Bifidobacterium Species Research Articles

Effects of a Flavonoid-Rich Blackcurrant Beverage on Markers of the Gut-Brain Axis in Healthy Females: Secondary Findings From a 4-Week Randomized Crossover Control Trial

The microbiota–gut–brain axis is a promising target to alleviate the growing burden of neurologic and mental health disorders. Dietary polyphenols act on multiple components of the microbiota–gut–brain axis, but this complex relationship requires further attention. This randomized, placebo-controlled, double-blind, crossover trial (ACTRN12622000850774) compared 4 wk of a commercially available flavonoid-rich blackcurrant beverage (FBB; 151 mg anthocyanins, 308 mg total polyphenols) with placebo in 40 healthy females (18–45 y). The primary outcome of stress reactivity was assessed by change in present feelings of stress, mood, and fatigue before and after completing a 20-min cognitive stressor [Purple multitasking framework (MTF)]. Secondary end points included cognitive performance (MTF), mood [profile of mood states (POMS)], sleep (Pittsburgh Sleep Quality Index), fecal microbiome composition and functional potential (shotgun sequencing), and blood biomarker concentrations (brain-derived neurotrophic factor, tryptophan, kynurenine, and interleukin 6). Statistical analyses were conducted on an intention-to-treat basis using linear mixed-effect models. Thirty-eight participants completed both intervention arms. There was no significant treatment effect on the primary outcome of stress reactivity. Compared with placebo, working memory (letter retrieval scores from MTF), and anxiety/tension and anger/hostility domains of the POMS improved with FBB supplementation (time × intervention interaction; P < 0.05). There were no treatment effects on gut microbiome composition or functional potential. Baseline abundances of Bifidobacterium genera and species (Bifidobacterium longum and Bifidobacterium bifidum) tended to be higher in participants with the greatest improvements in letter retrieval scores with FBB supplementation (nominally significant, P < 0.05). In conclusion, 4-wk FBB supplementation improved secondary outcomes of working memory performance during multitasking and mood outcomes in healthy adult females. These results should be confirmed in a larger cohort with a longer duration of follow-up.

Effect of Raw and Cooked Green Bananas on Cecal Fermentation Characteristics in Rats

AbstractRaw and cooked (autoclaved) green bananas are fed to rats for 4 weeks and their effects on cecal microbiota and biomarkers of fermentation are evaluated and compared with those of potato starch, which is rich in RS. Relative abundances of genera Lachnospiraceae_NK4A136_group and Roseburia, and species Bifidobacterium pseudolongum in rat cecum are higher in the raw green banana group with higher RS consumption than in the control group. The raw green banana group shows higher cecal acetate production and similarly high levels of cecal n‐butyrate production than that in the potato starch group. In the autoclaved green banana group, the cecal microbial composition is altered and the relative abundance of family Ruminococcaceae increased. Additionally, the molar proportion of n‐butyrate in the cecum of the autoclaved green banana group is higher than that in the control group. The levels of cecal mucin and IgA in the raw green banana and potato starch groups are found to be higher compared to those observed in the control and autoclaved green banana groups. Therefore, raw and autoclaved green bananas can alter cecal microbial composition and thus exhibit beneficial intestinal fermentation characteristics.

Enzymatic characterization of sucrose phosphorylase from Bifidobacterium dentium: The initial enzyme in the cascade reaction

Sucrose phosphorylase (SPase) catalyzes the conversion of sucrose to ⍺-Glucose 1-phosphate (G-1-P) and fructose. G-1-P functions as a glycosyl donor and is an initial substrate for biosynthesis cascades. This study characterized the enzymatic properties of a novel SPase from Bifidobacterium dentium (BdSP) and explored its potential as an initial enzyme in cascade reactions. BdSP displayed 91–93% homology with the SPase from Bifidobacterium species. Recombinant BdSP was characterized as a dimer with optimal temperatures of 55 °C and 60 °C and pH of 7.0 and 5.0 for the phosphorolysis and synthesis reactions, respectively. The melting temperature of BdSP was 68.91 °C, and its half-life was 235.1 min at 65 °C. Kinetic studies demonstrated that BdSP can produce G-1-P from sucrose more efficiently than other SPases, with a production rate of 68% at 55 °C for 2 h. Furthermore, the cascade reaction of BdSP and cellobiose phosphorylase from Clostridium thermocellum YM4 (CtCBP) reached an effective production of cellobiose (80.4%) at 55 °C for 18 h.

Characterization of the Small Bowel Microbiome Reveals Different Profiles in Human Subjects Who Are Overweight or Have Obesity.

Gut microbiome changes are linked to obesity, but findings are based on stool data. In this article, we analyzed the duodenal microbiome and serum biomarkers in subjects with normal weight, overweight, and obesity. Duodenal aspirates and serum samples were obtained from subjects undergoing standard-of-care esophagogastroduodenoscopy without colon preparation. Aspirate DNAs were analyzed by 16S rRNA and shotgun sequencing. Predicted microbial metabolic functions and serum levels of metabolic and inflammatory biomarkers were also assessed. Subjects with normal weight (N = 105), overweight (N = 67), and obesity (N = 42) were identified. Overweight-specific duodenal microbial features include lower relative abundance (RA) of Bifidobacterium species and Escherichia coli strain K-12 and higher Lactobacillus intestinalis , L. johnsonii , and Prevotella loescheii RA. Obesity-specific features include higher Lactobacillus gasseri RA and lower L. reuteri (subspecies rodentium ), Alloprevotella rava , and Leptotrichia spp RA. Escalation features (progressive changes from normal weight through obesity) include decreasing Bacteroides pyogenes , Staphylococcus hominis , and unknown Faecalibacterium species RA, increasing RA of unknown Lactobacillus and Mycobacterium species, and decreasing microbial potential for biogenic amines metabolism. De-escalation features (direction of change altered in normal to overweight and overweight to obesity) include Lactobacillus acidophilus , L. hominis , L. iners , and Bifidobacterium dentium . An unknown Lactobacillus species is associated with type IIa dyslipidemia and overweight, whereas Alloprevotella rava is associated with type IIb and IV dyslipidemias. Direct analysis of the duodenal microbiome has identified key genera associated with overweight and obesity, including some previously identified in stool, e.g., Bifidobacterium and Lactobacillus . Specific species and strains exhibit differing associations with overweight and obesity, including escalation and de-escalation features that may represent targets for future study and therapeutics.

A Mini Literature Review of Probiotics: Transforming Gastrointestinal Health Through Evidence-Based Insights.

As our understanding of the intricate interaction between gut bacteria and human health continues to expand, so too has interest in the ability of probiotics to manage gut microbiota and confer multiple health benefits to the host. The mini literature review focuses on the expanding potential of the use of probiotics in GI health, with a focus on probiotics' potential therapeutic advantages in a variety of gastrointestinal (GI) illnesses. Probiotics play a significant role in managing diarrhea and symptoms of irritable bowel syndrome with diarrhea (IBS-D) by modulating gut microbial communities. Specific probiotic strains have been found to reduce the abundance of harmful bacteria, regulate inflammatory markers like interleukin 6, and improve GI symptoms such as abdominal discomfort and stool consistency. Additionally, probiotic blends have shown potential for preventing GI infections and alleviating GI pain in IBS-D patients. Studies have demonstrated that certain multi-strain probiotics, including Bifidobacterium and Lactobacillus species, can significantly increase the frequency of bowel movements and reduce the proportion of individuals experiencing constipation. It has also been found that probiotic supplementation may reduce the incidence of postoperative complications and mortality, particularly in patients undergoing colorectal adenocarcinoma surgery. Additionally, probiotics have been associated with decreased levels of pro-inflammatory cytokines and improved clinical outcomes in patients with colorectal cancer. Furthermore, probiotics have been associated with enhanced digestive tolerance, reduced GI inflammation, and prolonged clinical remission in certain UC patients. Studies have also shown that probiotics, administered either directly to infants or pregnant women during the perinatal stage, can alleviate symptoms such as inconsolable crying and irritation associated with infant colic, improve bowel movement frequency in cases of functional constipation, and enhance overall conditions in premature infants, including reducing regurgitation and improving feeding tolerance. The review addresses both encouraging results and challenges with probiotic therapy, while also arguing for more studies to elucidate underlying mechanisms and enhance therapeutic techniques. As we traverse the complex field of probiotic therapy in the treatment of GI illnesses, researchers, physicians, and other healthcare professionals can benefit from the informative information provided by this study.

Abstract 2809: Bifidobacterium species BB_003 identified through metatranscriptomic analysis with experimentally validated antitumor actions

Abstract Introduction &amp; Objectives: A host's microbiome influences both gene expression and phenotype. Whole transcriptome sequencing (WTS) provides information about the microbiome in addition to gene expression. This research probes the correlation between microbial abundance, host gene transcription, and therapeutic efficacy, pinpointing a beneficial microbial strain and its mechanism of action. Materials &amp; Methods: Bladder tissue biopsies from NMIBC patients underwent WTS and subsequent bioinformatic analysis. After in silico evaluation, in vitro assays including WST, quantitative PCR, and immune cell profiling were performed on mouse splenocytes. These assays were followed by in vivo assessment in both subcutaneous and orthotopic murine tumor models. Results: Among 59 biopsies, non-recurrence correlated with heightened presence of Lactococcus species LC_001 and Bifidobacterium species BB_003. Notably, BB_003 was associated with an extended recurrence-free survival (RFS). Gene set enrichment analysis (GSEA) implicated BB_003 in mediating a pro-inflammatory cascade, accentuating macrophages and interferons. In vitro WST assays showed the antitumor potential of BB_003_β, characterized by upregulated pro-inflammatory gene transcription. This strain increased effector CD8 T cells and M2 macrophages. In vivo, direct live BB_003_β introduction into subcutaneous tumors curtailed tumor proliferation. An increase in effector CD8 T cell populations within tumors and elevated cDC1 and M1 macrophage counts in tumor-draining lymph nodes were observed. Intravesical administration of live bacteria markedly decreased bladder weight, amplifying interferon alpha and beta gene expressions compared to controls. Conclusions: According to this study, BB_003_β inhibits tumor growth and is involved in immune response. Our study confirmed the antitumor properties of BB_003_β and suggested that cytokine and immune cell stimulation play a key role in its mechanism of action. Augmented insights warrant further exploration, particularly in synergy with intravesical BCG treatment. Citation Format: Xuan-Mei Piao, Kyungchan Min, Young Joon Byun, Chuang-Ming Zheng, Seon-Kyu Kim, Seong-Hwan Park, Sungmin Moon, Kyeong Kim, Ho Won Kang, Won Tae Kim, Seok Joong Yun, Hansoo Park. Bifidobacterium species BB_003 identified through metatranscriptomic analysis with experimentally validated antitumor actions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2809.

A 21-day safety evaluation of biotechnologically produced 3-fucosyllactose (3-FL) in neonatal farm piglets to support use in infant formulas

3-Fucosyllactose (3-FL) is one of the most abundant fucosylated oligosaccharides in human breast milk and is an approved infant formula ingredient world-wide. 3-FL functions as a prebiotic to promote early microbial colonization of the gut, increase pathogen resistance and modulate immune responses. To investigate safety and potential gut microbiota effects, 3-FL was fed for 21-days to farm piglets beginning on Postnatal Day (PND) 2. Fructooligosaccharide (FOS), an approved infant formula ingredient, was used as a reference control. Standard toxicological endpoints were evaluated, and the gut microbiota were assessed. Neither 3-FL (245.77 and 489.72 mg/kg/day for males and 246.57 and 494.18 mg/kg/day for females) nor FOS (489.44 and 496.33 mg/kg/day males and females, respectively) produced any adverse differences in growth, food intake or efficiency, clinical observations, or clinical or anatomic pathology changes. Differences in the gut microbiota after 3-FL consumption (versus control and FOS groups) included the absence of Bifidobacterium species from the piglets, enrichment of Prevotellamassilia timonensis, Blautia species, Mediterranea massiliensis, Lachnospiraceae incertae sedis, and Eubacterium coprostanoligens and lower relative abundance of Allisonella histaminiformans and Roseburia inulinivorans. This study further supports the safe use of 3-FL produced using biotechnology as a nutritional ingredient in foods.

Anti-obesity effects of Bifidobacterium lactis YGMCC2013 by promoting adipocyte thermogenesis and beige remodelling in association with gut microbiota

Obesity, a global public health challenge, is closely associated with gut microbiota alterations. Probiotics have the potential to prevent obesity, but their effectiveness can vary depending on the specific strain. This study focused on evaluating the anti-obesity and probiotic properties of four Bifidobacterium species isolated from healthy Chinese individuals in vitro. The findings indicated that Bifidobacterium lactis YGMCC2013 showed notable cholesterol assimilation ability, bile salt hydrolase activity, gastrointestinal tolerance, cellular adhesion, and production of short-chain fatty acids. The anti-obesity effect of YGMCC2013 was then assessed in mice fed a high-fat diet. The results demonstrated that YGMCC2013 reduced body and liver weight, adipose tissue hypertrophy and inflammation, and influenced specific microbial genera associated with adipose tissue characteristics. Notably, the study observed associations between certain microbial genera and different types of adipose tissue, indicating that YGMCC2013 may impact the balance and function of adipose tissue through its effects on the gut microbiota. Furthermore, YGMCC2013 enhanced the thermogenic capacity of brown and beige adipocytes, and improved the structure and function of the gut microbiota. These improvements were reflected by an increase in short-chain fatty acids produced by beneficial bacteria in the intestine, and the activation of metabolic pathways related to energy and carbohydrate metabolism. Moreover, YGMCC2013 modulated the expression of il-27 and tgr5 signaling pathways in adipose tissue, which might be involved in regulating adipose tissue inflammation and energy expenditure, respectively. These findings collectively demonstrate that YGMCC2013 has potential as a probiotic candidate for preventing obesity and improving metabolic health by influencing the gut-adipose tissue axis.

Genomic and functional diversity of cultivated Bifidobacterium from human gut microbiota

The genus Bifidobacterium widely exists in human gut and has been increasingly used as the adjuvant probiotics for the prevention and treatment of diseases. However, the functional differences of Bifidobacterium genomes from different regions of the world remain unclear. We here describe an extensive study on the genomic characteristics and function annotations of 1512 genomes (clustered to 849 non-redundant genomes) of Bifidobacterium cultured from human gut. The distribution of some carbohydrate-active enzymes varied among different Bifidobacterium species and continents. More than 36% of the genomes of B. pseudocatenulatum harbored biosynthetic gene clusters of lanthipeptide-class-iv. 99.76% of the cultivated genomes of Bifidobacterium harbored genes of bile salt hydrolase. Most genomes of B. adolescentis, and all genomes of B. dentium harbored genes involved in gamma-aminobutyric acid synthesis. B. longum subsp. infantis were characterized harboring most genes related to human milk oligosaccharide utilization. Significant differences between the distribution of antibiotic resistance genes among different species and continents revealed the importance to use antibiotics precisely in the clinical treatment. Phages infecting Bifidobacterium and horizontal gene transfers occurring in genomes of Bifidobacterium were dependent on species and region sources, and might help Bifidobacterium adapt to the environment. In addition, the distribution of Bifidobacterium in human gut was found varied from different regions of the world. This study represents a comprehensive view of characteristics and functions of genomes of cultivated Bifidobacterium from human gut, and enables clinical advances in the future.

인체 분변에서 Bifidobacterium species의 선택적 분리를 위한 배지 비교

인체 분변에서 Bifidobacterium species의 선택적 분리를 위한 배지 비교

Irritable bowel syndrome in children: pathogenetic significance of disorders of intestinal microbiota

Irritable bowel syndrome (IBS) is the most common functional disorder of the intestine in children. In recent years, IBS has been defined as functional pathology of the intestine, manifested by visceral recurrent pain that occurs at least once per week, characterized by the following two or more signs: associated with defecation; with changes in the frequency and shape of stools. These symptoms had to be noted in the patient for the last 3 months, with a total duration of at least 6 months, without signs of organic damage to the gastrointestinal tract (GIT). The gut microbiota is of particular importance in the pathogenesis of IBS. In patients with IBS, an increase in Enterobacteriaceae, Ruminococcus, Clostridium, Dorea species and a decrease in the number of Lactobacillus, Bifidobacterium and Faecalibacterium species were found. At the same time, a similar microbial profile was found in patients with different subtypes of IBS. The established patterns of changes in the composition of the microbiota in IBS in children and adults indicate IBS and functional disorders of the GIT to have a pronounced microbial pathogenesis. In this regard, the personalized use of prebiotics, probiotics, synbiotics, and fecal microbiota transplantation can effectively affect the intestinal microbiome in IBS. &#x0D; Conclusion. Correction of disorders of intestinal microbiota is the most important method of treating IBS in children. Determining the patterns of formation of changes in the intestinal microbiome in IBS children creates new opportunities for improving methods of their correction.

Isolation and identification of Bifidobacterium species from human breast milk and infant feces in Indonesia

Abstract. Dosan R, Mudana SO, Julyanto CMP, Purnama ET, Sugata M, Jo J, Tan TJ. 2024. Isolation and identification of Bifidobacterium species from human breast milk and infant feces in Indonesia. Biodiversitas 25: 337-343. There has been a growing interest in identifying emerging probiotic strains because of their benefits for human health. Many bifidobacteria originated from humans have been reported to possess probiotics properties. They are commonly found in the intestine of breast-fed infants. Hence, this study aimed to isolate and identify bifidobacteria from human breast milk and infant fecal samples in Indonesia and evaluate their probiotic properties. Twenty colonies were isolated from two independent fecal samples and two independent breast milk samples. Ten isolates (BR1-M1, BR1-B1, BR2-5, BR2-6, BR2-12, BS2-PB3, BS2-PB5, BS2-PS1, BS2-PS2, BS2-MB1) showed a compatible phenotypic character with Bifidobacteria based on the Bergey’s Manual, including Gram-positive, irregular rods, no catalase activity, non-spore-forming, and non-motile. Subsequently, four isolates with similar carbohydrate fermentation patterns as Bifidobacterium spp. were selected for further molecular identification based on 16S rRNA gene sequencing analysis. The results showed that BR2-5 and BR2-6 were found to be closely related to Bifidobacterium animalis subspecies lactis with 100 and 98.39% similarity, respectively. Meanwhile, BS2-PS1 and BS2-PB3 were found to be closely related to Bifidobacterium breve with 100 and 98.26% similarity, respectively. Further investigation revealed that BR2-5 and BS2-PB3 were resistant to low pH (?4) and could tolerate the exposure of bile salts (1%). Both isolates survived under different oxidative stress conditions (aerobic and microaerophilic). In conclusion, BR2-5 and BS2-PB3 exhibited promising characteristics as probiotic candidates, though further investigations are required to substantiate these current findings.

Bifidobacterium species viability in dairy-based probiotic foods: challenges and innovative approaches for accurate viability determination and monitoring of probiotic functionality.

Bifidobacterium species are essential members of a healthy human gut microbiota. Their presence in the gut is associated with numerous health outcomes such as protection against gastrointestinal tract infections, inflammation, and metabolic diseases. Regular intake of Bifidobacterium in foods is a sustainable way of maintaining the health benefits associated with its use as a probiotic. Owing to their global acceptance, fermented dairy products (particularly yogurt) are considered the ideal probiotic carrier foods. As envisioned in the definition of probiotics as "live organisms," the therapeutic functionalities of Bifidobacterium spp. depend on maintaining their viability in the foods up to the point of consumption. However, sustaining Bifidobacterium spp. viability during the manufacture and shelf-life of fermented dairy products remains challenging. Hence, this paper discusses the significance of viability as a prerequisite for Bifidobacterium spp. probiotic functionality. The paper focuses on the stress factors that influence Bifidobacterium spp. viability during the manufacture and shelf life of yogurt as an archetypical fermented dairy product that is widely accepted as a delivery vehicle for probiotics. It further expounds the Bifidobacterium spp. physiological and genetic stress response mechanisms as well as the methods for viability retention in yogurt, such as microencapsulation, use of oxygen scavenging lactic acid bacterial strains, and stress-protective agents. The report also explores the topic of viability determination as a critical factor in probiotic quality assurance, wherein, the limitations of culture-based enumeration methods, the challenges of species and strain resolution in the presence of lactic acid bacterial starter and probiotic species are discussed. Finally, new developments and potential applications of next-generation viability determination methods such as flow cytometry, propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR), next-generation sequencing, and single-cell Raman spectroscopy (SCRS) methods are examined.

Longitudinal quantification of Bifidobacterium longum subsp. infantis reveals late colonization in the infant gut independent of maternal milk HMO composition

Breast milk contains human milk oligosaccharides (HMOs) that cannot be digested by infants, yet nourish their developing gut microbiome. While Bifidobacterium are the best-known utilizers of individual HMOs, a longitudinal study examining the evolving microbial community at high-resolution coupled with mothers’ milk HMO composition is lacking. Here, we developed a high-throughput method to quantify Bifidobacterium longum subsp. infantis (BL. infantis), a proficient HMO-utilizer, and applied it to a longitudinal cohort consisting of 21 mother-infant dyads. We observed substantial changes in the infant gut microbiome over the course of several months, while the HMO composition in mothers’ milk remained relatively stable. Although Bifidobacterium species significantly influenced sample variation, no specific HMOs correlated with Bifidobacterium species abundance. Surprisingly, we found that BL. infantis colonization began late in the breastfeeding period both in our cohort and in other geographic locations, highlighting the importance of focusing on BL. infantis dynamics in the infant gut.

Lactic Acid Bacteria-Fermented Diet Containing Bacterial Extracellular Vesicles Inhibited Pathogenic Bacteria in Striped Beakfish (Oplegnathus fasciatus)

In recent years, probiotics have received considerable attention for improving the health of aquaculture organisms, such as fish and shrimp, by stimulating immune activity and increasing growth rates. Oplegnathus fasciatus is a common and economically important cultured fish species in Asia. In this study, we aimed to investigate the potential of lactic acid bacteria (LAB; Limosilactobacillus reuteri)-fermented feed to promote growth and enhance immune function in O. fasciatus. The feed contained the highest proportion of LAB after L. reuteri fermentation for 3 days in anaerobic conditions. Oplegnathus fasciatus was fed LAB-fermented feed for 30 days. The administration of LAB-fermented feed (live bacteria &gt; 109 CFU/g) significantly increased the growth rate (weight gain = 174.8%; FCR = 4.23) and intestinal probiotic levels of O. fasciatus. After LAB-fermented feeding, the immunity index was evaluated by superoxide anion production, the phagocytic activity of leukocytes, and bactericidal and lysozyme activities in the serum of O. fasciatus. We found that LAB-fermented feed treatment potentially elevated the proportions of intestinal Bifidobacterium, Blautia, and Dorea species and reduced pathogenic bacterial growth (Acinetobacter, Escherichia_Shigella, and Megasphaera) in O. fasciatus. This study demonstrated that LAB-fermented feed containing extracellular vesicles improves growth performance and the inhibition of pathogenic Acinetobacter baumannii.

The Evolving Microbiome of Dental Caries.

Dental caries is a significant oral and public health problem worldwide, especially in low-income populations. The risk of dental caries increases with frequent intake of dietary carbohydrates, including sugars, leading to increased acidity and disruption of the symbiotic diverse and complex microbial community of health. Excess acid production leads to a dysbiotic shift in the bacterial biofilm composition, demineralization of tooth structure, and cavities. Highly acidic and acid-tolerant species associated with caries include Streptococcus mutans, Lactobacillus, Actinomyces, Bifidobacterium, and Scardovia species. The differences in microbiotas depend on tooth site, extent of carious lesions, and rate of disease progression. Metagenomics and metatranscriptomics not only reveal the structure and genetic potential of the caries-associated microbiome, but, more importantly, capture the genetic makeup of the metabolically active microbiome in lesion sites. Due to its multifactorial nature, caries has been difficult to prevent. The use of topical fluoride has had a significant impact on reducing caries in clinical settings, but the approach is costly; the results are less sustainable for high-caries-risk individuals, especially children. Developing treatment regimens that specifically target S. mutans and other acidogenic bacteria, such as using nanoparticles, show promise in altering the cariogenic microbiome, thereby combatting the disease.

Gut-targeted therapies for type 2 diabetes mellitus: A review.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia and insulin resistance. The global prevalence of T2DM has reached epidemic proportions, affecting approximately 463 million adults worldwide in 2019. Current treatments for T2DM include lifestyle modifications, oral antidiabetic agents, and insulin therapy. However, these therapies may carry side effects and fail to achieve optimal glycemic control in some patients. Therefore, there is a growing interest in the role of gut microbiota and more gut-targeted therapies in the management of T2DM. The gut microbiota, which refers to the community of microorganisms that inhabit the human gut, has been shown to play a crucial role in the regulation of glucose metabolism and insulin sensitivity. Alterations in gut microbiota composition and diversity have been observed in T2DM patients, with a reduction in beneficial bacteria and an increase in pathogenic bacteria. This dysbiosis may contribute to the pathogenesis of the disease by promoting inflammation and impairing gut barrier function. Several gut-targeted therapies have been developed to modulate the gut microbiota and improve glycemic control in T2DM. One potential approach is the use of probiotics, which are live microorganisms that confer health benefits to the host when administered in adequate amounts. Several randomized controlled trials have demonstrated that certain probiotics, such as Lactobacillus and Bifidobacterium species, can improve glycemic control and insulin sensitivity in T2DM patients. Mechanisms may include the production of short-chain fatty acids, the improvement of gut barrier function, and the reduction of inflammation. Another gut-targeted therapy is fecal microbiota transplantation (FMT), which involves the transfer of fecal material from a healthy donor to a recipient. FMT has been used successfully in the treatment of Clostridioides difficile infection and is now being investigated as a potential therapy for T2DM. A recent randomized controlled trial showed that FMT from lean donors improved glucose metabolism and insulin sensitivity in T2DM patients with obesity. However, FMT carries potential risks, including transmission of infectious agents and alterations in the recipient's gut microbiota that may be undesirable. In addition to probiotics and FMT, other gut-targeted therapies are being investigated for the management of T2DM, such as prebiotics, synbiotics, and postbiotics. Prebiotics are dietary fibers that promote the growth of beneficial gut bacteria, while synbiotics combine probiotics and prebiotics. Postbiotics refer to the metabolic products of probiotics that may have beneficial effects on the host. The NIH SPARC program, or the Stimulating Peripheral Activity to Relieve Conditions, is a research initiative aimed at developing new therapies for a variety of health conditions, including T2DM. The SPARC program focuses on using electrical stimulation to activate peripheral nerves and organs, in order to regulate glucose levels in the body. The goal of this approach is to develop targeted, non-invasive therapies that can help patients better manage their diabetes. One promising area of research within the SPARC program is the use of electrical stimulation to activate the vagus nerve, which plays an important role in regulating glucose metabolism. Studies have shown that vagus nerve stimulation can improve insulin sensitivity and lower blood glucose levels in patients with T2DM. Gut-targeted therapies, such as probiotics and FMT, have shown potential for improving glycemic control and insulin sensitivity in T2DM patients. However, further research is needed to determine the optimal dose, duration, and safety of these therapies.

Extraction of citrus pectin using pressurized carbon dioxide and production of its oligosaccharides

In this study, we utilized pressurized carbon dioxide (pCO2) for pectin extraction from citrus residues because of its potential to produce acid without chemicals, that is non-toxic, green technology for humans and the environment. The pCO2 was performed at 2.5 MPa and 90 °C for 90 min, while the conventional method (CM) for pectin extraction using HCl was performed under atmospheric pressure at 90 °C for 90 min. Pectin extraction yields with pCO2 depended on the type of citrus fruit and were lower than those obtained with the CM. However, pCO2-extracted pectin (pCO2-pectin) provided a higher degree of esterification (DE), neutral sugar side-chain substitution on the pectate backbone, and greater molecular size than those of pectin extracted using the conventional method (CM-pectin). Pectin oligosaccharide (POS) was prepared from CM-pectin and pCO2-pectin using viscozyme L hydrolysis under optimum conditions. These POSs were then designated as CM-POS and pCO2-POS, respectively. Both pCO2-POS and CM-POS stimulated the growth of Lactobacillus and Bifidobacterium species, and induced them to produce short-chain fatty acids, and slightly suppressed immunoglobulin E production in U266 cells. Furthermore, pCO2-POS had higher angiotensin-converting enzyme inhibitory activity compared to CM-POS. This study suggests that pCO2 is a novel method for extracting pectin with unique molecular properties affecting POS functionality in vitro.

CRISPR-Cas-based identification of a sialylated human milk oligosaccharides utilization cluster in the infant gut commensal Bacteroides dorei

The infant gut microbiome is impacted by early-life feeding, as human milk oligosaccharides (HMOs) found in breastmilk cannot be digested by infants and serve as nutrients for their gut bacteria. While the vast majority of HMO-utilization research has focused on Bifidobacterium species, recent studies have suggested additional HMO-utilizers, mostly Bacteroides, yet their utilization mechanism is poorly characterized. Here, we investigate Bacteroides dorei isolates from breastfed-infants and identify that polysaccharide utilization locus (PUL) 33 enables B. dorei to utilize sialylated HMOs. We perform transcriptional profiling and identity upregulated genes when growing on sialylated HMOs. Using CRISPR-Cas12 to knock-out four PUL33 genes, combined with complementation assays, we identify GH33 as the critical gene in PUL33 for sialylated HMO-utilization. This demonstration of an HMO-utilization system by Bacteroides species isolated from infants opens the way to further characterization of additional such systems, to better understand HMO-utilization in the infant gut.

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.