Application of infant-derived bifidobacterium bifidum DPUB-G1 in weight loss and lipid metabolism improvement

Abstract

The invention discloses application of infant-derived bifidobacterium bifidum DPUB-G1 in weight reduction and lipid metabolism improvement, and belongs to the field of microbial technology and medical application. The invention provides bifidobacterium bifidum DPUB-G1, and the preservation number of the bifidobacterium bifidum DPUB-G1 is CCTCC (China Center for Type Culture Collection) NO: M 20251161. Researches show that the bifidobacterium bifidum DPUB-G1 has the capacity of producing 2-hydroxyisocaproic acid at high yield, and the strain and metabolites thereof have obvious effects of reducing weight, improving glucose and lipid metabolism disorder and relieving insulin resistance, can reduce weight gain of model animals induced by high fat diet, regulate the blood fat level, and can be used for preparing the high-yield 2-hydroxyisocaproic acid. The compound can be used for preparing functional foods, health-care products or preventive or therapeutic pharmaceutical compositions beneficial to losing weight, lowering lipid, relieving metabolic syndromes and the like, and has good application prospects and industrialization potential.

Description

Technical Field

[0001] This invention relates to the application of an infant-derived Bifidobacterium bifidum strain DPUB-G1 in weight loss and improvement of lipid metabolism, and belongs to the fields of microbial technology, biomedicine and functional food development. Background Technology

[0002] Metabolic syndrome, a metabolic disorder characterized by insulin resistance, is clinically manifested by various metabolic abnormalities, including central obesity, hyperglycemia, dyslipidemia, and hypertension. With the Westernization of global dietary patterns and reduced physical activity, the prevalence of metabolic syndrome has exploded, becoming one of the most threatening chronic non-communicable diseases of the 21st century. Epidemiological data shows that approximately 20-25% of adults worldwide suffer from metabolic syndrome, which not only significantly increases the risk of type 2 diabetes and cardiovascular disease but is also a major contributing factor to various metabolic-related diseases such as non-alcoholic fatty liver disease and polycystic ovary syndrome.

[0003] Current clinical treatments largely rely on a multi-target approach using drugs to lower blood sugar, lipids, and promote weight loss. While this can improve some indicators in the short term, long-term use often leads to drug resistance, drug interactions, and side effects such as gastrointestinal discomfort, liver and kidney damage. For example, while metformin can effectively improve insulin resistance, long-term use may cause gastrointestinal adverse reactions and vitamin B12 deficiency; statins can lower low-density lipoprotein cholesterol (LDL-C), but carry risks of hepatotoxicity and myopathy. Therefore, current treatments generally lack the ability to systematically regulate the overall pathological processes of metabolic syndrome.

[0004] In recent years, gut microbiota imbalance has been recognized as a significant contributing factor to metabolic syndrome. The complex and dynamic interactions between the host and the microbiome, as well as among the microbiome itself, complicate efforts to define specific bacteria or microbial communities that offer metabolic benefits. However, certain specific gut microbiota, including Bifidobacteria, Lactobacillus, and Akkermansia myxophilus, have repeatedly been associated with beneficial metabolic outcomes in various studies. Among them, Bifidobacterium bifidum is a unique type of Bifidobacterium with the ability to degrade mucus and modulate immunity (Turroni, F. et al. Frontiers in microbiology 2014; 5, 437.). A large-scale cross-cohort analysis of 8117 metagenomics supports this view, showing a significant, but cohort-dependent, association between Bifidobacterium bifidum abundance and the risk of type 2 diabetes (Mei, Z. et al. Nature Medicine. 2024; 30, 2265–2276.). Other cohort analyses of obese patients with non-alcoholic fatty liver disease (NAFLD) and gestational diabetes mellitus (GDM) reported persistently lower levels of Bifidobacterium bifidum in affected individuals compared to healthy controls (Le Chatelier, E. et al. Nature 2013; 500, 541–546.; Kuang, Y.-S. et al. GigaScience 2017; 6, 1–12.; Hoyles, L. et al. NatureMedicine 2018; 24, 1070–1080.).

[0005] Furthermore, Bifidobacterium bifidum is the only known symbiotic bacterium capable of simultaneously degrading intestinal mucopolysaccharides and human milk oligosaccharides (HMOs), thus assuming a crucial role in the co-metabolism of host and dietary-derived polysaccharides (Martín R et al. Microorganisms. 2020; 8(9):1313.). Despite its enormous potential, existing research has largely focused on improving single metabolic indicators, lacking high-quality strains with clearly defined mechanisms, bioactive substances, and industrial commercialization potential.

[0006] Alpha-hydroxyisocaproic acid (HIC) is a downstream metabolite of leucine. Previous studies have shown that exogenous HIC supplementation can improve metabolically dysfunctional fatty liver in mice (Zhang et al., Cell Metabolism 2024; 36:1823–1838.e6). Currently, both common chemical-grade and high-optical-purity chiral HIC are readily available and inexpensive, making chemical synthesis sufficient for experimental and research needs from a cost perspective. However, chemically synthesized HIC remains difficult to directly apply in probiotic fermentation systems or intestinal delivery because its racemic form or direct addition cannot guarantee the continuous production of high concentrations of effective HIC in vivo or locally in the gut, nor can it mimic the locally active molecules produced by bacterial metabolism. Therefore, there is an urgent need to obtain a Bifidobacterium bifidum strain capable of producing high levels of HIC in vivo or in probiotic systems to achieve sustained local release and improve metabolic syndrome caused by a high-fat diet in multiple ways. Summary of the Invention

[0007] To address at least some of the technical problems in the prior art, a first aspect of the present invention provides a strain of Bifidobacterium bifidum (Bifidobacterium bifidum). Bifidobacterium bifidum DPUB-G1 has been deposited at the China Center for Type Culture Collection, Wuhan University, Wuhan, China, with accession number CCTCC NO: M 20251161.

[0008] The present invention also provides a microbial inoculant, which comprises live bacteria, inactivated bacteria, fermentation broth, or powder prepared by drying any of the above-mentioned Bifidobacterium DPUB-G1.

[0009] In one embodiment, the number of Bifidobacterium bifidum DPUB-G1 cells in the microbial agent is not less than 1 × 10⁻⁶. 8 CFU / mL or 1×10 8 CFU / g.

[0010] The present invention also provides a postbiotic prepared from the aforementioned Bifidobacterium DPUB-G1.

[0011] In one embodiment, the metabiotic is obtained by fermenting the Bifidobacterium bifidum DPUB-G1, centrifuging the fermentation broth, and collecting the supernatant.

[0012] The present invention also provides the Bifidobacterium bifidum DPUB-G1 or a composition containing the microbial agent or the postbiotic.

[0013] In one embodiment, the composition is a pharmaceutical, a general food, or a functional food.

[0014] In one embodiment, the drug further comprises a drug carrier and / or pharmaceutical excipients.

[0015] In one embodiment, the food also contains food-grade additives and other food ingredients.

[0016] The present invention also provides the use of the Bifidobacterium bifidum DPUB-G1 or the microbial agent or the postbiotic in the preparation of medicaments for the treatment and / or prevention of obesity or hyperlipidemia.

[0017] The present invention also provides the use of the Bifidobacterium bifidum DPUB-G1 or the microbial agent or the postbiotic in the preparation of functional foods that help control body fat, help maintain blood lipids and / or help reduce weight.

[0018] In one embodiment, the treatment and / or prevention of obesity or hyperlipidemia and the measures to help maintain blood lipids include lowering serum triglyceride (TG) and low-density lipoprotein (LDL) levels, raising high-density lipoprotein (HDL) levels, improving liver function, and lowering alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels.

[0019] The present invention also provides the use of the aforementioned Bifidobacterium DPUB-G1 in the preparation of 2-hydroxyisohexanoic acid or products containing 2-hydroxyisohexanoic acid.

[0020] In one embodiment, the Bifidobacterium bifidum DPUB-G1 is fermented in a culture medium, said culture medium including MRS medium.

[0021] The beneficial effects of this invention are: This invention has for the first time isolated and identified a strain of Bifidobacterium bifidum DPUB-G1 from infant feces. Studies have found that the fermentation broth of this strain significantly improved the elevated levels of serum triglycerides, total cholesterol, and low-density lipoprotein in obese mice induced by a high-fat diet; increased high-density lipoprotein levels; and alleviated weight gain in obese mice.

[0022] The Bifidobacterium bifidum DPUB-G1 strain described in this invention produces high levels of 2-hydroxyisocaproic acid in vitro, with a yield 3.2 times that of the model strain.

[0023] Preservation of biological materials Bifidobacterium bifidum ( Bifidobacterium bifidum DPUB-G1, taxonomically named Bifidobacterium bifidum DPUB-G1 was deposited on May 23, 2025, at the China General Microbiological Culture Collection Center (CGCCC) with accession number CCTCC NO: M 20251161, located at Wuhan University, Wuhan, China. Attached Figure Description

[0024] Figure 1 The sequencing results of the completed diagram of the Bifidobacterium bifidum DPUB-G1 gene; Figure 1 A: Evolutionary analysis of samples based on housekeeping genes; Figure 1 B: Evolutionary analysis of samples based on 16S rRNA.

[0025] Figure 2 To evaluate the effect of Bifidobacterium bifidum DPUB-G1 fermentation supernatant on improving obesity induced by a high-fat diet in mice; Figure 2 A: Experimental design diagram; Figure 2 B: Changes in food intake in mice; Figure 2 C: Changes in mouse body weight; Figure 2 D: Real images of a representative mouse body, including brown adipose tissue (BAT), inguinal subcutaneous white adipose tissue (iWAT), and epididymal fat (eWAT); Figure 2 E: Weights of BAT, iWAT, and eWAT; Figure F: Mouse insulin resistance index (HOMA-IR). Figure 2 G: Four blood lipid tests; Figure 2 H: Detection of alanine aminotransferase (ALT) and aspartate aminotransferase (AST).

[0026] Figure 3 Evaluation of the effect of live / pasteurized Bifidobacterium bifidum DPUB-G1 on improving obesity induced by a high-fat diet in mice: Figure 3 A: Experimental design diagram; Figure 3 B: Four blood lipid tests; Figure 3 C: ALT and AST. Detailed Implementation

[0027] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0028] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention is described. While only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail. Unless otherwise stated, “%” means percentage based on weight.

[0030] The following examples use R software (version 4.5.0) for plotting and statistical analysis. All statistical tests are fully described in the legends of the figures and are consistent with the criteria of a normal distribution with similar variances. No statistical methods were used to predetermine the sample size. t-tests were used for comparisons between two groups. Repeated measures ANOVA was performed for assessment data of relevant samples. One-way ANOVA and multiple comparisons were used for assessments of more than two groups. Two-way ANOVA with multiple comparisons was used for assessments of two independent variables. Log-rank tests were used for survival analysis. Linear regression analysis was used for correlation analysis. Otherwise, data are expressed as mean ± sem unless otherwise stated. P < 0.05 was considered statistically significant, expressed as *p < 0.05, **p < 0.01, **p < 0.001, NS, not significant.

[0031] The culture media involved in the following examples are as follows.

[0032] Modified MRS solid medium: Mupirocin lithium salt and cysteine ​​hydrochloride modified MRS medium, the formula is based on GB4789.35-2023.

[0033] Modified MRS liquid medium: Mupirocin lithium modified MRS medium, peptone 10.0 g / L, beef extract 5.0 g / L, yeast extract 4.0 g / L, glucose 20.0 g / L, dipotassium hydrogen phosphate 2.0 g / L, triammonium citrate 2.0 g / L, sodium acetate 5.0 g / L, magnesium sulfate 0.2 g / L, manganese sulfate 0.05 g / L, agar 15.0 g / L, Tween 80 1.0 g / L, mupirocin lithium 50 mg / L.

[0034] The Bifidobacterium bifidum JCM1255 involved in the following examples is a model strain that was purchased.

[0035] Example 1: Screening and identification of Bifidobacterium bifidum DPUB-G1 1. Strain screening and culture The bacterial strain was sampled in Dalian, Liaoning Province, China, and isolated from infant feces. It was stored under anaerobic conditions at 4 °C and processed within 24 hours. Approximately 0.1 g of fecal sample was taken and thoroughly mixed with anaerobic physiological saline, then added at a ratio of 10... - ¹~10 -6 Perform serial dilutions. Inoculate appropriate amounts of each dilution onto anaerobic MRS medium or modified Bifidobacterium selective medium plates and incubate at 37 °C under anaerobic conditions (or 5% CO2) for 48–72 hours. After incubation, select single colonies based on colony morphology and perform multiple streak purifications to obtain the stable strain DPUB-G1. The obtained strain can be suspended in 20% glycerol and stored frozen at –80 °C for later use.

[0036] 2. Strain genome analysis The whole genome of strain DPUB-G1 described in this invention was obtained using third-generation PacBio sequencing combined with second-generation Illumina sequencing. Each sample provided at least 100× PacBio sequencing data and 100× Illumina PE150 sequencing data to ensure complete and accurate assembly of the genome and plasmids, and to avoid the loss of small plasmid information caused by using only long-read libraries. Genome assembly was performed using Unicycler software, and sequence correction was performed using Pilon software to generate complete circular chromosome and plasmid sequences. Plasmid identification and annotation were performed using PlasFlow and BLAST / PLSDB databases, respectively. Gene prediction was performed using Prodigal, GeneMarkS, and Glammer software, and tRNA and rRNA were identified using tRNAscan-SE and Barrnap software, respectively. To determine the phylogenetic position of the strain, the genome sequence closest to the sample was obtained through automated alignment analysis, and a phylogenetic tree was constructed based on 16S rRNA and 31 housekeeping genes (such as dnaG, infC, rpoB, etc.). Evolutionary analysis was performed using the Neighbor-Joining (NJ) method in MEGA software.

[0037] The results showed that the genome of strain DPUB-G1 contained one chromosome, with a total length of 2,202,479 bp and a GC content of 62.73%. The genome encoded 1,788 genes, with a total coding region length of 1.88 Mbp, an average gene base number of 1053 bp, and the coding region accounting for 85.56% of the total genome length. Phylogenetic analysis of Bifidobacterium bifidum yielded the following results: Figure 1As shown. The results indicate that strain DPUB-G1 clusters with the reference genome of Bifidobacterium bifidum, therefore DPUB-G1 belongs to Bifidobacterium bifidum and is named Bifidobacterium bifidum DPUB-G1, with the accession number CCTCCNO: M 20251161.

[0038] Example 2: Evaluation of the effect of Bifidobacterium bifidum DPUB-G1 fermentation broth on improving obesity induced by a high-fat diet in mice. Animal experiments were conducted in accordance with the ethical guidelines and protocols approved by Dalian University of Technology. All experiments used sex- and age-matched mice, randomly assigned to groups. Mice were housed in a specific sterile animal facility with controlled temperature and humidity (25°C, 12:12h light:dark cycle), with free access to food and water. During the experiments, experimental mice were administered 200 μL of the corresponding contents orally via gavage daily, while the control group received an equal volume of solvent. The mouse conditions used in subsequent examples were the same.

[0039] Preparation of fermentation broth of Bifidobacterium bifidum DPUB-G1: The preserved glycerol-freezed *Bifidobacterium bifidum* DPUB-G1 strain was revived on modified MRS solid medium and cultured anaerobically at 37 °C for 48–72 hours. Single colonies were picked and inoculated into 10 mL of modified MRS liquid medium and pre-cultured anaerobically at 37 °C for 24 h to obtain seed culture. The seed culture was then inoculated into 500 mL of modified MRS liquid medium at a 1% (v / v) inoculation rate and statically cultured at 37 °C anaerobic for 48 h. After the culture was completed, the viable count in the fermentation broth was 5 × 10⁻⁶. 8 The bacterial cells were removed by centrifugation at 4 ℃ and 8000 rpm for 10 min, and the supernatant was collected and filtered through a 0.22 μm microporous membrane for sterilization. The resulting filtrate was the fermentation supernatant of Bifidobacterium bifidum DPUB-G1. The obtained supernatant and fermentation broth were used for subsequent component analysis and animal experiments, respectively.

[0040] Modeling of high-fat diet-induced obesity (DIO) in mice: 4-6 week old C57BL / 6J mice were purchased from Liaoning Changsheng Biotechnology Co., Ltd. After a 1-week acclimatization period, the mice were randomly divided into three groups (n=8 / group): a high-fat diet-induced obesity group (HFD group, 200 μL deionized water per mouse per day by gavage), an MRS medium gavage group (MRS group, 200 μL MRS medium per mouse per day by gavage), and a Bifidobacterium bifidum DPUB-G1 MRS fermentation broth gavage group (Sup group, 200 μL fermentation broth per mouse per day by gavage). After 4 weeks of high-fat diet feeding (XTHF60 diet, synergistic organisms, free access to food), intervention was initiated. The high-fat diet was continuously fed during the intervention period for a total of 6 weeks. Figure 2 A). Monitor food intake weekly during the intervention period ( Figure 2 B) and weight changes ( Figure 2 C). The HOMA-IR index in mice was measured 6 weeks after intervention. Figure 2 F), HOMA-IR = fasting blood glucose × fasting insulin / 22.5, where fasting blood glucose is in mmol / L, fasting insulin is in μU / mL, and the coefficient 22.5 is a correction factor. Fasting blood glucose was measured by a Roche blood glucose meter using blood collected from the tail vein of mice, and insulin was measured using a commercial ELISA kit (Jianglai) according to the instructions. Tissue samples collected after sacrifice: macroscopic morphology of epididymal fat, subcutaneous fat, and scapular brown fat (…). Figure 2 D) Weight Figure 2 E). Serum lipid markers (TG, TC, HDL-C, and LDL-C) and liver function markers (ALT and AST) were detected in mice using commercially available kits developed in Nanjing. Figure 2 G and Figure 2 H). Data are expressed as mean ± standard error (mean ± sem) of independent biological samples. Statistical significance is indicated by p < 0.05, p < 0.01, p < 0.001 (two-tailed t-test).

[0041] The results showed that, compared with the high-fat diet-induced obesity group (HFD group), gavage treatment with MRS fermentation supernatant of Bifidobacterium bifidum DPUB-G1 did not affect the food intake of mice ( Figure 2 B) significantly reduced the body weight of mice ( Figure 2 C, p<0.05, after six weeks of intervention, the weight gain of mice was inhibited, and their average weight was about 2.1 g lower than that of the model group. Figure 2 C), relative body weight decreased by approximately 8.4%. The weight of both epididymal white adipose tissue (eWAT) and inguinal white adipose tissue (iWAT) was significantly reduced in the Sup group. Figure 2 In the DE group, the eWAT weight was reduced by 27.6% compared to the HFD group, and the iWAT weight was reduced by 29.7% compared to the HFD group. The HOMA-IR of the Sup group was significantly reduced ( Figure 2 F, p<0.05). Furthermore, gavage treatment with the MRS fermentation supernatant of Bifidobacterium bifidum DPUB-G1 significantly reduced serum triglyceride (TG) and low-density lipoprotein (LDL) levels in mice, and significantly increased high-density lipoprotein (HDL) levels. Figure 2 G, p<0.05), and also significantly reduced the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Figure 2H, p<0.05). Specifically, compared with the HFD group, the Sup group showed a 29.6% decrease in TG, a 30.3% increase in HDL, a 27.3% decrease in LDL, a 59% decrease in ALT, and a 48.6% decrease in AST. In conclusion, the fermentation supernatant of Bifidobacterium bifidum DPUB-G1 can reduce the body weight and adipose tissue of high-fat diet-induced obese mice and improve lipid metabolism in mice.

[0042] Example 3: Bifidobacterium bifidum DPUB-G1 improves biochemical indicators in mice on a high-fat diet Bifidobacterium bifidum DPUB-G1 was cultured according to the method in Example 2. After culture, the bacterial cells were collected, resuspended in physiological saline, and the effect of live / pasteurized Bifidobacterium bifidum DPUB-G1 on improving obesity induced by a high-fat diet was evaluated in mice. Mice were divided into four groups: a normal diet control group (NCD group), a high-fat diet feeding group (HFD group), a Bifidobacterium bifidum DPUB-G1 gavage group (BB group), and a pasteurized Bifidobacterium bifidum DPUB-G1 gavage group (pBB group). After one week of acclimatization, the HFD group, BB group, and pBB group were fed a high-fat diet for four weeks, followed by corresponding interventions. The BB group received 1×10⁻⁶ spores of Bifidobacterium bifidum gavage daily. 8 CFU-Bifidobacterium bifidum DPUB-G1 live bacteria, pBB group, daily oral administration of pasteurized 1×10 8 CFU-Bifidobacterium bifidum DPUB-G1, the NCD group, and the HFD group were administered an equal volume of physiological saline by gavage for six weeks. After the experiment, blood lipids and liver function-related indicators were measured in each group of mice.

[0043] The results showed that, in terms of blood lipids, compared with the high-fat diet group (HFD group), pasteurized Bifidobacterium bifidum (pBB group) significantly reduced LDL in mice. Figure 2 G, p<0.05). Regarding liver function, 1×10 gavage was administered daily. 8 The CFU-Bifidobacterium bifidum DPUB-G1 group (BB group) reduced AST levels in mice (p = 0.08), with an average reduction of 29.6%.

[0044] Example 4: Fermentation of 2-hydroxyisocaproic acid by Bifidobacterium bifidum DPUB-G1 The ability of Bifidobacterium bifidum DLPB-G1 and Bifidobacterium bifidum JCM1255 to produce HIC in vitro was compared.

[0045] 1. Experimental Methods Fermentation supernatants of Bifidobacterium bifidum DPUB-G1 and Bifidobacterium bifidum JCM1255 were obtained according to the method in Example 2. MRS medium was used as a control to detect the concentration of 2-hydroxyisohexanoic acid (HIC) in the fermentation supernatant.

[0046] Targeted metabolomics: The concentration of 2-hydroxyisohexanoic acid (HIC) was determined by LC-MS / MS. The specific method was as follows: Analysis was performed using a QTRAP 4500 mass spectrometry system (AB SCIEX, Framingham, MA, USA) with a Waters SunFire C18 column (4.6 × 250 mm, 5 μm; Waters Corporation, USA). The mobile phase consisted of an aqueous solution containing 0.1% formic acid (phase A) and an acetonitrile solution containing 0.1% formic acid (phase B), with a constant flow rate (0.25 mL / min). The target analyte was detected in negative ion mode with a mass-to-charge ratio from m / z 131.1 to 85.0.

[0047] 2. Experimental Results As shown in Table 1, under the same culture system, the concentration of α-hydroxyisocaproic acid (HIC) produced by *Bifidobacterium bifidum* DPUB-G1 reached 248.2 ± 24.5 μM, which is approximately 3.2 times (77.3 ± 5.3 μM) that of the standard strain *Bifidobacterium bifidum* JCM1255, and significantly higher than that of the culture medium control (10.1 ± 6.9 μM). These results indicate that DPUB-G1 possesses significantly enhanced HIC biosynthetic capacity.

[0048] Table 1. Detection of α-hydroxyisohexanoic acid (HIC) content

[0049] Note: Tukey's HSD multiple comparison analysis showed that different letters indicated significant differences between groups (p<0.05).

[0050] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A type of Bifidobacterium ( Bifidobacterium bifidum Bifidobacterium bifidum DPUB-G1 has been deposited at the China Center for Type Culture Collection (CCTCC) with accession number CCTCC No: M 20251161.

2. A microbial inoculant, characterized in that, The microbial agent comprises live bacteria, inactivated bacteria, fermentation broth, or powder prepared by drying any of the above-mentioned Bifidobacterium bifidum DPUB-G1 as described in claim 1; wherein the number of Bifidobacterium bifidum DPUB-G1 cells in the microbial agent is not less than 1 × 10⁻⁶. 8 CFU / mL or 1×10 8 CFU / g.

3. The metabiotic prepared from *Bifidobacterium bifidum* DPUB-G1 according to claim 1, characterized in that, The postgenetic includes either (a) or (b): (a) After fermentation by the aforementioned Bifidobacterium DPUB-G1, the fermentation broth is centrifuged and the supernatant is collected. (b) Fermentation broth obtained from the fermentation of Bifidobacterium bifidum DPUB-G1.

4. A composition containing Bifidobacterium bifidum DPUB-G1 as described in claim 1, or containing the microbial agent as described in claim 2, or containing the postbiotic as described in claim 3.

5. The composition according to claim 4, characterized in that, The composition is a pharmaceutical, a general food, or a functional food.

6. The composition according to claim 5, characterized in that, The medicine also contains a drug carrier and / or pharmaceutical excipients; the food also contains food-grade excipients and other food ingredients.

7. The use of the Bifidobacterium bifidum DPUB-G1 of claim 1, the microbial agent of claim 2, or the metabiotic of claim 3 in the preparation of a medicament for treating and / or preventing obesity or hyperlipidemia, characterized in that, The treatment and / or prevention of obesity or hyperlipidemia includes lowering serum triglyceride (TG) and low-density lipoprotein (LDL) levels, raising high-density lipoprotein (HDL) levels, improving liver function, and lowering alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels.

8. The use of the Bifidobacterium bifidum DPUB-G1 of claim 1, or the microbial agent of claim 2 or 3, or the postbiotic of claim 4 in the preparation of functional foods that help control body fat, help maintain blood lipids, and / or help reduce weight.

9. The application as described in claim 8, characterized in that, The benefits of maintaining blood lipids include lowering serum triglyceride (TG) and low-density lipoprotein (LDL) levels, raising high-density lipoprotein (HDL) levels, improving liver function, and lowering alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels.

10. The use of Bifidobacterium bifidum DPUB-G1 according to claim 1 in the preparation of 2-hydroxyisohexanoic acid or products containing 2-hydroxyisohexanoic acid, characterized in that, The Bifidobacterium bifidum DPUB-G1 was fermented in a culture medium, including MRS medium.

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