[Characterization of a microbial community isolated from honey bee colonies]. / Caracterización de una comunidad microbiana aislada de colonias de abejas melíferas.

The microbial communities within honey bee colonies contribute to the defense against pathogens. The goal of this study was to isolate, identify, and lyophilize lactic acid bacteria and bifidobacteria from the gut of nurse bees and bee bread in Apis mellifera colonies. Bacterial cultures from the intestinal content were conducted, and subsequently identified, sequenced, and lyophilized. Cross-antagonism among them was also assessed. Studies based on 16 S rRNA gene Sanger sequencing revealed that the MC3 strain had 100% identity with Bifidobacterium choladohabitans, the PP2B strain showed 99.16% similarity with Enterococcus faecium, while the PP1 strain exhibited 99.49% similarity with Lacticaseibacillus sp. and the PP1B strain showed 99.32% similarity with Lacticaseibacillus sp. There was no evidence of cross-antagonism among the strains, and the lyophilization process showed good stability and conservation. This is the first report of the isolation of B. choladohabitans from honey bee gut in Argentina, and also associates the presence of E. faecium with bee bread.

Bifidobacterium longum and Chlorella sorokiniana Combination Modulates IFN-γ, IL-10, and SOCS3 in Rotavirus-Infected Cells.

Rotavirus is the main cause of acute diarrhea in children up to five years of age. In this regard, probiotics are commonly used to treat or prevent gastroenteritis including viral infections. The anti-rotavirus effect of Bifidobacterium longum and Chlorella sorokiniana, by reducing viral infectivity and improving IFN-type I response, has been previously reported. The present study aimed to study the effect of B. longum and/or C. sorokiniana on modulating the antiviral cellular immune response mediated by IFN-γ, IL-10, SOCS3, STAT1, and STAT2 genes in rotavirus-infected cells. To determine the mRNA relative expression of these genes, HT-29 cells were treated with B. longum and C. sorokiniana alone or in combination, followed by rotavirus infection. In addition, infected cells were treated with B. longum and/or C. sorokiniana. Cellular RNA was purified, used for cDNA synthesis, and amplified by qPCR. Our results demonstrated that the combination of B. longum and C. sorokiniana stimulates the antiviral cellular immune response by upregulating IFN-γ and may block pro-inflammatory cytokines by upregulating IL-10 and SOCS3. The results of our study indicated that B. longum, C. sorokiniana, or their combination improve antiviral cellular immune response and might modulate pro-inflammatory responses.

Probiotics supplementation in the treatment of male infertility: A Systematic Review.

Infertility is a widespread global issue that affects approximately 15% of sexually active and active couples, which contributes to about 50% of cases. Currently, the condition remains prevalent and often inadequately treated. This systematic review aims to evaluate existing studies investigating the effects of probiotic supplementation in men. A comprehensive search was conducted across major databases, including PubMed, Cochrane, Science Direct, and Scielo, using relevant keywords such as 'probiotic' OR 'Lactobacillus' OR 'Bifidobacterium' AND 'Male infertility' OR 'male fertility' OR 'sperm quality' OR 'sperm motility' OR 'oligoasthenoteratozoospermia' and their Portuguese equivalents. Four randomized clinical studies met the inclusion criteria, focusing on men diagnosed with idiopathic male infertility (oligozoospermia, teratozoospermia, and asthenozoospermia). The findings revealed that probiotic administration exhibited promising antioxidant properties by combating reactive oxygen species (ROS), consequently protecting sperm DNA from damage that correlates with declining sperm quality. Significant improvements were observed across all sperm parameters, with notable enhancement in motility. Consequently, probiotic supplementation emerges as a potential therapeutic alternative for men diagnosed with idiopathic infertility, demonstrating positive effects on sperm quality.

Effect of Bifidobacterium Intake on Body Weight and Body Fat in Overweight and Obese Adult Subjects: A Systematic Review and Meta-Analysis.

This systematic review aimed to assess the impact of Bifidobacterium genus probiotics on body weight and body composition parameters in overweight and obese individuals.A systematic search for randomized controlled trials was conducted in MEDLINE, EMBASE, LILACS, and Google Scholar databases until April 17, 2023. The inclusion criteria required the trials to involve Bifidobacterium genus probiotics interventions and the evaluation of obesity-related anthropometric and body composition outcomes in overweight or obese subjects. Studies were excluded when involving obese individuals with genetic syndromes or pregnant women, as well as probiotic mixture interventions. The revised Cochrane risk-of-bias tool for randomized trials was utilized to assess the quality of the included studies. A random-effects meta-analysis was performed using the mean difference between endpoint measurements and change from baseline for body mass index, body weight, body fat mass, body fat percentage, waist circumference, waist-to-hip ratio, and visceral fat area.From 1,527 retrieved reports, 11 studies (911 subjects) were included in this review. Bifidobacterium probiotics administration resulted in significant reductions in body fat mass (MD = -0.64 kg, 95% CI: -1.09, -0.18, p = 0.006), body fat percentage (MD = -0.64%, 95% CI: -1.18, -0.11, p = 0.02), waist circumference (MD = -1.39 cm, 95% CI: -1.99, -0.79, p < 0.00001), and visceral fat area (MD = -4.38 cm2, 95% CI: -7.24, -1.52, p = 0.003). No significant differences were observed for body mass index, body weight, or waist-to-hip ratio.This systematic review suggests that Bifidobacterium genus probiotics may contribute to managing overweight and obesity by reducing body fat mass, body fat percentage, waist circumference, and visceral fat area. Further research is required to understand strain and species interactions, optimal dosages, and effective delivery methods for probiotics in obesity management. This review was pre-registered under the PROSPERO record CRD42022370057.

Probiotics from the Bifidobacterium genus show promise in reducing body fat mass, body fat percentage, waist circumference, and visceral fat area in overweight and obese adults.Further research is needed to identify the most effective species and strains within the Bifidobacterium genus for achieving these outcomes.There is an urgent need to determine the best probiotic delivery vehicle among enriched foods, capsules, or powders.More randomized controlled trials are necessary to determine optimal probiotic doses and intervention durations.

The Gut Microbiome in the First One Thousand Days of Neurodevelopment: A Systematic Review from the Microbiome Perspective.

Evidence shows that the gut microbiome in early life is an essential modulator of physiological processes related to healthy brain development, as well as mental and neurodegenerative disorders. Here, we conduct a systematic review of gut microbiome assessments on infants (both healthy and with conditions that affect brain development) during the first thousand days of life, associated with neurodevelopmental outcomes, with the aim of investigating key microbiome players and mechanisms through which the gut microbiome affects the brain. Bacteroides and Bifidobacterium were associated with non-social fear behavior, duration of orientation, cognitive and motricity development, and neurotypical brain development. Lachnospiraceae, Streptococcus, and Faecalibacterium showed variable levels of influence on behavior and brain development. Few studies described mechanistic insights related to NAD salvage, aspartate and asparagine biosynthesis, methanogenesis, pathways involved in bile acid transformation, short-chain fatty acids production, and microbial virulence genes. Further studies associating species to gene pathways and robustness in data analysis and integration are required to elucidate the functional mechanisms underlying the role of microbiome-gut-brain axis in early brain development.

Screening competition and cross-feeding interactions during utilization of human milk oligosaccharides by gut microbes.

Background: The infant gut microbiome is a complex community that influences short- and long-term health. Its assembly and composition are governed by variables such as the feeding type. Breast milk provides infants an important supply of human milk oligosaccharides (HMO), a broad family of carbohydrates comprising neutral, fucosylated, and sialylated molecules. There is a positive association between HMOs and the overrepresentation of Bifidobacterium species in the infant gut, which is sustained by multiple molecular determinants present in the genomes of these species. Infant-gut-associated Bifidobacterium species usually share a similar niche and display similar HMO inclinations, suggesting they compete for these resources. There is also strong evidence of cross-feeding interactions between HMO-derived molecules and bifidobacteria. Methods: In this study, we screened for unidirectional and bidirectional interactions between Bifidobacterium and other species using individual HMO. Bifidobacterium bifidum and Bacteroides thetaiotaomicron increased the growth of several other species when their supernatants were used, probably mediated by the partial degradation of HMO. In contrast, Bifidobacterium longum subsp. infantis. supernatants did not exhibit positive growth. Results: Bifidobacterium species compete for lacto-N-tetraose, which is associated with reduced bidirectional growth. The outcome of these interactions was HMO-dependent, in which the two species could compete for one substrate but cross-feed on another. 2'-fucosyllactose and lacto-N-neotetraose are associated with several positive interactions that generally originate from the partial degradation of these HMOs. Conclusion: This study presents evidence for complex interactions during HMO utilization, which can be cooperative or competitive, depending on the nature of the HMO. This information could be useful for understanding how breast milk supports the growth of some Bifidobacterium species, shaping the ecology of this important microbial community.

Genome-scale metabolic modeling of the human milk oligosaccharide utilization by Bifidobacterium longum subsp. infantis.

Bifidobacterium longum subsp. infantis is a representative and dominant species in the infant gut and is considered a beneficial microbe. This organism displays multiple adaptations to thrive in the infant gut, regarded as a model for human milk oligosaccharides (HMOs) utilization. These carbohydrates are abundant in breast milk and include different molecules based on lactose. They contain fucose, sialic acid, and N-acetylglucosamine. Bifidobacterium metabolism is complex, and a systems view of relevant metabolic pathways and exchange metabolites during HMO consumption is missing. To address this limitation, a refined genome-scale network reconstruction of this bacterium is presented using a previous reconstruction of B. infantis ATCC 15967 as a template. The latter was expanded based on an extensive revision of genome annotations, current literature, and transcriptomic data integration. The metabolic reconstruction (iLR578) accounted for 578 genes, 1,047 reactions, and 924 metabolites. Starting from this reconstruction, we built context-specific genome-scale metabolic models using RNA-seq data from cultures growing in lactose and three HMOs. The models revealed notable differences in HMO metabolism depending on the functional characteristics of the substrates. Particularly, fucosyl-lactose showed a divergent metabolism due to a fucose moiety. High yields of lactate and acetate were predicted under growth rate maximization in all conditions, whereas formate, ethanol, and 1,2-propanediol were substantially lower. Similar results were also obtained under near-optimal growth on each substrate when varying the empirically observed acetate-to-lactate production ratio. Model predictions displayed reasonable agreement between central carbon metabolism fluxes and expression data across all conditions. Flux coupling analysis revealed additional connections between succinate exchange and arginine and sulfate metabolism and a strong coupling between central carbon reactions and adenine metabolism. More importantly, specific networks of coupled reactions under each carbon source were derived and analyzed. Overall, the presented network reconstruction constitutes a valuable platform for probing the metabolism of this prominent infant gut bifidobacteria.IMPORTANCEThis work presents a detailed reconstruction of the metabolism of Bifidobacterium longum subsp. infantis, a prominent member of the infant gut microbiome, providing a systems view of its metabolism of human milk oligosaccharides.

Beneficial Bacteria and Plant Extracts Promote Honey Bee Health and Reduce Nosema ceranae Infection.

The research aims to give new insights on the effect of administering selected bacterial strains, isolated from honey bee gut, and/or a commercial plant extract blend (HiveAlive®) on Nosema ceranae. Analyses were first performed under laboratory conditions such as different infective doses of N. ceranae, the effect of single strains and their mixture and the influence of pollen administration. Daily survival and feed consumption rate were recorded and pathogen development was analysed using qPCR and microscope counts. Biomarkers of immunity and physiological status were also evaluated for the different treatments tested using one bacterial strain, a mixture of all the bacteria and/or a plant extract blend as treatments. The results showed an increase of abaecin transcript levels in the midgut of the honey bees treated with the bacterial mixture and an increased expression of the protein vitellogenin in the haemolymph of honey bees treated with two separate bacterial strains (Bifidobacterium coryneforme and Apilactobacillus kunkeei). A significant effectiveness in reducing N. ceranae was shown by the bacterial mixture and the plant extract blend regardless of the composition of the diet. This bioactivity was seasonally linked. Quantitative PCR and microscope counts showed the reduction of N. ceranae under different experimental conditions. The antiparasitic efficacy of the treatments at field conditions was studied using a semi-field approach which was adapted from research on insecticides for the first time, to analyse antiparasitic activity against N. ceranae. The approach proved to be reliable and effective in validating data obtained in the laboratory. Both the mixture of beneficial bacteria and its association with Hive Alive® are effective in controlling the natural infection of N. ceranae in honey bee colonies.

Analysis of Bifidobacterium animalis subsp. lactis BB-12 ® and Lactobacillus rhamnosus GG on underweight and malabsorption in premature infants

SUMMARY OBJECTIVE: This study aimed to explore and analyze the therapeutic effect of the combination of Bifidobacterium animalis subsp. lactis BB-12® and Lactobacillus rhamnosus GG on underweight and malabsorption in premature infants. METHODS: This is a retrospective study. The clinical data of 68 premature infants admitted to Beijing United Family Hospital (Private Secondary Comprehensive Hospital, Chaoyang District, Beijing, China) from January 2016 to January 2022 were analyzed retrospectively. Preterm infants less than 37 weeks of gestational age admitted to the neonatal intensive care unit were included in the study. Patients with intestinal malformations, necrotizing enterocolitis, etc., who require long-term fasting were excluded. A telephone follow-up was performed 3-6 months after discharge. They were classified as treatment groups A and B according to the treatment plan. The treatment group A included parenteral nutrition, enteral nutrition, etc. In treatment group B, based on treatment group A, the premature infants were treated with Bifidobacterium animalis subsp. lactis BB-12® and Lactobacillus rhamnosus GG. The time to regain birthweight and the weight on day 30 were compared between the two groups, as was the duration of transition from parenteral nutrition to total enteral nutrition. RESULTS: The time of weight regain birthweight in group B was shorter than that in group A (t=-2.560; t=-4.287; p<0.05). The increase of weight on day 30 in group B was significantly higher than that in group A (t=2.591; t=2.651; p<0.05). The time from parenteral nutrition to total enteral nutrition in group B was shorter than that in group A (z=-2.145; z=-2.236; p<0.05). CONCLUSION: In the treatment of premature infants, the combination of Bifidobacterium animalis subsp. lactis BB-12® and Lactobacillus rhamnosus GG can have a better therapeutic effect on the underweight and malabsorption of premature infants, and this treatment method can be popularized in clinics.

Microbial interactions and the homeostasis of the gut microbiome: the role of Bifidobacterium.

The human gut is home to trillions of microorganisms that influence several aspects of our health. This dense microbial community targets almost all dietary polysaccharides and releases multiple metabolites, some of which have physiological effects on the host. A healthy equilibrium between members of the gut microbiota, its microbial diversity, and their metabolites is required for intestinal health, promoting regulatory or anti-inflammatory immune responses. In contrast, the loss of this equilibrium due to antibiotics, low fiber intake, or other conditions results in alterations in gut microbiota composition, a term known as gut dysbiosis. This dysbiosis can be characterized by a reduction in health-associated microorganisms, such as butyrate-producing bacteria, enrichment of a small number of opportunistic pathogens, or a reduction in microbial diversity. Bifidobacterium species are key species in the gut microbiome, serving as primary degraders and contributing to a balanced gut environment in various ways. Colonization resistance is a fundamental property of gut microbiota for the prevention and control of infections. This community competes strongly with foreign microorganisms, such as gastrointestinal pathogens, antibiotic-resistant bacteria, or even probiotics. Resistance to colonization is based on microbial interactions such as metabolic cross-feeding, competition for nutrients, or antimicrobial-based inhibition. These interactions are mediated by metabolites and metabolic pathways, representing the inner workings of the gut microbiota, and play a protective role through colonization resistance. This review presents a rationale for how microbial interactions provide resistance to colonization and gut dysbiosis, highlighting the protective role of Bifidobacterium species.

Fermentation of araticum, baru, and pequi by-products by probiotic strains: effects on microorganisms, short-chain fatty acids, and bioactive compounds.

Fruit by-products, due to their unique chemical composition containing dietary fibers and bioactive compounds, may favor the growth of probiotic strains. This study evaluated the fermentation of araticum, baru, and pequi by-products using Lactobacillus acidophilus (La-5, LA3, and NCFM) and Bifidobacterium animalis subsp. lactis (Bb-12) probiotic strains. We assessed probiotic viability, short-chain fatty acid levels, and bioactive compound levels after 48 h of fermentation. Araticum and pequi by-products led to counts higher than 6 log CFU/mL after 48-h fermentation for all Lactobacillus strains, but only the araticum by-product supported the growth of the Bb-12 strain. Fermentation of araticum by-product resulted in greater amounts of acetate (39.97 mM for LA3 and 39.08 mM for NCFM) and propionate (0.20 mM for NCFM), while baru by-product showed greater amounts of butyrate (0.20 mM for La-5 and Bb-12). Fermentation of araticum and baru by-products resulted in an increase in bioactive compounds, with the latter showing total phenolic compounds and antioxidant activity from 1.4 to 1.7 and from 1.3 to 3.1 times higher, respectively, than the negative control treatment. Araticum by-product exhibited a higher potential for prebiotic effects, and fermentation by the tested probiotic strains is essential to increase bioactive compound levels.

Production of Reactive Oxygen (ROS) and Nitrogen (RNS) Species in Macrophages J774A.1 Activated by the Interaction between Two Escherichia coli Pathotypes and Two Probiotic Commercial Strains.

Probiotics play an important role against infectious pathogens, such as Escherichia coli (E. coli), mainly through the production of antimicrobial compounds and their immunomodulatory effect. This protection can be detected both on the live probiotic microorganisms and in their inactive forms (paraprobiotics). Probiotics may affect different cells involved in immunity, such as macrophages. Macrophages are activated through contact with microorganisms or their products (lipopolysaccharides, endotoxins or cell walls). The aim of this work was the evaluation of the effect of two probiotic bacteria (Escherichia coli Nissle 1917 and Bifidobacterium animalis subsp. lactis HN019 on macrophage cell line J774A.1 when challenged with two pathogenic strains of E. coli. Macrophage activation was revealed through the detection of reactive oxygen (ROS) and nitrogen (RNS) species by flow cytometry. The effect varied depending on the kind of probiotic preparation (immunobiotic, paraprobiotic or postbiotic) and on the strain of E. coli (enterohemorrhagic or enteropathogenic). A clear immunomodulatory effect was observed in all cases. A higher production of ROS compared with RNS was also observed.

Bifidobacterium longum LBUX23 Isolated from Feces of a Newborn; Potential Probiotic Properties and Genomic Characterization.

Bifidobacterium longum is considered a microorganism with probiotic potential, which has been extensively studied, but these probiotic effects are strain dependent. This work aims to characterize the probiotic potential, based on the biochemical and genomic functionality, of B. longum LBUX23, isolated from neonates' feces. B. longum LBUX23 contains one circular genome of 2,287,838 bp with a G+C content of 60.05%, no plasmids, no CRISPR-Cas operon, possesses 56 tRNAs, 9 rRNAs, 1 tmRNA and 1776 coding sequences (CDSs). It has chromosomally encoded resistance genes to ampicillin and dicloxacillin, non-hemolytic activity, and moderate inhibition of Escherichia coli ATCC 25922 and to some emergent pathogen's clinical strains. B. longum LBUX23 was able to utilize lactose, sucrose, fructooligosaccharides (FOS), and lactulose. The maximum peak of bacterial growth was observed in sucrose and FOS at 6 h; in lactose and lactulose, it was shown at 8 h. B. longum LBUX23 can survive in gastrointestinal conditions (pH 4 to 7). A decrease in survival (96.5 and 93.8%) was observed at pH 3 and 3.5 during 120 min. argC, argH, and dapA genes could be involved in this tolerance. B. longum LBUX23 can also survive under primary and secondary glyco- or tauro-conjugated bile salts, and a mixture of bile salts due to the high extracellular bile salt hydrolase (BSH) activity (67.3 %), in taurocholic acid followed by taurodeoxycholic acid (48.5%), glycocholic acid (47.1%), oxgall (44.3%), and glycodeoxycholic acid (29.7%) probably due to the presence of the cbh and gnlE genes which form an operon (start: 119573 and end: 123812). Low BSH activity was determined intracellularly (<7%), particularly in glycocholic acid; no intracellular activity was shown. B. longum LBUX23 showed antioxidant effects in DPPH radical, mainly in intact cells (27.4%). In the case of hydroxyl radical scavenging capacity, cell debris showed the highest reduction (72.5%). In the cell-free extract, superoxide anion radical scavenging capacity was higher (90.5%). The genome of B. longum LBUX23 contains PNPOx, AhpC, Bcp, trxA, and trxB genes, which could be involved in this activity. Regarding adherence, it showed adherence up to 5% to Caco-2 cells. B. longum LBUX23 showed in vitro potential probiotic properties, mainly in BSH activity and antioxidant capacity, which indicates that it could be a good candidate for antioxidant or anti-cholesterol tests using in vivo models.

Bifidobacterium animalis subspecies lactis HN019 can reduce the sequelae of experimental periodontitis in rats modulating intestinal parameters, expression of lipogenic genes, and levels of hepatic steatosis.

OBJECTIVE: To determine whether Bifidobacterium animalis subspecies lactis HN019 (B. lactis HN019) can reduce the sequelae of experimental periodontitis (EP) in rats modulating systemic parameters. BACKGROUND: This study evaluated the effects of probiotic therapy (PROB) in the prevention of local and systemic damage resulting from EP. METHODS: Forty-eight rats were allocated into four groups: C (control), PROB, EP, and EP-PROB. PROB (1 × 1010 CFU/mL) administration lasted 8 weeks and PE was induced on the 7th week by placing ligature on the animals' lower first molars. All animals were euthanized in the 9th week of the experiment. Biomolecular analyses, RT-PCR, and histomorphometric analyses were performed. The data obtained were analyzed statistically (ANOVA, Tukey, p < .05). RESULTS: The EP group had higher dyslipidemia when compared to the C group, as well as higher levels of insulin resistance, proteinuria levels, percentages of systolic blood pressure, percentage of fatty hepatocytes in the liver, and expression of adipokines was up-regulated (LEPR, NAMPT, and FABP4). All these parameters (except insulin resistance, systolic blood pressure, LEPR and FABP4 gene expression) were reduced in the EP-PROB group when compared to the EP group. The EP group had lower villus height and crypt depth, as well as a greater reduction in Bacteroidetes and a greater increase in Firmicutes when compared to the EP-PROB group. Greater alveolar bone loss was observed in the EP group when compared to the EP-PROB group. CONCLUSION: Bifidobacterium lactis HN019 can reduce the sequelae of EP in rats modulating intestinal parameters, attenuating expression of lipogenic genes and hepatic steatosis.

Bifidobacterium longum and Chlorella sorokiniana Improve the IFN Type I-Mediated Antiviral Response in Rotavirus-Infected Cells.

Probiotics are effective to treat or prevent gastrointestinal infections, and microalgae have demonstrated important health-promoting effects and in some cases function as prebiotics. In this regard, the anti-rotavirus effect of Bifidobacterium longum and Chlorella sorokiniana by reducing viral infectivity is well known. However, their effect on immune response against rotavirus has not yet been investigated. Therefore, the aim of this study was to determine the role of Bifidobacterium longum and/or Chlorella sorokiniana in influencing an IFN type I-mediated antiviral response in rotavirus-infected cells. In pre-infection experiments, HT-29 cells were treated with B. longum and C. sorokiniana alone or in combination, followed by rotavirus infection, whereas in post-infection assays, HT-29 cells were treated after infection. The cells' mRNA was then purified to determine the relative expression level of IFN-α, IFN-ß, and precursors of interferons such as RIG-I, IRF-3, and IRF-5 by qPCR. We showed that combination of B. longum and C. sorokiniana significantly increased IFN-α levels in pre-infection and IFN-ß in post-infection assays, as compared with individual effects. Results indicate that B. longum, C. sorokiniana, or their combination improve cellular antiviral immune response.

Proteomic analyses of Bacteroides ovatus and Bifidobacterium longum in xylan bidirectional culture shows sugar cross-feeding interactions.

The intestinal microbiome is a community of anaerobic microorganisms whose activities significantly impact human health. Its composition can be modulated by consuming foods rich in dietary fiber, such as xylan, a complex polysaccharide that can be considered an emerging prebiotic. In this work, we evaluated how certain gut bacteria acted as primary degraders, fermenting dietary fibers, and releasing metabolites that other bacteria can further use. Different bacterial strains of Lactobacillus, Bifidobacterium, and Bacteroides were evaluated for their ability to consume xylan and interact with one another. Results from unidirectional assays gave indications of possible cross-feeding between bacteria using xylan as a carbon source. Bidirectional assays showed that Bifidobacterium longum PT4 increased its growth in the presence of Bacteroides ovatus HM222. Proteomic analyses indicated that B. ovatus HM222 synthesizes enzymes facilitating xylan degradation, such as ß-xylanase, arabinosidase, L-arabinose isomerase, and xylosidase. Interestingly, the relative abundance of these proteins remains largely unaffected in the presence of Bifidobacterium longum PT4. In the presence of B. ovatus, B. longum PT4 increased the production of enzymes such as α-L-arabinosidase, L-arabinose isomerase, xylulose kinase, xylose isomerase, and sugar transporters. These results show an example of positive interaction between bacteria mediated by xylan consumption. Bacteroides degraded this substrate to release xylooligosaccharides, or monosaccharides (xylose, arabinose), which might support the growth of secondary degraders such as B. longum.

Screening Microbial Interactions During Inulin Utilization Reveals Strong Competition and Proteomic Changes in Lacticaseibacillus paracasei M38.

Competition for resources is a common microbial interaction in the gut microbiome. Inulin is a well-studied prebiotic dietary fiber that profoundly shapes gut microbiome composition. Several community members and some probiotics, such as Lacticaseibacillus paracasei, deploy multiple molecular strategies to access fructans. In this work, we screened bacterial interactions during inulin utilization in representative gut microbes. Unidirectional and bidirectional assays were used to evaluate the effects of microbial interactions and global proteomic changes on inulin utilization. Unidirectional assays showed the total or partial consumption of inulin by many gut microbes. Partial consumption was associated with cross-feeding of fructose or short oligosaccharides. However, bidirectional assays showed strong competition from L. paracasei M38 against other gut microbes, reducing the growth and quantity of proteins found in the latter. L. paracasei dominated and outcompeted other inulin utilizers, such as Ligilactobacillus ruminis PT16, Bifidobacterium longum PT4, and Bacteroides fragilis HM714. The importance of strain-specific characteristics of L. paracasei, such as its high fitness for inulin consumption, allows it to be favored for bacterial competence. Proteomic studies indicated an increase in inulin-degrading enzymes in co-cultures, such as ß-fructosidase, 6-phosphofructokinase, the PTS D-fructose system, and ABC transporters. These results reveal that intestinal metabolic interactions are strain-dependent and might result in cross-feeding or competition depending on total or partial consumption of inulin. Partial degradation of inulin by certain bacteria favors coexistence. However, when L. paracasei M38 totally degrades the fiber, this does not happen. The synergy of this prebiotic with L. paracasei M38 could determine the predominance in the host as a potential probiotic.

Combination of vitamin D and probiotics inhibits chemically induced colorectal carcinogenesis in Wistar rats.

The modulation of inflammatory elements, cell differentiation and proliferation by vitamin D and the role of probiotics in the intestinal microbiota and immunogenic response have sparked interest in the application of both in chemotherapeutics and chemoprevention of colorectal tumors. AIMS: The present study aimed to investigate the effects of isolated and/or combined treatment of vitamin D3 and probiotics on colorectal carcinogenesis. MAIN METHODS: Pre-neoplastic lesions were induced with 1,2-dimethylhydrazine in the colon of Wistar rats, which were treated with probiotics and/or vitamin D in three different approaches (simultaneous, pre-, and post-treatment). We investigated the frequency of aberrant crypt foci (ACF) and aberrant crypt (AC) in the distal colon, fecal microbiome composition, gene and protein expression through immunohistochemical and RT-PCR assays, and general toxicity through water consumption and weight gain monitoring. KEY FINDINGS: Results confirm the systemic safety of treatments, and show a protective effect of vitamin D and probiotics in all approaches studied, as well as in combined treatments, with predominance of different bacterial phyla compared to controls. Treated groups show different levels of Nrf2, GST, COX2, iNOS, ß-catenin and PCNA expression. SIGNIFICANCE: These experimental conditions explore the combination of vitamin D and probiotics supplementation at low doses over pathways involved in distinct stages of colorectal carcinogenesis, with results supporting its application in prevention and long-term strategies.

Probiotic fermented whey-milk beverages: Effect of different probiotic strains on the physicochemical characteristics, biological activity, and bioactive peptides.

The effect of probiotic strains (Lactobacillus acidophilus La-03 (La-03); Lactobacillus acidophilus La-05 (La-05); Bifidobacterium Bb-12 (Bb-12) or Lacticaseibacillus casei-01 (L. casei-01)) on the characteristics of fermented whey-milk beverages during storage (4 °C, 30 days) was evaluated. The products were assessed for biological and antioxidant activities, physicochemical characteristics, and bioactive peptides. Probiotic addition increased α-amylase and α-glucosidase inhibition and antioxidant activities, mainly at 15 days of storage. L. casei-01 showed higher metabolic activity (higher titratable acidity and lower pH values) and the presence of anti-hypertensive peptides, while La-5 and Bb-12 showed higher α-glucosidase inhibition, improvements in the high saturated hypercholesterolemic index, and peptides with ACE-inhibitory, antimicrobial, immunomodulatory, and antioxidant activities. Our findings suggest that probiotic fermented whey-milk beverages may exert antidiabetic and antioxidant properties, being suggested La-5 or Bb-12 as probiotics and 15 days of storage.

Structure of co-expression networks of Bifidobacterium species in response to human milk oligosaccharides.

Biological systems respond to environmental perturbations and a large diversity of compounds through gene interactions, and these genetic factors comprise complex networks. Experimental information from transcriptomic studies has allowed the identification of gene networks that contribute to our understanding of microbial adaptations. In this study, we analyzed the gene co-expression networks of three Bifidobacterium species in response to different types of human milk oligosaccharides (HMO) using weighted gene co-expression analysis (WGCNA). RNA-seq data obtained from Geo Datasets were obtained for Bifidobacterium longum subsp. Infantis, Bifidobacterium bifidum and Bifidobacterium longum subsp. Longum. Between 10 and 20 co-expressing modules were obtained for each dataset. HMO-associated genes appeared in the modules with more genes for B. infantis and B. bifidum, in contrast with B. longum. Hub genes were identified in each module, and in general they participated in conserved essential processes. Certain modules were differentially enriched with LacI-like transcription factors, and others with certain metabolic pathways such as the biosynthesis of secondary metabolites. The three Bifidobacterium transcriptomes showed distinct regulation patterns for HMO utilization. HMO-associated genes in B. infantis co-expressed in two modules according to their participation in galactose or N-Acetylglucosamine utilization. Instead, B. bifidum showed a less structured co-expression of genes participating in HMO utilization. Finally, this category of genes in B. longum clustered in a small module, indicating a lack of co-expression with main cell processes and suggesting a recent acquisition. This study highlights distinct co-expression architectures in these bifidobacterial genomes during HMO consumption, and contributes to understanding gene regulation and co-expression in these species of the gut microbiome.