Beneficial microbes最新文献

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.

Several studies have documented the safety and tolerance of probiotics in infants, however, most studies have been conducted with supplements. This randomised, double-blind, multicenter trial evaluated growth of healthy term infants fed infant formula supplemented with Limosilactobacillus reuteri DSM17938 (L. reuteri; n = 92) or Bifidobacterium lactis CNCM I-3446 (B. lactis; n = 92) or the same formula without probiotics ( n = 95). Mixed feeding with breast milk was allowed in each group. Exclusively breastfed infants ( n = 100) were included for reference. Non-inferiority in weight gain (margin -3 g/day) from enrolment to age 6 months was the primary outcome. Length, BMI, head circumference, and WHO z-scores from birth to 12 months were assessed, as was digestive tolerance, and, in a subset of infants, urinary D-lactate parameters and abundance of key bacteria in fecal matter. Of 279 infants randomised, 256 completed the study. The mean difference in weight gain between each probiotic group and the standard group at age 6 months was -0.378 g/day (97.5% confidence interval (CI), -1.541, 0.776; P < 0.001) for L. reuteri and -1.724 g/day (97.5% CI, -2.845, -0.603; P = 0.005) for B. lactis, indicating non-inferior growth. Anthropometric z-scores were not significantly different between any of the formulas, over the entire study, except for a slightly lower weight-for-age z-score in the B. lactis vs standard group at 8 months ( P = 0.034). No differences in adverse events or urinary D-lactate levels were observed. Significantly higher fecal lactobacilli counts were observed with L. reuteri supplementation ( 7.0 log 10 (CFU/g); n = 24) compared with standard formula ( 6.2 log 10 (CFU/g); n = 21). Parent-reported digestive tolerance symptoms were similar between the formula groups and comparable to the breastfed group. Weight gain from enrolment to age 6 months in infants fed formula containing probiotics L. reuteri DSM17938 or B. lactis CNCM I-3446 was non-inferior versus infants fed the same formula without probiotics. Both probiotic formulas were safe and well-tolerated.

Although several internationally recognised scientific groups and non-governmental organisations have attempted to define 'postbiotics,' there remains no consensus. Leading experts have highlighted persistent problems of terminological inconsistency, lack of standardisation, and unclear boundaries between related concepts. What is needed is a comprehensive analysis that integrates existing definitions with considerations of manufacturing processes, mechanisms of action, and clinical applications. Ultimately, progress requires harmonisation of terminology to ensure comparability across studies and to provide a solid foundation for both academic and industry development.

Irritable bowel syndrome (IBS) is faced by gastroenterologists daily, and probiotics are a potential therapeutic tool; however, there are no strain recommendations. This multicenter, real-world, single-arm, open-label study aims to assess a novel probiotic mixture's effectiveness, safety, and patient satisfaction in patients with IBS. This study was conducted by 52 Italian gastroenterologists across 16 of the 21 Italian regions who enrolled patients with IBS (n = 1,098). Throughout the 8-week treatment (T1) period with a probiotic mixture (Lactobacillus paracasei 101/37 LMG P-17504, Lactobacillus plantarum 14D CECT 4528, Bifidobacterium breve Bbr8 LMG P-17501, Bifidobacterium breve BL10 LMG P-17500, and Bifidobacterium animalis ssp. lactis Bi1 LMG P-17502), participants completed a questionnaire to evaluate IBS symptoms at baseline, at the end of treatment, and after one-month follow-up (T2). The primary outcome was the progress of abdominal pain and bloating according with a 5-point Likert scale, (0 absence and 5 highly intense symptoms) and treatment success was defined as a change towards categories of lower IBS severity for abdominal pain and/or bloating. Treatment success for abdominal pain and bloating was achieved in 73% and 81.9% at T1 and 68% and 73.1% at T2, respectively. The probiotic was associated with significantly reducing abdominal pain and bloating at T1 and T2 (P < 0.001). Patients with regular bowel movements increased to 68.5% at T1 and 68.7% at T2, respectively (P < 0.001). Patients reporting that IBS did not affect their daily life increased from 1.8% at entry to 22.7% at T1 and 41.6% at T2 (P < 0.001). This real-world, single-arm, open-label study showed that an 8-week treatment with a novel probiotic mixture is effective, safe, well tolerated, and can improve patients' social lives during and after treatment. Future randomised placebo-controlled studies are necessary to validate these findings. The trial is registered at www.ClinicalTrials.gov (NCT06610149).

Abnormal colonisation of the ileal mucosa by adherent-invasive Escherichia coli (AIEC) is a key feature of Crohn's disease. To date, no curative treatment for this disease exists, highlighting the need to develop new therapies targeting the origin of the inflammation, in particular the intestinal microbiota and more specifically AIEC. This study investigated the anti-virulence properties of 17 bacterial strains (lactobacilli and bifidobacteria) and three plant extracts (walnut and green tea leaves and liquorice roots) against AIEC. In vitro, six lactobacilli strains and one bifidobacterium strain reduced AIEC LF82 adhesion to Caco-2/TC7 cells and/or suppressed IL-8 secretion induced by AIEC. Although plant extracts did not prevent adhesion or inflammation, they inhibited AIEC growth. In a murine model of dextran sulfate sodium-induced colitis exacerbated by LF82 infection, two Lacticaseibacillus strains, one Bifidobacterium strain, and walnut and green tea extracts efficiently alleviated colitis and reduced faecal lipocalin-2 levels. For the green tea extract and one Lacticaseibacillus strain, beneficial effects were correlated with a decreased number of AIEC associated with the colonic mucosa. Building on these findings, bacteria and plant extract combinations were tested in the same model. A formulation combining two Lacticaseibacillus strains (Lbs. casei and Lbs. rhamnosus) with the walnut extract demonstrated the greatest efficacy, markedly reducing colitis score and preserving intestinal mucosa integrity. While untreated mice remained heavily colonised, the combination promoted AIEC elimination from the gut of half the mice, contributing to the alleviation of colitis symptoms. These results highlight the ability of combinations of specific bacteria/plant extracts to limit the presence of AIEC in the ileal mucosa of Crohn's disease patients, presenting a promising approach for disease management.

The effects of probiotics on the gut microbiota and microbial metabolites in healthy individuals are not well understood. Faecal and serum samples were collected at the start and end of a 3-month, double-blind, placebo-controlled, randomised study with three different probiotic formulations in free-living, healthy adults. The composition of the faecal microbiota and levels of faecal and/or serum short-chain fatty acids (SCFA) and bile acids (BA) were measured and the probiotic formulations were found to impart differing effects including shifts in the composition and structure of the faecal microbiota, enhanced levels of circulating short chain fatty acids such as butyrate and propionate, and elevated levels of sulphated bile acids in faeces. This was in contrast to the outcomes for the placebo population where very little change occurred over the study. These findings demonstrate that probiotic supplementation elicits formulation specific effects and that there are potential benefits for healthy individuals.

Equol is an isoflavone produced by intestinal microbiota from daidzein. It has been assumed that individuals with equol-producing microbiota are those who mainly benefit from isoflavone consumption. However, no obvious genotypic differences can be found between the microbiota of equol-producing individuals and non-equol-producing individuals. The aim of this work was to find phenotypic differences in isoflavone metabolism between equol-producing and non-equol-producing intestinal microbiota. Of the 17 faecal samples used in this work, six produced equol from both daidzein and dihydrodaidzein (DHD); however, only equol-producing faecal samples produced 5-hydroxy-equol from genistein and dihydrogenistein (DHG). The equol producing microbiota metabolised most of daidzein, genistein, DHD and DHG present in the medium, while the metabolism of daidzein and genistein by non-equol producing microbiota is much lower, and they do not metabolise DHD and DHG. Moreover, equol-producing faecal samples produced lower concentrations of O-DMA than the non-equol-producing faecal samples. In addition, we demonstrated that most of the O-DMA is produced from daidzein. Therefore, there are important phenotypic differences between equol-producing and non-equol-producing intestinal microbiota, and these differences explain the differentiation between equol-producing and non-equol-producing individuals, and help to understand the metabolism of isoflavones by microbiota and how intestinal microbiota is responsible for the benefits of isoflavone intake.

Lactobacillus johnsonii CRL1647 has been studied due to its beneficial effects on Apis mellifera L. bee colonies. In this work, we analyzed the characteristics of its cell envelope and the relationship of this bacterial structure with adhesion. The study revealed that CRL1647 cells did not harbor S-layer proteins, whereas L. acidophilus ATCC4356, used as a positive control, showed a typical S-layer protein band. L. johnsonii CRL1647 hemagglutinated with sheep erythrocytes. Interestingly, the hemagglutination abilities of L. johnsonii CRL1647 were affected by the treatments with proteinase K and sodium metaperiodate. Transmission electron microscopy (TEM) analysis confirmed that L. acidophilus ATCC4356 has S-layer and revealed that the L. johnsonii CRL1647 cell surface was full of prolongations like 'hairs'. These ultra-structures completely disappeared after the treatment with proteinase K. The CRL1647 strain was able to efficiently adhere to intestinal epithelial cells and was phagocyted by macrophages. Both, adhesion and phagocytosis were significantly diminished when CRL1647 cells were pretreated with proteinase K. From these results, it can be inferred that the principal molecules involved in the adherence of L. johnsonii CRL1647 have a glycoprotein structure, differing them from S-layer proteins.

This study investigated the effects of Dysosmobacter welbionis J115T on stress- and anxiety-related behaviours, inflammation, and neurobiological markers under different dietary conditions in female mice. Daily oral gavage with D. welbionis J115T for six weeks did not significantly impact body weight or fat mass, regardless of dietary treatment. Notably, high-fat diet (HFD)-fed female mice displayed increased body weight and adipose tissue accumulation compared to control diet (CTD) counterparts; however, this was not significantly altered by D. welbionis J115T administration. Behavioural testing revealed that HFD-fed female mice exhibited a mild stress/anxiety-like phenotype, especially in the elevated plus maze (EPM) and forced swim test (FST), which was attenuated by D. welbionis J115T treatment. These mice showed increased exploratory behaviour in the light-dark test (LDT), reduced time spent in closed arms of the EPM, and longer cumulative time in a highly active state in the FST. Plasma corticosterone levels, elevated post-behavioural testing in all female groups, increased less in HFD-fed D. welbionis-treated mice, suggesting a blunted stress response. These findings highlight sex-specific behavioural and molecular responses to dietary and probiotic interventions and suggest that D. welbionis J115T may modulate stress-related behaviours in female mice via the gut-brain axis.