Identification and functional analyses of CD4-1+ cells in grass carp (Ctenopharyngodon idella).

In mammals, CD4 is found to be expressed on T cells and innate immune cells, however, teleost cells bearing CD4 have not been well identified and characterized. In this study, we identified two different CD4-1+ cell subsets in grass carp (Ctenopharyngodon idella): CD4-1+ lymphocytes (Lym) and CD4-1+ myeloid cells (Mye), both of which had the highest proportions in the head kidney. The mRNA expression analysis showed that CD4-1, CD4-2, TCRß, CD3γ/δ, and LCK1 are highly expressed in CD4-1+ Lym and also expressed in CD4-1+ Mye. Furthermore, we found that CD4-1+ Lym have a Lym morphology and highly express T-cell cytokines, suggesting that they are CD4+ T cells equivalent to mammalian Th cells. On the other hand, CD4-1+ Mye were found to have a morphology of macrophage and highly express macrophage marker gene MCSFR, indicating that they are macrophages. In addition, functional analysis revealed that CD4-1+ Mye possess phagocytic ability and great antigen-processing ability. Taken together, our study sheds further light on the composition and function of CD4+ cells in teleost fish.

Synergistic effects of the combination of trametinib and alpelisib in anaplastic thyroid cancer with BRAF and PI3KCA co-mutations.

Background: Anaplastic thyroid cancer (ATC), a rare and aggressive malignancy with a poor prognosis, has shown promise with the approved dabrafenib/trametinib combination for BRAFV600E mutation. Co-occurring PI3KCA mutations, identified as negative prognostic factors in lung cancer with BRAFV600E mutation, emphasize the need to target both pathways. Exploring trametinib and alpelisib combination becomes crucial for ATC. Methods: A patient-derived xenograft (PDX) and primary cell line were obtained from an ATC patient with BRAF and PI3KCA co-mutation. Individual testing of targeted therapies against BRAF, MEK, and PI3KCA was followed by a combination treatment. Synergistic effects were evaluated using the combination index. Immunoblotting assessed the efficacy, with validation performed using a PDX model. Results: In this study, the ATC0802 cell line and PDX were established from a refractory ATC patient. NGS revealed BRAF and PI3KCA co-mutations pre- and post-dabrafenib/trametinib treatment. Trametinib/alpelisib combination showed synergy, suppressing both pERK and pAKT levels, unlike monotherapies or BRAF knockdown. The combination induced apoptosis and, in the PDX model, demonstrated superior tumor growth inhibition compared to monotherapies. Conclusions: The combination of trametinib and alpelisib showed promise as a strategy for treating ATC with co-mutations in BRAF and PI3KCA, both in vitro and in vivo. This combination offers insights into overcoming resistance to BRAF-targeted treatments in ATC with mutations in BRAF and PI3KCA.

PLK1 and its substrate MISP facilitate intrahepatic cholangiocarcinoma progression by promoting lymphatic invasion and impairing E-cadherin adherens junctions.

Intrahepatic cholangiocarcinoma (iCCA) is a subtype of CCA and has a high mortality rate and a relatively poor prognosis. However, studies focusing on increased cell motility and loss of epithelial integrity during iCCA progression remain relatively scarce. We collected seven fresh tumor samples from four patients to perform RNA sequencing (RNA-seq) and assay for transposase-accessible chromatin using sequencing (ATAC-seq) to determine the transcriptome profile and chromatin accessibility of iCCA. The increased expression of cell cycle regulators, including PLK1 and its substrate MISP, was identified. Ninety-one iCCA patients were used to validate the clinical significance of PLK1 and MISP. The upregulation of PLK1 and MISP was determined in iCCA tissues. Increased expression of PLK1 and MISP was significantly correlated with tumor number, N stage, and lymphatic invasion in an iCCA cohort. Knockdown of PLK1 or MISP reduced trans-lymphatic endothelial migration and wound healing and affected focal adhesions in vitro. In cell‒cell junctions, MISP localized to adherens junctions and suppressed E-cadherin dimerization. PLK1 disrupted adherens junctions in a myosin-dependent manner. Furthermore, PLK1 and MISP promoted cell proliferation in vitro and tumorigenesis in vivo. In iCCA, PLK1 and MISP promote aggressiveness by increasing lymphatic invasion, tumor growth, and motility through the repression of E-cadherin adherens junctions.

Athermal panoramic annular lens design with a thermal analysis method.

An athermal 360∘×(30∘-100∘) and F/3.5 panoramic annular lens (PAL) system is designed. Through the optical mechanical thermal analysis results based on finite element analysis (FEA), it is expected that the system will have excellent performance under extreme temperature fluctuations. Simulation shows that the system is thermally insensitive in the temperature range from -40∘ C to 60°C, consistently providing great imaging capability with the modulation transfer function (MTF) value at 133 lp/mm greater than 0.3. The proposed design and analysis workflow contains an evaluation of thermal optical performance with a higher accuracy, thus having significance in future athermal optical design. We expect the designed PAL system to have a broad application prospect in the field of outdoor applications, including automatic navigation of vehicles and all-weather surveillance systems.

Zinc supplementation decreased incidence of grade ≥2 hand-foot skin reaction induced by regorafenib: A phase II randomized clinical trial.

To the editor: Hand-foot skin reaction (HFSR), characterized by skin abnormalities on palmoplantar surfaces, has an overall incidence of about 35% upon vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs) treatment.1 Zinc, which plays a role in maintaining skin health, may be implicated in the pathogenesis of HFSR.2 Zinc deficiency has been shown to associate with dermatological toxicities of epidermal growth factor receptor (EGFR)-TKI.3, 4 Regorafenib, an oral multi-kinase inhibitor targeting VEGFR 1-3, PDGFR, cKIT, BRAF, and RET1, is approved for the treatment of metastatic colorectal cancer (mCRC) but commonly causes HFSR.5 This phase II randomized trial aimed to investigate whether zinc supplementation can reduce the severity of HFSR induced by regorafenib within the first 8 weeks of treatment (NCT03898102).

Elaiophylin Elicits Robust Anti-Tumor Responses via Apoptosis Induction and Attenuation of Proliferation, Migration, Invasion, and Angiogenesis in Pancreatic Cancer Cells.

Pancreatic cancer remains a formidable challenge in oncology due to its aggressive nature and limited treatment options. In this study, we investigate the potential therapeutic efficacy of elaiophylin, a novel compound, in targeting BxPC-3 and PANC-1 pancreatic cancer cells. We comprehensively explore elaiophylin's impact on apoptosis induction, proliferation inhibition, migration suppression, invasion attenuation, and angiogenesis inhibition, key processes contributing to cancer progression and metastasis. The results demonstrate that elaiophylin exerts potent pro-apoptotic effects, inducing a substantial increase in apoptotic cells. Additionally, elaiophylin significantly inhibits proliferation, migration, and invasion of BxPC-3 and PANC-1 cells. Furthermore, elaiophylin exhibits remarkable anti-angiogenic activity, effectively disrupting tube formation in HUVECs. Moreover, elaiophylin significantly inhibits the Wnt/ß-Catenin signaling pathway. Our findings collectively demonstrate the multifaceted potential of elaiophylin as a promising therapeutic agent against pancreatic cancer via inhibition of the Wnt/ß-Catenin signaling pathway. By targeting diverse cellular processes crucial for cancer progression, elaiophylin emerges as a prospective candidate for future targeted therapies. Further investigation of the in vivo efficacy of elaiophylin is warranted, potentially paving the way for novel and effective treatment approaches in pancreatic cancer management.

Wee1 inhibition by MK1775 potentiates gemcitabine through accumulated replication stress leading to apoptosis in biliary tract cancer.

Patients with advanced biliary tract cancer (BTC) have a poor prognosis, and novel treatments are needed. Gemcitabine, the standard of care for BTC, induces DNA damage; however, the ability of cancer cells to repair DNA dampens its effects. To improve the efficacy of gemcitabine, we combined it with MK1775, a Wee1 inhibitor that prevents activation of the G2/M checkpoint. BTC cell lines were treated with gemcitabine only or in combination with MK1775 to determine the therapeutic potential of BTC. Gemcitabine inhibited the growth and induced the apoptosis of four BTC cell lines to a greater extent when added with MK1775 than when added alone. The effects of the combination treatment were observed in both p53 wild-type and p53 mutant cell lines and were unaffected by knockdown of wild-type p53. The combination treatment increased the percentage of apoptotic cells and decreased the percentage of cells synthesizing DNA, suggesting that it caused DNA-damaged cells to accumulate and possibly die in S phase. It did not induce apoptosis when cells were arrested in mitosis using nocodazole. In a xenograft mouse model, gemcitabine plus MK1775 (but not either alone) inhibited the growth of tumors generated from inoculated BTC cells. Our results show that MK1775 highly enhances gemcitabine cytotoxicity in BTC regardless of p53 status. We suggest that the combination treatment elicits a DNA damage response and consequent apoptosis. Our preclinical study provides a basis for future clinical trials of gemcitabine plus MK1775 in patients with BTC.

Poly (ADP-ribose) polymerase 1 and neurodegenerative diseases: Past, present, and future.

Poly (ADP-ribose) polymerase 1 (PARP1) is a first responder that recognizes DNA damage and facilitates its repair. Neurodegenerative diseases, characterized by progressive neuron loss driven by various risk factors, including DNA damage, have increasingly shed light on the pivotal involvement of PARP1. During the early phases of neurodegenerative diseases, PARP1 experiences controlled activation to swiftly address mild DNA damage, thereby contributing to maintain brain homeostasis. However, in late stages, exacerbated PARP1 activation precipitated by severe DNA damage exacerbates the disease condition. Consequently, inhibition of PARP1 overactivation emerges as a promising therapeutic approach for neurodegenerative diseases. In this review, we comprehensively synthesize and explore the multifaceted role of PARP1 in neurodegenerative diseases, with a particular emphasis on its over-activation in the aggregation of misfolded proteins, dysfunction of the autophagy-lysosome pathway, mitochondrial dysfunction, neuroinflammation, and blood-brain barrier (BBB) injury. Additionally, we encapsulate the therapeutic applications and limitations intrinsic of PARP1 inhibitors, mainly including limited specificity, intricate pathway dynamics, constrained clinical translation, and the heterogeneity of patient cohorts. We also explore and discuss the potential synergistic implementation of these inhibitors alongside other agents targeting DNA damage cascades within neurodegenerative diseases. Simultaneously, we propose several recommendations for the utilization of PARP1 inhibitors within the realm of neurodegenerative disorders, encompassing factors like the disease-specific roles of PARP1, combinatorial therapeutic strategies, and personalized medical interventions. Lastly, the encompassing review presents a forward-looking perspective along with strategic recommendations that could guide future research endeavors in this field.

Intestinal flora in the constipation patients before versus after lactulose intervention.

This study aimed to investigate the characteristics of intestinal flora in patients with chronic functional constipation before and after lactulose intervention. Twenty-nine patients with constipation in the treatment group received oral lactulose (15 mL/d) for a month. Twenty healthy subjects served as controls. Stool specimens were collected before and after lactulose treatment. Fecal bacteria were examined by 16SrRNA gene sequencing and bioinformatics analysis. After lactulose treatment, most bacteria in the constipation group, including Bifidobacteria, Bacillus cereus, Prevotella, Bacillus, Anaerostipes, Oribacterium, and Mogibacterium increased as compared to those in the healthy control group. Anaerotruncus declined in the healthy control group after lactulose treatment. Our study shows lactulose can increase the abundance of probiotics, optimize the intestinal microenvironment, and alleviate constipation.

An Atlas of Grass Carp IgM+ B Cells in Homeostasis and Bacterial Infection Helps to Reveal the Unique Heterogeneity of B Cells in Early Vertebrates.

Teleost B cells are primitive lymphocytes with both innate and adaptive immune functions. However, the heterogeneity and differentiation trajectory of teleost B cells remain largely unknown. In this study, the landscape of grass carp IgM+ (gcIgM+) B cells was revealed by single-cell RNA sequencing. The results showed that gcIgM+ B cells mainly comprise six populations: (im)mature B cells, innate B cells, proliferating B cells, plasma cells, CD22+ cells, and CD34+ cells, among which innate B cells and proliferating B cells were uncommon B cell subsets with, to our knowledge, new characteristics. Remarkably, three functional IgMs were discovered in grass carp, and a significant percentage of gcIgM+ B cells, especially plasma cells, expressed multiple Igµ genes (Igµ1, Igµ2, and/or Igµ3). More importantly, through single-cell sorting combined with Sanger sequencing, we found that distinct VHDJH recombination patterns of Igµ genes were present in single IgM+ B cells, indicating that individual teleost B cells might produce multiple Abs by coexpressing rearranged IgM subclass genes. Moreover, the percentage of IgM1highIgM2highIgM3high plasma cells increased significantly after bacterial infection, suggesting that individual plasma cells might tend to produce multiple IgMs to resist the infection in teleost fish. In summary, to our knowledge, this study not only helps to uncover the unique heterogeneity of B cells in early vertebrates but also provided significant new evidence supporting the recently proposed "one cell-multiple Abs" paradigm, challenging the classical rule of "one cell-one Ab."

Mucin 4 Confers Gemcitabine Resistance and an Unfavorable Prognosis in Patients with Cholangiocarcinoma via AKT Activation.

Cholangiocarcinoma (CCA) exhibits aggressive biological behavior and a poor prognosis. Gemcitabine (GEM)-based chemotherapy is the first-line chemotherapy for advanced CCA but has a response rate of only 20-30%. Therefore, investigating treatments to overcome GEM resistance in advanced CCA is crucial. Among mucin (MUC) family members, MUC4 showed the greatest increase in the resistant versus parental sublines. MUC4 was upregulated in whole-cell lysates and conditioned media from gemcitabine-resistant (GR) CCA sublines. MUC4 mediated GEM resistance by activating AKT signaling in GR CCA cells. The MUC4-AKT axis induced BAX S184 phosphorylation to inhibit apoptosis and downregulated GEM transporter human equilibrative nucleoside transporter 1 (hENT1) expression. The combination of AKT inhibitors and GEM or afatinib overcame GEM resistance in CCA. In vivo, capivasertib (an AKT inhibitor) increased GEM sensitivity in GR cells. MUC4 promoted EGFR and HER2 activation to mediate GEM resistance. Finally, MUC4 expression in patient plasma correlated with MUC4 expression. Paraffin-embedded specimens from non-responders expressed significantly more MUC4 than did those from responders, and this upregulation was associated with poor progression-free survival and overall survival. In GR CCA, high MUC4 expression promotes sustained EGFR/HER2 signaling and AKT activation. The combination of AKT inhibitors with GEM or afatinib might overcome GEM resistance.

Targeting autophagy to discover the Piper wallichii petroleum ether fraction exhibiting antiaging and anti-Alzheimer's disease effects in Caenorhabditis elegans.

BACKGROUND: With population aging, the incidence of aging-related Alzheimer's disease (AD) is increasing, accompanied by decreased autophagy activity. At present, Caenorhabditis elegans (C. elegans) is widely employed to evaluate autophagy and in research on aging and aging-related diseases in vivo. To discover autophagy activators from natural medicines and investigate their therapeutic potential in antiaging and anti-AD effects, multiple C. elegans models related to autophagy, aging, and AD were used. METHOD: In this study, we employed the DA2123 and BC12921 strains to discover potential autophagy inducers using a self-established natural medicine library. The antiaging effect was evaluated by determining the lifespan, motor ability, pumping rate, lipofuscin accumulation of worms, and resistance ability of worms under various stresses. In addition, the anti-AD effect was examined by detecting the paralysis rate, food-sensing behavior, and amyloid-ß and Tau pathology in C. elegans. Moreover, RNAi technology was used to knock down the genes related to autophagy induction. RESULTS: We discovered that Piper wallichii extract (PE) and the petroleum ether fraction (PPF) activated autophagy in C. elegans, as evidenced by increased GFP-tagged LGG-1 foci and decreased GFP-p62 expression. In addition, PPF extended the lifespan and enhanced the healthspan of worms by increasing body bends and pumping rates, decreasing lipofuscin accumulation, and increasing resistance to oxidative, heat, and pathogenic stress. Moreover, PPF exhibited an anti-AD effect by decreasing the paralysis rate, improving the pumping rate and slowing rate, and alleviating Aß and Tau pathology in AD worms. However, the feeding of RNAi bacteria targeting unc-51, bec-1, lgg-1, and vps-34 abolished the antiaging and anti-AD effects of PPF. CONCLUSION: Piper wallichii may be a promising drug for antiaging and anti-AD. More future studies are also needed to identify autophagy inducers in Piper wallichii and clarify their molecular mechanisms.

Comparative study on antibacterial characteristics of the multiple liver expressed antimicrobial peptides (LEAPs) in teleost fish.

Antimicrobial peptides are important components of the host innate immune system, forming the first line of defense against infectious microorganisms. Among them, liver-expressed antimicrobial peptides (LEAPs) are a family of antimicrobial peptides that widely exist in vertebrates. LEAPs include two types, named LEAP-1 and LEAP-2, and many teleost fish have two or more LEAP-2s. In this study, LEAP-2C from rainbow trout and grass carp were discovered, both of which are composed of 3 exons and 2 introns. The antibacterial functions of the multiple LEAPs were systematically compared in rainbow trout and grass carp. The gene expression pattern revealed that rainbow trout and grass carp LEAP-1, LEAP-2A, LEAP-2B and/or LEAP-2C were differentially expressed in various tissues/organs, mainly in liver. After bacterial infection, the expression levels of LEAP-1, LEAP-2A, LEAP-2B and/or LEAP-2C in the liver and gut of rainbow trout and grass carp increased to varying degrees. Moreover, the antibacterial assay and bacterial membrane permeability assay showed that rainbow trout and grass carp LEAP-1, LEAP-2A, LEAP-2B and LEAP-2C all have antibacterial activities against a variety of Gram-positive and Gram-negative bacteria with varying levels through membrane rupture. Furthermore, cell transfection assay showed that only rainbow trout LEAP-1, but not LEAP-2, can lead to the internalization of ferroportin, the only iron exporter on cell surface, indicating that only LEAP-1 possess iron metabolism regulation activity in teleost fish. Taken together, this study systematically compared the antibacterial function of LEAPs in teleost fish and the results suggest that multiple LEAPs can enhance the immunity of teleost fish through different expression patterns and different antibacterial activities to various bacteria.

A Potential Association of Zinc Deficiency and Tyrosine Kinase Inhibitor-Induced Hand-Foot Skin Reaction.

Hand-foot skin reaction (HFSR) is a common skin-related adverse event induced by multikinase inhibitors targeting both platelet-derived growth factor receptor and vascular endothelial growth factor receptor, possibly due to inadequate repair following frictional trauma. Zinc is a trace element and essential nutrient in humans that plays critical roles in the development and differentiation of skin cells. Zinc transporters (Zrt- and Irt-like proteins and Zn transporters) and metallothioneins are involved in zinc efflux, uptake, and homeostasis and have been reported to be involved in skin differentiation. The underlying mechanism of HFSR remains unclear, and the association between HFSR and zinc has not been previously studied. However, some case reports and case series provide potential evidence to suggest that zinc deficiency may be involved in HFSR development and zinc supplementation may relieve HFSR symptoms. However, no large-scale clinical studies have been conducted to examine this role. Therefore, this review summarizes the evidence supporting a possible link between HFSR development and zinc and proposes potential mechanisms underlying this association based on current evidence.

Universality and scaling in complex networks from periods of Chinese history.

Critical physical systems with large numbers of molecules can show universal and scaling behaviors. It is of interest to know whether human societies with large numbers of people can show the same behaviors. Here, we use network theory to analyze Chinese history in periods 209 BCE-23 CE and 515-618 CE) related to the Western Han-Xin Dynasty and the late Northern Wei-Sui Dynasty, respectively. Two persons are connected when they appear in the same historical event. We find that the historical networks from two periods separated about 500 years have interesting universal and scaling behaviors, and they are small-world networks; their average cluster coefficients as a function of degree are similar to the network of movie stars. In the historical networks, the persons with larger degrees prefer to connect with persons with a small degree; however, in the network of movie stars, the persons with larger degrees prefer to connect with persons with large degrees. We also find an interesting similar mechanism for the decline or collapse of historical Chinese dynasties. The collapses of the Xin dynasty (9-23 CE) and the Sui dynasty (581-618 CE) were initiated from their arrogant attitude toward neighboring states.

Chimeric immune checkpoint protein vaccines inhibit the tumorigenesis and growth of rat cholangiocarcinoma.

Cholangiocarcinoma (CCA) is the second most common primary liver malignancy and carries a dismal prognosis due to difficulties in achieving an optimal resection, and poor response to current standard-of-care systemic therapies. We previously devised a CTLA4-PD-L1 DNA cancer vaccine (DNA vaccine) and demonstrated its therapeutic effects on reducing tumor growth in a thioacetamide (TAA)-induced rat intrahepatic CCA (iCCA) model. Here, we developed a CTLA4-PD-L1 chimeric protein vaccine (Protein vaccine), and examined its effects in the rat iCCA model. In a therapeutic setting, iCCA-bearing rats received either DNA plus Protein vaccines or Protein vaccine alone, resulting in increased PD-L1 and CTLA-4 antibody titers, and reduced iCCA tumor burden as verified by animal positron emission tomography (PET) scans. Treating iCCA-bearing rats with Protein vaccine alone led to the increase of CTAL4 antibody titers that correlated with the decrease of tumor SUV ratio, indicating regressed tumor burden, along with increased <i>CD8</i> and granzyme A (<i>GZMA</i>) expression, and decreased PD-L1 expression on tumor cells. In a preventive setting, DNA or Protein vaccines were injected in rats before the induction of iCCA by TAA. Protein vaccines induced a more sustained PD-L1 and CTLA-4 antibody titers compared with DNA vaccines, and was more potent in preventing iCCA tumorigenesis. Correspondingly, Protein vaccines, but not DNA vaccines, downregulated PD-L1 gene expression and hindered the carcinogenesis of iCCA. Taken together, the CTLA4-PD-L1 chimeric protein vaccine may function both as a therapeutic cancer vaccine and as a preventive cancer vaccine in the TAA-induced iCCA rat model.

In vitro and in vivo study of GSK2830371 and RG7388 combination in liver adenocarcinoma.

Intrahepatic cholangiocarcinoma (iCCA) is an adenocarcinoma arising from the intrahepatic bile duct and accounts for the second highest incidence of primary liver cancers after hepatocellular carcinoma. The lack of effective treatment leads to a poor prognosis for advanced iCCA, so new targeted therapy is needed. The impairment of wild-type (WT) p53 tumor suppressor function by its negative regulators frequently occurs in iCCA. Therefore, restoration of WT p53 function by inhibiting its negative regulators is a therapeutic strategy being explored for cancer treatment. Combining an MDM2 inhibitor (MDM2i, RG7388) to stabilize p53 and a WIP1 inhibitor (WIP1i, GSK2830371) to increase p53 phosphorylation enhances p53 function. The combination of MDM2 and WIP1 inhibitors has been reported in several cancer types but in vivo studies are lacking. In the current study, liver adenocarcinoma cell lines, RBE and SK-Hep-1, were treated with RG7388 alone and in combination with GSK2830371. Cell proliferation, clonogenicity, protein and mRNA expressions, and cell cycle distribution were performed to investigate the effect and mechanism of growth suppression. To evaluate the antitumor efficacy of RG7388 and GSK2830371 in vivo, SK-Hep-1 xenografts in NOD-SCID mice were treated with combination therapy for two weeks. The combination of MDM2i and WIP1i significantly increased the growth inhibition, cytotoxicty, p53 protein expression, and phosphorylation (Ser15), leading to transactivation of downstream targets (p21WAF1 and MDM2). The in vivo results demonstrated that the combination treatment can significantly inhibit tumor growth. In this study, the liver adenocarcinoma cell lines responded to combination treatment via reactivation of p53 function evidenced by increased p53 expression, phosphorylation and expression of its downstream targets. This efficacy was also demonstrated in vivo. The current research provides a novel strategy for targeting the p53 pathway in liver adenocarcinoma that warrants further investigation.

Influence of Flax Seeds on the Gut Microbiota of Elderly Patients with Constipation.

Purpose: This study was to explore the influence of flax seeds on the gut microbiota of elderly patients with functional constipation. Patients and Methods: Sixty elderly patients (68.68±8.73 years) with functional constipation were recruited between January 2018 and March 2018. They received oral flax seeds (50 g/d) for one month. Bowel habits and adverse events were recorded before and after treatment. Fresh stool was collected before and after treatment and the amplification product of 16S rRNA V5 region was sequenced using the next-generation sequencing technique on the Ion Torrent PGM platform. The gut microbiota were analyzed before and after flax seeds treatment in the same subject. Results: Flax-seed treatment significantly increased the frequency of defecation and decreased abdominal distension in elderly patients with chronic constipation. The majority of gut bacteria belonged to the phyla of Firmicutes, Bacteroidetes, and Proteobacteria, accounting for 98.71%. After flax seeds treatment, the diversity of bacterial clusters significantly increased with increases of Roseburia_hominis, Pseudomonas_azotoformans, uncultured_Clostridiales_bacterium, Blautia_obeum, Ruminococcus_sp._16442, Pyramidobacter_piscolens, Acinetobacter_lwoffii, Prevotella_melaninogenica. The abundance of Blautia in patients with chronic constipation was significantly lower than healthy controls, while Blautia_obeum increased significantly after flax seed treatment. Blautia_obeum might be the predominant genus accounting for the therapeutic effect of flax seeds. Conclusion: Flax seeds may improve the defecation in elderly patients with chronic constipation and change intestinal microecological structure. Thus, flax seeds may serve as an effective diet supplement in the management of chronic constipation.