Lysozyme-like Protein Produced by Bifidobacterium longum Regulates Human Gut Microbiota Using In Vitro Models.
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ABSTRACT:
SUBMITTER: Du M
PROVIDER: S-EPMC8587964 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Bifidobacterium longum subsp. longum is a prevalent group in the human gut microbiome. Its persistence in the intestinal microbial community suggests a close host-microbe relationship according to age. The subspecies adaptations are related to metabolic capabilities and genomic and functional diversity. In this study, 154 genomes from public databases and four new Chilean isolates were genomically compared through an in silico approach to identify genomic divergence in genes associated with carbohydrate consumption and their possible adaptations to different human intestinal niches. The pangenome of the subspecies was open, which correlates with its remarkable ability to colonize several niches. The new genomes homogenously clustered within subspecies longum, as observed in phylogenetic analysis. B. longum SC664 was different at the sequence level but not in its functions. COG analysis revealed that carbohydrate use is variable among longum subspecies. Glycosyl hydrolases participating in human milk oligosaccharide use were found in certain infant and adult genomes. Predictive genomic analysis revealed that B. longum M12 contained an HMO cluster associated with the use of fucosylated HMOs but only endowed with a GH95, being able to grow in 2-fucosyllactose as the sole carbon source. This study identifies novel genomes with distinct adaptations to HMOs and highlights the plasticity of B. longum subsp. longum to colonize the human gut microbiota.
| S-EPMC8470182 | biostudies-literature
Project description:Extracellular proteins are important factors in host-microbe interactions; however, the specific factors that enable bifidobacterial adhesion and survival in the gastrointestinal (GI) tract are not fully characterized. Here, we discovered that Bifidobacterium longum NCC2705 cultured in bacterium-free supernatants of human fecal fermentation broth released a myriad of particles into the extracellular environment. The aim of this study was to characterize the physiological properties of these extracellular particles. The particles, approximately 50 to 80 nm in diameter, had high protein and double-stranded DNA contents, suggesting that they were extracellular vesicles (EVs). A proteomic analysis showed that the EVs primarily consisted of cytoplasmic proteins with crucial functions in essential cellular processes. We identified several mucin-binding proteins by performing a biomolecular interaction analysis of phosphoketolase, GroEL, elongation factor Tu (EF-Tu), phosphoglycerate kinase, transaldolase (Tal), and heat shock protein 20 (Hsp20). The recombinant GroEL and Tal proteins showed high binding affinities to mucin. Furthermore, the immobilization of these proteins on microbeads affected the permanence of the microbeads in the murine GI tract. These results suggest that bifidobacterial exposure conditions that mimic the intestine stimulate B. longum EV production. The resulting EVs exported several cytoplasmic proteins that may have promoted B. longum adhesion. This study improved our understanding of the Bifidobacterium colonization strategy in the intestinal microbiome.IMPORTANCEBifidobacterium is a natural inhabitant of the human gastrointestinal (GI) tract. Morphological observations revealed that extracellular appendages of bifidobacteria in complex microbial communities are important for understanding its adaptations to the GI tract environment. We identified dynamic extracellular vesicle (EV) production by Bifidobacterium longum in bacterium-free fecal fermentation broth that was strongly suggestive of differing bifidobacterial extracellular appendages in the GI tract. In addition, export of the adhesive moonlighting proteins mediated by EVs may promote bifidobacterial colonization. This study provides new insight into the roles of EVs in bifidobacterial colonization processes as these bacteria adapt to the GI environment.
| S-EPMC7499026 | biostudies-literature
Project description:The Bifibobacterium longum subsp. longum 35624™ strain (formerly named Bifidobacterium longum subsp. infantis) is a well described probiotic with clinical efficacy in Irritable Bowel Syndrome clinical trials and induces immunoregulatory effects in mice and in humans. This paper presents (a) the genome sequence of the organism allowing the assignment to its correct subspeciation longum; (b) a comparative genome assessment with other B. longum strains and (c) the molecular structure of the 35624 exopolysaccharide (EPS624). Comparative genome analysis of the 35624 strain with other B. longum strains determined that the sub-speciation of the strain is longum and revealed the presence of a 35624-specific gene cluster, predicted to encode the biosynthetic machinery for EPS624. Following isolation and acid treatment of the EPS, its chemical structure was determined using gas and liquid chromatography for sugar constituent and linkage analysis, electrospray and matrix assisted laser desorption ionization mass spectrometry for sequencing and NMR. The EPS consists of a branched hexasaccharide repeating unit containing two galactose and two glucose moieties, galacturonic acid and the unusual sugar 6-deoxy-L-talose. These data demonstrate that the B. longum 35624 strain has specific genetic features, one of which leads to the generation of a characteristic exopolysaccharide.
| S-EPMC5033381 | biostudies-literature
Project description:Bifidobacterium longum colonizes mammalian gastrointestinal tracts where it could metabolize host-indigestible oligosaccharides. Although B. longum strains are currently segregated into three subspecies that reflect common metabolic capacities and genetic similarity, heterogeneity within subspecies suggests that these taxonomic boundaries may not be completely resolved. To address this, the B. longum pangenome was analyzed from representative strains isolated from a diverse set of sources. As a result, the B. longum pangenome is open and contains almost 17,000 genes, with over 85% of genes found in ≤28 of 191 strains. B. longum genomes share a small core gene set of only ~500 genes, or ~3% of the total pangenome. Although the individual B. longum subspecies pangenomes share similar relative abundances of clusters of orthologous groups, strains show inter- and intrasubspecies differences with respect to carbohydrate utilization gene content and growth phenotypes.
| S-EPMC7022738 | biostudies-literature
Project description:ObjectivesInflammatory bowel disease (IBD) is a chronic lifelong inflammatory disease. Probiotics such as Bifidobacterium longum are considered to be beneficial to the recovery of intestinal inflammation by interaction with gut microbiota. Our goals were to define the effect of the exclusive use of BAA2573 on dextran sulfate sodium (DSS)-induced colitis, including improvement of symptoms, alleviation of histopathological damage, and modulation of gut microbiota.MethodsIn the present study, we pretreated C57BL/6J mice with Bifidobacterium longum BAA2573, one of the main components in an over-the-counter (OTC) probiotic mixture BIFOTO capsule, before modeling with DSS. 16S rDNA sequencing and liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based non-targeted metabolomic profiling were performed with the collected feces.ResultsWe found that pretreatment of Bifidobacterium longum BAA2573 given by gavage significantly improved symptoms and histopathological damage in DSS-induced colitis mice. After the BAA2573 intervention, 57 genera and 39 metabolites were significantly altered. Pathway enrichment analysis demonstrated that starch and sucrose metabolism, vitamin B6 metabolism, and sphingolipid metabolism may contribute to ameliorating colitis. Moreover, we revealed that the gut microbiome and metabolites were interrelated in the BAA2573 intervention group, while Alistipes was the core genus.ConclusionOur study demonstrates the impact of BAA2573 on the gut microbiota and reveals a possible novel adjuvant therapy for IBD patients.
| S-EPMC10280014 | biostudies-literature
Project description:Rotavirus is one of the main causes of acute diarrhea and enteritis in infants. Currently, studies are underway to assess the use of probiotics to improve rotavirus vaccine protection. A previous work demonstrated that the probiotic strain Bifidobacterium longum subsp. infantis CECT 7210 is able to hinder rotavirus replication both in vitro and in vivo. The present study takes a systematic approach in order to identify the molecule directly involved in rotavirus inhibition. Supernatant protease digestions revealed both the proteinaceous nature of the active substance and the fact that the molecule responsible for inhibiting rotavirus replication is released to the supernatant. Following purification by cationic exchange chromatography, active fractions were obtained and the functional compound was identified as an 11-amino acid peptide (MHQPHQPLPPT, named 11-mer peptide) with a molecular mass of 1.282 KDa. The functionality of 11-mer was verified using the synthesized peptide in Wa, Ito, and VA70 rotavirus infections of both HT-29 and MA-104 cell lines. Finally, protease activity was detected in B. longum subsp. infantis CECT 7210 supernatant, which releases 11-mer peptide. A preliminary identification of the protease is also included in the study.
| S-EPMC4855034 | biostudies-literature
Project description:Probiotics are well known as health-promoting agents that modulate intestinal microbiota. However, the molecular mechanisms underlying this effect remain unclear. Using gnotobiotic mice harboring 15 strains of predominant human gut-derived microbiota (HGM), we investigated the effects of Bifidobacterium longum BB536 (BB536-HGM) supplementation on the gut luminal metabolism. Nuclear magnetic resonance (NMR)-based metabolomics showed significantly increased fecal levels of pimelate, a precursor of biotin, and butyrate in the BB536-HGM group. In addition, the bioassay revealed significantly elevated fecal levels of biotin in the BB536-HGM group. Metatranscriptomic analysis of fecal microbiota followed by an in vitro bioassay indicated that the elevated biotin level was due to an alteration in metabolism related to biotin synthesis by Bacteroides caccae in this mouse model. Furthermore, the proportion of Eubacterium rectale, a butyrate producer, was significantly higher in the BB536-HGM group than in the group without B. longum BB536 supplementation. Our findings help to elucidate the molecular basis underlying the effect of B. longum BB536 on the gut luminal metabolism through its interactions with the microbial community.
| S-EPMC4552000 | biostudies-literature
Project description:BackgroundThe importance of the gut microbiota at the early stage of life and their longitudinal effect on host health have recently been well investigated. In particular, Bifidobacterium longum subsp. longum, a common component of infant gut microbiota, appears in the gut shortly after birth and can be detected there throughout an individual's lifespan. However, it remains unclear whether this species colonizes in the gut over the long term from early infancy. Here, we investigated the long-term colonization of B. longum subsp. longum by comparing the genotypes of isolates obtained at different time points from individual subjects. Strains were isolated over time from the feces of 12 subjects followed from early infancy (the first six months of life) up to childhood (approximately six years of age). We also considered whether the strains were transmitted from their mothers' perinatal samples (prenatal feces and postnatal breast milk).ResultsIntra-species diversity of B. longum subsp. longum was observed in some subjects' fecal samples collected in early infancy and childhood, as well as in the prenatal fecal samples of their mothers. Among the highlighted strains, several were confirmed to colonize and persist in single individuals from as early as 90 days of age for more than six years; these were classified as long-term colonizers. One of the long-term colonizers was also detected from the corresponding mother's postnatal breast milk. Quantitative polymerase chain reaction data suggested that these long-term colonizers persisted in the subjects' gut despite the existence of the other predominant species of Bifidobacterium.ConclusionsOur results showed that several strains belonging to B. longum subsp. longum colonized in the human gut from early infancy through more than six years, confirming the existence of long-term colonizers from this period. Moreover, the results suggested that these strains persisted in the subjects' gut while co-existing with the other predominant bifidobacterial species. Our findings also suggested the importance of microbial-strain colonization in early infancy relative to their succession and showed the possibility that probiotics targeting infants might have longitudinal effects.Trial registrationTRN: ISRCTN25216339 . Date of registration: 11/03/2016. Prospectively registered.
| S-EPMC6292050 | biostudies-literature
Project description:Interest in faecal microbiota transplantation (FMT) has increased as therapy for intestinal diseases, but safety issues limit its widespread use. Intestinal fermentation technology (IFT) can produce controlled, diverse and metabolically active 'artificial' colonic microbiota as potential alternative to common FMT. However, suitable processing technology to store this artificial microbiota is lacking. In this study, we evaluated the impact of the two cryoprotectives, glycerol (15% v/v) and inulin (5% w/v) alone and in combination, in preserving short-chain fatty acid formation and recovery of major butyrate-producing bacteria in three artificial microbiota during cryopreservation for 3 months at -80°C. After 24 h anaerobic fermentation of the preserved microbiota, butyrate and propionate production were maintained when glycerol was used as cryoprotectant, while acetate and butyrate were formed more rapidly with glycerol in combination with inulin. Glycerol supported cryopreservation of the Roseburia spp./Eubacterium rectale group, while inulin improved the recovery of Faecalibacterium prausnitzii. Eubacterium hallii growth was affected minimally by cryopreservation. Our data indicate that butyrate producers, which are key organisms for gut health, can be well preserved with glycerol and inulin during frozen storage. This is of high importance if artificially produced colonic microbiota is considered for therapeutic purposes.
| S-EPMC5743790 | biostudies-literature
Project description:IntroductionObesity, a pervasive global epidemic, has heightened susceptibility to chronic ailments and diminished the overall life expectancy on a global scale. Probiotics and inulin (IN) have been documented to mitigate obesity by exerting an influence on the composition of the gut microbiota. Whether heat-killed Bifidobacterium longum BBMN68 (MN68) and IN have an anti-obesity effect remains to be investigated.MethodsIn this study, Wistar rats were fed a high-fat diet (HFD), and orally administered heat-killed MN68 (2 × 1011 CFU/kg) and/or inulin (0.25 kg/kg) for 12 weeks. Histological analysis, serology analysis and 16S rRNA gene sequencing were performed.ResultsHeat-killed MN68 + IN treatment showed an enhanced effect on preventing weight gain, diminishing fat accumulation, and regulating lipid metabolism, compared to either heat-killed MN68 treatment or inulin treatment. Gut microbiota results showed that heat-killed MN68 + IN treatment significantly increased the relative abundance of Bacteroidota, Oscillospira, Intestinimonas, Christensenella, and Candidatus_Stoquefichus, and reduced the relative abundance of Enterococcus. Furthermore, heat-killed MN68 + IN significantly increased the SCFA levels, which were correlated with changes in the gut microbiota.DiscussionThis research provides support for the application of heat-killed MN68 and IN in the treatment of obesity, and highlights the combination of heat-killed BBMN68 and IN as functional food ingredients.
| S-EPMC11351561 | biostudies-literature