Beneficial microbes最新文献

Prebiotics or fermentable dietary fibres are known for their potential to shape the gut microbial community and could be used as a tool in treating gut dysbiotic states found in a wide range of diseases. However, it remains unclear whether the microbiota of individuals with distinct diseases respond to fibre treatments in the same way as healthy individuals do. In this study, a mechanistic understanding of fibre responses across health conditions was performed through in vitro faecal fermentations with various dietary fibres and faecal microbial communities from healthy individuals (HC) as well as Crohn's disease (CD), ulcerative colitis (UC), and Parkinson's disease (PD). Production of short chain fatty acids (SCFAs) was measured, and microbial community structure shifts were assessed using 16S rRNA gene amplicon sequencing. All tested dietary fibres increased short chain fatty acid production upon fermentation, with variations based on both, disease state and fibre type. The magnitude of shifts in microbial community structure resulting from in vitro fermentation varied by condition; for example, samples from individuals with UC responded weakly to fibre fermentation, while those from individuals with PD underwent dramatic changes. Still, each health condition had distinct fibre types that were more effective in shifting the community structure and increasing SCFAs. Overall, these results suggest that the response to fibres on gut microbiota varies by disease. The selection of disease-specific prebiotics could be tailored according to health conditions for optimal desired gut microbiota responses.

Lactic acid bacteria are a group of microorganisms recognised for their health-promoting properties, with several strains being commercially utilised as probiotics. Probiotics offer numerous benefits, including modulation of the immune system, enhancement of nutrient absorption, regulation of intestinal microbiota, protection against intestinal pathogens, and strengthening of the intestinal barrier. However, the precise mechanisms by which probiotics exert their effects remain incompletely understood. In recent years, research into new therapeutic applications for probiotics has intensified, driven by the urgent need for strategies to combat antibiotic-resistant bacteria. Among the newly discovered properties of probiotics is their ability to produce antivirulence compounds. These compounds reduce the virulence of pathogens without inhibiting microbial growth, thereby imposing less selective pressure for the development of resistance compared to traditional antibiotics. Given the potential for these compounds in clinical settings, this study aims to provide a comprehensive review of the antivirulence activities of probiotics, with particular focus on lactic acid bacteria. It discusses their effects on two-component and quorum sensing systems, which regulate the simultaneous expression of various virulence genes, as well as their anti-adhesion, anti-biofilm, anti-toxin, and anti-enzymatic activities against a range of pathogens. Thus, this review offers insight into the novel mechanisms by which lactic acid bacteria contribute to health, potentially broadening their applications.

Hydrogen metabolism plays a central role in microbial fermentation. However, how hydrogenotrophic microbes impact microbiota composition and metabolite production in gut ecosystems remains largely unknown. Hence this study aims to investigate the impact of altering hydrogenotrophic activities, namely methanogenesis and sulphate reduction, on human gut microbiota composition and metabolite production. Faecal slurries from three methane excretors (MEs) and three non-methane excretors (NMEs) were inoculated into a basal medium with pectin or a carbohydrate mixture as substrates. Methanogenesis was inhibited by adding 2-bromoethanesulfonate to ME incubations or stimulated by adding Methanobrevibacter smithii to NME incubations. Sulphate reduction was stimulated by adding sodium sulphate to both incubations. Our observations revealed that microbial richness and composition, and propionate and methane production differed significantly between MEs and NMEs. Lower hydrogen concentrations were observed in MEs compared to NMEs in the incubations with pectin, but not with the carbohydrate mixture. Remarkably, sulphate was not consumed in either ME or NME incubations. Adding M. smithii to the NME inocula resulted in its persistence in the community and methane production during incubations. The addition of 2-bromoethanesulfonate inhibited methane production in the ME incubations, accompanied with a lower relative abundance of methanogens when pectin was used as substrate. However, altering methanogenesis did not significantly change overall microbiota composition and short-chain fat acid production in MEs and NMEs. These findings suggest that methanogens can occupy a niche in a microbiota that originally lacks methanogens, but that modulating methanogenesis has a minor effect on overall microbiota composition and activity.

The elucidation of the gut-brain axis underscores the critical role of probiotics in enhancing mental wellbeing through immunomodulatory mechanisms. We thus aimed to investigate the effects of a probiotic Lactiplantibacillus plantarum Probio87 (orally administered one sachet/day; 9 log cfu/sachet) or placebo for 12-weeks, on immunity and brain health, via possible mechanisms of inflammation and neurotransmitter functions in a generally healthy women population. A parallel, randomised, double-blind and placebo-controlled study was performed in generally healthy women (n = 112). Women were randomised to either the probiotic (n = 58, mean age 38.38 ± 0.85 years) or placebo (n = 54, mean age 38.91 ± 0.98 years) for 12-weeks. Immunity and mental wellbeing profiles were evaluated via questionnaires and blood gene expression profiles. Over the study period, the Probio87 group demonstrated a better impact on general women's health as compared to the control group, as measured by the Women's Health Questionnaire (WHQ), particularly in domains related to depressed mood, somatic symptoms, anxiety, sexual health, sleep, and menstrual health. The probiotic effects were exhibited later, typically after 6-weeks of intervention, taking over placebo effects that primarily faded off during early stages of the intervention. Regarding immunity, women in the Probio87 group exhibited upregulation of more immunity-related genes than those in the placebo group, primarily associated with NK cells and anti-inflammatory effects via IL-10. Additionally, Probio87 provided gut-brain axis benefits by enhancing the actions of neurotransmitters serotonin and GABA, while also balancing hunger and satiety. The probiotic Lactiplantibacillus plantarum Probio87 significantly improved general health, mood, anxiety, and sleep in a generally healthy women population over 12 weeks. It enhanced immune function through increased expression of immunity-related genes and positively modulated neurotransmitters involved in brain health. All these findings supported from our WHQ data, where the administration of probiotic improved domains related to depressed mood, anxiety, sexual behaviour and sleep problems. The study is registered at ClinicalTrials.gov under identifier number: NCT05302687.

An altered gut microbiota has been shown to contribute to the development of metabolic diseases such as obesity. In this study gut microbiota profile of 30 obese and 23 lean Lebanese individuals was performed via DNA isolation and sequencing of the V3-V4 region of the 16S rRNA of faecal samples. The abundance of the phylum Verrucomicrobiota was higher in lean subjects and there was no significant difference in the Bacillota/ Bacteroidota ratio between the obese and lean groups. The evenness and Shannon alpha diversity indices were significantly higher in the lean group than in the obese group ( q = 0.012 and q = 0.030, respectively). Beta diversity was higher in the obese group based for unweighted uniFrac distance variability ( q = 0.047). Lachnoclostridium was the only genus that was higher in obese ( q = 0.013) and it is linked to diet induced obesity, while the abundance of the genera Peptococcus, Ruminococcus_2, Lachnospiraceae UCG-001, Ruminiclostridium 6, the uncharacterised taxon within Coriobacteriaceae, Ruminococcaceae UCG-005, Ruminococcaceae UCG-010 and Oxalobacter, were significantly higher in lean subjects. These bacterial species that were higher in lean people, possess anti-inflammatory properties through the production of short chain fatty acids and are linked with lower body mass index, promote satiety and weight loss and may play a role in the protection against obesity and type 2 diabetes. Further research to generate a clear understanding of the interaction of the gut microbiota and health is needed.

It has already been recognised that lung microbiota differs in healthy and diseased lungs. In chronic obstructive pulmonary disease (COPD), a change in the structure, abundance and diversity of lung microbiota correlates with the severity of disease. But how the members of lung microbiota influence healthy and diseased lungs, as well as how they are affected by the lung health status is still largely unknown. In this study, we applied a dual RNA sequencing in order to scrutinise an early interspecies interaction between healthy and diseased human primary bronchial epithelial cells exposed to the beneficial bacteria Lactiplantibacillus plantarum BGPKM22. In healthy and diseased cells interaction with BGPKM22 led to a change in expression of 52 and 45 genes, respectively. The genes IQCN, LINC01554, KCNB1, and CDK7 indicated a specific response of human bronchial epithelial cells exposed to the BGPKM22 strain, regardless of the health status. Markedly more genes showed a change in expression in the BGPKM22 strain in interaction with healthy than with diseased cells, 486 and 101, respectively. Interaction with human bronchial epithelial cells caused a stress to bacteria, but the response of bacteria depended on the health status of the cells. The adhesion of the BGPKM22 strain was better to healthy, than to diseased cells. The fitness of the BGPKM22 strain increased only in interaction with healthy, but not with diseased cells. Remarkably, interaction with healthy, but not with diseased cells, stimulated the synthesis of exopolysaccharide layer of the strain BGPKM22. So, beneficial effects of bacteria can be diminished in interaction with diseased cells. Also, a lowered affinity of bacteria towards diseased environment can explain microbiota dysbiosis in the diseased lungs, such as lungs in patients with COPD.

Faecalibacterium is an essential probiotic in the human gut; changes in its abundance are associated with various disease states in many studies. However, the causal nature of such associations remains obscure. Therefore, we aimed to thoroughly investigate the causal relationships between Faecalibacterium and its related diseases. A two-sample bi-directional Mendelian randomisation analysis was conducted using publicly available genome-wide association studies summary statistics for Faecalibacterium and its related diseases. We found that Faecalibacterium was negatively correlated with the risk of ankylosing spondylitis (odds ratio [OR] = 0.526, 95% confidence interval [CI]:0.304-0.908, P = 0.021), atopic dermatitis (OR = 0.484, 95%CI: 0.261-0.898, P = 0.021) and heart failure (OR = 0.657, 95%CI: 0.467-0.924, P = 0.016), while Faecalibacterium was positively associated with autism spectrum disorder risk (OR = 2.529, 95%CI: 1.012-6.319, P = 0.047). The results of reverse Mendelian randomisation analysis showed that acute sinusitis (OR = 0.902, 95%CI: 0.839-0.970, P = 0.005) and Alzheimer's disease (OR = 0.976, 95%CI: 0.958-0.993, P = 0.008) was causally associated with lower Faecalibacterium abundance, respectively, while cirrhosis (OR = 1.154, 95%CI: 1.028-1.295, P = 0.015) and multiple myeloma (OR = 2.619 × 1012, 95%CI: 2.492-2.754 × 1024, P = 0.043) was causally associated with higher Faecalibacterium abundance. Our findings firstly showed that changes in Faecalibacterium abundance may contribute to the risk of ankylosing spondylitis, atopic dermatitis, heart failure and autism spectrum disorders, and potentially as a result of acute sinusitis, Alzheimer's disease, cirrhosis and multiple myeloma.

Probiotics can confer a beneficial effect on gastrointestinal-related symptoms and their impact on daily life. This randomised, double-blind, placebo-controlled study assessed the efficacy of a novel probiotic strain Bacillus subtilis ATCC 122264 as a probiotic on gas-related symptoms in healthy adults. One hundred healthy adults with functional bloating/distension according to the ROME IV criteria, were randomised in a 1:1 ratio to receive either 5 billion cfu of B. subtilis) or placebo daily for 8 weeks. Intestinal gas symptoms and impact on daily life were assessed weekly by the 17-item Intestinal Gas Questionnaire (IGQ) and the change from baseline was analysed by ANCOVA at 4 and 8 weeks. Post-hoc analyses were conducted on the two parts of the IGQ, scored separately. Sub-group analyses based on sex were also done on the IGQ global and dimension scores as well as the scores from the two individual parts of the IGQ. Safety was assessed by reports of adverse events. B. subtilis did not differ from placebo in the change from baseline to Weeks 4 or 8 in IGQ global score or dimension scores of bloating, flatulence, belching, bad breath, stomach rumbling and difficult gas evacuation ( P > 0.05). In females taking B. subtilis, the severity of belching and flatulence significantly decreased after 4 ( P = 0.046) and 8 weeks ( P = 0.039) respectively, compared to females taking placebo. The impact of flatulence on daily life decreased after 8 weeks in females taking B. subtilis compared to placebo ( P = 0.03). B. subtilis was safe and well tolerated over the 8-week study period. The results suggest that B. subtilis may reduce gas-related symptoms, such as bloating and flatulence, in females. Further studies are needed to confirm the sex-related effects of B. subtilis in populations with gastrointestinal symptoms. Registered at Clinicaltrials.gov: NCT06308146.

Prebiotics are becoming increasingly recognized by consumers, health care professionals and regulators as important contributors to health. Nonetheless, the development, progress, and adoption of prebiotics is hindered by loose terminology, various misconceptions about sources and types of compounds that may be classified as prebiotics, and the lack of consensus on a definition that satisfies regulators. Evolving knowledge of the microbiome and its effects on host health has generated opportunities for modulation of the microbiota that can support host health. Various types of biotics - probiotics, prebiotics, and postbiotics, are compounds that either modulate the microbiota or arise from the microbiota, affecting health locally and distally. Each of these classes of biotic compounds have distinct, yet complementary benefits. While many scientists have proposed definitions for prebiotics, and there have been attempts by selected scientists to develop a 'consensus definition', the fact remains that globally, scientists, manufacturers, and marketers have adopted different definitions to suit their own interests and purposes, leading to confusion among consumers and health care professionals. The pathway to regulatory acceptance and to reduce/eliminate confusion is a definition that puts the focus on the consumer, and the benefits that consumers can realise from consumption of prebiotics. This consumer-focused approach, supported by science, will also align with regulators and support broader regulatory approval of prebiotics as a category. In this review, we discuss the history of prebiotics, and introduce criteria and a decision tree to classify compounds as prebiotics, supported by the scientific literature to date. This includes a summary of compounds that have been clearly recognised as prebiotics. We also review the microbiota, microbiome, and the various ways in which prebiotics can beneficially affect the microbiota and health. The safety and efficacy of prebiotics is also reviewed, along with effective doses and limitations associated with prebiotic use. This includes scientific tools and methods that help to establish the function, safe use and efficacy of a prebiotic. We also identify misconceptions that can be addressed in communications to consumers and health care professionals. Manufacturing guidelines and the current regulatory status of prebiotics in various jurisdictions are also reviewed. Collectively, this review provides an in-depth overview of the role for prebiotics to support the health of consumers. This consumer-focused approach provides clear criteria for the product category, safe use, effective communication of health benefits and limitations, and a pathway towards regulatory approval.

Understanding the viability of ingested probiotics within the gastrointestinal tract is essential for evaluating their efficacy and deciphering their mechanisms of action. Detecting Bifidobacterium longum subspecies longum BB536 is particularly challenging owing to its indistinguishability from the naturally abundant B. longum species in the human gut. We aimed to address this challenge by developing a selective culture medium for B. longum BB536 and employing a propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) method to verify the survival of the probiotic after consumption. To achieve this, we designed a novel lactose-mupirocin-trimethoprim (LMT) medium that facilitates the cultivation of B. longum BB536 under anaerobic conditions at 42 °C. We screened 52 healthy adults and enrolled 39 who met the eligibility criteria. The participants were randomised into two groups, with 34 completing the protocol: 17 received commercial yogurt containing B. longum BB536 (9.30 log10 cfu/day) and 17 received a placebo. Prior to the intervention, B. longum BB536 was undetectable in all participants. However, following supplementation, LMT culturing identified viable B. longum BB536, with average counts of 6.33 ± 0.69 log10 cfu/g on day 3 and 6.16 ± 0.74 log10 cfu/g on day 17. PMA-qPCR further validated these results, showing viable cell counts of 6.09 ± 0.68 log10 cells/g wet faeces on day 3 and 6.44 ± 0.64 log10 cells/g wet faeces on day 17. While each method detected B. longum BB536 in some participants where the other did not, no participant tested negative by both methods at any time point. This complementarity between LMT culturing and PMA-qPCR ensures a comprehensive detection strategy, confirming the presence and resilience of B. longum BB536 in the gastrointestinal tract and underscoring its potential as a beneficial probiotic strain (UMIN000052110). Japan Conference of Clinical Research: registration number: BYG2B-01; University Hospital Medical Information Network: study protocol registration UMIN000052110.