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At least 19 recordsLinked to original sources

PubMed1989

Electron microscopic, biochemical and physiological studies of Bifidobacterium pseudolongum SS-24 and Bifidobacterium thermophilum SS-19.

Comparative studies of physiology, biochemical characteristics, and morphology by electron microscopy were conducted on Bifidobacterium pseudolongum SS-24 isolated from dogs and Bifidobacterium thermophilum SS-19 isolated from swine. Both B. pseudolongum and B. thermophilum grow unusually rapidly in the rumen fluid medium of Scott and Dehority, and reached a maximum of optical density after only 6 to 7 h of incubation. B. pseudolongum and B. thermophilum showed similar patterns of results for 21 biochemical characteristics tested, with a difference found only for N-acetyl-glucosaminidase. Scanning electron micrographs revealed that B. pseudolongum produced extensive amounts of extracellular material. The cell walls of B. pseudolongum and B. thermophilum were totally different. Transmission electron micrographs of ruthenium red-stained preparations of B. pseudolongum showed a very thick (ca. 0.2 microns) Gram-positive cell wall, whereas B. thermophilum was found to have a thin (ca. 0.05 microns) Gram-positive cell wall.

Animals↗

PubMed1991

Bifidobacterium ruminantium sp. nov. and Bifidobacterium merycicum sp. nov. from the rumens of cattle.

Among several hundred bifidobacteria isolated from bovine rumens, eight strains were recognized primarily on the basis of DNA-DNA hybridization results as members of two new distinct DNA homology groups. We studied the morphology, oxygen, carbon dioxide, temperature, and pH requirements, fermentation patterns, end products of glucose fermentation, biochemical reactions, protein electrophoretic patterns, isozyme patterns, DNA homology relationships, and guanine-plus-cytosine contents of these organisms, and we propose that these two groups of strains should be considered new species, Bifidobacterium ruminantium (type strain, strain ATCC 49390) and Bifidobacterium merycicum (type strain, strain ATCC 49391).

Animals↗

PubMed1992

Relationship between oxygen sensitivity and oxygen metabolism of Bifidobacterium species.

Bifidobacteria, which are obligate anaerobes, were studied to determine the relationship between their sensitivity to oxygen and oxygen metabolism. Among the four species tested, Bifidobacterium infantis, Bifidobacterium breve, and Bifidobacterium longum differed from Bifidobacterium adolescentis in sensitivity to oxygen. The former three species showed marked growth under conditions of partial aeration, whereas the growth of B. adolescentis was suppressed by low concentrations of oxygen. Bifidobacteria express reduced NAD-oxidase and -peroxidase activities, which function in a pathway for two-electron reduction of molecular oxygen, producing hydrogen peroxide and, subsequently, water. Activities of reduced NAD-oxidase and -peroxidase were inversely correlated with their sensitivities to oxygen. Bifidobacterium adolescentis exhibited lowered activities of these two enzymes; the activities were 10 to 20% of those observed with B. infantis, B. breve, and B. longum. These observations are compatible with the hypothesis that reduced NAD-oxidase and reduced NAD-peroxidase in Bifidobacterium species play a role in prevention of oxygen toxicity. Superoxide dismutase activity was also detected in Bifidobacterium species. Superoxide dismutase is probably not involved in detoxification of oxygen, because the activity of this enzyme was extremely low, and the sensitivity to oxygen varied independently of superoxide dismutase activity.

Bifidobacterium↗

PubMed1990

Growth promotion of Bifidobacterium species by whey and casein fractions from human and bovine milk.

An in vitro assay was used to study the growth-promotional activity of human milk (HM), cow's milk (CM), and whey and casein fractions of HM and CM for five strains of Bifidobacterium species isolated originally from stools of human infants. Whey- and casein-predominant CM-based infant formulas were studied as well. When compared on an equivalent protein basis, the growth promotion activity of HM was greater than that of CM for Bifidobacterium bifidum serovar pennsylvanicus and Bifidobacterium longum but comparable for B. bifidum, Bifidobacterium infantis, and Bifidobacterium breve. Pasteurization of HM and CM resulted in an increase of growth promotion activity for B. bifidum serovar pennsylvanicus and B. bifidum, a decrease for B. infantis, and no change for B. longum and B. breve. The growth promotion activity of HM whey was slightly higher than that of HM casein for four strains of bifidobacteria. When CM casein was a substrate, virtually no growth occurred for B. bifidum serovar pennsylvanicus, B. bifidum, B. infantis, and B. longum. The growth promotion activity of CM whey, however, was similar to that of HM whey. A similar trend was observed for CM-based infant formula. Whey-dominant formulas promoted better growth of B. bifidum serovar pennsylvanicus, B. bifidum, and B. infantis than casein-dominant formulas. The data suggest a direct relationship between amount of whey-specific factors and the ability to promote growth of clinically relevant strains of Bifidobacterium species by HM, CM, and CM-based infant formulas.

Animals↗

PubMed1990

Occurrence of Bifidobacterium in the feces of newborns delivered by cesarean section.

In cesarean section newborns, colonization by Bifidobacterium occurs generally within 4 days of life. Breast-fed infants, independent of the delivery procedure, harbor a gastrointestinal flora characterized by a predominance of Bifidobacterium. Breast-fed [corrected] newborns delivered by cesarean section present a predominance of Bifidobacterium bifidum and bifidobacterium infantis in their stools. Investigation of variation in the incidence of Bifidobacterium among cesarean section newborns shows a larger variety of bifidobacterial species in an urban hospital. The prevalence of Bifidobacterium is lower in a newly constructed suburban hospital. Alimentation and environment hence seem to constitute important factors in the control of bifidobacterial flora.

Bifidobacterium↗

PubMed1991

Response of bifidobacterium species to growth promoters in human and cow milk.

We used an in vitro assay to study and compare the growth-promotional activity of protein and nonprotein components in human milk (HM) and cow milk (CM) samples for infant strains of Bifidobacterium species. HM samples varied considerably in growth-promotion activity for Bifidobacterium bifidum var pennsylvanicus, Bifidobacterium infantis, and Bifidobacterium breve. Pooled CM samples showed similar but less variable levels of activity when compared with HM samples. Separation of milk samples by ultrafiltration into protein nitrogen and nonprotein nitrogen (NPN) fractions revealed that the bifidobacteria growth-promotion activity of HM was associated primarily with the NPN fraction, whereas activity in CM whey was found in both protein nitrogen and NPN fractions. Testing of purified CM whey proteins showed that alpha-lactalbumin and lactoferrin were potent growth promoters, showing greater activity for B. infantis and B. breve than for two strains of B. bifidum. Conversely, N-acetylglucosamine and purified gastric mucin were highly active for B. bifidum strains but inactive for other Bifidobacterium species. Collectively, the data indicate that both protein nitrogen and NPN factors in HM and CM promote the growth of bifidobacteria and suggest that Bifidobacterium species differ in responsiveness to protein and oligosaccharide growth promoters.

Animals↗

PubMed2025

Survival and safety evaluation of Bifidobacterium longum subsp. longum ZS-8 in healthy adults, determined using PMAxx-qPCR and amplicon sequencing.

UNLABELLED: Species-level quantitative PCR (qPCR) provides in-depth knowledge of oral probiotics in the human gastrointestinal tract (GIT). However, it lacks the capability to differentiate exogenous strains from native microbiota, nor can it distinguish between live and dead bacteria. In this study, we employed improved propidium monoazide (PMAxx)-qPCR to evaluate the survival and colonization of Bifidobacterium longum subsp. longum ZS-8 (designated ZS-8) on the strain level in the GIT and its impact on human gut microbiota. By spiking in live and dead ZS-8, we demonstrated that strain-level PMAxx-qPCR could identify and quantify the viable ZS-8 in fecal samples accurately. Using this method, we found that, in healthy humans, oral administration of ZS-8 can transiently survive in the GIT, and multi-layer seamless capsules (MLSC) significantly improve the gastrointestinal tolerance and survivability of ZS-8 compared to its powder form. Furthermore, through selective cultivation and PMAxx-microbiome sequencing, we investigated the response of gut viable microbiome to ZS-8. Results showed that, while the microbiota diversity and total viable counts of Bifidobacterium and Lactobacillus remained stable, certain indigenous species of Bifidobacterium and Lactobacillus increased in abundance, confirming ZS-8's probiotic potential in healthy individuals. Overall, our study demonstrates the effectiveness of combining strain-specific comparative genomics with PMAxx-qPCR for evaluating probiotic survival and colonization in the human gut and highlights the safety of ZS-8 oral administration in healthy individuals. IMPORTANCE: The survival and colonization of probiotics in the gut are critical for their functional efficacy, yet conventional species-level quantitative PCR (qPCR) fails to distinguish exogenous strains from native microbiota or differentiate live from dead bacteria. By integrating strain-specific comparative genomics with propidium monoazide (PMAxx)-qPCR, we precisely quantified the viability of Bifidobacterium longum ZS-8 at the strain level in the human gut after its oral administration. Our study demonstrated that 1.53-6.90% of cells surviving transit and multi-layer seamless capsules (MLSC) significantly enhanced the gastrointestinal tolerance of ZS-8. While ZS-8 administration did not alter gut microbiota diversity or total viable counts of Bifidobacterium and Lactobacillus, it selectively increased the abundance of specific indigenous beneficial species. This method overcomes the dual limitations of traditional techniques (strain-level specificity and viability discrimination), providing a robust tool for probiotic research. Furthermore, our findings confirm the safety of ZS-8 in healthy individuals and its potential to modulate gut ecology, offering a scientific foundation for personalized probiotic development and clinical translation.

Humans↗

PubMed1992

Fecal recovery in humans of viable Bifidobacterium sp ingested in fermented milk.

Bifidobacterium sp is a natural component of the dominant colonic microflora that was recently introduced into several fermented dairy products. The aim of the present study was to study the fate of this microorganism in the human gut. On the basis of antibiotic resistance characters, a variant of Bifidobacterium sp that could be distinguished from indigenous bifidobacteria in the fecal flora was selected, and its survival and colonization in the colon was examined. This strain was used to ferment milk, and 125 g of the fermented product obtained was ingested by eight healthy volunteers three times daily for 8 days. Stools were recovered and weighed throughout the study. The results showed that the exogenous Bifidobacterium sp appeared in the stools and reached a mean level of 8.8 +/- 0.1 log colony-forming units per gram. This level was maintained as long as the fermented dairy product was consumed. When its ingestion stopped, the exogenous Bifidobacterium sp gradually decreased and was no longer detectable 8 days after cessation. The mean recovered quantity during the 8-day period of administration of the ingested bifidobacteria excreted in stools was 12.1 +/- 0.1 log colony-forming units per gram, i.e., 29.7% +/- 6% of the ingested bacteria, which was similar to the percentage that reached the colon in previous studies. It is concluded that under physiological conditions, exogenously administered Bifidobacterium sp do not colonize the human colon. However, the high fecal concentrations of exogenous bifidobacteria reached are compatible with metabolic "probiotic" activities.

Adult↗

PubMed1990

Uncoupling of growth and acids production in Bifidobacterium ssp.

Kinetics of batch cultivation of four species of Bifidobacterium in milk were examined in detail. Bifidobacteria could grow well in milk inoculated with cultures prepared in a synthetic medium. Cessation of growth occurred, however, in pH-controlled batch cultures, although incomplete utilization of lactose was observed. Lactate and acetate accumulation caused limitation on growth of bifidobacteria leading to an uncoupling of biomass and product formation. From 70 to 75% of both final lactate and acetate concentrations were produced during the stationary growth phase of Bifidobacterium bifidum, Bifidobacterium breve, and Bifidobacterium longum cultivated in milk, whereas Bifidobacterium infantis produced less acetate or lactate during this phase.

Acetates↗

PubMed1992

[Survival of Lactobacillus acidophilus and Bifidobacterium sp. in the small intestine following ingestion in fermented milk. A rational basis for the use of probiotics in man].

Oro-ileal intubation was performed in 6 healthy volunteers who ingested, either 100 g of a fermented milk containing 10(8)/g Lactobacillus acidophilus and 10(7)/g Bifidobacterium sp or sterilized fermented milk along with a meal in random order. Lactobacillus acidophilus and Bifidobacterium were counted in the ileal fluid which was aspirated continuously for 8 h, and flow rates were calculated using the constant slow infusion of PEG 4000. After ingestion of fermented milk but not after control, hourly ileal flow rates of Lactobacillus acidophilus and Bifidobacterium increased form 4.8 +/- 0.2 and 4.9 +/- 0.6 to 7.2 +/- 0.3 and 8.0 +/- 0.3, respectively (mean +/- SE log10 CFU). 8.3 +/- 0.2 Lactobacillus acidophilus and 8.8 +/- 0.1 Bifidobacterium were recovered in the ileum which represented 1.5 percent and 37.5 percent of the ingested bacteria, respectively. In conclusion, under usual conditions of fermented milk ingestion, a large number of living Lactobacillus acidophilus and Bifidobacterium pass through the upper gastrointestinal tract and reach the colon.

Adult↗

PubMed2025

Human gut Bifidobacterium longum subsp. suillum is enriched in vitro by a pectic polysaccharide isolated from the flowers of Lilium lancifolium.

Although pectins have been explored widely, knowledge of their effects on the gut microbiota is lacking owing their complex structure. The aim of this study was to investigate whether pectin enriched gut microbes in vitro. To address this, a homogeneous RG-I like pectin, L01-B1, with a molecular weight of 43.9 kDa was extracted from the flowers of Lilium lancifolium. Structural analysis revealed that L01-B1 contained rhamnose, glucuronic acid, galacturonic acid, galactose, and arabinose in a molar ratio of 13.4: 1.8: 11.1: 37.2: 36.5. The backbone of L01-B1 was composed of 1, 6-β-Galp, 1, 4-α-GalpA, and 1, 2-α-Rhap, whereas the branches included 1, 5-α-Araf, 1, 4-β-Galp, and T-β-GlcpA attached to C-4 of rhamnose, and 1, 3-β-Galp and T-β-Galp linked to C-3 of galactose. L01-B1 altered the composition of human gut microbiota in vitro and increased the abundance of Bifidobacterium longum. Furthermore, Bifidobacterium longum subsp. suillum strain DK001 was isolated and identified from human feces. The DK001 genome was found to be circular with a genome size of approximately 2.4 M. Notably, L01-B1 might possibly be degraded by two kinds of enzymes and change the metabolism of human gut microbiota. Overall, these findings provide insights into intervention strategies that target Bifidobacterium longum.

Humans↗

PubMed1985

Immunochemical studies on the lipoteichoic acids of Bifidobacterium bifidum subsp. pennsylvanicum.

Antisera to lipoteichoic acid of Bifidobacterium bifidum subsp. pennsylvanicum were obtained by injecting lipoteichoic acid/methylated BSA complexes into rabbits. Precipitin tests showed that the glycerol phosphate backbone is primarily responsible for serological specificity while the polysaccharide part of the molecule plays a minor role. Whole cells of B. bifidum subsp. pennsylvanicum were capable of absorbing antibodies, indicating the presence of lipoteichoic acid (14% of the total content) at or near the bacterial surface. Cross-reactivity with strains of the genera Bifidobacterium and Lactobacillus was tested using absorption of antiserum by whole bacteria and reactivity of phenol extracts. The results indicated that lipoteichoic acid is a common antigen within the genus Bifidobacterium. The cross-reactivity with the lactobacilli tested was very low.

Animals↗

PubMed1992

Species-specific oligonucleotide probes for five Bifidobacterium species detected in human intestinal microflora.

Portions of the 16S rRNA from closely related species of the genus Bifidobacterium that are found in the human intestinal microflora were sequenced in order to design species-specific oligonucleotide probes. Five oligonucleotide probes ranging from 16 to 19 bases in length and complementary to 16S rRNA sequences from Bifidobacterium adolescentis, B. bifidum, B. breve, B. infantis, and B. longum were synthesized. With crude high-molecular-weight RNA preparations as targets, these probes showed the desired species specificity, even down to a 1-nucleotide difference. For the practical evaluation of these probes, their specificity and sensitivity were tested against seven strains of the same species and 54 strains of heterologous bacteria with fixed whole cells as targets. The probes for B. adolescentis, B. breve, and B. longum showed efficient and specific hybridization. Although the probes for B. bifidum and B. infantis cross-reacted with a few bacterial strains not isolated from humans, these probes showed species specificity for human intestinal bacteria. These 16S rRNA probes should prove valuable for the identification and detection of human intestinal Bifidobacterium species.

Base Sequence↗

PubMed1990

Structure of macroamphiphiles from several Bifidobacterium strains.

Lipoteichoic acid-like substances, macroamphiphiles, were isolated from cell homogenates of Bifidobacterium bifidum YIT 4007 and YIT 4013, Bifidobacterium breve YIT 4010 and YIT 4014, and Bifidobacterium longum YIT 4021 by phenol extraction followed by nuclease digestion, gel chromatography, ion-exchange chromatography, and hydrophobic interaction chromatography. The macroamphiphile preparations from these five strains contained D-glucose, D-galactose, glycerol, phosphorus, L-alanine, and fatty acids in molar ratios of 1.00, 1.57 to 1.95, 1.02 to 1.99, 0.97 to 1.72, 0.15 to 0.46, and 0.16 to 0.43. Data from structural analyses including methylation, 1H nuclear magnetic resonance measurement, alkaline hydrolysis, mild acid hydrolysis, and hydrogen fluoride treatment led to the most likely common structure for the macroamphiphiles of the examined strains, (formula; see text) where Gro-P is glycerophosphate, m is the number of repeating units of galactofuranan, and n is the number of repeating units of glucan. Whereas the polymers from the respective strains differed in the numbers of repeating units of the galactofuranan and glucan moieties and in the number of fatty acid residues, the proposed structure is essentially the same as that reported previously for the macroamphiphile of B. bifidum subsp. pennsylvanicum DSM 20239 by W. Fischer (Eur. J. Biochem. 165:639-646, 1987).

Bifidobacterium↗

PubMed2025

Diverse defense systems and prophages in human-associated Bifidobacterium species reveal coevolutionary "arms race" dynamics.

Bacteria of the genus Bifidobacterium are pivotal for human health, especially in early life, where they dominate the gut microbiome in healthy infants. Bacteriophages, as drivers of gut bacterial composition, can affect bifidobacterial abundance. Here, we use a bioinformatics approach to explore direct interactions between human-associated Bifidobacterium spp. and prophages, as evidenced by their genomes. Analysis of 1,086 bifidobacterial genomes reveals the presence of complex systems that prevent viral invasion, with 34 defense systems and 56 subtypes detected, including several different CRISPR-Cas systems. CRISPR spacers target almost three-quarters of bifidobacteria-derived prophages, indicating dynamic interactions. At least one prophage is present in ∼67% of strains, with phages exhibiting high genomic diversity and evidence of historical recombination. These prophages encode various defense and anti-defense systems, such as anti-CRISPR genes and restriction-modification mechanisms. Overall, this investigation reveals that coevolutionary "arms race" dynamics drive genomic diversity in both bifidobacteria and their phages.

Prophages↗

PubMed1991

Quantitative fluorometric assay for rapid enzymatic characterization of Bifidobacterium longum and related bifidobacteria.

The quantitative, semi-automated assay described here is an alternative characterization method allowing for highly sensitive and specific detection of bifidobacterial enzymes. Twenty strains of Bifidobacterium longum, including the type strain ATCC 15707, and type strains of 15 other Bifidobacterium species were enzymatically characterized using 20 4-methylumbelliferyl conjugated substrates. Enzyme activities were determined by directly measuring the intensity of fluorescence derived from 4-methylumbelliferone, a fluorescent metabolic by-product. For this method, a Titertek Fluoroskan II fluorometer was used. Enzymes included glycosidases, an esterase, phosphatase, sulphatase, and neuraminidase. B. longum showed strong activity (greater than 1,000 absolute fluorescence units, afu) for alpha-L-Arabinopyranosidase and alpha-L-Arabinofuranosidase, beta-D-Fucosidase, alpha- and beta-D-Galactosidase, alpha-D-Glucosidase, and alpha-D-Mannosidase. No activity (less than or equal to 50 afu) was observed for beta-D-Cellobiosidase, alpha- and beta-L-Fucosidase, beta-D-Glucuronidase, beta-D-Mannosidase, Neuraminidase and Sulphatase. Enzymatic activity profiles in other bifidobacteria were different according to the species. This assay is simple and rapid (6 hr). Special cultural requirements are unnecessary. Results are objective and quantitative. This assay may be a useful tool for bifidobacterial taxonomy.

Adolescent↗

PubMed1990

Detection of Bifidobacterium species by enzymatic methods.

The properties of Bifidobacterium strains of human origin were examined by three enzymic tests and the amounts of acetic and lactic acids produced were also quantified. It was evident that two strains of the American Type Culture Collection (ATCC) did not belong to the genus. Moreover, at least one strain of Bifidobacterium added to some milk preparations did not show distinctive characteristics of the genus. It was also shown that most of bifidobacteria studied produced alpha-galactosidase (EC 3.2.1.22) and alpha-glucosidase (EC 3.2.1.20). The presence of alpha-galactosidase could afford a rapid differentiation of bifidobacteria used in some dairy products since this enzyme was not detected in Lactobacillus strains studied.

Acetates↗

PubMed1991

Bifidobacterium from fermented milks: survival during gastric transit.

Two Bifidobacterium strains contained in two different fermented milks behave very differently when exposed to an in vitro simulated gastric environment. One strain survives very well during at least 90 min (greater than 10(7)/g), but the second strain studied is much less resistant. These in vitro results, with slight differences, were confirmed by an in vivo study in humans. The assessment of the gastric emptying rate of these products allows an estimation of the amount of Bifidobacterium that may pass into the small intestine.

Adult↗