Beneficial microbes最新文献

Stress significantly affects gastrointestinal and mental health, and the gut microbiota plays a pivotal role in this process. Enterococcus faecalis strain EC-12 (EC-12) is a lactic acid bacterium that has several health benefits. To investigate the impact of oral supplementation with heat-killed EC-12 on the discomfort caused by stress, a randomised, double-blind, placebo-controlled trial was conducted with students under academic stress taking EC-12 (n = 14) or a placebo (n = 13) daily for one week. Improvement in the students' symptoms was assessed using the visual analogue scale. Faecal microbiota was characterised by next-generation sequencing of 16S rRNA genes, and faecal metabolites and short-chain fatty acids were analysed using a GC-MS metabolomics approach. Significant improvements in abdominal pain and rumbling of the stomach were found in the EC-12 group compared to the placebo group, but no changes were observed in mental symptoms or salivary cortisol levels. The relative abundance of E. faecalis significantly increased in the EC-12 group after the trial; however, the composition and diversity of the gut microbiota did not change significantly. Functional analysis of the gut microbiota suggested that EC-12 intake alters specific metabolic pathways. Although the levels of faecal short-chain fatty acids did not change between the groups before and after the trial, EC-12 intake altered the composition of faecal metabolites, with a significant increase in tryptamine levels. The ratio of students with improved symptoms to those with increased tryptamine levels was calculated based on the number of students with elevated faecal tryptamine levels who showed symptomatic improvements. The ratio of improved rumbling stomach was higher than that of other types of digestive discomfort. These results suggest that oral supplementation with EC-12 has a potentially beneficial effect on stress-induced gastrointestinal discomfort, which may occur through alterations in gut microbiota composition and metabolism. This study was registered at the University Hospital Medical Information Network Center (UMIN) under the UMIN ID: UMIN000048184.

Cow's milk protein allergy (CMPA) in infancy is associated with intestinal microbial dysbiosis, characterised by low Bifidobacteriaceae levels. The present study aimed to investigate the impact of two human milk oligosaccharides (HMO), lactose (L), and their combination on the faecal microbiome and metabolome of infants with CMPA. Stool samples of 12 term infants with probable CMPA (mean age 4.3 months) were analysed using a validated intestinal fermentation assay (SIFR® technology). For each substrate (i.e. HMO (2'-fucosyllactose [2'-FL] and lacto-N-neotetraose [LNnT]), L and HMO + L), taxonomic microbiome characterisation and untargeted metabolite profiling were performed at multiple timepoints. At baseline, the tested faecal microbiota overall displayed low abundances of Bifidobacteriaceae. Fermentation with either HMO or lactose significantly enriched Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium pseudocatenulatum and, for HMO + L, also Bifidobacterium bifidum. The increase in HMO-utilising bifidobacteria was associated with a significant rise in levels of short-chain fatty acids, aromatic lactic acids and N-acetylated amino acids, with additive effects being observed for HMO + L. The above data suggest that the combination of 2'-FL, LNnT and lactose helps to alleviate the previously reported CMPA-associated intestinal bacterial dysbiosis and induces the production of several beneficial metabolites. The clinical significance of these findings for infants with CMPA requires further investigation.

Hyperlipidaemia, the abnormally high concentration of lipids such as cholesterol in the body, has a series of deleterious effects on health that are least in part are due to increased inflammation and oxidative stress. Probiotics are living microorganisms that possess the efficacy to improve health. Among the many effects that have been ascribed to probiotics is the potential to lower the body lipid content. Here, we used a rat model of induced hyperlipidaemia to assess the lipid-lowering and antioxidant properties of the probiotic strain Bifidobacterium animalis MSMC83 as well as its impact on intestinal barrier immunity and the intestinal microbiota. Oral probiotic intake led to a reduction of body weight, fasting blood glucose, and lipid levels, and increased expression of cholesterol-7α-hydroxylase and antioxidant enzymes. Additionally, B. animalis MSMC83 decreased the levels of liver enzymes and pro-inflammatory cytokines, leading to reduced hepatic steatosis. Furthermore, it re-established intestinal barrier integrity as shown by restoration of the tight junction protein zonula occludens-1 amount and reduced pathogen-induced inflammation in the intestinal epithelium as shown by readjusted expression of toll-like receptors (TLRs). Moreover B. animalis MSMC83 contributed to the maintenance of a balanced, diverse microbiome. Thus, our results indicate that B. animalis MSMC83 alleviates risk factors associated with hyperlipidaemia, suggesting its use as a probiotic to counter the effects associated with unhealthy diets.

The human gut microbiota is increasingly being recognised to play an important role in maintaining health. The families Lachnospiraceae and Oscillospiraceae in particular, are often reduced in disease states but are relatively poorly represented in culture collections. Cultured representatives are required to investigate the physiology and host interactions of gut microbes. Establishing cultured isolate collections can be laborious and expensive owing to the fastidious growth requirements of these organisms and the costs associated with taxonomic classification. This study proposes a culturomics platform combining a single basal culture medium with matrix-assisted laser adsorption/ionisation coupled to time-of-flight mass spectrometry (MALDI-TOF MS) for fast and reliable isolation and identification of hundreds of novel isolates. In this study, basal YCFA medium supplemented with either glucose, apple pectin, or porcine mucin was used to cultivate a total of 724 different isolates derived from only 11 different faecal samples from healthy volunteers, of which 389 isolates belonged to the Lachnospiraceae and Oscillospiraceae families. Moreover, 27 isolates could not be assigned to known species based on their 16S rRNA gene, 17 of which may even represent novel genera. To aid MALDI-TOF MS identification of gut bacteria, the commercial database was complemented with the MaldiGut database presented here, containing a collection of 132 different Main Spectrum Profiles, including the profiles of 125 Firmicutes species, 3 Bacteroidetes species, 3 Actinobacteria species, and one Verrucomicrobia species. The culturomics platform and MaldiGut database presented here will enable further expansion of the gut culturome, especially within the understudied Lachnospiraceae and Oscillospiraceae families.

Chronic constipation is a multi-symptomatic, multifactorial, and heterogeneous gastrointestinal disorder. Current pharmacological treatments for chronic constipation are limited and might negatively impact the patients' quality of life. Although probiotics have been shown to improve constipation symptoms, their specific regulatory mechanisms remain unclear. This study sought to explore how probiotic complexes may affect chronic constipation by improving patients' defecation habits. Furthermore, microbial profiles and non-targeted metabolites were assessed to explore the metabolic pathways involved in the improvement of constipation by probiotics. Patients with chronic constipation were treated using a single-blind, randomised, placebo-controlled trial design. The experimental group was administered Lactobacillus powder prepared from 15 probiotic products, and maltodextrin was used as a placebo. Samples were collected twice daily for 4 weeks, and faecal samples were analysed using 16S rRNA sequencing and untargeted metabolic histology. Probiotic treatment changed the makeup of the gut microbiota, enhanced the quantity of Bifidobacterium and Lactobacillus, and markedly reduced clinical symptoms. The 16S rRNA analysis revealed that the abundance of Bifidobacterium and Prevotella increased while that of Thickettsia declined. Moreover, there was a decrease in the abundance of Faecalibacterium and Roseburia. Non-targeted metabolomics analysis identified several differential metabolites, including succinic acid, fumaric acid, cholesterol, xanthurenic acid, 3-alpha,7-alpha-trihydroxy-5beta-cholestan-26-oic, and N-methyltryptamine. KEGG analysis showed that these metabolites were mainly associated with metabolic pathways such as primary bile acid biosynthesis, tryptophan metabolism, alanine, aspartate and glutamate metabolism, phenylalanine metabolism, cholesterol metabolism, and propanoate metabolism. In this study, gut microbiome and non-targeted metabolome analyses were performed on collected faecal samples to compare characteristic microorganisms and differential metabolites to provide new insights and references for probiotic intervention in constipation. Trial registered at chictr.org.cn under number: ChiCTR2200056274.

Asthma prevalence has been increasing in communities that become more urbanised. Our previous results showed that Saccharomyces cerevisiae UFMG A-905 prevented the development of asthma symptoms and characteristics in a dose-dependent manner. Perinatal programming theory proposes that early exposure to some stimuli may have a protective effect in adult life. The aim of this study was to evaluate the effects of perinatal administration of S. cerevisiae UFMG A-905 in the prevention of asthma in the offspring of mice. S. cerevisiae UFMG A-905 was cultured in YPD broth medium and administered to three groups of mice: before conception, during gestation and lactation (CGL group); during gestation and lactation (GL group); and only during lactation (L group). The offspring of these animals were sensitised and challenged with ovalbumin. Two control groups received saline in the same periods. After, in vivo measurements of airway hyperresponsiveness (AHR) were performed. Total and differential cell count in bronchoalveolar lavage (BAL); ELISA for interleukin (IL)-4, IL-5, IL-10, IL-13, and IL-17A in the lung homogenate or BAL; and ELISA for ovalbumin (OVA)-specific immunoglobulin E (IgE) were performed. The animals of the CGL, GL, and L group, when compared to the OVA group, presented a significant reduction of AHR ( P < 0.01), levels of IL-5 ( P < 0.001) in BAL, and IL-4 ( P < 0.05) and IL-13 ( P < 0.01) in the lung homogenate. Serum IgE levels were significantly higher ( P < 0.05) in CGL and GL groups when compared to the OVA group, but not in the L group. Only in the group L, there was a significant decrease in the number of total cells ( P < 0.01) and eosinophils ( P < 0.05). Perinatal administration of S. cerevisiae UFMG A-905 prevented the development of asthma-like characteristics and may be an option for asthma management. The protective effects on the offspring were more prominent when the yeast was given during lactation.

The world is witnessing an increasing incidence of chronic non-communicable diseases (NCDs), such as inflammatory bowel disease (IBD), a group of complex gastrointestinal disorders characterised by inflammation. It is believed that environmental factors, such as exposure to pollutants and endocrine-disrupting chemicals (i.e. bisphenol A [BPA]), are playing a role in IBD pathophysiology. New research suggests a potential treatment solution: next-generation probiotic (NGP) strains isolated from human gut microbiota that can biodegrade xenobiotics and thus possibly modulate IBD triggered by these xenobiotics. In this study, we hypothesised that specific BPA-tolerant bacteria would exhibit beneficial, anti-inflammatory properties that could counter the effects of BPA exposure and concomitantly reduce colitis severity. We observed that two such strains, Bacillus sp. AM1 and Paeniclostridium sp., exhibited potential anti-inflammatory properties in vitro and in vivo. First, these bacteria were able to decrease the secretion of interleukin (IL)-8 cytokines by HT-29 cells that had been exposed to the proinflammatory cytokine tumour necrosis factor (TNF)-α. Second, when treated with Bacillus sp. AM1 and Paeniclostridium sp. (this latter had a stronger reducing effect on inflammatory markers), mice with chemically induced colitis displayed lower levels of colon damage, monocyte chemotactic protein 1 (MCP-1), lipocalin-2 (LCN-2), and proinflammatory cytokines (IL-1β and IL-6). Future research should clarify the underlying mechanisms at play and identify potential strategies for counteracting the systemic effects of IBD, including those exacerbated by BPA exposure. Our results suggest that one such strategy could be treatment with BPA-tolerant bacteria that possess anti-inflammatory properties.

Obesity is a risk factor for cardio-metabolic and neurological disease. The contribution of gut microbiota to derangements of the gut-brain axis in the context of obesity has been acknowledged, particularly through physiology modulation by short-chain fatty acids (SCFAs). Thus, probiotic interventions and administration of SCFAs have been employed with the purpose of alleviating symptoms in both metabolic and neurological disease. We investigated the effects of four butyrate-producing bacteria from the Lachnospiraceae family on the development of metabolic syndrome and behavioural alterations in a mouse model of diet-induced obesity. Male mice were fed either a high-fat diet (HFD) or an ingredient-matched control diet for 2 months, and bacteria cultures or culture medium were given by gavage to HFD-fed mice every second day. Mice were assessed through a battery of metabolic and behaviour tests, and fluxes through the gut barrier and blood-brain barrier were determined using Dextran-based tracers. One of the administered bacteria from the Coprococcus genus, which produces butyrate and formate, afforded some degree of protection against the development of obesity and its complications. Results from this study, however, are insufficient to support brain health benefits of the bacteria tested. None of the bacteria modulated permeability through the gut or blood-brain barriers. Our results suggest health benefits of a bacteria from Lachnospiraceae family, and encourage further exploration of its use as probiotic.

The causes and characteristics of gut microbiota abnormalities and whether microbiota manipulation can prevent atherosclerosis in the postmenopausal stage remain to be determined. Aortic oestrogen receptor expression, histological changes and gut microbiota in women before and after menopause were detected. Serum oestrogen levels, systemic inflammation, intestinal oestrogen receptor expression and histological changes, atherosclerosis, and gut microbiota in low density lipoprotein deletion (LDLR-∕-) female mice before and after ovariectomy were tested. This study examined aortic oestrogen receptor expression, histological changes, and gut microbiota in women before and after menopause, and tested serum oestrogen levels, systemic inflammation, intestinal oestrogen receptor expression, histological changes, atherosclerosis, and gut microbiota in low-density lipoprotein receptor knockout (LDLR-∕-) female mice before and after ovariectomy. We demonstrated that the downregulation of oestrogen and oestrogen receptors after menopause promotes gut microbiota disturbance in both women and female mice. We found that gut microbiota disturbance amplifies the intestinal barrier damage and aggravates systemic inflammation, thereby promoting atherosclerosis in female mice. Faecal microbiota transplantation and antibiotics inhibit the proinflammatory properties of gut microbiota and prevent atherosclerosis by reducing intestinal barrier damage in postmenopausal mice. Together, our study highlights the causes of gut microbiota disturbances and the role of microbiota manipulation in preventing atherosclerosis in postmenopausal stage.

Chronic unpredictable mild stress (CUMS) is a widely accepted method for inducing depressive-like states in animal models. We decided to explore the effects of CUMS on the CantonS lineage of Drosophila melanogaster, which differs from the OregonR lineage in various ways. Additionally, we wanted to investigate the potential benefits of kefir in treating these chronically stressed flies, as previous research has shown promising results in using kefir components for depression treatment. To begin, we exposed male CantonS flies to a 10-day CUMS protocol and compared them to non-stressed flies. Within the stressed group, we had two subgroups: one treated with kefir (CUMS + Kefir group) and the other treated with sertraline (positive control). We then analysed various factors including serotonin levels, brain structure, markers of oxidative damage in lipids and proteins, and behavioural manifestations such as sociability, locomotor function, and anhedonic-like behaviour. Our results showed that flies exposed to CUMS experienced a decrease in serotonin levels without any signs of degeneration. They also exhibited reduced sociability, increased motor agitation, and decreased sucrose consumption, which are all indicative of stress-induced depressive-like behaviour. However, treatment with sertraline partially reversed these effects. Interestingly, treatment with kefir not only restored serotonin levels but also improved sociability and anhedonic-like behaviours. Additionally, flies in the CUMS + Kefir group had a longer lifespan compared to their untreated counterparts. These findings suggest that kefir has multiple advantageous effects on flies subjected to the 10-day CUMS protocol. In conclusion, our study demonstrates that the CantonS lineage of D. melanogaster displays depressive-like manifestations after exposure to CUMS. Furthermore, kefir emerges as a powerful nutritional tool capable of reversing these effects and promoting beneficial outcomes in chronically stressed flies.