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1.
Food Res Int ; 186: 114287, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38729740

ABSTRACT

The gut microbiota is widely acknowledged as a crucial factor in regulating host health. The structure of dietary fibers determines changes in the gut microbiota and metabolic differences resulting from their fermentation, which in turn affect gut microbe-related health effects. ß-Glucan (BG) is a widely accessible dietary fiber to humans, and its structural characteristics vary depending on the source. However, the interactions between different structural BGs and gut microbiota remain unclear. This study used an in vitro fermentation model to investigate the effects of BG on gut microbiota, and microbiomics and metabolomics techniques to explore the relationship between the structure of BG, bacterial communities, and metabolic profiles. The four sources of BG (barley, yeast, algae, and microbial fermentation) contained different types and proportions of glycosidic bonds, which differentially altered the bacterial community. The BG from algal sources, which contained only ß(1 â†’ 4) glycosidic bonds, was the least metabolized by the gut microbiota and caused limited metabolic changes. The other three BGs contain more diverse glycosidic bonds and can be degraded by bacteria from multiple genera, causing a wider range of metabolic changes. This work also suggested potential synergistic degradation relationships between gut bacteria based on BG. Overall, this study deepens the structural characterization-microbial-functional understanding of BGs and provides theoretical support for the development of gut microbiota-targeted foods.


Subject(s)
Bacteria , Fermentation , Gastrointestinal Microbiome , beta-Glucans , beta-Glucans/metabolism , Gastrointestinal Microbiome/physiology , Humans , Bacteria/metabolism , Bacteria/classification , Dietary Fiber/metabolism , Metabolomics
2.
BMC Microbiol ; 24(1): 163, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38745280

ABSTRACT

Spontaneous fermentation of cereals like millet involves a diverse population of microbes from various sources, including raw materials, processing equipment, fermenting receptacles, and the environment. Here, we present data on the predominant microbial species and their succession at each stage of the Hausa koko production process from five regions of Ghana. The isolates were enumerated using selective media, purified, and phenotypically characterised. The LAB isolates were further characterised by 16S rRNA Sanger sequencing, typed using (GTG)5 repetitive-PCR, and whole genome sequencing, while 28S rRNA Sanger sequencing was performed for yeast identification. The pH of the millet grains ranged from mean values of 6.02-6.53 to 3.51-3.99 in the final product, depending on the processors. The mean LAB and yeast counts increased during fermentation then fell to final counts of log 2.77-3.95 CFU/g for LAB and log 2.10-2.98 CFU/g for yeast in Hausa koko samples. At the various processing stages, the counts of LAB and yeast revealed significant variations (p < 0.0001). The species of LAB identified in this study were Limosilactobacillus pontis, Pediococcus acidilactici, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Pediococcus pentosaceus, Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Schleiferilactobacillus harbinensis, and Weissella confusa. The yeasts were Saccharomyces cf. cerevisiae/paradoxus, Saccharomyces cerevisiae, Pichia kudriavzevii, Clavispora lusitaniae and Candida tropicalis. The identification and sequencing of these novel isolates and how they change during the fermentation process will pave the way for future controlled fermentation, safer starter cultures, and identifying optimal stages for starter culture addition or nutritional interventions. These LAB and yeast species are linked to many indigenous African fermented foods, potentially acting as probiotics in some cases. This result serves as the basis for further studies into the technological and probiotic potential of these Hausa koko microorganisms.


Subject(s)
Fermentation , Fermented Foods , Food Microbiology , Millets , Yeasts , Ghana , Yeasts/classification , Yeasts/isolation & purification , Yeasts/genetics , Yeasts/metabolism , Fermented Foods/microbiology , Millets/microbiology , Lactobacillales/classification , Lactobacillales/isolation & purification , Lactobacillales/genetics , Lactobacillales/metabolism , RNA, Ribosomal, 16S/genetics , Phylogeny , Hydrogen-Ion Concentration , Edible Grain/microbiology
4.
Food Chem ; 450: 139309, 2024 Aug 30.
Article in English | MEDLINE | ID: mdl-38631200

ABSTRACT

Flammulina velutipes, a widely cultivated species of edible fungus, exhibits diverse functional activities attributed to its polysaccharides. In this study, we employed an in vitro model to investigate the impact of F. velutipes polysaccharides (FVP) fermentation on gut microbiota, with a particular focus on Bacteroides. FVP fermentation resulted in the proliferation of microbiota associated with short-chain fatty acid (SCFA) metabolism and suppression of Escherichia-Shigella. Bacteroides emerged as potential primary degraders of FVP, with species-level analysis identifying the preference of B. thetaiotaomicron and B. intestinalis in FVP degradation. Metabolomics analysis revealed significant increases in hypoxanthine and 7-methyladenine contents, with histidine metabolism emerging as the most enriched pathway. B. nordii and B. xylanisolvens exhibited the most influence on amino acid and SCFA metabolism. Understanding the mechanisms by which gut microbiota metabolize FVP can provide valuable insights into the potential of FVP to promote intestinal health and disease prevention.


Subject(s)
Bacteroides , Feces , Fermentation , Flammulina , Gastrointestinal Microbiome , Humans , Flammulina/metabolism , Flammulina/chemistry , Feces/microbiology , Bacteroides/metabolism , Polysaccharides/metabolism , Polysaccharides/chemistry , Fatty Acids, Volatile/metabolism , Bacteria/metabolism , Bacteria/classification , Bacteria/isolation & purification , Bacteria/genetics , Male , Adult
5.
Nutr Neurosci ; : 1-14, 2024 Jan 03.
Article in English | MEDLINE | ID: mdl-38170169

ABSTRACT

Over recent decades, dietary patterns have changed significantly due to the increasing availability of convenient, ultra-processed refined foods. Refined foods are commonly depleted of key bioactive compounds, which have been associated with several deleterious health conditions. As the gut microbiome can influence the brain through a bidirectional communication system known as the 'microbiota-gut-brain axis', the consumption of refined foods has the potential to affect cognitive health. In this study, multi-omics approaches were employed to assess the effect of a refined diet on the microbiota-gut-brain axis, with a particular focus on bile acid metabolism. Mice maintained on a refined low-fat diet (rLFD), consisting of high sucrose, processed carbohydrates and low fibre content, for eight weeks displayed significant gut microbial dysbiosis, as indicated by diminished alpha diversity metrics (p < 0.05) and altered beta diversity (p < 0.05) when compared to mice receiving a chow diet. Changes in gut microbiota composition paralleled modulation of the metabolome, including a significant reduction in short-chain fatty acids (acetate, propionate and n-butyrate; p < 0.001) and alterations in bile acid concentrations. Interestingly, the rLFD led to dysregulated bile acid concentrations across both the colon (p < 0.05) and the brain (p < 0.05) which coincided with altered neuroinflammatory gene expression. In particular, the concentration of TCA, TDCA and T-α-MCA was inversely correlated with the expression of NF-κB1, a key transcription factor in neuroinflammation. Overall, our results suggest a novel link between a refined low-fat diet and detrimental neuronal processes, likely in part through modulation of the microbiota-gut-brain axis and bile acid dysmetabolism.

6.
Environ Pollut ; 344: 123357, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38228262

ABSTRACT

Nonylphenol (NP), an endocrine disruptor absorbed through food intake, was investigated in this study for its potential dose-response relationship with the manifestation of depression-like behavior in rats. Based on this, the mechanisms of NP-induced depressive behavior, encompassing neurotransmitters, gut barrier function, inflammatory response, gut microbiota composition and metabolites were further explored. At medium and high NP doses, both mRNA and protein levels of zonula occludens protein-1 and claudin-1 were considerably downregulated, concomitant with an elevation in tumor necrosis factor-α and interleukin-1ß expression in a dose-dependent effect, resulting in damage to the gut mucosa. Despite a minimal impact on behavior and gut barriers at low NP doses, alterations in gut microbiota composition were observed. During NP exposure, dose-dependent changes in the gut microbiota revealed a decline in microbial diversity linked to the synthesis of short-chain fatty acids. NP not only adversely affected the gut microbiota structure but also exacerbated central nervous system damage through the gut-brain axis. The accumulation of NP may cause neurotransmitter disturbances and inflammatory responses in the hippocampus, which also exacerbate depressed behavior in rats. Therefore, NP could exacerbate the inflammatory response in the hippocampus and colon by compromising intestinal barrier integrity, facilitating the proliferation of pathogenic bacteria, impairing butyrate metabolism, and perturbing neurotransmitter homeostasis, thus aggravating the depressive behavior of rats. It is noteworthy that the changes in these indicators were related to the NP exposure dose.


Subject(s)
Gastrointestinal Microbiome , Animals , Rats , Phenols/pharmacology , Tumor Necrosis Factor-alpha , Neurotransmitter Agents
7.
Microb Cell Fact ; 22(1): 256, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38087304

ABSTRACT

BACKGROUND: Gamma-aminobutyric acid (GABA) is a non-protein amino acid with neuroinhibitory, antidiabetic, and antihypertensive properties and is used as a drug for treating anxiety and depression. Some strains of lactobacilli are known to produce GABA and strengthen the gut barrier function which play an important role in ameliorating the effects caused by the pathogen on the gut barrier. The probiotic bacteria are also known to modulate the human fecal microbiota, however, the role of GABA-producing strains on the gut epithelium permeability and gut microbiota is not known. RESULTS: In this study, we report the production of high levels of GABA by potential probiotic bacterium Limosilactobacillus fermentum L18 for the first time. The kinetics of the production of GABA by L18 showed that the maximum production of GABA in the culture supernatant (CS) occurred at 24 h, whereas in fermented milk it took 48 h of fermentation. The effect of L18 on the restoration of lipopolysaccharide (LPS)-disrupted intestinal cell membrane permeability in Caco-2 monolayers showed that it significantly restored the transepithelial electrical resistance (TEER) values, by significantly increasing the levels of junction proteins, occludin and E-cadherin in L18 and LPS-treated Caco-2 cells as compared to only LPS-treated cells. The effect of GABA-secreting L18 on the metataxonome of human stool samples from healthy individuals was investigated by a batch fermentor that mimics the conditions of the human colon. Although, no differences were observed in the α and ß diversities of the L18-treated and untreated samples at 24 h, the relative abundances of bacterial families Lactobacillaceae and Bifidobacteriaceae increased in the L18-treated group, but both decreased in the untreated groups. On the other hand, the relative abundance of Enterobacteriaceae decreased in the L18 samples but it increased in the untreated samples. CONCLUSION: These results indicate that Li. fermentum L18 is a promising GABA-secreting strain that strengthens the gut epithelial barrier by increasing junction protein concentrations and positively modulating the gut microbiota. It has the potential to be used as a psychobiotic or for the production of functional foods for the management of anxiety-related illnesses.


Subject(s)
Gastrointestinal Microbiome , Limosilactobacillus fermentum , Probiotics , Humans , Caco-2 Cells , Lipopolysaccharides , Intestinal Barrier Function , Bacteria/metabolism , Probiotics/therapeutic use
8.
Food Funct ; 14(22): 10135-10150, 2023 Nov 13.
Article in English | MEDLINE | ID: mdl-37901912

ABSTRACT

Aging is characterized by a decline in biological functions, leading to various health issues. There is significant interest in mitigating age and age-related health issues. Gut microbiota has emerged as a crucial target for combating aging and influencing host health. This study evaluated the anti-aging effects of Lactiplantibacillus plantarum CCFM8661 in mice and the role of the gut microbiota in mediating its effects. Aging was induced in mice using D-galactose, and L. plantarum CCFM8661 was orally administered for 8 weeks to evaluate its effects on age-related decline and the gut microbiota. The results demonstrated that supplementation with L. plantarum CCFM8661 effectively alleviated cognitive impairment and oxidative stress in the aging brain, as well as liver oxidation and bone damage, and impaired intestinal barrier function in aging mice. Furthermore, L. plantarum CCFM8661 modulated the gut microbiota of aging mice, increasing the abundance of beneficial bacteria, such as Ruminococcaceae, and influenced the functionality of the gut microbiota to promote the production of active metabolites. These findings suggest that L. plantarum CCFM8661 has a mitigating effect on organismal aging, especially brain aging.


Subject(s)
Galactose , Gastrointestinal Microbiome , Mice , Animals , Galactose/adverse effects , Aging , Oxidative Stress , Brain
9.
Food Res Int ; 172: 113187, 2023 10.
Article in English | MEDLINE | ID: mdl-37689939

ABSTRACT

Cranberry (poly)phenols may have potential health benefits. Circulating (poly)phenol metabolites can act as mediators of these effects, but they are subjected to an extensive inter-individual variability. This study aimed to quantify both plasma and urine (poly)phenol metabolites following a 12-week intake of a cranberry powder in healthy older adults, and to investigate inter-individual differences by considering the existence of urinary metabotypes related to dietary (poly)phenols. Up to 13 and 67 metabolites were quantified in plasma and urine respectively. Cranberry consumption led to changes in plasma metabolites, mainly hydroxycinnamates and hippuric acid. Individual variability in urinary metabolites was assessed using different data sets and a combination of statistical models. Three phenolic metabotypes were identified, colonic metabolism being the main driver for subject clustering. Metabotypes were characterized by quali-quantitative differences in the excretion of some metabolites such as phenyl-γ-valerolactones, hydroxycinnamic acids, and phenylpropanoic acids. Metabotypes were further confirmed when applying a model only focused on flavan-3-ol colonic metabolites. 5-(3',4'-dihydroxyphenyl)-γ-valerolactone derivatives were the most relevant metabolites for metabotyping. Metabotype allocation was well preserved after 12-week intervention. This metabotyping approach for cranberry metabolites represents an innovative step to handle the complexity of (poly)phenol metabolism in free-living conditions, deciphering the existence of metabotypes derived from the simultaneous consumption of different classes of (poly)phenols. These results will help contribute to studying the health effects of cranberries and other (poly)phenol-rich foods, mainly considering gut microbiota-driven individual differences.


Subject(s)
Phenol , Vaccinium macrocarpon , Phenols , Cluster Analysis , Dietary Supplements
10.
Mol Nutr Food Res ; 67(19): e2300036, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37525336

ABSTRACT

SCOPE: The consumption of dietary anthocyanins is associated with various health benefits. However, anthocyanins are poorly bioavailable, and most ingested anthocyanins will enter the colon where they are degraded to small phenolic metabolites that are the main absorbed forms. Little is known about the processes of anthocyanin degradation in the gut and the role of the human gut microbiota. This study aims to determine the contribution of spontaneous and microbiota-dependent degradation of anthocyanins in the human colon. METHODS AND RESULTS: Purified anthocyanin extracts from black rice and bilberry were incubated in an in vitro human fecal-inoculated pH-controlled colon model over 24 h and anthocyanins were analyzed using HPLC-DAD. The study shows that the loss of anthocyanins occurs both spontaneously and as a consequence of metabolism by the gut microbiota. The study observes that there is high variability in spontaneous degradation but only modest variation in total degradation, which included the microbiota-dependent component. The degradation rate of anthocyanins is also shown to be dependent on the B-ring substitution pattern and the type of sugar moiety, both for spontaneous and microbiota-dependent degradation. CONCLUSION: Anthocyanins are completely degraded in a model of the human colon by a combination of spontaneous and microbiota-dependent processes.


Subject(s)
Anthocyanins , Microbiota , Humans , Anthocyanins/pharmacology , Anthocyanins/metabolism , Diet , Phenols/metabolism , Colon/metabolism
11.
Crit Rev Food Sci Nutr ; : 1-26, 2023 Jun 05.
Article in English | MEDLINE | ID: mdl-37272431

ABSTRACT

Beta-glucan (BG), a polysaccharide comprised of interfacing glucose monomers joined via beta-glycosidic linkages, can be defined as a type of dietary fiber with high specificity based on its interaction with the gut microbiota. It can induce similar interindividual microbiota responses, thereby having beneficial effects on the human body. In this paper, we review the four main sources of BG (cereals, fungi, algae, and bacteria) and their differences in structure and content. The interaction of BG with gut microbiota and the resulting health effects have been highlighted, including immune enhancement, regulation of serum cholesterol and insulin levels, alleviation of obesity and improvement of cognitive disorders. Finally, the application of BG in food products and its beneficial effects on the gut microbiota of consumers were discussed. Although some of the mechanisms of action remain unclear, revealing the beneficial functions of BG from the perspective of gut microbiota can help provide theoretical support for the development of diets that target the regulation of microbiota.

12.
Crit Rev Food Sci Nutr ; : 1-19, 2023 Jun 16.
Article in English | MEDLINE | ID: mdl-37326367

ABSTRACT

The human gut microbiota plays numerous roles in regulating host growth, the immune system, and metabolism. Age-related changes in the gut environment lead to chronic inflammation, metabolic dysfunction, and illness, which in turn affect aging and increase the risk of neurodegenerative disorders. Local immunity is also affected by changes in the gut environment. Polyamines are crucial for cell development, proliferation, and tissue regeneration. They regulate enzyme activity, bind to and stabilize DNA and RNA, have antioxidative properties, and are necessary for the control of translation. All living organisms contain the natural polyamine spermidine, which has anti-inflammatory and antioxidant properties. It can regulate protein expression, prolong life, and improve mitochondrial metabolic activity and respiration. Spermidine levels experience an age-related decrease, and the development of age-related diseases is correlated with decreased endogenous spermidine concentrations. As more than just a consequence, this review explores the connection between polyamine metabolism and aging and identifies advantageous bacteria for anti-aging and metabolites they produce. Further research is being conducted on probiotics and prebiotics that support the uptake and ingestion of spermidine from food extracts or stimulate the production of polyamines by gut microbiota. This provides a successful strategy to increase spermidine levels.

13.
Polymers (Basel) ; 15(9)2023 Apr 28.
Article in English | MEDLINE | ID: mdl-37177246

ABSTRACT

Hyaluronan (HA) has various biological functions and is used extensively as a dietary supplement. Previous studies have shown that the probiotic effects of polysaccharides are closely associated with their molecular properties. The intestinal microbiota has been demonstrated to degrade HA; however, the regulatory effects of different molecular weights (MW) of HA on gut microbiota and metabolites are unknown. In the present study, we performed in vitro fermentation of human-derived feces for three MWs of HA (HA1, 32.3 kDa; HA2, 411 kDa; and HA3, 1510 kDa) to investigate the differences in the fermentation properties of HA with different MWs. We found that gut microbiota can utilize all HAs and, consequently, produce large amounts of short-chain fatty acids (SCFAs). In addition, we showed that all three HA MWs promoted the growth of Bacteroides, Parabacteroides, and Faecalibacterium, with HA1 being more effective at promoting the growth of Bacteroides. HAs have various regulatory effects on the structure and metabolites of the gut microbiota. Spearman's correlation analysis revealed that alterations in gut microbiota and their metabolites were significantly correlated with changes in metabolic markers. For instance, HA1 enriched α-eleostearic acid and DL-3-aminoisobutyric acid by regulating the abundance of Bacteroides, and HA3 enriched Thymidin by regulating Faecalibacterium. Collectively, the fermentation properties of HA vary across MW, and our results provide insights into the potential association between the MW of HA and its fermentation characteristics by the gut microbiota. These findings provide insights into the influence of the gut microbiota and HAs on the health of the host.

14.
Gut Microbes ; 15(1): 2181930, 2023.
Article in English | MEDLINE | ID: mdl-36864554

ABSTRACT

Cholestasis is a condition characterized by the abnormal production or excretion of bile, and it can be induced by a variety of causes, the factors of which are extremely complex. Although great progress has been made in understanding cholestasis pathogenesis, the specific mechanisms remain unclear. Therefore, it is important to understand and distinguish cholestasis from different etiologies, which will also provide indispensable theoretical support for the development of corresponding therapeutic drugs. At present, the treatment of cholestasis mainly involves several bile acids (BAs) and their derivatives, most of which are in the clinical stage of development. Multiple lines of evidence indicate that ecological disorders of the gut microbiota are strongly related to the occurrence of cholestasis, in which BAs also play a pivotal role. Recent studies indicate that probiotics seem to have certain effects on cholestasis, but further confirmation from clinical trials is required. This paper reviews the etiology of and therapeutic strategies for cholestasis; summarizes the similarities and differences in inducement, symptoms, and mechanisms of related diseases; and provides information about the latest pharmacological therapies currently available and those under research for cholestasis. We also reviewed the highly intertwined relationship between gut microbiota-BA-cholestasis, revealing the potential role and possible mechanism of probiotics in the treatment of cholestasis.


Subject(s)
Body Fluids , Cholestasis , Gastrointestinal Microbiome , Probiotics , Humans , Bile Acids and Salts , Cholestasis/therapy , Probiotics/therapeutic use
15.
Int J Biol Macromol ; 236: 123967, 2023 May 01.
Article in English | MEDLINE | ID: mdl-36906201

ABSTRACT

Glucansucrase AP-37 was extracted from the culture supernatant of Lactobacillus kunkeei AP-37 and characteristics of the glucan produced by the active glucansucrase in terms of structural and functional roles were determined in this study. A molecular weight around 300 kDa was observed for glucansucrase AP-37 and its acceptor reactions with maltose, melibiose and mannose were also conducted to unveil the prebiotic potential of the poly-oligosaccharides formed via these reactions. The core structure of glucan AP-37 was determined by 1H and 13C NMR and GC/MS analysis which revealed that glucan AP-37 was a highly branched dextran composing of high levels of (1 â†’ 3)-linked α-d-glucose units with low levels of (1 â†’ 2)-linked α-d-glucose units. The structural features of the glucan formed, demonstrated that glucansucrase AP-37 was an α-(1 â†’ 3) branching sucrase. Dextran AP-37 was further characterised by FTIR analysis and XRD analysis demonstrated its amorphous nature. A fibrous compact morphology was observed for dextran AP-37 with SEM analysis whereas TGA and DSC analysis revealed its high stability as no degradation was observed up to 312 °C. Finally, the prebiotic potential of the dextran AP-37 and the gluco-oligosaccharides produced with the acceptor reaction of α-(1 â†’ 3) branching sucrase AP-37 were determined and promising results were found for the gluco-oligosaccharides to act as prebiotics.


Subject(s)
Dextrans , Sucrase , Dextrans/metabolism , Sucrase/chemistry , Oligosaccharides/chemistry , Glycosyltransferases/metabolism , Glucans , Glucose , Prebiotics
16.
Microorganisms ; 11(1)2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36677471

ABSTRACT

A balanced gut microbiota and their metabolites are necessary for the maintenance of the host's health. The antibiotic-induced dysbiosis can cause the disturbance of the microbial community, influence the immune homeostasis and induce susceptibility to metabolic- or immune-mediated disorders and diseases. The Lactobacillus and their metabolites or components affect the function of the host's immune system and result in microbiota-mediated restoration. Recent data have indicated that, by altering the composition and functions of gut microbiota, antibiotic exposure can also lead to a number of specific pathologies, hence, understanding the potential mechanisms of the interactions between gut microbiota dysbiosis and immunological homeostasis is very important. The Lactobacillus strategies for detecting the associations between the restoration of the relatively imbalanced microbiome and gut diseases are provided in this discussion. In this review, we discuss the recently discovered connections between microbial communities and metabolites in the Lactobacillus treatment of ß-lactam antibiotic-induced dysbiosis, and establish the relationship between commensal bacteria and host immunity under this imbalanced homeostasis of the gut microbiota.

17.
Food Res Int ; 163: 112222, 2023 01.
Article in English | MEDLINE | ID: mdl-36596151

ABSTRACT

Lytic bacteriophages (phages) offer a great potential as biocontrol agents for spoilage Clostridium tyrobutyricum, responsible for butyric acid fermentation in semi-hard and hard ripened cheeses, resulting in late gas blowing defect. With this aim, we have isolated, identified and characterized new lytic phages of C. tyrobutyricum, and have evaluated their efficacy to control cheese late blowing by adding them to manufacture milk. Silage, soil, milk and cheese from dairy farms were screened for anti-clostridial phages, obtaining 96 isolates active against C. tyrobutyricum. According to host range, source and plaque morphology, we obtained 20 phage profiles, 8 of them (represented by phages FA3, FA21, FA29, FA52, FA58, FA67, FA70 and FA88) showing a wider host range and high quality lysis, which were further characterized. Selected isolates showed a non-contractile tail, belonging to the Siphoviridae family, and were grouped into 3 restriction profiles. Viable phages were detected after storage in sodium-magnesium buffer (SM buffer), skim milk and acidified skim milk (pH 5) for 7 d at 4 °C, 12 °C and 37 °C, although a decline in infectivity was observed in some cases. Good phage survival was also detected during semi-hard cheese manufacture and ripening (60 d), and cheese lactococci counts, pH, dry matter values, and volatile compounds were not affected by phage addition. In semi-hard cheese, phage FA67 impaired the early germination of C. tyrobutyricum spores and caused a significant decrease in clostridial vegetative cells counts at 14 d of ripening, delaying by 2 weeks the consumption of lactic acid, formation of butyric acid and appearance of late blowing symptoms, compared to the spoilt control cheese without the phage. This is the first report on the application of phage to control C. tyrobutyricum in cheese.


Subject(s)
Bacteriophages , Cheese , Clostridium tyrobutyricum , Butyric Acid , Clostridium
19.
Food Res Int ; 160: 111640, 2022 10.
Article in English | MEDLINE | ID: mdl-36076376

ABSTRACT

The potential probiotic function of Latilactobacills curvatus has attracted the attention of researchers. To explore the differences in the genomes of L. curvatus, nine strains were isolated from various sources, including feces and fermented vegetables and compared with 25 strains from the NCBI database. The findings indicated that the average genome size, GC content, and CDS of L. curvatus were 1.94 MB, 41.9%, and 1825, respectively. Its core genome is associated with transcription, translation, carbohydrate transport and metabolism, and defense functions. The pan-genome of L. curvatus was in a closed state. The genetic diversity of L. curatus is mainly manifested in its ability to use carbohydrates, antibiotic resistance, bacteriocin operon, and polymeric regularly interspaced short palindromic repeats (CRISPR)-Cas for bacterial immunity. The CRISPR system of 34 strains of L. curvatus was predominantly found to be of the IIA type with a few IIC and IE types. These findings will contribute to a better understanding of this species.


Subject(s)
Bacteriocins , Bacteriophages , Bacteriocins/genetics , Bacteriophages/genetics , CRISPR-Cas Systems , Carbohydrate Metabolism/genetics , Drug Resistance, Microbial , Genome, Bacterial/genetics , Genotype , Phenotype
20.
Front Nutr ; 9: 849902, 2022.
Article in English | MEDLINE | ID: mdl-35662954

ABSTRACT

Background: Ageing is highly associated with cognitive decline and modifiable risk factors such as diet are believed to protect against this process. Specific dietary components and in particular, (poly)phenol-rich fruits such as berries have been increasingly recognised for their protection against age-related neurodegeneration. However, the impact of cranberries on cognitive function and neural functioning in older adults remains unclear. Design: A 12-week parallel randomised placebo-controlled trial of freeze-dried cranberry powder was conducted in 60 older adults aged between 50 and 80 years. Cognitive assessment, including memory and executive function, neuroimaging and blood sample collection were conducted before and after the intervention to assess the impact of daily cranberry consumption on cognition, brain function and biomarkers of neuronal signalling. Results: Cranberry supplementation for 12 weeks was associated with improvements in visual episodic memory in aged participants when compared to placebo. Mechanisms of action may include increased regional perfusion in the right entorhinal cortex, the accumbens area and the caudate in the cranberry group. Significant decrease in low-density lipoprotein (LDL) cholesterol during the course of the intervention was also observed. No significant differences were, however, detected for BDNF levels between groups. Conclusions: The results of this study indicate that daily cranberry supplementation (equivalent to 1 small cup of cranberries) over a 12-week period improves episodic memory performance and neural functioning, providing a basis for future investigations to determine efficacy in the context of neurological disease. This trial was registered at clinicaltrials.gov as NCT03679533 and at ISRCTN as ISRCTN76069316.

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