Beneficial microbes最新文献

Oxidative stress plays a key role in colitis, a type of Inflammatory Bowel Disease, particularly when associated with a high-fat diet (HFD). Probiotics are known to alleviate inflammation through multiple mechanisms. This study aimed to evaluate the efficacy of a potential probiotic mixture with high antioxidant activity in attenuating colitis in mice fed either a normal diet (ND) or an HFD, with a focus on oxidative stress-related pathways. Eighty-eight Lactobacillus and Bifidobacterium strains isolated from healthy human faeces and milk were screened for antioxidant capacity. The six most active strains were selected to formulate a probiotic cocktail. Male C57BL/6 mice were divided into ND and HFD groups, each receiving dextran sulphate sodium (DSS) alone or combined with the probiotic cocktail. Disease indices, histopathology, and the expression of genes related to NF-kB and Nrf2 signalling, as well as oxidative and inflammatory markers, were assessed. Mice treated with the probiotic cocktail showed significant attenuation of DSS-induced colitis, evidenced by lower Disease Activity Index and pathological scores, and improved intestinal morphology ( P < 0.05). Both dietary groups exhibited elevated antioxidant enzyme activity and anti-inflammatory cytokine levels ( P < 0.05). The modulation of Nrf2 and NF-kB-related gene expression was more pronounced in ND-fed mice. The findings suggest that this novel probiotic cocktail can effectively alleviate colitis symptoms, likely by regulating oxidative stress and inflammatory pathways. Its incorporation as an adjunct therapy, particularly alongside a balanced diet, may offer a promising strategy for colitis management.

We investigated the therapeutic potential of Lactobacillus salivarius in colitis mice, and the mice were randomly allocated into three groups with each consisting of 10 mice (n = 10): a control group (CSG), a DSS-induced colitis model group (DSG), and a L. salivarius intervention group (LSG). The intervention group received daily oral administration of L. salivarius for seven consecutive days. Compared to the DSS model group, mice receiving L. salivarius exhibited significantly reduced weight loss, lower DAI scores, lessened colon shortening, and improved histopathological profiles, indicating a substantial reduction in inflammatory damage. Additionally, ITS sequencing revealed that L. salivarius significantly influenced the composition of the intestinal fungal community, decreasing the abundance of pathogenic fungi, such as Candida species, by approximately 40%, and restoring fungal homeostasis by reducing the Basidiomycota/Ascomycota ratio. Moreover, L. salivarius effectively alleviated DSS-induced oxidative stress by lowering serum MDA levels while enhancing the activity of SOD and GSH-Px. Furthermore, the probiotic intervention resulted in 30-40% reduction in pro-inflammatory factors (TNF-α, IL-6, and IL-1β) and an increase in the anti-inflammatory factor IL-10 levels, suggesting a pronounced anti-inflammatory effect. In conclusion, L. salivarius exerts significant protective effects against DSS-induced colitis by modulating the gut fungal community, mitigating oxidative stress, and suppressing inflammatory responses. This study is novel in that few probiotic studies have investigated the impact of L. salivarius on gut fungi in DSS-induced colitis. These findings highlight its potential as a therapeutic candidate for managing inflammatory bowel disease.

Lacticaseibacillus paracasei strain Shirota (LcS), promotes intestinal homeostasis, modulates immune cells, and provides anti-stress benefits. Four years of BLP (Biolactis powder: LcS preparation) administration is known to suppress the recurrence of highly dysmorphic polyps in participants who underwent colorectal adenoma resection. Furthermore, adenoma development tended to be suppressed in patients undergoing colorectal adenoma resection who consumed BLP for >20 years, accompanied by a reduction in aging weight loss. However, the underlying mechanisms and effects of prolonged BLP intake on gut mucosa and microbiota remain unclear. Hence, we aimed to analyse the gut microbiota and host gene expression in endoscopically obtained colonic mucosal tissue from participants who had been voluntarily consuming BLP for more than 20 years, as well as from non-consumers of BLP. The faecal and mucosal microbiota of the BLP group revealed a high detection rate and abundance of Coprococcus genus and a rich population of butyrate-producing bacteria. Conversely, the mucosa of the control group was enriched in opportunistic pathogens and environmental bacteria, including those from the families Pseudomonadaceae and Brachyspiraceae. RNA-seq of the colon mucosa of BLP-consuming patients revealed high expression of genes related to the oxidative phosphorylation (OXPHOS) pathway, including those of the mitochondrial electron transfer system. Additionally, T cell- and G-protein-coupled receptor-related genes were overexpressed in BLP-consuming patients. These findings indicate that prolonged BLP intake increases the abundance of butyrate-producing bacteria and activates the OXPHOS pathway in colonic mucosal tissue, which alters the enteroenvironment and limits colonisation by opportunistic pathogens. These findings may contribute to the prevention of colorectal cancer development and have implications for promoting healthy longevity. Clinical Trial Registry number: 000025389.

The effects of Lactiplantibacillus mudanjiangensis IYO1739 and Lactiplantibacillus plantarum IYO1653, isolated from Japanese post-fermented tea, and their type strains on skin cells were evaluated. The normal human epidermal keratinocyte (NHEK) cells were treated with each strain, and after 2 h, the cells were washed and the number of adhered bacteria was measured. L. mudanjiangensis showed high adhesion, while L. plantarum strains showed little adhesion. After washing, the cells were cultured in bacteria-free medium for an additional 4 h and 24 h, and the expression levels of genes related to maintaining skin health were evaluated. Cells treated with L. mudanjiangensis showed increased expression of hyaluronan synthases (HAS1 and HAS3), sphingomyelinases involved in ceramide synthesis (SGMS1 and SGMS2), sphingomyelin phosphodiesterase 1 (SMPD1), involucrin, and transglutaminase 1 (TGM1) genes. These effects were weak or absent in L. plantarum strains. In addition, the IYO1739 strain of L. mudanjiangensis was more effective than the type strain DSM28402T. Furthermore, IYO1739 grew faster in MRS broth than DSM28402T, and showed particularly good growth at 37 °C. In addition, the expression of skin-related genes was enhanced by even heat-killed bacteria. These results suggest that L. mudanjiangensis strains, especially IYO1739, are beneficial for maintaining healthy skin.

Anaemia in the elderly increases the risk of cardiovascular disease, cognitive decline, and death. Probiotics have recently been shown to be potentially effective in preventing the onset or improving the condition of anaemia. Here, we retrospectively investigated the relationship between fermented milk intake over the prior 10 years and the risk of developing anaemia during the same period. The participants were community-dwelling Japanese aged 65-94 years who had not developed anaemia in the 10 years prior to the time of the survey. They were divided into two groups based on their intake frequency (<3 or ≥3 days/week, n = 1,186 and n = 238, respectively) of fermented milk products containing Lacticaseibacillus paracasei strain Shirota (LcS products) for the prior 10 years. The incidence and risk of anaemia in the participants were analysed using chi-squared test and Cox proportional hazards regression analysis. The results indicated that incidence of anaemia over the 10-year interval was significantly lower in those who took LcS products ≥3 rather than <3 days/week (anaemia incidence: 0.8% vs 4.0%, P = 0.016). Furthermore, multivariable analysis using Cox proportional hazards regression to adjust for potential confounders also showed a significantly lower relative risk of developing anaemia in the group consuming LcS products ≥3 days/week (hazard ratio 0.219; 95% confidence interval 0.053-0.902; P = 0.035). These findings suggest that habitual consumption of LcS products on ≥3 days/week by individuals 65 years or older may reduce their risk of developing anaemia.

Predicting probiotic strain properties that translate into beneficial effects in the host is challenging and could be considered the holy grail in developing new probiotics. One approach is to selectively evolve well-studied probiotic strains known to elicit beneficial effects in clinical studies. In this study, Limosilactobacillus reuteri DSM 17938, among the world's most studied probiotic strains, constituted the origin from which the novel strain L. reuteri BG-R46® (DSM 32846) was obtained by exposure to bile, a major stressor of the gastrointestinal tract. The bioactivity of DSM 32846 in preclinical models is documented elsewhere; this work adds crucial strain characteristics, genomic and phenotypic safety profiles, and safety and tolerability in a randomised human study. DSM 32846 was compared to DSM 17938 in terms of tolerance to bile and synthetic gastric juice, with DSM 32846 showing increased bile tolerance and slightly reduced tolerance to gastric pH. Morphological examination by scanning electron microscopy revealed high abundance of extracellular membrane vesicles on the surface of DSM 32846, a previously described bioactive feature of the strain. In addition, the activity of 5'-nucleotidase, an adenosine-producing enzyme expressed on the bacterial cell surface and membrane vesicles, was increased in large-scale production batches of DSM 32846 compared to DSM 17938. Phenotypic safety assessment showed that DSM 32846 does not produce any of the evaluated biogenic amines, produces D- and L-lactate with a ratio typical for the species, and lacks haemolytic activity. The minimum inhibitory concentration profile for antibiotics did not raise any safety concerns. A genome safety assessment revealed no antibiotic resistance and virulence genes. DSM 32846 was found safe for human consumption with no differences from the control group in any of the evaluated parameters. In conclusion, L. reuteri DSM 32846 is a safe strain that shows interesting differences to its parent strain DSM 17938.

Wheat is a staple food for human consumption thanks to its nutritional and technological quality. Worldwide, around 8% of the population is affected by wheat-related disorders, such as wheat allergy, celiac disease or non-celiac gluten-sensitivity. Food processing can modify gluten protein structure and immunoreactivity. Bacterial fermentation by Lactic Acid Bacteria (LAB) is of particular interest, as fermentation can cause the hydrolysis of gluten proteins. Our study aimed to identify LAB capable of hydrolysing gluten and to establish optimal fermentation conditions. Fifteen bacterial strains were screened on a liquid medium containing gluten as the sole nitrogen source. The protein profile of all fermentation products was characterised by SDS-PAGE. Of selected strains, a detailed peptide analysis of hydrolysed fermentation products was performed using mass spectrometry. Protein immunoreactivity was assessed by competitive ELISA. Finally, the bacterial enzyme class responsible for gluten hydrolysis was identified. One strain of Enterococcus faecalis (CIRM-BIA2928) was capable of hydrolysing gluten during fermentation. Fermentation time and bacterial cell concentration were identified as two factors modulating proteolysis. Gluten proteolysis led to a clear reduction in the immunoreactivity of the R5 peptide, implicated in celiac disease. This proteolysis was caused by zinc metalloprotease enzymes. Enterococcus faecalis CIRM-BIA2928 has interesting characteristics for hydrolysing wheat proteins. Hydrolyzed gluten could be used for preventive purposes to induce oral tolerance or for therapeutic purposes in wheat-allergic patients to avoid triggering a reaction.

Acute diarrhoea in young children is very common and remains an important health problem. This study aimed to assess the effectiveness of a multistrain synbiotic compound in a drops formulation for treating acute diarrhoea of probable viral origin in children aged ≤2 years. A prospective, multicentre, randomised, open-label and controlled study was conducted in a cohort of 75 children (40 received a one-week treatment with a 7-multistrain synbiotic drops plus supportive therapy and 35 received supportive therapy alone). Based on the WHO definition of diarrhoea (≥3 loose/liquid stools/day) and the Bristol Stool Form Scale (BSFS) (stool consistency 5-7), a higher percentage of children in the synbiotic group experienced less diarrhoea (70%) vs controls (88.6%) ( P = 0.050). This statistically significant difference was present since day two of treatment. When diarrhoea was defined as ≥3 bowel movements/day for ≥3 consecutive days, diarrhoea was absent in 20% of children in the synbiotic group, whereas none of those in the control group was free of diarrhoea ( P = 0.006). The median days with diarrhoea was 4 (range 3-6.5) in the synbiotic group and 6 (range 5-7) in the control group ( P = 0.002). The use of this synbiotic product allowed children's diarrhoeal process to be shortened by two days and promoted a faster recovery. These results along a very favourable safety and tolerability profile supports the use of this multistrain synbiotic product in acute diarrhoea of suspected viral origin in children two years old or younger.

Autoaggregation is an often-overlooked but critical phenotypic trait in Lactobacillus species that plays a pivotal role in host colonisation, pathogen exclusion, and probiotic functionality. This review explores the molecular mechanisms, surface factors, and environmental cues influencing aggregation, distinguishing it from but also linking it to biofilm formation. While traditionally associated with initial steps in biofilm development, autoaggregation in lactobacilli can occur independently of and sometimes conversely to biofilm production. We assess the contributions of surface proteins, such as S-layer proteins and aggregation-promoting factors, and those of exopolysaccharides, pili, and environmental modulators in shaping aggregation behaviour. In addition, we discuss how aggregation enhances mucosal adhesion, immune modulation, and competitive exclusion of pathogens, making it a promising selection marker for next-generation probiotics and live biotherapeutics. Finally, we stress the need for standardised methods and advanced tools to elucidate the complex interplay between bacterial surface architecture and lifestyle strategies like aggregation and biofilm formation.

We hypothesised and investigated whether commensal probiotic bacteria from bovine organs are capable of synthesising β-carotene and retinol. A total of 111 potentially probiotic bacteria were isolated from the liver (β-carotene storage site), intestine (β-carotene bioconversion site) and rumen (β-carotene absorption site) tissues. Among these strains, 33 were screened based on vitamin A biosynthesis capability using UV spectroscopy and identified through matrix-assisted laser desorption/ionisation coupled with time-of-flight mass spectrometry analysis. Four Lactiplantibacillus plantarum (22.82 ± 1.85 to 111.95 ± 3.10 μg β-carotene g-1 dry cell weight) and one Escherichia coli (44.77 ± 2.08 μg β-carotene g-1 dry cell weight) strains with higher β-carotene and or retinol production capacity were further quantified through ultra (high) performance liquid chromatography-quadrupole-time of flight mass spectrometer. Lactiplantibacillus plantarum (VLL1) of liver origin showed good viability in gastric acid (pH 2.0) and bile salts (0.3%) and better tolerance in other probiotic properties. Hence, this study shows the β-carotene producing Lactiplantibacillus strains from the bovine origin as a potential source of vitamin A biofortification. Perhaps this study also establishes that the gut-friendly property of these probiotic strains with metabolic machinery for bioconversion of β-carotene to retinoids will be useful in eradicating vitamin A deficiency through probiotic therapy.