A multi-channel electrochemical biosensor based on polyadenine tetrahedra for the detection of multiple drug resistance genes.

Antimicrobial resistance poses a serious threat to human health due to the high morbidity and mortality caused by drug-resistant microbial infections. Therefore, the development of rapid, sensitive and selective identification methods is key to improving the survival rate of patients. In this paper, a sandwich-type electrochemical DNA biosensor based on a polyadenine-DNA tetrahedron probe was constructed. The key experimental conditions were optimized, including the length of polyadenine, the concentration of the polyadenine DNA tetrahedron, the concentration of the signal probe and the hybridization time. At the same time, poly-avidin-HRP80 was used to enhance the electrochemical detection signal. Finally, excellent biosensor performance was achieved, and the detection limit for the synthetic DNA target was as low as 1 fM. In addition, we verified the practicability of the system by analyzing E. coli with the MCR-1 plasmid and realized multi-channel detection of the drug resistance genes MCR-1, blaNDM, blaKPC and blaOXA. With the ideal electrochemical interface, the polyA-based biosensor exhibits excellent stability, which provides powerful technical support for the rapid detection of antibiotic-resistant strains in the field.

Triblock PolyA-Mediated Protein Biosensor Based on a Size-Matching Proximity Hybridization Analysis.

The antibodies in the natural biological world utilize bivalency/multivalency to achieve a higher affinity for antigen capture. However, mimicking this mechanism on the electrochemical sensing interface and enhancing biological affinity through precise spatial arrangement of bivalent aptamer probes still pose a challenge. In this study, we have developed a novel self-assembly layer (SAM) incorporating triblock polyA DNA to enable accurate organization of the aptamer probes on the interface, constructing a "lock-and-key-like" proximity hybridization assay (PHA) biosensor. The polyA fragment acts as an anchoring block with a strong affinity for the gold surface. Importantly, it connects the two DNA probes, facilitating one-to-one spatial proximity and enabling a controllable surface arrangement. By precisely adjusting the length of the polyA fragment, we can tailor the distance between the probes to match the molecular dimensions of the target protein. This design effectively enhances the affinity of the aptamers. Notably, our biosensor demonstrates exceptional specificity and sensitivity in detecting PDGF-BB, as confirmed through successful validation using human serum samples. Overall, our biosensor presents a novel and versatile interface for proximity assays, offering a significantly improved surface arrangement and detection performance.

Development of Optical Differential Sensing Based on Nanomaterials for Biological Analysis.

The discrimination and recognition of biological targets, such as proteins, cells, and bacteria, are of utmost importance in various fields of biological research and production. These include areas like biological medicine, clinical diagnosis, and microbiology analysis. In order to efficiently and cost-effectively identify a specific target from a wide range of possibilities, researchers have developed a technique called differential sensing. Unlike traditional "lock-and-key" sensors that rely on specific interactions between receptors and analytes, differential sensing makes use of cross-reactive receptors. These sensors offer less specificity but can cross-react with a wide range of analytes to produce a large amount of data. Many pattern recognition strategies have been developed and have shown promising results in identifying complex analytes. To create advanced sensor arrays for higher analysis efficiency and larger recognizing range, various nanomaterials have been utilized as sensing probes. These nanomaterials possess distinct molecular affinities, optical/electrical properties, and biological compatibility, and are conveniently functionalized. In this review, our focus is on recently reported optical sensor arrays that utilize nanomaterials to discriminate bioanalytes, including proteins, cells, and bacteria.

Construction of an Enzyme Cascade Based on the Accurate Adjacent Arrangement of Coupled Enzymes Using a Triblock PolyA DNA Probe.

Intracellular enzyme cascades are essential for various biological processes, and mimicking their functions in artificial systems has attracted significant research attention. However, achieving convenient and efficient spatial organization of enzymes on interfaces remains a critical challenge. In this work, we designed a simple single-DNA scaffold using triblock polyA single-stranded DNA for the arrangement of coupled enzymes. The scaffold was assembled onto a gold electrode through the affinity of polyA-Au, and two enzymes (glucose oxidase and horseradish peroxidase) were captured through hybridization. The molecular distance between the enzymes was regulated by changing the length of the polyA fragment. As a proof of concept, a glucose biosensor was constructed based on the enzyme cascade amplification. The biosensor exhibited excellent detection capability for glucose in human serum samples with a limit of detection of 1.6 µM. Additionally, a trienzyme cascade reaction was successfully activated, demonstrating the potential scalability of our approach for multienzyme reactions. This study provides a promising platform for the development of easy-to-operate, highly efficient, and versatile enzyme cascade systems using DNA scaffolds.

Development of a Single-Molecule Nanobalance Ratiometric Electrochemical DNA Biosensor Using a Triblock Poly-Adenine Probe.

The development of electrochemical DNA biosensors has been limited by their reliability and reproducibility due to many interfering factors such as electrode properties, DNA surface densities, and complex biological samples. In this work, we developed a nanobalance polyA hairpin probe (polyA-HP), which was effectively assembled onto the gold electrode surface through the affinity between the central polyA fragment and the Au surface. One flanking probe of the polyA-HP captured the target sequence together with a MB-labeled signal probe, and the other flanking probe captured a reference probe simultaneously. The MB signal related to the amount of target was normalized by the reference Fc signal; thus, the signal-to-noise (S/N) was as high as 2000, and the reproducibility was remarkably improved to 2.77%, even facing deliberately changed experiment conditions. By designing a hairpin structure at the terminal of the polyA-HP, the selectivity and specificity were dramatically improved for the analysis of mismatched sequences. The analysis performance of biological samples was dramatically improved after normalization, which is critical for its practicability. Our novel biosensor is a universal single-molecule platform for ratiometric biosensors with excellent performance in real samples, indicating great potential for next-generation high-precision electrochemical sensors.

Medium- to long-term outcomes of vaginally assisted laparoscopic sacrocolpopexy in the treatment of stage III-IV pelvic organ prolapse.

BACKGROUND: Vaginally assisted laparoscopic sacrocolpopexy (VALS) refers to the placement of synthetic meshes through the vagina in addition to traditional laparoscopic sacrocolpopexy. In this study, we aimed to investigate the medium- to long-term efficacy and safety of VALS for treating stage III-IV pelvic organ prolapse (POP). METHODS: The study was designed as a case series at a single center. Patients with stage III-IV POP in our hospital from January 2010 to December 2018 were included. Perioperative parameters, objective and subjective outcomes, and complications were assessed. RESULTS: A total of 106 patients completed the follow-up and were included in our study. Within a median follow-up duration of 35.4 months, the objective cure ratio of VALS reached 92.45% (98/106), and the subjective success rate was 99.06% (105/106). Patients reported significant improvements in subjective symptoms. In eight patients suffering anatomic prolapse recurrence, two posterior POP cases were treated by posterior pelvic reconstruction surgery, while six anterior POP cases did not need surgical therapies. The reoperation rate was 1.89% (2/106). No intraoperative complications occurred. Three patients (2.83%) had postoperative fever, and one (0.94%) had wound infection during hospitalization. Six patients (5.66%) had mesh exposure on the vaginal wall, and de novo urinary incontinence occurred in two patients (1.89%) during the follow-up period. CONCLUSION: VALS is an effective and safe surgical method for treating severe POP. Therefore, VALS should be considered in the treatment of severe POP due to its favorable subjective and objective outcomes, relatively low rate of infection and acceptable rate of mesh exposure.

Triblock probe-polyA-probe electrochemical interfacial engineering for the sensitive analysis of RNAi plants.

RNA interference (RNAi) is currently under fast development, which brings improved crop quality and new activity against pests in agriculture, by producing RNAs to specifically inhibit gene expression. This technology, in turn, creates a pressing need for sensitive and specific analytical methods of exogenous RNA molecules in genetically modified (GM) crops for safety assessment and regulation of RNAi plants and their products. In this work, we developed a novel RNA electrochemical biosensor for the analysis of GM maize samples based on a polyA-DNA capturing probe containing three DNA segments: the central polyA segment combined onto a gold electrode surface with adjustable configuration and density, and two flanking DNA probes simultaneously captured the RNA targets through hybridization. Both the assembling and hybridization capability of our probe were demonstrated, and we systematically optimized the analytical conditions. Finally, the ultrasensitive detection of 10 fM RNA was realized without any amplification processes, and the specificity was verified by analyzing non-target maize samples. Our electrochemical biosensor provided a reliable and convenient measurement strategy for RNAi safety and quality assessment, and more importantly, our PAP (probe-polyA-probe) capturing probe exhibited an innovative design for the detection of large RNA molecules with complex secondary structures.

Fishing unfunctionalized SERS tags with DNA hydrogel network generated by ligation-rolling circle amplification for simple and ultrasensitive detection of kanamycin.

Simple assay format-based SERS methods for sensitive target substance analysis is of great significance for the development of on-site monitoring biosensors. Herein, taking the typical antibacterial kanamycin (KANA) as a subject, a simple, highly sensitive and specific SERS aptasensor was developed by manipulating DNA hydrogel network to fish plasmonic core-shell nanoparticles. A competitive binding mode of aptamer, ligation-rolling circle amplification (L-RCA), gap-containing Au@Au nanoparticles (GCNPs) with embedded Raman reporters were integrated into the sensor. In the presence of KANA, the double stranded DNA (dsDNA) structure of the aptamer was disrupted, and the released primers were used to construct two kinds of circularized padlock probes (CPPs) which were partially complementary. DNA hydrogel network was formed through the intertwining and self-assembly of two RCA-generated single stranded DNA (ssDNA) chains, during which GCNPs and magnetic beads (MBs) were entangled and incorporated. Finally, KANA quantification was successfully achieved through the quantification of the DNA hydrogel. Overall, this novel SERS aptasensor realized a simple and ultrasensitive quantification of KANA down to 2.3 fM, plus excellent selectivity, and precision even for real food samples. In view of innovative fusion across L-RCA-based DNA hydrogel and SERS technique, the proposed method has promising potential for application in on-site detection and quantification of trace food contaminants.

Effect of Clinical Nursing Pathway Intervention Based on Evidence-Based Medicine on Venous Thrombosis in Long-Term Bedridden Patients.

Background: Venous thrombosis is a type of medical condition that establishes as deep vein thrombosis of the limb or pulmonary embolism. This disease arises as a result of interrelating hereditary, ecological, and interactive risk aspects. Clinical nursing pathways also known as critical pathways are pathways that guide nurses when developing a patient's care plan. However, the effect of nursing intervention on venous thrombosis in long-term bedridden patients from the perspective of evidence-based medicine had not been reported. Methods: A total of 170 patients hospitalized in the hospital from January 2021 to October 2021 were selected, and the bed time was more than 2 weeks. The patients were randomly divided into the control group and observation group. 85 cases in the control group received routine nursing in cardiology, and 85 cases in the observation group received clinical nursing pathway. Venous thrombosis, lower limb pain, swelling, D-dimer level, hemodynamic parameters, and nursing satisfaction were compared in two groups. Results: The incidence of deep venous thrombosis in the observation group was 8.2%, lower than 24.7% in the control group (P < 0.05). The incidence of lower limb pain and elevated D-dimer in the observation group was lower than that in the control group (P < 0.05). The improvement of hemodynamic parameters such as SBP, DBP, CBV, PR, CI, and CO in the study group was better than that in the control group (P < 0.05). The satisfaction of the observation group was 90.58%, which was higher than that of the control group (82.35%) (P < 0.05). Conclusion: Clinical nursing pathway can improve patients' nursing efficiency, improve the treatment effect, shorten hospital stay, and improve nursing satisfaction.

A competitive colorimetric aptasensor for simple and sensitive detection of kanamycin based on terminal deoxynucleotidyl transferase-mediated signal amplification strategy.

We developed a rapid and sensitive colorimetric biosensor based on competitive recognition between kanamycin (KAN), magnetic beads-kanamycin (MBs-KAN) and aptamer and terminal deoxynucleotidyl transferase (TdT)-mediated signal amplification strategy. In the absence of KAN, aptamers recognize MBs-KAN. TdT can amplify oligonucleotides to the 3'-OH ends of aptamers, with biotin-dUTP being embedded in the long single stranded DNA (ssDNA). Then the assay produced visual readout due to the horseradish peroxidase (HRP)-catalyzed color change of the substrate after the linkage between biotin and streptavidin (SA)-HRP. In the presence of KAN, however, aptamers tend to bind free KAN rather than MBs-KAN. In this case, aptamers are isolated by magnetic separation, resulting in the failure of signal amplification and catalytic signals. This competitive colorimetric sensor showed excellent selectivity toward KAN with the limit of detection (LOD) as low as 9 pM. And recovery values were between 93.8 and 107.8% when spiked KAN in milk and honey samples.

Development of pattern recognition based on nanosheet-DNA probes and an extendable DNA library.

Pattern recognition, also called "array sensing," is a recognition strategy with a wide and expandable analysis range, based on high-throughput analysis data. In this work, we constructed a sensor array for the identification of targets including bacterial pathogens and proteins by using FAM-labeled DNA probes and 2D nanosheet materials. We designed an ordered and extendible DNA library for the collection of recognition probes. Unlike traditional DNA probes with random and massive sequences, our DNA library was constructed following a 5-digit binary number (00000-11111, 0 = CCC, and 1 = TTT), and especially, 8 special symmetry sequences were chosen from the library. Two different nanosheet materials were used as the quencher. When targets were added, the interaction between DNA and the nanosheets was competitively affected, and as a result, the fluorescence signal changed accordingly. Finally, by using our fluorescent sensor array, 17 bacteria and 8 proteins were precisely recognized. We believe that our work has provided a simple and valuable strategy for the improvement of the recognition range and discrimination precision for the development of pattern recognition.

A polyA DNA probe-based ultra-sensitive and structure-distinguishable electrochemical biosensor for the analysis of RNAi transgenic maize.

Since the application of RNA interference (RNAi) is rapidly developing in GMO technology, accurate and sensitive detection of functional RNA molecules was urgently needed, for the safety and functional assessment of RNAi crops. In this work, we developed an electrochemical biosensor for transgene-derived long RNA based on a poly-adenine (polyA) DNA capture probe. The polyA self-assembling monolayer (SAM) provided enhanced interface stability and optimized surface density for the subsequent hybridization of the long RNA molecule. A multiple reporter probe system (MRP) containing 12 reporter probes (RPs) and 2 spacers was applied to open the complex molecular secondary structure and hybridize with the long RNA, with the critical assistance of dimethyl sulfoxide (DMSO). By using 3 addressable RPs, structural recognition was performed among long stem-loop RNA, long dsRNA (no loop), and siRNA. Excellent selectivity was achieved when the extracted total RNA samples were directly analyzed. When reverse transcription recombinase polymerase amplification (RT-RPA) technology was combined, the sensitivity was improved to 10 aM. To the best of our knowledge, this is the first electrochemical biosensor with the excellent capability of quantification and structural analysis of the long RNA of the RNAi GMO. Our work shows great potential in a wide range of RNAi GMO samples.

Controllable design of a nano-bio aptasensing interface based on tetrahedral framework nucleic acids in an integrated microfluidic platform.

The limited reaction time and sample volume in the confined space of microfluidic devices give considerable importance to the development of more effective biosensing interfaces. Herein, the self-assembling of tetrahedral framework nucleic acids (FNAs) with controllable size on the interface of the microfluidic microchannels is studied. Compared with macroscopic turbulence control on traditional micro-structured microfluidic surface, the novel FNA-engineered microfluidic interface successfully constructs a 3D reaction space at nanoscale by raising DNA probes away from the surface. This FNA interface dramatically improves the reaction kinetics during molecular recognition due to extremely ordered orientation, configuration and density of DNA probes on the surface. Finally, the FNA-engineered interface is applied in a novel multi-functional microfluidic platform, towards a "one-stop" assay of Escherichia coli O157: H7 (E. coli O157: H7), integrating capture, release, enrichment, cell culture and antimicrobial susceptibility testing (AST). With the FNA-aptamer probe, we achieved an enhanced bacterial detecting efficiency (10 CFU/mL) plus excellent selectivity and precision. The appicability was strongly demonstrated when the biosensor was successfully applied in real samples, including the analysis of antibiotic susceptibility and minimum inhibitory concentration (MIC) of E. coli O157: H7 among different antibiotics. The application of FNA interface will open a wide avenue for the development of microfluidic biosensors for other pathogenic microorganisms or circulating tumor cells (CTC) simply by changing the aptamers.

DNA Framework-Mediated Electrochemical Biosensing Platform for Amplification-Free MicroRNA Analysis.

MicroRNAs (miRNAs) have been explored as biomarkers for early diagnosis of diseases like cancers. However, it remains challenging to detect low-level miRNAs in the total RNA from real samples in a facile approach. In this work, we report a two-phase miRNA biosensing strategy based on a modular framework nucleic acid (FNA) platform, which combines the high efficiency of homogeneous reaction and the convenience of heterogeneous biosensing. In the first phase, free DNA probes bind target miRNAs in a homogeneous solution, forming a DNA-RNA complex with high base stacking energy. Then, at the second phase, the universal FNA interface on the electrode selectively mediated the transition of the complex from the solution onto the interface for electrochemical signal generating and transduction. By applying this method, we detected as few as 1 aM of miR-141, a cancer marker miRNA, without the need for nucleic acid amplification. The dynamic range spans 10 orders of magnitude. We demonstrate multiplex miRNA detection and discrimination of highly homologous miRNAs with mismatches as few as a single base. We also show that this system can detect miR-141 in only 50 ng of total RNA samples from real cells, which allows discrimination of prostate cancer cells with normal cells. We envision this platform may satisfy the need for facile and high-throughput screening of early cancer markers.

Multiplexed aptasensing of food contaminants by using terminal deoxynucleotidyl transferase-produced primer-triggered rolling circle amplification: application to the colorimetric determination of enrofloxacin, lead (II), Escherichia coli O157:H7 and tropomyosin.

A colorimetric assay is described for simultaneous detection of multiple analytes related to food safety. It is based on the use of a sandwich aptasensor and terminal deoxynucleotidyl transferase (TdT) which produces a primer for subsequent rolling circle amplification (RCA). Two split aptamer fragments (Apt1 and Apt2) are firstly immobilized, Apt1 on gold nanoparticles (AuNPs), and Apt2 on magnetic beads (MBs). They are then used in a sandwich aptasensor. In the presence of analyte, two probes could specifically recognize target and form a ternary assembly, and the magnetic beads also act to separate rapidly and enrich the target. Then, the extension of template-free DNA is triggered by TdT at the exposed 3'-hydroxy terminals of Apt1. This produces polyA sequences that serve as primers for subsequent RCA. The product of RCA is hybridized with a complementary horse radish peroxidase (HRP) DNA probe. HRP catalyzes the H2O2-mediated oxidation of tetramethylbenzidine (TMB) and forms a blue chromogenic product. After magnetic separation, the absorption values of the blue product in the supernatant are measured at a wavelength of 600 nm. Based on this dual amplification mechanism, the assay was applied to multiplexed determination of enrofloxacin (ENR), lead(II), Escherichia coli O157:H7 and tropomyosin. Exemplarily, ENR is detectable at concentrations down to 2.5 pg mL-1 with a linear range that extends from 1 pg mL-1 to 1 µg·mL-1. The assay was validated by analysis of spiked fish samples. Recoveries range between 87.5 and 92.1%. Graphical abstractSchematic representation of a TdT-RCA based aptasensor for multiple analytes related to food safety. It makes use of sandwich aptasensors and TdT-produced universal primer-triggered RCA reaction. dATP: deoxyadenosine triphosphate, TdT: Terminal Deoxynucleotidyl Transferase, RCA: rolling circle amplification, TMB: 3,3',5,5'-Tetramethylbenzidine.

Ultrasensitive Electrochemical DNA Biosensor Based on a Label-Free Assembling Strategy Using a Triblock polyA DNA Probe.

Multiblock DNA probe attracted a large amount of scientific attention, for the development of multitarget biosensor and improved specificity/sensitivity. However, the development of multiblock DNA probes highly relied on the chemical synthesis of organic linkers or nanomaterials, which limited their practicability and biological compatibility. In this work, we developed a label-free assembling strategy using a triblock DNA capture probe, which connects two DNA probes with its intrinsic polyA fragment (probe-PolyA-probe, PAP). The middle polyA segment has a high affinity to the gold electrode surface, leading to excellent reproducibility, stability, and regeneration of our biosensor. Two flanking capture probes were tandemly co-assembled on the electrode surface with consistent spatial relationship and exactly the same amount. When combined with the target DNA, the hybridization stability was improved, because of the strong base stacking effect of two capture probes. The sensitivity of our biosensor was proved to be 10 fM, with a wide analysis range between 10 fM to 1 nM. Our PAP-based biosensor showed excellent specificity when facing mismatched DNA sequences. Even single nucleotide polymorphisms can be distinguished by each probe. The excellent practicability of our biosensor was demonstrated by analyzing genomic DNA both with and without PCR amplification.

Graphene-based biosensors for the detection of prostate cancer protein biomarkers: a review.

Prostate cancer (PC) is the sixth most common cancer type in the world, which causes approximately 10% of total cancer fatalities. The detection of protein biomarkers in body fluids is the key topic for the diagnosis and prognosis of PC. Highly sensitive screening of PC is the most effective approach for reducing mortality. Thus, there are a growing number of literature that recognizes the importance of new technologies for early diagnosis of PC. Graphene is playing an important role in the biosensor field with remarkable physical, optical, electrochemical and magnetic properties. Many recent studies demonstrated the potential of graphene materials for sensitive detection of protein biomarkers. In this review, the graphene-based biosensors toward PC analysis are mainly discussed in two groups: Firstly, novel biosensor interfaces were constructed through the modification of graphene materials onto sensor surfaces. Secondly, ingenious signal amplification strategies were developed using graphene materials as catalysts or carriers. Graphene-based biosensors have exhibited remarkable performance with high sensitivities, wide detection ranges, and long-term stabilities.

Ultrasensitive Electrochemical Biosensor of Bacterial 16S rRNA Gene Based on polyA DNA Probes.

Traditional microbiology analysis is usually hindered by the long time-cost and lack of portability in many urgent situations. In this work, we developed a novel electrochemical DNA biosensor (E-biosensor) for sensitive analysis of the 16S rRNA gene of five bacteria, using a consecutive adenine (polyA) probe. The polyA probe consists of a polyA tail and a recognition part. The polyA tail can combine onto the gold surface with improved controllability of the surface density, by conveniently changing the length of polyA. The recognition part of the capture probe together with two biotin-labeled reporter probes hybridize with the target DNA and form a stable DNA-tetramer sandwich structure, and then avidin-HRP enzyme was added to produce a redox current signal for the following electrochemical detection. Finally, we realized sensitive quantification of artificial target DNA with a limit of detection (LOD) of 10 fM, and excellent selectivity and reusability were also demonstrated. Importantly, the detection capability was equally good when facing bacterial genomic DNA, due to the base-stacking force of our multireporter-probe system, which can help to break the second structure and stabilize the probe-target complexes. Our biosensor was constructed on a 16-channel electrode chip without any polymerase chain reaction (PCR) process needed, which took a significant step toward a portable bacteria biosensor.

Fluorometric determination of HIV DNA using molybdenum disulfide nanosheets and exonuclease III-assisted amplification.

A convenient and ultrasensitive fluorometric method is described for the determination of HIV DNA. It exploits the strong difference in the affinities of MoS2 nanosheets for long ssDNA versus short oligonucleotide fragments. In addition, efficient signal amplification is accomplished by exonuclease III-assisted target recycling. When absorbed on the MoS2 nanosheets, the fluorescence of the FAM-labeled ssDNA probe (FP) is quenched. However, in the presence of HIV DNA, the FP hybridizes with target to form a duplex. As a result, the FP in the duplex will be stepwise hydrolyzed into short fragments by Exo III, and the fluorescence signal thus is retained because short fragments have low affinity for the MoS2 nanosheets. By using the Exo III-assisted target recycling amplification, the detection sensitivity is strongly improved. The sensor can detect DNA in a concentration as low as 5.3 pM (at an S/N ratio of 3), and the analytical range extends from 0.01 nM to 10 nM. The assay is simple, sensitive and specific, and conceivably represents a valuable tool in clinical studies related to the HIV. Graphical abstract Schematic presentation of fluorometric determination of HIV DNA based on molybdenum disulfide nanosheets and Exo III. When the fluorescence-tagged ssDNA probe hybridized with target to form a duplex, the Exo III-assisted target recycling amplification is generated. The method can detect as low as 5.3 pM HIV DNA.

Effectiveness of vitamin D for irritable bowel syndrome: A protocol for a systematic review of randomized controlled trial.

BACKGROUND: Irritable bowel syndrome (IBS) is a prevalent and debilitating condition for patients who experience this disorder. Clinical researches indicate that vitamin D (VD) can help relief the symptoms of IBS. However, no systematic review has addressed this issue yet. Thus, this systematic review aims to investigate the effectiveness and safety of VD for patients with IBS. METHODS: We will retrieve the following databases for randomized controlled trials to assess the effectiveness and safety of VD for patients with IBS: Cochrane Library, EMBASE, MEDICINE, Web of Science, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. Each database will be retrieved from its inception to January 31, 2019. Two researchers will independently selection studies, extract data and assess methodological quality. RevMan 5.3 software will be used to pool the data, and carry out the meta-analysis if it is possible. RESULTS: This systematic review will evaluate the effectiveness and safety of VD for patients with IBS. The primary outcomes include stool frequency and abdominal pain. The secondary outcomes consist of stool status, quality of life, and adverse effects. CONCLUSIONS: The findings of this systematic review may provide the existing evidence on the effectiveness and safety of VD for patients with IBS. ETHICS AND DISSEMINATION: This systematic review will not require ethical approval, because all data will be extracted from the published literature. The findings of this study will be disseminated at peer-reviewed journals.PROSPERO registration number: PROSPERO CRD42019122641.