhibition of bacterial adherence and invasion capacity in the intestinal epithelium, boosting of the immune system and regulation of the central nervous system. It is accepted that there is a mutual communication between the gut microbiota and the liver, the so-called “microbiota-gut-liver axis” as well as a reciprocal communication between the intestinal microbiota and the central nervous system through the “microbiota-gut-brain axis.” Moreover, recently the “gut-lung axis” in bacterial and viral infections is considerably discussed for bacterial and viral infections, as the intestinal microbiota amplifies the alveolar macrophage activity having a protective role in the host defense against pneumonia. The importance of the normal human intestinal microbiota is recognized in the preservation of health. Disease states such as, infections, autoimmune conditions, allergy and other may occur when the intestinal balance is disturbed. Probiotics seem to be a promising approach to prevent and even reduce the symptoms of such clinical states as an adjuvant therapy by preserving the balance of the normal intestinal microbiota and improving the immune system. The present review states globally all different disorders in which probiotics can be given. To date, Stronger data in favor of their clinical use are provided in the prevention of gastrointestinal disorders, antibiotic-associated diarrhea, allergy and respiratory infections. We hereby discuss the role of probiotics in the reduction of the respiratory infection symptoms and we focus on the possibility to use them as an adjuvant to the therapeutic approach of the pandemic COVID-19. Nevertheless, it is accepted by the scientific community that more clinical studies should be undertaken in large samples of diseased populations so that the assessment of their therapeutic potential provide us with strong evidence for their efficacy and safety in clinical use.

Therapeutic, Prophylactic, and Functional Use of Probiotics: A Current Perspective

Probiotics are considered as the twenty-first century panpharmacon due to their competent remedial power to cure from gastrointestinal dysbiosis, systematic metabolic diseases, and genetic impairments up to complicated neurodegenerative disorders. They paved the way for an innovative managing of various severe diseases through palatable food products. The probiotics' role as a "bio-therapy" increased their significance in food and medicine due to many competitive advantages over traditional treatment therapies. Their prophylactic and therapeutic potential has been assessed through hundreds of preclinical and clinical studies. In addition, the food industry employs probiotics as functional and nutraceutical ingredients to enhance the added value of food product in terms of increased health benefits. However, regardless of promising health-boosting effects, the probiotics' efficacy still needs an in-depth understanding of systematic mechanisms and factors supporting the healthy actions.

Salmonella Strain Specificity Determines Post-typhoid Central Nervous System Complications: Intervention by Lactiplantibacillus plantarum at Gut-Brain Axis

Neurological complications occurring due to Salmonella infection in some typhoid patients remain a relatively unexplored serious complication. This study firstly aimed to explore whether disseminative ability of Salmonella from gut to brain is strain specific or not and on the basis of bacterial load, histopathology, and behavioral changes, it was observed that Salmonella enterica serovar Typhimurium NCTC 74 did not cause brain infection in murine model in contrast to Salmonella Typhimurium SL1344. Simultaneously, alarming escalation in antimicrobial resistance, making the existing antibiotics treatment inefficacious, prompted us to evaluate other bio-compatible strategies as a potential treatment option. In this context, the role of gut microbiota in influencing behavior, brain neurochemistry, and physiology by modulating key molecules associated with gut-brain axis has captured the interest of the scientific community. Followed by in vitro screening of potential probiotic strains for beneficial attributes, efficacy of the selected strain was systematically evaluated at various levels of gut-brain axis against Salmonella induced brain infection. Analysis of behavioral (depression, anxiety, and locomotor), neurochemical [gamma amino butyric acid and acetylcholinesterase (AChE)], neuropathological (brain and intestinal histology; bacterial burden), and immunohistochemical studies (tight junction proteins expression) revealed its role in preventing serious manifestations and proving its potential as "psychobiotic." To the best of our knowledge, this is the first report elaborating strain specificity of Salmonella in causing post-typhoidal neurological manifestations and simultaneous use of probiotic in managing the same by influencing the pathophysiology at gut-brain axis.

Enhanced Viability and Anti-rotavirus Effect of Bifidobacterium longum and Lactobacillus plantarum in Combination With Chlorella sorokiniana in a Dairy Product

Microalgae and probiotics such as Bifidobacterium and Lactobacillus genera are associated with human beneficial effects. The aim of this study was to evaluate the activity of Chlorella sorokiniana on Bifidobacterium longum and Lactobacillus plantarum viability in a dairy product (flan) and its microbial effect against rotavirus, which is one of the major diarrhea-causing pathogens worldwide. Microalge were isolated from a Mexican river and characterized by molecular tools. Their prebiotic activity was evaluated by determining Bifidobacterium longum and Lactobacillus plantarum shelf-life after incorporation in the food matrix. In addition, HT-29 cells were infected with rotavirus Wa and treated with 1 × 10⁹ CFU/mL L. plantarum and B. longum metabolites alone or in combination with 1 × 10⁹ cells/mL Chlorella sorokiniana; viral titers in probiotics- and/or microalgae-treated cells were evaluated for antiviral activity. Results indicated that C. sorokiniana not only significantly (p < 0.05) improved L. plantarum and B. longum viability in flan, but also increased their antiviral activity; potent anti-rotavirus effect of C. sorokiniana alone was observed. Although more studies are needed, results suggest that incorporation of this microalga into a dairy product confers enhanced viability and antiviral effects, which indicates that C. sorokiniana might be used as an ingredient to design products with additional health benefits.