Sublactobacillus paracasei gold gut-lc12345

Abstract

This application relates to the field of biomedicine. Specifically, this application relates to *Lactobacillus paracasei*, compositions comprising the same, pharmaceutical compositions and cultures thereof, and uses thereof. The *Lactobacillus paracasei* of this application not only synergistically enhances the antitumor efficacy of paclitaxel but also effectively alleviates drug side effects, reverses tumor drug resistance, and exerts comprehensive probiotic effects by regulating gut microbiota and the immune microenvironment, demonstrating promising application prospects.

Description

Technical Field

[0001] This application relates to the field of biomedicine. Specifically, this application relates to a *Lactobacillus paracasei*, compositions comprising the same, pharmaceutical compositions and cultures thereof, and uses thereof. Background Technology

[0002] Oral cancer is one of the most common malignant tumors worldwide, seriously affecting patients' health and quality of life. Data from the Global Cancer Watch (GCO) shows that approximately 377,000 new cases of oral squamous cell carcinoma (OSCC) were diagnosed globally in 2020, and the incidence rate continues to rise, projected to increase by about 40% by 2040. Currently, clinical treatment for oral cancer primarily involves surgery, often supplemented by chemotherapy, radiotherapy, and other comprehensive methods. Among chemotherapy drugs, paclitaxel, as a natural anti-tumor drug, exerts significant anti-cancer effects by promoting microtubule polymerization and inhibiting tumor cell mitosis, and is widely used in the treatment of oral cancer.

[0003] However, paclitaxel is accompanied by a series of serious side effects in clinical applications, including leukopenia and thrombocytopenia caused by bone marrow suppression, liver and kidney damage, neurotoxicity, and gastrointestinal reactions, which seriously affect treatment tolerance and patients' quality of life. More importantly, the overexpression of P-glycoprotein (P-gp) in tumor cells is one of the main mechanisms leading to multidrug resistance (MDR), limiting further improvement in the efficacy of paclitaxel. Due to the existence of side effects, the problem of drug resistance cannot be overcome by infinitely increasing the drug dosage in clinical practice. Therefore, there is an urgent need to develop adjuvant strategies that can synergistically enhance the efficacy of paclitaxel, reduce its toxic side effects, and reverse drug resistance.

[0004] In recent years, the role of the gut microbiota in regulating host immunity, metabolism, and drug response has received increasing attention. Studies have shown that specific probiotics, such as Bifidobacterium, Akkermansia, and Faecalibacterium, can influence the efficacy and toxicity of chemotherapy drugs by regulating gut microbiota structure, enhancing intestinal barrier function, and modulating immune responses and metabolite synthesis. Furthermore, gut microbiota and their metabolites (such as short-chain fatty acids) have been shown to participate in the regulation of systemic inflammatory responses, oxidative stress, and drug transporter protein expression, suggesting their potential value in alleviating chemotherapy side effects and reversing tumor drug resistance. However, systematic research on the synergistic antitumor effects of specific probiotic strains in oral cancer chemotherapy and their mechanisms of alleviating paclitaxel side effects remains relatively lacking.

[0005] Probiotics, as a class of live microorganisms beneficial to host health, are characterized by high safety, wide availability, and diverse mechanisms of action, and have been applied as adjunctive interventions for various metabolic and inflammatory diseases. Their potential in cancer treatment is also being gradually explored, with possible mechanisms including competitive inhibition of pathogens, binding to carcinogens, regulating the immune microenvironment, and influencing microbiota-host co-metabolism.

[0006] Therefore, screening probiotic strains with anti-tumor adjuvant functions and elucidating their synergistic effects and molecular mechanisms when used in combination with chemotherapy drugs is of great significance for developing novel adjuvant cancer treatment strategies. Summary of the Invention

[0007] Based on the above background, the inventors of this invention screened a large number of strains and identified *Lactobacillus paracasei* GOLDGUT-LC12345, a probiotic strain with potential regulatory functions. By constructing a nude mouse model of oral cancer, it was found that this probiotic has significant effects in enhancing the antitumor effect of paclitaxel, alleviating drug side effects, and reversing P-gp-mediated drug resistance. This strain provides a new method for adjuvant therapy of oral cancer, thus, the applicant completed this invention.

[0008] Lacticaseibacillus paracasei

[0009] In a first aspect, this application provides a *Lactobacillus paracasei* (… Lacticaseibacillus paracasei It is deposited at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 36872.

[0010] Composition

[0011] In a second aspect, this application provides a composition comprising the *Lactobacillus paracasei* described in the first aspect.

[0012] In some embodiments, the composition further comprises microorganisms selected from bacteria, fungi (e.g., yeast), or any combination thereof.

[0013] In some embodiments, the *Lactobacillus paracasei* can be used in combination with one or more other species of microorganisms and can have a beneficial effect on the health of the host to which it is applied. Those skilled in the art are capable of selecting suitable other species of microorganisms (e.g., bacteria) to use in combination with the *Lactobacillus paracasei* without antagonistic effects.

[0014] In some implementations, the bacteria are probiotics.

[0015] As used herein, the term “probiotic” is defined as any non-pathogenic bacteria that, when administered to a host in sufficient quantities, either live or dead, can have a beneficial effect on the host’s health.

[0016] In some embodiments, the bacteria are selected from Lactobacillus, Bifidobacterium, Bacillus, Propionibacterium, Streptococcus, Lactococcus, Pediococcus, Enterococcus, Staphylococcus, or any combination thereof.

[0017] In some embodiments, the Lactobacillus bacteria are selected from: Lactobacillus paracasei ( Lacticaseibacillus paracasei Lactobacillus acidophilus ( Lactobacillus acidophilus ), Lactobacillus brevis ( Lactobacillus brevis Lactobacillus japonicus ( ), Lactobacillus japonicus ( Lactobacillus jensenii ), Lactobacillus inertis ( Lactobacillus iners Lactobacillus casei ( Lactobacillus casei ), Lactobacillus curvature ( Lactobacillus crispatus Lactobacillus curvaturei ( Lactobacillus curvatus Lactobacillus delbrueckii ( Lactobacillus delbrueckii ), Lactobacillus fermentum ( Lactobacillus fermentum Lactobacillus gasseri ( Lactobacillus gasseri Lactobacillus helveticus ( Lactobacillus helveticus ), Lactobacillus johnsonii ( Lactobacillus johnsonii Lactobacillus plantarum ( Lactobacillus plantarum Lactobacillus reuteri ( Lactobacillus reuteri Lactobacillus rhamnosus ( Lactobacillus rhamnosus Lactobacillus sakei ( Lactobacillus sakei ), Lactobacillus salivarius ( Lactobacillus salivarius ), or any combination thereof.

[0018] In some embodiments, the Bifidobacterium species are selected from: Bifidobacterium animalis (Bifidobacterium spp.) Bifidobacterium animalis Bifidobacterium bifidum ( Bifidobacterium bifidum ), Bifidobacterium breve Bifidobacterium breve ), Bifidobacterium infantis ( Bifidobacterium infantis Bifidobacterium longum ( Bifidobacterium longum ), Bifidobacterium adolescentis ( Bifidobacterium adolescentis ), or any combination thereof.

[0019] In some embodiments, the Bifidobacterium species is *Bifidobacterium animalis* subsp. *lactobacter* (…). Bifidobacterium animalis subsp. lactis ).

[0020] In some embodiments, the Bacillus species is selected from: Bacillus subtilis ( Bacillus subtilis ), Bacillus coagulans ( Bacillus coagulans ), or any combination thereof.

[0021] In some embodiments, the bacteria of the genus *Propionibacterium* are selected from: *Propionibacterium sheareri* (… Propionibacterium shermanii ), Propionibacterium fischeri ( Propionibacterium freudenreichii Propionibacterium propionitum ( Propionibacterium acidipropionici ), or any combination thereof.

[0022] In some embodiments, the Streptococcus bacteria are selected from: Streptococcus thermophilus (Streptococcus thermophilus) Streptococcusthermophilus ), Streptococcus salivarius ( Streptococcus salivarius ), or any combination thereof.

[0023] In some embodiments, the bacteria of the genus *Lactococcus* are *Lactococcus lactis* (…). Lactococcus lactis ).

[0024] In some embodiments, the Enterococcus spp. bacteria are selected from: Enterococcus faecalis ( Enterococcus faecalis ), Enterococcus faecalis ( Enterococcus faecium ), or any combination thereof.

[0025] In some embodiments, the yeast is selected from Saccharomyces cerevisiae (Saccharomyces cerevisiae). Saccharomyces cerevisiae ), Saccharomyces boulardii ( Saccharomyces boulardii) Max Kluyveromycin ( Kluyveromyces marxianus ), or any combination thereof.

[0026] In some embodiments, the composition further includes additional additives.

[0027] Those skilled in the art can select and adjust additional additives as needed. In some embodiments, the additional additives are selected from nutrients, minerals, vitamins, or any combination thereof.

[0028] In some implementations, the additional additive can have a beneficial effect on the health of the host to which it is applied.

[0029] In some embodiments, the nutrients are selected from dietary fiber, prebiotics, proteins (e.g., enzymes), carbohydrates, lipids (e.g., fats), minerals, vitamins, plant components (e.g., plant extracts), amino acids, immunomodulators, milk substitutes, or any combination thereof.

[0030] Pharmaceutical composition

[0031] In a third aspect, this application provides a pharmaceutical composition comprising the *Lactobacillus paracasei* described in the first aspect or the composition described in the second aspect, and additional pharmaceutically active agents.

[0032] In some embodiments, the pharmaceutically active agent is selected from antitumor drugs (e.g., paclitaxel (PTX)), anti-inflammatory drugs, antioxidants, antifungals, antivirals, analgesics, healing promoters, or any combination thereof.

[0033] In some embodiments, the pharmaceutically active agent is a mitotic inhibitor, such as paclitaxel.

[0034] In this article, paclitaxel includes any taxane drug (especially taxane drugs that can be used to treat cancer), such as paclitaxel injection, docetaxel, paclitaxel liposomes, and paclitaxel for injection.

[0035] In some embodiments, the *Lactobacillus paracasei* and the additional pharmaceutically active agent are provided as separate components or as a mixture of components. Therefore, the *Lactobacillus paracasei* and the additional pharmaceutically active agent of the present invention can be administered simultaneously, separately, or sequentially.

[0036] In some embodiments, the pharmaceutical composition further comprises a pharmaceutically acceptable carrier and / or excipient.

[0037] In some embodiments, the pharmaceutically acceptable carrier and / or excipient includes: cryoprotectants, fillers, binders, lubricants, flow aids, thickeners, flavoring agents, edible oils, stabilizers, suspending agents, surfactants, or any combination thereof.

[0038] In some embodiments, the pharmaceutical composition is formulated for oral or in vitro administration.

[0039] In some embodiments, the pharmaceutical composition is in the form of pills, powders, capsules, tablets (e.g., effervescent tablets), oil drops, capping films, orally soluble granules, liquids, suppositories, enemas, gels, and / or creams.

[0040] In some embodiments, the pharmaceutical composition contains Lactobacillus paracasei at a concentration of 10... 6 Up to 10 12 The amount of CFU / dose present (e.g., 10) 8 Up to 10 10 (CFU / ml).

[0041] The pharmaceutical compositions of this application can be formulated into any dosage form known in the medical field, such as tablets, pills, suspensions, emulsions, solutions, gels, capsules, powders, granules, elixirs, lozenges, suppositories, injections (including injection solutions, sterile powders for injection, and concentrated solutions for injection), inhalers, sprays, etc. Preferred dosage forms depend on the intended route of administration and therapeutic use. The pharmaceutical compositions of this application should be sterile and stable under the conditions of manufacture and storage. A preferred dosage form is an injection. Such injections can be sterile injectable solutions. For example, sterile injectable solutions can be prepared by incorporating an essential dose of *Lactobacillus paracasei* as described in the first aspect or the composition as described in the second aspect into a suitable solvent, and optionally, simultaneously incorporating other desired ingredients (including, but not limited to, pH adjusters, surfactants, adjuvants, ionic strength enhancers, isotonic agents, preservatives, diluents, or any combination thereof), followed by sterile filtration. Furthermore, sterile injectable solutions can be prepared as sterile lyophilized powders (e.g., by vacuum drying or freeze-drying) for easy storage and use. Such sterile lyophilized powders can be dispersed in a suitable carrier, such as sterile pyrogen-free water, before use.

[0042] Furthermore, the *Lactobacillus paracasei* described in the first aspect of this disclosure or the composition described in the second aspect may be present in the pharmaceutical composition in unit dose form for ease of administration.

[0043] The pharmaceutical compositions disclosed herein can be administered by any suitable method, including but not limited to oral, oral, sublingual, ocular, topical, parenteral, rectal, intrathecal, intracytoplasmic reticulum groove, groin, bladder, topical (e.g., powder, ointment, or drops), or nasal routes. However, for many therapeutic uses, the preferred route / method of administration is parenteral administration (e.g., intravenous, subcutaneous, intraperitoneal, intramuscular). Those skilled in the art will understand that the route and / or method of administration will vary depending on the intended purpose.

[0044] Culture

[0045] In a fourth aspect, this application provides a culture comprising Lactobacillus paracasei as described in the first aspect, or a composition as described in the second aspect, or a pharmaceutical composition as described in the third aspect.

[0046] In some embodiments, the culture also contains a nutrient-providing component (e.g., a solid or liquid culture medium).

[0047] In some embodiments, the nutritional components are selected from proteins, carbohydrates, fats, probiotics, enzymes, vitamins, immunomodulators, milk substitutes, minerals, amino acids, or any combination thereof.

[0048] In some embodiments, the culture also comprises a cell-free culture filtrate of Lactobacillus paracasei.

[0049] Food product or dietary supplement

[0050] In a fifth aspect, this application provides a food product or dietary supplement comprising Lactobacillus paracasei as described in the first aspect, or the composition described in the second aspect, or the culture described in the fourth aspect.

[0051] In this text, the term "food product" is used broadly to include food and drink for humans, as well as food and drink for animals (i.e., feed). In some embodiments, the food product is suitable for and designed for human consumption.

[0052] It is understood that, depending on the purpose, method of application or method of administration, the food product or dietary supplement of this application may be in the form of liquid, solid, suspension or powder.

[0053] In some embodiments, the food product is selected from beverages, solid beverages, confectionery or juice, or the food product is a dairy product (e.g., yogurt, flavored fermented milk, lactic acid bacteria beverage, cheese).

[0054] In some embodiments, the food product or dietary supplement is formulated for oral administration.

[0055] In some embodiments, the food product or dietary supplement is in the form of pills, powders, capsules, tablets, granular powders, opercula, orally soluble granules, sachets, sugar-coated pills, or liquids.

[0056] In some embodiments, the food product or dietary supplement may also include (but is not limited to) one or any combination of the following substances: probiotics (e.g., probiotic bacteria), dietary fiber, prebiotics, proteins (e.g., enzymes), carbohydrates, lipids (e.g., fats), vitamins, minerals, plant ingredients (e.g., plant extracts), amino acids, and immunomodulators. In some embodiments, the food product or dietary supplement of the present invention may also be combined with various sweeteners or flavorings, colorants, stabilizers, flow aids, fillers, and other food-acceptable excipients.

[0057] In some implementations, Lactobacillus paracasei is present in the food product or dietary supplement in the form of a concentrate.

[0058] In some embodiments, the food product or dietary supplement contains Lactobacillus paracasei at a concentration of 10... 6 Up to 10 12 The amount of CFU / dose present (e.g., 10) 8Up to 10 10 (CFU / ml).

[0059] Use

[0060] In a sixth aspect, this application provides the use of the *Lactobacillus paracasei* of the first aspect, or the composition of the second aspect, or the pharmaceutical composition of the third aspect, or the culture of the fourth aspect, in the preparation of a medicament for use in a subject to: (a) prevent and / or treat a tumor; (b) enhance the preventive and / or therapeutic effect of an antitumor drug on a tumor; and / or, (c) alleviate the side effects of an antitumor drug on the subject.

[0061] In another aspect, this application provides a method for (a) preventing and / or treating tumors in a subject; (b) enhancing the preventive and / or therapeutic effects of an antitumor drug on tumors; and / or, (c) mitigating the side effects of an antitumor drug on a subject, said method comprising administering to a subject in need an effective amount of the *Lactobacillus paracasei* of the first aspect or the composition of the second aspect or the pharmaceutical composition of the third aspect or the culture of the fourth aspect.

[0062] In some embodiments, it further includes administering a second therapy to the subject, the second therapy being selected from surgery, chemotherapy, radiotherapy, immunotherapy, gene therapy, DNA therapy, RNA therapy, nanotherapy, viral therapy, adjuvant therapy, and any combination thereof. In some embodiments, the second therapy may be applied simultaneously, separately, or sequentially with the methods described above.

[0063] In some embodiments, the tumor is a solid tumor. In some embodiments, the solid tumor includes oral cancer, breast cancer, pancreatic cancer, lung cancer, glioblastoma, renal cell carcinoma, head and neck cancer, liver cancer, stomach cancer, colorectal cancer, kidney cancer, bladder cancer, and melanoma.

[0064] In some implementations, the tumor is oral cancer.

[0065] In some embodiments, the antitumor drug includes alkylating agents, mitotic inhibitors, antitumor antibiotics, antimetabolites, topoisomerase inhibitors, tyrosine kinase inhibitors, radionuclides, radiosensitizers, antiangiogenic agents, cytokines, molecularly targeted drugs, immune checkpoint inhibitors, or oncolytic viruses.

[0066] In some embodiments, the antitumor drug is paclitaxel (PTX).

[0067] In some embodiments, the side effects alleviated by the strain are selected from liver damage, kidney damage, inflammatory response, gut microbiota dysbiosis, multidrug resistance (MDR), or any combination thereof.

[0068] In a seventh aspect, this application provides the use of the *Lactobacillus paracasei* described in the first aspect, or the composition described in the second aspect, or the pharmaceutical composition described in the third aspect, or the culture described in the fourth aspect, in the preparation of a medicament for use in a subject to: (a) suppress inflammation or alleviate inflammatory diseases; (b) enhance antioxidant capacity; (c) regulate cytokine levels; (d) regulate gut microbiota; and / or, (e) enhance immunity or improve immunosuppression.

[0069] In another aspect, this application provides a method for (a) suppressing inflammation or alleviating inflammatory diseases in a subject; (b) enhancing antioxidant capacity; (c) regulating cytokine levels; (d) regulating gut microbiota; and / or, (e) enhancing immunity or improving immunosuppression, the method comprising administering to a subject in need an effective amount of the *Lactobacillus paracasei* of the first aspect or the composition of the second aspect or the pharmaceutical composition of the third aspect or the culture of the fourth aspect.

[0070] In some embodiments, the inflammatory disease is selected from diseases caused by skin inflammation (e.g., dermatitis, eczema), related diseases caused by respiratory inflammation (e.g., upper respiratory tract infection), and related diseases caused by gastrointestinal inflammation (e.g., inflammatory bowel disease).

[0071] In some implementations, the enhanced antioxidant capacity includes increasing the GSH level in the subject's body.

[0072] In some embodiments, the regulation of cytokine levels includes: reducing the level of pro-inflammatory factors (e.g., IL-6) and / or increasing the level of anti-inflammatory factors (e.g., IL-10, IL-12).

[0073] In some embodiments, the regulation of the gut microbiota includes: reducing the ratio of Firmicutes to Bacteroidota, and increasing the ratio of probiotics (such as Lactobacillus intestinalis). Lactobacillus intestinalis The relative abundance of and / or reduction of potentially harmful bacteria (e.g., *Heliotropium indicum*) Herbaspirillum huttiense The relative abundance of ) and / or

[0074] In some embodiments, the enhancement of immunity or improvement of immunosuppression includes: increasing the infiltration of CD8+ T cells in tumor tissue and / or reducing the infiltration of FOXP3+ regulatory T cells.

[0075] Terminology Definition

[0076] In this article, the term "paclitaxel (Ptx)" refers to a natural antitumor drug derived from plants (such as yew), belonging to the microtubule stabilizer class of chemotherapy drugs. Paclitaxel's main mechanism of action is to stabilize tubulin and inhibit microtubule depolymerization, thereby blocking tumor cell mitosis, inducing apoptosis, and exerting its antitumor effect. Studies have shown that long-term use of paclitaxel can lead to a series of adverse reactions, including liver damage, kidney damage, inflammatory responses, and induction of overexpression of the multidrug resistance protein P-glycoprotein (P-gp) in tumor cells, thus limiting further improvement in its efficacy. In this article, paclitaxel includes any taxane drug (especially those used for cancer treatment), such as paclitaxel injection, docetaxel, paclitaxel liposomes, and injectable paclitaxel.

[0077] As used herein, the term "prevention" refers to a method implemented to prevent or delay the occurrence of a disease, condition, or symptom (e.g., a tumor) in a subject. As used herein, the term "treatment" refers to a method implemented to obtain a beneficial or desired clinical outcome. For the purposes of this disclosure, beneficial or desired clinical outcomes include, but are not limited to, alleviating symptoms, reducing the extent of the disease, stabilizing (i.e., no longer worsening) the state of the disease, delaying or slowing the progression of the disease, improving or alleviating the state of the disease, and relieving symptoms (whether partial or complete), whether detectable or undetectable. Furthermore, "treatment" can also mean prolonged survival compared to expected survival (if no treatment was received).

[0078] As used herein, the term "subject" refers to a mammal, such as a primate mammal, like a human. In some embodiments, the subject (e.g., a human) has a tumor (e.g., oral cancer), or is at risk of having the aforementioned disease.

[0079] As used herein, the term "effective amount" means an amount sufficient to achieve, or at least partially achieve, the desired effect. For example, an effective amount for preventing disease (e.g., cancer) means an amount sufficient to prevent, stop, or delay the onset of disease (e.g., cancer); an effective amount for treating disease means an amount sufficient to cure or at least partially stop the disease and its complications in a patient already suffering from the disease. Determining such an effective amount is entirely within the capabilities of those skilled in the art. For example, an effective amount for therapeutic use will depend on the severity of the disease to be treated, the overall state of the patient's own immune system, the patient's general characteristics such as age, weight, and sex, the manner of administration of the drug, and other concurrent treatments, etc.

[0080] As used herein, the term "pharmaceutically acceptable carrier and / or excipient" means a carrier and / or excipient that is pharmacologically and / or physiologically compatible with the subject and the active ingredient, which is well known in the art (see, for example, Remington's Pharmaceutical Sciences. Edited by Gennaro AR, 19th ed. Pennsylvania: Mack Publishing Company, 1995), and includes, but is not limited to: pH adjusters, surfactants, adjuvants, ionic strength enhancers, diluents, osmotic pressure maintaining agents, absorption delaying agents, and preservatives. For example, pH adjusters include, but are not limited to, phosphate buffers. Surfactants include, but are not limited to, cationic, anionic, or nonionic surfactants, such as Tween-80. Ionic strength enhancers include, but are not limited to, sodium chloride. Preservatives include, but are not limited to, various antibacterial and antifungal agents, such as parabens, chlorobutanol, phenol, sorbic acid, etc. Osmotic pressure maintaining agents include, but are not limited to, sugars, NaCl, and their analogues. Absorption delaying agents include, but are not limited to, monostearates and gelatin. Diluents include, but are not limited to, water, aqueous buffers (such as buffered saline), alcohols, and polyols (such as glycerol). Stabilizers have the meaning commonly understood by those skilled in the art for stabilizing the desired activity of the active ingredient in a pharmaceutical product, including but not limited to monosodium glutamate, gelatin, SPGA, sugars (such as sorbitol, mannitol, starch, sucrose, lactose, dextran, or glucose), amino acids (such as glutamic acid, glycine), proteins (such as dried whey, albumin, or casein) or their degradation products (such as lactalbumin hydrolysate).

[0081] As used herein, the term "dietary supplement" refers to an edible product that provides a beneficial effect to a consumer (e.g., nutritional, preventative, therapeutic, or other beneficial effect).

[0082] As used in this article, the term "CFU (Colony-Forming Units)" refers to the total number of microbial communities such as bacteria, fungi, and yeast in a product, and is usually used to calculate the number of viable cells.

[0083] As used herein, the term "CFU / dosage" refers to the amount of bacteria present in a composition / food product or dietary supplement / pharmaceutical composition provided to a subject daily or per dose. For example, in some embodiments, the pharmaceutical composition contains *Lactobacillus paracasei* at a concentration of 10... 6 Up to 10 12 The amount of CFU / dose present (e.g., 10) 8 Up to 10 12(CFU / dosage). In this embodiment, if *Lactobacillus paracasei* is administered into the pharmaceutical composition, the pharmaceutical composition provided to the subject daily or per dose may contain approximately 10 CFU. 6 Up to 10 12 CFU of *Lactobacillus paracasei*. Alternatively, the amount of this bacteria can be divided into multiple administrations, provided that the total amount of *Lactobacillus paracasei* received by the subject at any given time (e.g., every 24-hour period) is less than approximately 10. 6 To about 10 12 The bacteria in CFU, namely Lactobacillus paracasei in the above-mentioned pharmaceutical composition at 10 6 Up to 10 12 The amount of CFU / dose present (e.g., 10⁸ to 10⁸) 12 CFU / dosage).

[0084] Advantages of the invention

[0085] The *Lactobacillus paracasei* GOLDGUT-LC12345 described in this application exhibits good physiological activity and probiotic properties, demonstrating multifaceted beneficial effects in a nude mouse model of oral cancer. Compared with paclitaxel alone, it has at least the following significant effects: (1) When used in combination with paclitaxel, it can synergistically enhance the anti-tumor effect, significantly inhibit tumor growth, and reduce tumor volume and weight; (2) It can effectively alleviate liver and kidney damage caused by paclitaxel, significantly reduce serum ALT and BUN levels, and reduce drug side effects; (3) It can significantly reduce the level of pro-inflammatory factor IL-6, increase the level of anti-inflammatory factor IL-10, and upregulate the expression of tumor necrosis factor TNF-α, thereby enhancing the body's anti-tumor immune response; (4) It can increase the infiltration of CD8+ T cells in tumor tissue, reduce the proportion of FOXP3+ regulatory T cells, and improve the tumor immune microenvironment; (5) It can significantly inhibit the overexpression of P-glycoprotein (P-gp) induced by paclitaxel and reduce the multidrug resistance of tumor cells; (6) It can improve the intestinal flora imbalance caused by paclitaxel, restore the richness of the flora, restore the function of the suppressed flora metabolic pathways, and enhance the metabolic activity of the flora.

[0086] In conclusion, Lactobacillus paracasei GOLDGUT-LC12345 not only synergistically enhances the anti-tumor efficacy of paclitaxel, but also effectively alleviates drug side effects, reverses tumor drug resistance, and exerts comprehensive probiotic effects by regulating gut microbiota and immune microenvironment, showing promising application prospects.

[0087] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples. However, those skilled in the art will understand that the following drawings and examples are for illustrative purposes only and are not intended to limit the scope of the invention. Various objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the drawings and preferred embodiments. Attached Figure Description

[0088] Figure 1 : Schematic diagram of the design process for immune experiments.

[0089] Figure 2 The effect of probiotics on tumor morphology in nude mice.

[0090] Figure 3 Effects of probiotics on tumor volume in nude mice.

[0091] Figure 4 The effect of probiotics on the final tumor weight in nude mice.

[0092] Figure 5 The effect of probiotics on the body weight of nude mice.

[0093] Figure 6 Effects of probiotics on IL-10 in the serum of nude mice.

[0094] Figure 7 Effects of probiotics on IL-6 in the serum of nude mice.

[0095] Figure 8 Effects of probiotics on GSH levels in nude mouse serum.

[0096] Figure 9 Effects of probiotics on TNF-α in the serum of nude mice.

[0097] Figure 10 Effects of probiotics on ALT levels in nude mouse serum.

[0098] Figure 11 Effects of probiotics on BUN levels in nude mouse serum.

[0099] Figure 12 Effects of probiotics on apoptosis of tumor cells in nude mice.

[0100] Figure 13 Effects of probiotics on immune infiltration of tumor tissue in nude mice.

[0101] Figure 14 Effects of probiotics on the expression of P-gp and its mRNA in tumors of nude mice.

[0102] Figure 15 The effects of probiotics on the structure and composition of the gut microbiota in nude mice.

[0103] Figure 16 : Influence of probiotics on the analysis of differentially abundant strains in the intestine of nude mice.

[0104] Figure 17 : Influence of probiotic intervention on differentially abundant functional pathways in the intestine of nude mice.

[0105] Instructions on the Deposition of Biological Materials

[0106] Lactobacillus paracasei GOLDGUT-LC12345 ( Lacticaseibacillus paracasei GOLDGUT-LC12345) has been deposited with the China General Microbiological Culture Collection Center (CGMCC) at No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. It has the deposit number CGMCC No. 36872, and the deposit date is December 1, 2025. Detailed Embodiments

[0107] The present invention will now be described in the following non-limiting examples.

[0108] Those skilled in the art will appreciate that the examples are illustrative of the invention and are not intended to limit the scope claimed in the present application. The experimental methods in the examples are conventional methods unless otherwise specified. For those conditions not specified in the examples, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments without indicating the manufacturer are all conventional products that can be obtained commercially.

[0109] Example 1. Experimental Materials and Methods

[0110] 1.1 Experimental Animals and Rearing Environment

[0111] 30 four-week-old female BALB / C nude mice were purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd. (Laboratory Animal License No.: SCXK(Beijing)2021-0012). During the experiment, the animals had free access to food and water and were housed in a SPF-level environment (temperature 22±2°C, humidity 50%±10%, 12-hour light-dark cycle). The SPF-level maintenance feed and bedding were purchased from Jiangsu Xietong Bioengineering Co., Ltd. This animal experiment protocol was approved by the Laboratory Animal Ethics Committee of Hainan University (Approval No.: HNUAUCC-2025-00238), and the experimental process followed the animal welfare and ethics guidelines.

[0112] 1.2 Main Reagents and Materials

[0113] Paclitaxel was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; sodium carboxymethyl cellulose (CMC-Na) was purchased from Sinopharm Chemical Reagent Co., Ltd.; Matrigel was purchased from Corning Incorporated, Inc.; KB / MDR cell line was provided by our university's cell bank; ELISA kits (IL-6, IL-10, TNF-α, GSH, ALT, BUN, etc.) were purchased from Beyotime Biotechnology Co., Ltd.; Western blotting and q-PCR reagents were purchased from Wuhan Sewell Biotechnology Co., Ltd.

[0114] The probiotic used in this experiment was the first isolated and identified Lactobacillus paracasei, which was named Lactobacillus paracasei GOLDGUT-LC12345 and preserved.

[0115] The isolation and identification process of the strain is briefly as follows: Multiple strains were isolated from fermented yogurt samples from Sichuan. After plate culture, single colonies were picked, and the isolated strains were revived and purified. 16S rDNA sequencing was used to identify the isolated strain as *Lactobacillus paracasei*. Furthermore, it was named *Lactobacillus paracasei* GOLDGUT-LC12345 and deposited on December 1, 2025.

[0116] 1.3 Establishment of oral cancer model and experimental design

[0117] This experiment used 4-week-old female BALB / c nude mice of similar weight, housed in an SPF-grade environment with controlled temperature (22±2℃) and humidity (50±10%), with free access to food and water. The experiment was conducted after 2 weeks of acclimatization. An oral cancer nude mouse model was established by subcutaneous inoculation with the human-derived drug-resistant oral cancer cell line KB / MDR, which characteristically highly expresses P-gp. Specifically, KB / MDR cells in the logarithmic growth phase were collected, resuspended in sterile PBS, and mixed with Matrigel at a 1:1 volume ratio. 200 μL of the cell suspension (containing approximately 4 × 10⁻⁶ cells) was subcutaneously inoculated into the right leg of each nude mouse. 6 (cells). Continue to monitor after inoculation until the tumor volume reaches 100 mm. 3 Neptunes were randomly assigned to three groups: a Mod group, a paclitaxel (Ptx) group, and a probiotic intervention (GOLDGUT-LC12345) group, with 10 animals in each group. Paclitaxel was purchased from Aladdin Reagent Company and administered by gavage at a dose of 10 mg / kg once daily for 4 consecutive weeks. The probiotic Lactobacillus paracasei GOLDGUT-LC12345 was also administered by gavage at a dose of 1×10⁻⁶ mg / kg. 9 CFU / animal / day, dissolved in 200 μL sterile saline), intervention until the end of the experiment.

[0118] During the experiment, changes in mouse body weight and tumor volume were recorded weekly (volume was measured and calculated using calipers: V = major axis × minor axis² / 2). At the end of the experiment, mouse feces were collected, placed in sterile centrifuge tubes, and immediately stored at -80℃ for subsequent metagenomic sequencing analysis. After euthanizing the mice, blood was collected through the orbital cavity, allowed to stand at room temperature for 1 h, and then centrifuged at 3500 rpm and 4℃ for 15 min to separate the serum, which was aliquoted and stored at -80℃ for biochemical and inflammatory factor detection. After dissection, liver, kidney, and tumor tissues were collected and weighed, and organ indices (organ weight / body weight, mg / g) were calculated. Some tissues were fixed in 4% paraformaldehyde for histopathological examination, while the remaining tissues and contents were flash-frozen in liquid nitrogen and stored at -80℃ for subsequent analysis.

[0119] Experimental design flowchart as shown Figure 1 As shown. Specifically, the intervention details for each group are as follows: Mod group: No special intervention.

[0120] Drug group (Ptx group): Paclitaxel (10 mg / kg) was administered by gavage once daily for 4 weeks.

[0121] Probiotic intervention group (GOLDGUT-LC12345 group): Paclitaxel by gavage (10 mg / kg, once daily) + Lactobacillus paracasei GOLDGUT-LC12345 by gavage (1×10 9 CFU / animal / day, dissolved in 200 μL sterile saline), continuous intervention for 4 weeks.

[0122] 1.4 Study on the effect of probiotics on the antitumor activity of paclitaxel and the alleviation of its side effects

[0123] 1.4.1 Monitoring of general physiological indicators

[0124] During the experiment, mice had free access to food and water, and their food and water intake were recorded daily. The mice were weighed every two days, and the length and width of the tumor were measured using calipers. The tumor volume was calculated using the formula V = 1 / 2 × a × b² (where a is the major axis and b is the minor axis).

[0125] 1.4.2 Detection of serum physiological and biochemical indicators

[0126] After euthanasia, blood was collected from the orbital sinus and serum was separated. The following indicators were measured according to the instructions of the relevant ELISA kits: inflammatory factors: IL-10, IL-6; tumor necrosis factor: TNF-α; oxidative stress indicator: GSH; liver function indicator: ALT; kidney function indicator: BUN.

[0127] 1.4.3 Tumor histological and immunohistochemical analysis

[0128] (1) Tumor tissue was fixed with 4% paraformaldehyde, embedded in paraffin, and then sectioned for TUNEL cell apoptosis detection to analyze the changes in the apoptosis ratio of tumor cells.

[0129] (2) Immunohistochemical staining was performed on tumor tissue sections to detect the infiltration of CD8+ T cells and FOXP3+ regulatory T cells, and the proportion of positive cells was calculated.

[0130] 1.4.4 Detection of P-gp protein and mRNA expression in tumor tissue

[0131] (1) Total protein was extracted from a portion of tumor tissue, and the expression level of P-gp protein was detected by Western blotting.

[0132] (2) Total RNA was extracted from a portion of tumor tissue, and the expression level of P-gp mRNA was detected by quantitative real-time PCR (q-PCR).

[0133] 1.4.5 Gut metagenomics analysis

[0134] The contents of the terminal colon of mice were collected, and total microbial DNA was extracted using a fecal DNA extraction kit. After passing quality testing, shotgun metagenomic sequencing was performed. MetaPhlAn was used for species composition analysis, HUMAnN2 was used for functional pathway annotation, and R software was used to analyze the α-diversity (Shannon index, Richness index), β-diversity (PCoA analysis of Bray-Curtis distance), and differentially expressed species and metabolic pathways between groups.

[0135] Example 2. In vivo oncology marker results

[0136] 1. Effects of probiotics on tumor growth dynamics, terminal tumor volume, and final tumor weight in mice.

[0137] Tumor volume in mice was monitored every two days during the experiment. On day 28, mice were sacrificed, and tumor weight was measured and photographed. Changes in tumor morphology in nude mice across the three groups are shown below. Figure 2 As shown. Figure 3 As shown, the tumor growth rate differed significantly among the intervention groups: Mod group > Ptx group > GOLDGUT-LC12345 group. The final tumor volume showed a significant decrease in the Ptx group compared to the Mod group. P <0.05), while the GOLDGUT-LC12345 group showed a further reduction compared to the Ptx group ( P <0.05. The trend in tumor weight change was consistent with the volume results. Figure 4This indicates that paclitaxel monotherapy can effectively inhibit the growth of oral cancer tumors, and that the combination with Lactobacillus paracasei GOLDGUT-LC12345 can synergistically enhance the tumor-suppressing effect, with a significant synergistic effect. P <0.05).

[0138] 2. Effects of probiotics on body weight changes in mice

[0139] Statistical analysis at the end of the experiment revealed that the mice in the probiotic intervention group were lighter in weight compared to the Mod and Ptx groups, but there was no significant difference between the groups. This may be because the tumors in the probiotic intervention group were smaller, resulting in lighter weight. p >0.05).

[0140] Example 3. Results of serum biochemical indicators in mice

[0141] 3.1 Effects of probiotics on inflammatory factors in nude mice

[0142] IL-10 is an anti-inflammatory factor ( Figure 6 The content of Ptx in the group was higher than that in the Mod group. P< 0.05). Compared with the Ptx group, the IL-10 content was significantly increased after intervention with Lactobacillus paracasei GOLDGUT-LC12345 ( P< 0.05). IL-6 acts as a pro-inflammatory factor ( Figure 7 In mice, oral administration of paclitaxel alone resulted in a significant increase in IL-6 levels in the Ptx group compared to the Mod group, thus inducing an inflammatory response. Intervention with *Lactobacillus paracasei* GOLDGUT-LC12345 significantly alleviated this symptom, bringing IL-6 levels to a level comparable to the Mod group. This indicates that GOLDGUT-LC12345 can significantly alleviate the Ptx-induced increase in IL-6 levels. Therefore, GOLDGUT-LC12345 can reduce inflammation by increasing IL-10 and decreasing IL-6 levels.

[0143] 3.2 Effects of probiotics on oxidative stress in nude mice

[0144] Glutathione (GSH) is an important antioxidant, and changes in its level can reflect the body's oxidative stress state and antioxidant capacity. Figure 8 Compared with the Mod group and Ptx group, intervention with Lactobacillus paracasei GOLDGUT-LC12345 via gavage significantly increased the GSH content in nude mice. p <0.05), which improves the antioxidant stress resistance of nude mice.

[0145] 3.3 Effects of probiotics on tumor-related factors in nude mice

[0146] Elevated TNF-α levels can better inhibit tumor cell proliferation and metastasis; compared with Mod, the Ptx level showed no significant change. P >0.05), while after intervention with Lactobacillus paracasei GOLDGUT-LC12345, TNF-α levels significantly increased ( P< 0.05), GOLDGUT-LC12345 showed significantly better tumor growth inhibition than Ptx alone. Figure 9 ).

[0147] 3.4 Effects of probiotics on liver function in nude mice

[0148] ALT ( Figure 10 ALT was a liver function indicator, and its level was significantly higher in the Ptx group than in the Mod group. P <0.05), after gavage administration of probiotics, the ALT content returned to the same level as the Mod group, indicating that gavage administration of paclitaxel may cause liver damage in nude mice, while intervention with Lactobacillus paracasei GOLDGUT-LC12345 can alleviate Ptx-induced liver damage.

[0149] 3.5 Effects of probiotics on renal function in nude mice

[0150] BUN ( Figure 11 Reflecting renal function in mice, BUN in the Ptx group was significantly higher than that in the Mod group. p <0.05), indicating that paclitaxel alone can cause abnormal renal function in nude mice, while intervention with Lactobacillus paracasei GOLDGUT-LC12345 can significantly improve this condition.

[0151] Example 4. Results of apoptosis and immune infiltration in mouse tumor cells

[0152] 4.1 Effect of probiotics on the apoptosis rate of tumor cells in nude mice

[0153] Analysis of tumor cell apoptosis showed that ( Figure 12 The Ptx group significantly increased the proportion of apoptotic cells in tumor tissue compared to the Mod group, and the co-intervention of Lactobacillus paracasei GOLDGUT-LC12345 and paclitaxel significantly increased this proportion. p <0.05). These results indicate that the combined use of Lactobacillus paracasei GOLDGUT-LC12345 and paclitaxel can increase tumor cell apoptosis and significantly enhance the antitumor effect of paclitaxel.

[0154] 4.2 Effects of probiotics on immune infiltration of tumor cells in nude mice

[0155] Immunohistochemical analysis showed that, compared with the Mod group, oral administration of paclitaxel alone significantly increased the proportion of CD8+ infiltration in tumor tissue, and the proportion of CD8+ T cell infiltration in tumor tissue further increased after intervention with Lactobacillus paracasei GOLDGUT-LC12345. Figure 13 B, P <0.05). Conversely, the proportion of FOXP3+ regulatory T cell infiltration decreased after paclitaxel intervention, but there was no significant difference compared to the Mod group. Lactobacillus paracasei GOLDGUT-LC12345 intervention further reduced this proportion, and the difference was significant compared to the Mod group. Figure 13 C, P <0.05). These results indicate that intervention with Lactobacillus paracasei GOLDGUT-LC12345 may improve the tumor immune microenvironment by enhancing effector T cell infiltration and inhibiting immunosuppressive cell infiltration, and that the combination of GOLDGUT-LC12345 and paclitaxel is significantly more effective than paclitaxel alone in improving the tumor immune microenvironment.

[0156] Example 5. Results of P-gp and mRNA expression in nude mouse tumor tissues

[0157] Overexpression of P-glycoprotein (P-gp; ABCB1, Gene ID: 5243, NCBI Gene database) in tumor cells is one of the main mechanisms leading to multidrug resistance (MDR), limiting further improvement in the efficacy of paclitaxel.

[0158] P-gp in nude mouse tumor tissue ( Figure 14 A, Figure 14 B) Expression level of its mRNA ( Figure 14 C) Expression level detection revealed that oral administration of paclitaxel alone resulted in significantly higher levels of P-gp and its mRNA expression in tumor tissues compared to the Mod group. P <0.05). Intervention with *Lactobacillus paracasei* GOLDGUT-LC12345 significantly improved this situation, restoring P-gp and its mRNA expression to the same levels as the Mod group. This indicates that GOLDGUT-LC12345 can reduce multidrug resistance, enhance the antitumor intervention effect of paclitaxel, and mitigate the side effect of multidrug resistance by reducing P-gp expression.

[0159] Example 6. Results of gut microbiota in nude mice

[0160] At the level of ( Figure 15 A) and genus level ( Figure 15 In C), there was no significant difference in Shannon index among the groups. P>0.05), paclitaxel and probiotic intervention did not significantly affect gut microbiota diversity. However, regarding the Richness index, paclitaxel alone led to a decrease in species-level richness in the Ptx group, which was alleviated by probiotic intervention. Furthermore, intervention with *Lactobacillus paracasei* GOLDGUT-LC12345 significantly increased the genus-level richness of gut microbiota in nude mice. Figure 15 E) richness.

[0161] PCoA analysis based on Bray-Curtis distance showed significant differences in gut microbiota structure among different groups at both the species and genus levels. Figure 15 C, 15F). Adonis analysis showed that the differences in community structure among groups were statistically significant (C, 15F). P <0.05). Among them, Mod and Ptx and probiotic intervention groups showed some separation, but the probiotic intervention group and Ptx group showed obvious separation, indicating that different intervention methods can significantly change the composition of gut microbiota in model mice.

[0162] At the phylum level, the mouse gut microbiota is mainly composed of Firmicutes and Bacteroidota. Figure 15 G). Compared with the Mod group, the relative abundance of Firmicutes was significantly increased and Bacteroidota was significantly decreased in the Ptx group, resulting in a significant increase in its F / B ratio (G). P <0.05, Figure 15 H). Intervention with Lactobacillus paracasei GOLDGUT-LC12345 reduced the F / B ratio to levels comparable to those in the Mod group.

[0163] At the genus level ( Figure 15 I), Muribaculaceae unclassified , Duncaniella (Duncanella) Bacteroides The relative abundance of *Bacteroides* species significantly decreased after paclitaxel intervention, while intervention with *Lactobacillus paracasei* GOLDGUT-LC12345 partially restored the abundance of these bacterial groups. For example, Duncaniella Belonging to the Bacteroidetes phylum, it is believed to be associated with the production of short-chain fatty acids in the mouse intestine and has potential anti-inflammatory and intestinal homeostasis maintenance effects; Bacteroides They are important conditional symbiotic bacteria in the gut, participating in immune regulation; a decrease in their abundance usually indicates impaired intestinal barrier function. Muribaculaceae unclassified As the most abundant bacterial group in the gut of nude mice, its abundance has been shown to be closely related to inflammation levels and intestinal barrier status; a decrease in its abundance may reflect an aggravated inflammatory environment and weakened barrier function. Therefore, probiotic intervention, by restoring the relative abundance of these beneficial bacteria, may help improve drug-induced gut microbiota imbalance.

[0164] In the analysis at the gut microbiota species level, compared with the Mod and Ptx groups, the intervention with *Lactobacillus paracasei* GOLDGUT-LC12345 had a positive impact on the gut microbiota composition, showing an increase in beneficial bacteria (such as...). Lactobacillus intestinalis An increase in intestinal lactobacilli, and potentially harmful bacteria (such as...) Herbaspirillum huttiense The decrease in *Heliotropium indicum* indicates that probiotics improved the gut environment to some extent. It also significantly regulated functional flora associated with short-chain fatty acid production and carbohydrate metabolism, such as those capable of producing butyrate. Oscillospiraceae bacterium (Bacteria of the Oscillatoriaceae family) and those involved in dietary fiber fermentation and maintaining intestinal immune balance Bacteroides caccae (Bacteroides fecalith), indicating that this probiotic intervention exhibits a comprehensive effect of both probiotic and metabolic regulation. Figure 16 ).

[0165] Compared to the Ptx group, the Mod group had a higher abundance of most metabolic pathways. Figure 17Specifically, several pathways related to energy metabolism and coenzyme synthesis (such as the superpathway of coenzyme A biosynthesis I) were inhibited in the Ptx group, possibly indicating that drug treatment reduced the gut microbiota's potential to participate in tricarboxylic acid cycle-related reactions. The decrease in Pyridoxal 5'-phosphate biosynthesis I suggests a reduced genetic potential for synthesizing the active form of vitamin B6 (PLP) in the community, which may consequently affect the ability to perform various PLP-dependent metabolic reactions (including amino acid metabolism and neurotransmitter synthesis). The downregulation of Pyrimidine deoxyribonucleotide de novo biosynthesis IV suggests a weakened potential to provide raw materials for DNA replication and RNA synthesis, indicating that the proliferative activity and growth metabolism of the microbial community may be inhibited. The decrease in L-methionine biosynthesis III is not only related to protein biosynthesis but may also reduce the production of S-adenosylmethionine (SAM), an important methyl donor, thus potentially affecting methylation-related processes in both the community and the host. Overall, these results suggest that paclitaxel treatment may impair the gut microbiota's potential ability to maintain host nutritional and energy homeostasis. In contrast, compared to the *Lactobacillus paracasei* GOLDGUT-LC12345 group, most previously downregulated pathways showed a trend of reverting to or partially recovering at Mod levels. For example, energy and coenzyme metabolism pathways such as Pyridoxal 5'-phosphate biosynthesis I showed increases, indicating that probiotic intervention may improve the energy supply and enzymatic function of the gut microbiota. Meanwhile, the reverting of nucleotide synthesis-related pathways such as UMP biosynthesis I suggests a trend of recovery in the microbiota's replication and functional activity.

[0166] Although specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and variations can be made to the details based on all the published teachings, and all such changes are within the scope of protection of the invention. The full scope of the invention is given by the appended claims and any equivalents thereof.

Claims

1. A type of Lactobacillus paracasei ( Lacticaseibacillus paracasei It is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 36872.

2. A composition comprising the *Lactobacillus paracasei* as described in claim 1; Preferably, the composition further comprises microorganisms selected from bacteria, fungi (e.g., yeast), or any combination thereof; preferably, the bacteria are probiotics.

3. The composition of claim 2, wherein, The bacteria are selected from Lactobacillus, Bifidobacterium, Bacillus, Propionibacterium, Streptococcus, Lactococcus, Pediococcus, Enterococcus, Staphylococcus, or any combination thereof; Preferably, the bacteria is *Bifidobacterium animalis* subsp. *lactamase* (…). Bifidobacterium animalis subsp. lactis ).

4. A pharmaceutical composition comprising Lactobacillus paracasei as claimed in claim 1 or the composition of claim 2 or 3, and additional pharmaceutically active agents; Preferably, the pharmaceutically active agent is selected from antitumor drugs (e.g., paclitaxel (PTX)), anti-inflammatory drugs, antioxidants, antifungals, antivirals, analgesics, healing promoters, or any combination thereof; Preferably, the pharmaceutically active agent is paclitaxel.

5. The pharmaceutical composition of claim 4, wherein, The pharmaceutical composition further comprises a pharmaceutically acceptable carrier and / or excipient; Preferably, the pharmaceutically acceptable carrier and / or excipient includes: cryoprotectants, fillers, binders, lubricants, flow aids, thickeners, flavoring agents, edible oils, stabilizers, suspending agents, surfactants, or any combination thereof; Preferably, the pharmaceutical composition is formulated for oral or in vitro administration; Preferably, the pharmaceutical composition is in the form of pills, powders, capsules, tablets (e.g., effervescent tablets), oil drops, capping films, orally soluble granules, liquids, suppositories, enemas, gels, and / or creams. Preferably, the pharmaceutical composition contains Lactobacillus paracasei at a concentration of 10... 6 Up to 10 12 The amount of CFU / dose present (e.g., 10) 8 Up to 10 10 (CFU / ml).

6. A culture comprising Lactobacillus paracasei as claimed in claim 1, or the composition of claim 2 or 3, or the pharmaceutical composition of claim 4 or 5; Preferably, the culture further comprises a nutrient-providing component (e.g., a solid or liquid culture medium). Preferably, the nutritional components are selected from proteins, carbohydrates, fats, probiotics, enzymes, vitamins, immunomodulators, milk substitutes, minerals, amino acids, or any combination thereof. Preferably, the culture further comprises a cell-free culture filtrate of Lactobacillus paracasei.

7. A food product or dietary supplement comprising Lactobacillus paracasei as claimed in claim 1, or the composition as claimed in claim 2 or 3, or the culture as claimed in claim 6; Preferably, the food product is a beverage; Preferably, the food product or dietary supplement is formulated for oral administration.

8. Use of the *Lactobacillus paracasei* of claim 1, or the composition of claim 2 or 3, or the pharmaceutical composition of claim 4 or 5, or the culture of claim 6, in the preparation of a medicament for use in a subject: (a) Prevention and / or treatment of cancer; (b) Enhance the preventive and / or therapeutic effects of antitumor drugs on tumors; and / or, (c) Reduce the side effects of antitumor drugs on subjects.

9. The use according to claim 8, wherein it has one or more features selected from the following: (1) The tumor is a solid tumor; preferably, the tumor is oral cancer; (2) The antitumor drug is paclitaxel (PTX); (3) The side effects relieved by the Lactobacillus paracasei are selected from liver damage, kidney damage, inflammatory response, intestinal flora disorder, multidrug resistance (MDR), or any combination thereof.

10. Use of the *Lactobacillus paracasei* of claim 1, or the composition of claim 2 or 3, or the pharmaceutical composition of claim 4 or 5, or the culture of claim 6, in the preparation of a medicament for use in a subject: (a) Suppressing inflammation or alleviating inflammatory diseases; (b) Enhances antioxidant capacity; (c) Regulates cytokine levels; (d) Regulating the gut microbiota; and / or, (e) Enhance immunity or improve immunosuppression.

11. The use according to claim 10, wherein it has one or more features selected from the following: (1) The inflammatory disease is selected from diseases caused by skin inflammation (e.g., dermatitis, eczema), diseases related to respiratory inflammation (e.g., upper respiratory tract infection) and diseases related to digestive tract inflammation (e.g., inflammatory bowel disease). (2) The enhanced antioxidant capacity includes: Increases GSH levels in subjects; (3) The regulation of cytokine levels includes: reducing the level of pro-inflammatory factors (e.g., IL-6) and / or increasing the level of anti-inflammatory factors (e.g., IL-10, IL-12); (4) The regulation of intestinal flora includes: reducing the ratio of Firmicutes to Bacteroidota, and increasing the ratio of probiotics (such as intestinal lactobacilli). Lactobacillus intestinalis The relative abundance of and / or reduction of potentially harmful bacteria (e.g., *Heliotropium indicum*) Herbaspirillum huttiense The relative abundance of )); and / or (5) The enhancement of immunity or improvement of immunosuppression includes: increasing the infiltration of CD8+ T cells in tumor tissue and / or reducing the infiltration of FOXP3+ regulatory T cells.

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