Assessment of Some Secondary Metabolites, Minerals and Alcohol Content of Noni Juice Obtained by Fermentation of Morinda citrifolia L. Fruit from Senegal

The fruit of Morinda citrifolia L., commonly known as noni, has an extensive history of use as a food and traditional medicine around the world. Adding value to Morinda citrifolia L. products, particularly the fruit, could be one way of building resilience in vulnerable farming households. The aim of this study was to determine the secondary metabolite and mineral composition of noni juice obtained by fermenting the fruit of Morinda citrifolia L. Fruits were collected in August 2022 from the local field in Thiès region, West of Senegal. Extraction yields were determined and the secondary metabolites were determined using conventional analytical methods. Calcium, magnesium, iron, sodium and potassium were determined by atomic absorption spectrophotometer coupled with a CCD detector. The results show that an average fruit mass (503.2 ± 110.96 g) consists of 171.44 ± 50.01 g pulp and 34.06 ± 10.35 g seeds. The traditional extraction yield of noni juice is 16.46% after three weeks of fermentation. The contents of total polyphenols, flavonoids and tannins obtained in noni are 608.97 ± 4.53 mg EAG/100mL, 7.78 ± 0.01 mg EQ/100mL and 0.191 ± 0.01 mg EC/100mL respectively. The ethanol content of noni varies from 3.57 to 5.23 mL/100mL during extraction. Noni has a high calcium content with a concentration of 383.79 ± 33.23 mg/L. This is followed by a good concentration of magnesium, potassium and sodium, at 278.47 ± 26.30, 187.43 ± 10.7 and 155.95 ± 28.66 mg/L respectively. Noni also has an iron content of 202.15 ± 0.05 mg/L.

Enzymatic Characterization of Pectinex XXL,a Pectinase Produced by Aspergillus niger,and Its Application in Fruit Juice Production

Pectinex XXL,a commercially prepared pectinase,was investigated for its potential application in the fruit juice industry.Polygalacturonic acid was used as the substrate for determining the enzymatic properties of Pectinex XXL using the DNS method.According to the results,the optimal pH for Pectinex XXL activity was 4.5,and the enzyme was stable in the pH range of 3.0~4.5.The optimal pH and pH stability range are consistent with those of some tropical and subtropical fruits.The optimal temperature for Pectinex XXL activity was 60℃,and the enzyme remained stable after one hour in a water bath set at 40℃.Additionally,the enzymatic activity was not inhibited in the presence of 1 mmol/L of Na^(+),Mg^(2+),Ba^(2+),Co^(2+),Zn^(2+),and Fe^(2+),whereas it was slightly inhibited in the presence of 2 mmol/L of K^(+)and Fe^(2+)and partially inhibited in the presence of 1 and 2 mmol/L of Ca^(2+)and Mn^(2+),demonstrating its good stability in acids and excellent thermal catalytic performance.Based on the above experimental results,depectinization experiments were performed on plantain and cherry tomato juices using different amounts of Pectinex XXL.After one hour reaction with 16 U/mL of the enzyme,the yields of the plantain and cherry tomato juices were substantially increased by 119.03%and 15.97%,respectively,while their light transmittance was remarkably enhanced by 37.65%and 12.35%,respectively.Furthermore,the enzyme reduced the viscosity of the plantain and cherry tomato juices by 88.29%and 29.50%,respectively.The juice production experiments confirmed that this enzyme can significantly improve the yield and light transmittance of plantain juice,while effectively reducing its viscosity.These findings indicate the potential of Pectinex XXL in the industrial production of plantain juice.

Health effects of fruit juices and beverages with varying degrees of processing

The degree of processing is rarely considered an independent factor in the health effects of fruit juices and beverages(FJBs)consumption.In fact,the consumption of ultra-processed foods has been shown to pose health risks.In this study,we first integrated 4 systems used to classify the degree of food processing and then classified FJBs into three major categories,low(minimal),moderate and high.Second,we compared the differences in attitudes towards FJBs in dietary guidelines.Third,we integrated the results of existing epidemiological surveys,randomized controlled trials,and animal experiments to explore the health risks associated with consuming FJBs.Deepening the processing of FJBs has been found to lead to an increased risk of diseases.Dietary pattern,nutrients,addition agents and consumer preferences may be influential factors.Finally,we investigated whether there were any changes in the health benefits of 100%fruit juices produced by different processing methods.In conclusion,minimally/moderately processed 100%fruit juices provide more health benefits than highly processed fruit beverages.The results support the need to consider the extent of FJBs processing in future studies to adjust official nutritional recommendations for beverage consumption.

Study on Compound Stabilizer Formulation for Mango Juice with Skin

[Objectives]The effects of stabilizers such as sodium carboxymethyl cellulose,pectin,sodium alginate and xanthan gum on the stability of mango juice with skin were discussed using mango as the raw material.[Methods]The formula and stability of mango beverage with skin were studied using mango juice with skin as the raw material.Four stabilizers,including pectin,sodium alginate and sodium carboxymethyl cellulose,were added to improve the stability of the juice.Based on single factor experiments and a response surface experiment,the stability model of mango juice was established to determine the best compound stabilizer.[Results]According to an orthogonal experiment on the stability of mango juice with skin,the optimum technical parameters were as follows:sodium carboxymethyl cellulose 0.20%,xanthan gum 0.08%,sodium alginate 0.18%,and pectin 0.14%,with which the optimal suspension stability was 69.12%.The optimum technical parameters from the response surface experiment were as follows:sodium carboxymethyl cellulose 0.199%,pectin 0.1185%,sodium alginate 0.163%,and xanthan gum 0.077%,with which the suspension stability was 70.32%.It was found that the stability of mango juice with skin obtained by the response surface experiment was better than that by the orthogonal experiment,and the order of factors affecting the stability of mango was sodium alginate(C)>sodium carboxymethyl cellulose(A)>pectin(D)>xanthan gum(B).[Conclusions]The formula of compound stabilizer for mango juice was optimized by the orthogonal experiment and the response surface method,providing a theoretical basis for the actual production of mango juice with skin.

Simultaneous Determination of Four Pesticide Residues in Fruit Juice by HPLC

[Objective] This study was conducted to develop a system for simultaneous determination of imidacloprid, diflubenzuron, thiabendazole and carbendazim in fruit juice by HPLC. [Method] Using acetonitrile as the extraction solvent, the pesticides in fruit juice were purified through a NH2 solid phase extraction （SPE） cartridge, then detected by HPLC. [Result] There was a good linear relationship between the peak area and the concentrations of imidacloprid, diflubenzuron, thiabendazole and carbendazim in a range of 0.05-5.0 μg/ml, and the linear correlation coefficient varied in a range of 0.999 0-0.999 8; the limit of detection for imidacloprid, diflubenzuron, thiabendazole and carbendazim was 0.003, 0.005, 0.003 and 0.007 mg/kg, respectively. The recovery rate of imidacloprid, diflubenzuron, thiabendazole and carbendazim standards added at three levels （0.1, 0.5 and 1.0 mg/kg） ranged from 82% to 107%, with RSD less than 4.5%. [Conclusion] The sensitivity, accuracy and precision of this method were able to meet the requirements for pesticide residue analysis.

Study on Processing of Clear Banana Juice Using Hot Water Extraction Method

In this study, the effects of hot water temperature on clarity, total soluble solids, polyphenol oxidase （PPO） and color of banana juice during hot water ex-traction were discussed based on the theory in which heat treatment might induce the pectin and protein in banana pulp to form insoluble products. The results showed the hot water temperature had a significant effect on the formation of insol-uble polymers in banana pulp from pectin and protein. In 75 ℃ water, the pectin and protein in banana pulp were most inclined to form insoluble products. Under this condition, the clarity of banana juice was also highest. The light transmittance at 660 nm was close to 90%. In the banana juice, extracted by 75 ℃ water, the pectin and protein contents were lowest, and they were lower than 7.3 mg/100 ml and 12.9 mg/100 ml respectively. The 75 ℃ water could not inactivate completely the pectin in banana pulp due to its high heat resistance, Therefore, 0.05% L-cys-teine or ascorbic acid needed to be added into banana pulp to inhibit the browning of juice induced by residual PPO.

Role of pomegranate and citrus fruit juices in colon cancer prevention

Colorectal cancer is the second leading cause of cancer-related deaths in the United States.Recent studies prove that though chemotherapeutic agents are being used for the treatment of colon cancer,they become non-effective when the cancer progresses to an invasive stage.Since consumption of certain dietary agents has been linked with various cancers,fruit juices have been investigated for their consistently protective effect against colon cancer.The unique biochemical composition of fruit juices is responsible for their anticancer properties.In this review,the chemo-preventive effect of fruit juices such as pomegranate and citrus juices against colon cancer are discussed.For this purpose,the bioavailability,in vitro and in vivo effects of these fruit juices on colorectal cancer are highlighted.Moreover,there is a scarcity of studies involving human trials to estimate the preventive nature of these juices against colon cancer.This review will support the need for more preclinical tests with these crude juices and their constituents in different colorectal cancer cell lines and also some epidemiological studies in order to have a better understanding and promote pomegranate and citrus juices as crusaders against colon cancer.

Gastric juice acidity in upper gastrointestinal diseases

AIM: To search the independent factors determining gastric juice acidity and to investigate the acidity of gastric juices in various benign and malignant upper gastrointestinal diseases. METHODS: Fasting gastric juice acidity of 165 healthysubjects and 346 patients with esophageal ulcer (n = 21), gastric ulcer (n = 136), duodenal ulcer (n = 100) or gastric cancer (n = 89) were measured and compared. Additionally, gastric specimens were taken from the antrum and body for rapid urease test and histological examination. RESULTS: Multivariate analysis revealed that bile stain of gastric juice, high acute inflammatory score of the corpus, and atrophy of the corpus were independent risk factors for the development of gastric hypoacidity with odds ratios of 3.1 (95% CI: 1.3-7.3), 3.1 (95% CI: 1.2-7.9) and 3.5 (95% CI: 1.3-9.2). Esophageal ulcer and duodenal ulcer patients had a lower pH level (1.9 and 2.1 vs 2.9, both P < 0.05) of gastric juices than healthy subjects. In contrast, gastric ulcer and gastric cancer patients had a higher pH level (3.4 and 6.6 vs 2.9, both P < 0.001) than healthy controls. Hypoacidity existed in 22%, 5%, 29%, 5% and 88% of healthy subjects, esophageal ulcer, gastric ulcer, duodenal ulcer and gastric cancer patients, respectively. CONCLUSION: Bile reflux, atrophy and dense neutrophil infiltrate of the corpus are three independent factors determining the acidity of gastric juice.

Chemical composition, antioxidant activity and GC-MS analysis of juice and peel oil of grapefruit varieties cultivated in India

Citrus family especially Grapefruit,has attained considerable attention due to the presence of a number of essential components that have cardiovascular and anti-hypertensive properties.The juice and essential oil extracted from eight recently released grapefruit cultivars were used to study physicochemical and antioxidant properties.The total soluble solids(TSS),titratable acidity(TA) and pH of juice samples extracted from various grapefruit varieties differed significantly.The refractive index,specific gravity and optical rotation values for the oil varied from 1.473 to 1.396,0.863 to 0.847 and +93 to +86,respectively.The percent 2,2-diphenyl-1-picrylhydrazyl radical activity(% DPPH activity) and ferric reducing antioxidant power(FRAP) values for grapefruit juice and peel oil varied from 24.06 to 18.79,2.91 to 1.44 mmol g^–1 and 84.87 to 74.73,7.76 to 5.73 mmol g^-1,respectively.There were significant differences in physicochemical,antioxidant properties and volatile profiles of extracted juice and oil.The oil exhibited higher DPPH and FRAP values than the juice.Among different components identified which accounted for over 99% of the volatile fraction,limonene,myrcene,and benzopyran were major components in all oil samples.

Detection of k-ras gene point mutation in fine needle aspiration and pancreatic juice by sequence special primer method and its clinical significance

INTRODUCTIONThe point mutation rate of k-ras gene at codon 12 inpancreatic adenocarcinoma is reported to be as highas 90%,and with no mutations in normalpancreas tissues or other pancreatic disorders.Wehave detected the presence of k-ras gene

Extraction and Characterization of Antioxidant Compositions From Fermented Fruit Juice of Morinda citrifolia (Noni)

Extraction and characterization of antioxidative compositions from the extracts of fermented Xisha Noni （Morinda citrifolia L.） juice were studied. The antioxidative constituents of 184.6 g freeze-dried extracts of naturally fermented Xisha Noni juice were isolated successfully by petroleum ether, EtOAc and n-BuOH solvents, and the antioxidative effects were measured according to scavenging activity against hydroxyl generated in Fenton reaction system and superoxide anion radicals in pyrogallol autoxidation system. The EtOAc extract exhibited most significantly higher （P 〈 0.01） antioxidative activity than mannitol or vitamin C, while the petroleum ether and n-BuOH extracts showed lower activities compared to mannitol. Three antioxidant phenolic compounds, isoscopoletin, aesculetin and 3,3＇,4＇,5,7-pentahydroxyflavone （quercetin） were isolated from the EtOAc extract by several chromatography techniques for the first time. The results suggest that several compounds, in particular, the phenolic compounds, contribute separately or synergistically to the antioxidative activity of fermented Noni fruit juice.

Synthesis of highly fluorescent carbon dots from lemon and onion juices for determination of riboflavin in multivitamin/mineral supplements

In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (CDs). The structure and optical properties of CDs were investigated by TEM, XRD, XRF, UV-Vis, FTIR, and fluorescence spectroscopy. CDs displayed satisfactory optical pro-prieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the CDs and riboflavin was achieved with CDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 μg/mL was observed, allowing the development of an accurate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, CDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and <2.6% (n = 3), respectively. CDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of CDs and determination of riboflavin.

Thermal Degradation Kinetics of Anthocyanins and Visual Color of Blood Orange Juice

Thermal degradation kinetics of anthocyanins and visual color （Hunter α value） of blood orange juice were studied at selected temperatures （70-90℃）. Results indicated that both the thermal degradation of anthocyanin and visual color all followed first-order reaction kinetics, and they could be expressed by Arrhenius equation. The activation energy values for the anthocyanins degradation and visual color degradation were 55.81 and 47.51 kJ tool-1, respectively. The linear relationship between visual color and anthocyanin content was obtained. Furthermore, during thermal processing of blood orange juice, the formulas about the linear relationships showed no significant difference at selected temperatures. So, the relationships between visual color and anthocyanins content during thermal processing at selected temperatures could be described by the same equation： α＊/αo＇=0.559（C/Co）＋0.43. It might be inferred that visual color measured instantaneously by tristimulus colorimeters for on-line quality control, could be used to predict the anthocyanins degradation during thermal processing of blood orange juice.

A novel aeration strategy in repeated-batch fermentation for efficient ethanol production from sweet sorghum juice

To improve the efficiency of ethanol production in a batch fermentation from sweet sorghum juice under a very high gravity(VHG)condition(~290 g/L of total sugar)by Saccharomyces cerevisiae NP01,repeatedbatch fermentation under an aerated condition(2.5 vvm for the first 4 h during every cycle)was done in a5-L fermenter.The average ethanol concentration(P),productivity(Qp)and yield(Yp/s)for five successive cycles were 112.31 g/L,1.55 g/L·h^-1 and 0.44,respectively with 80.97%sugar consumption.To complete sugar consumption,the total sugar of the juice was reduced to a high gravity(HG)level(~240 g/L).The results showed that yeast extract was not necessary for ethanol production,and aeration during every other cycle i.e.,alternating cycles,was sufficient to promote both yeast growth and ethanol production.The average P,Qpand Yp/svalues for eight successive cycles with aeration during alternating cycles were97.58 g/L,1.98 g/Láh and 0.41,respectively with 91.21%sugar consumption.The total fatty acids in the yeast cells under the aerated condition were^50%higher than without aeration,irrespective the initial sugar concentration,whereas the ergosterol contents under aeration condition were^29%to 49%higher than those without aeration.

Effects of Temperature and pH on the Physiological Activity of Grape Juice

This study was conducted to investigate the effects of temperature and pH on polyphenol and flavonoid contents in grape juice and its antioxidant activity. Two groups(group A and group B) were set. Group A was set with different pH values: 3.0, 3.5, 4.0, 4.5 and 5.0; and group B was set with different temperatures: 65, 72, 79, 86 and 93 ℃. The grape juice was treated according to set methods, and two groups of samples were obtained. The contents of polyphenols and flavonoids in each test solution were determined, and the DPPH·free radical system and trivalent Fe reduction system were established to measure and compare the antioxidant activity of groups A and B. The results showed that within the set ranges, the effects of pH and temperature on the content of flavonoids in grape juice were not significant; the test solution with a pH of 4.5 and the test solution with a temperature at 72 ℃ had the strongest capacities of scavenging free radicals, and exhibited scavenging rates of 6.82% and 9.43%, respectively; the test solution with a pH of 4.5 and the test solution with a temperature at 65 ℃ had the strongest capacities of reducing ferric ions. It could be seen from the above four aspects comprehensively, within the set test ranges, the suitable pH was 4.5, and the suitable temperature was 65 ℃.

Potential prognostic biomarkers in pancreatic juice of resectable pancreatic ductal adenocarcinoma

Despite potentially curative surgery pancreatic cancer has a dismal prognosis.Serum cancer antigen 19-9(CA 19-9) correlates with tumor burden,resectability and survival in patients with pancreatic ductal adenocarcinoma.Identification of novel biomarkers may facilitate early diagnosis of pancreatic cancer and improve survival.Pancreatic juice is a rich source of cancer-specific proteins rendering it a promising tool for identifying biomarkers.Recent proteomic and micro RNA expression analyses have identified several biomarkers of potential diagnostic and prognostic value.Tumor markers CA 19-9 and carcinoembryonic antigen(CEA) are widely used in the characterization of premalignant and malignant lesions of the pancreas.Elevated level of CEA in bile is a marker for malignancy and a predictor of hepatic recurrence.The potential value of CA 19-9,CEA and lactate dehydrogenase as prognostic biomarkers in pancreatic juice and bile is unknown.Specimens of pancreatic juice and bile can be readily collected during surgical resection of the tumor.Profiling of pancreatic juice and bile to identify novel prognostic biomarkers may improve selection of patients for adjuvant therapy with a favorable impact on overall survival in patients diagnosed with pancreatic cancer.

Effects of tomato juice on the pharmacokinetics of CYP3A4-substrate drugs

We previously demonstrated that tomato juice(TJ) contains potent mechanism-based inhibitor(s) of CYP3A4. In this study, we investigated the effects of TJ and grapefruit juice(GFJ)on the pharmacokinetics of the CYP3A4-substrate drugs, nifedipine(NFP) and midazolam(MDZ), in male Wistar rats. Oral administration of GFJ 90 min before the intraduodenal administration of NFP or MDZ increased the area under the concentration–time curves(AUCs)of NFP and MDZ by 32.4% and 89.4%, respectively. TJ increased MDZ blood concentrations and AUC after intraduodenal MDZ administration;however, it had no effect on NFP. When MDZ and NFP were intravenously administered, GFJ significantly increased the AUC of MDZ,but only slightly increased that of NFP. In contrast, TJ only slightly increased the AUC of MDZ.These results suggest that, similar to GFJ, TJ influences the pharmacokinetics of CYP3A4-substrate drugs;however, it may be a drug-dependent partial effect.

Production, Quality Evaluation and Sensory Acceptability of Mixed Fruit Juice from Pawpaw and Lime

Pawpaw and lime juices were blended to produce mixed pawpaw/lime juice samples in the ratios of 90:10, 80:20, 70:30, 60:40 and 50:50) v/v giving samples A, B, C, D and E respectively. The moisture, mineral and vitamin contents, as well as the physical, microbiological and sensory qualities of the individual juices and blended samples were evaluated. While lime juice had higher moisture, calcium and vitamin C with values of 97.90%, 2.21 mg/100 g and 67.47 mg/100 g as compared to pawpaw juice with 92.96%, 1.53 mg/100 g and 35.49 mg/100 g respectively;the pawpaw juice had higher ash, phosphorus and vitamin A contents, with values of 3.12%, 54.97 mg/100 g and 5.90 IU/100 g as against 2.84%, 29.53% and 0.16% for lime juice respectively. While there was a general increase in moisture, calcium and vitamin C contents with blending, ash, phosphorus and vitamin A contents increased with increase in lime. The total solids content and specific gravity of pawpaw juice were remarkably higher at 7.04% and 1.15 g/m3 compared to 2.09% and 1.09 g/m3 respectively for lime juice. However, lime juice had a higher titratable acidity, while recording a lower pH of 2.89 as compared to 5.36 for pawpaw juice. The Total Viable Count (TVC) of lime juice was much lower (2.33 × 105 CFU/ml) than that of pawpaw juice (5.33 × 106 CFU/ml). There was significant difference (p < 0.05) in all the sensory parameters evaluated. Generally, there was an increase in the scores of each parameter from sample A to B and then a decline through to sample E. Sample B (80:20) mixed pawpaw/lime juice was most preferred, while sample E (50:50) was least preferred.

Study on chronic pancreatitis and pancreatic cancer using MRS and pancreatic juice samples

AIM:To investigate the markers of pancreatic diseases and provide basic data and experimental methods for the diagnosis of pancreatic diseases.METHODS:There were 15 patients in the present study,among whom 10 had pancreatic cancer and 5,chronic pancreatitis.In all patients,pancreatic cancer or chronic pancreatitis was located on the head of the p-a-ncrea-s.Pa-thology da-ta-of a-ll p-a-tients wa-s confirmed by biopsy and surgery.Among the 10 patients with pancreatic cancer,3 people had a medical history of longterm alcohol consumption.Of 5 patients with chronic pancreatitis,4 men suffered from alcoholic chronic pancreatitis.Pancreatic juice samples were obtained from patients by endoscopic retrograde cholangiopancreatography.Magnetic resonance spectroscopyn was performed on an 11.7-T scanner (Bruker DRX-500) using Call-Purcell-Meiboom-Gill pulse sequences.The parameters were as follows:spectral width,15 KHz;time domain,64 K;number of scans,512;and acquisition time,2.128 s.RESULTS:The main component of pancreatic juice included leucine,iso-leucine,valine,lactate,alanine,acetate,aspartate,lysine,glycine,threonine,tyrosine,histidine,tryptophan,and phenylalanine.On performing 1D 1H and 2D total correlation spectroscopy,we found a triplet peak at the chemical shift of 1.19 ppm,which only appeared in the spectra of pancreatic juice obtained from patients with alcoholic chronic pancreatitis.This triplet peak was considered the resonance of the methyl of ethoxy group,which may be associated with the metabolism of alcohol in the pancreas.CONCLUSION:The triplet peak,at the chemical shift of 1.19 ppm is likely to be the characteristic metabolite of alcoholic chronic pancreatitis.

Microbiome changes in the gastric mucosa and gastric juice in different histological stages of Helicobacter pylori-negative gastric cancers

BACKGROUND The gastric microbiota in patients with gastric cancer(GC)has received increasing attention,but the profiling of the gastric microbiome through the histological stages of gastric tumorigenesis remains poorly understood,especially for patients with Helicobacter pylori-negative GC(HPNGC).AIM To characterize microbial profiles of gastric mucosa and juice for HPNGC carcinogenesis and identify distinct taxa in precancerous lesions.METHODS The 16S rRNA gene analysis was performed on gastric mucosa from 134 Helicobacter pylori-negative cases,including 56 superficial gastritis(SG),9 atrophic gastritis(AG),27 intestinal metaplasia(IM),29 dysplasia(Dys),and 13 GC cases,to investigate differences in gastric microbial diversity and composition across the disease stages.In addition,paired gastric mucosa and juice samples from 18 SG,18 IM,and 18 Dys samples were analyzed.α-Diversity was measured by Shannon and Chao1 indexes,andβ-diversity was calculated using partial least squares discrimination analysis(PLS-DA).Differences in the microbial composition across disease stages in different sample types were assessed using the linear discriminant analysis effect size.RESULTS The diversity and composition of the bacterial microbiota in the gastric mucosa changed progressively across stages of gastric carcinogenesis.The diversity of the gastric mucosa microbiota was found to be significantly lower in the IM and Dys groups than in the SG group,and the patients with GC had the lowest bacterial community richness(P<0.05).Patients with IM and those with Dys had similar gastric mucosa microbiota profiles with Ralstonia and Rhodococcus as the predominant genera.Microbial network analysis showed that there was increasing correlation strength between IM and Dys(|correlation threshold|≥0.5,P<0.05).GC and its precancerous lesions have distinguishable bacterial taxa;our results identified HPNGC-associated bacteria Streptococcaceae and Lactobacillaceae(P<0.05).Additionally,across precancerous lesion stages from AG to Dys in Helicobacter pylori-negative patients,Burkholderiaceae abundance continuously increased,while Streptococcaceae and Prevotellaceae abundance presented a continuous downward trend.Furthermore,the microbial diversity was higher in gastric juice(P<0.001)than in the mucosa,while PLS-DA revealed a statistically significant difference between the two groups(ANOSIM,P=0.001).A significant difference in the microbial structure was identified,with Proteobacteria being more prevalent in the gastric mucosa and Firmicutes being more abundant in gastric juice.CONCLUSION Our results provide insights into potential taxonomic biomarkers for HPNGC and its precancerous stages and assist in predicting the prognosis of IM and Dys based on the mucosal microbiota profile.