Low molecular weight chitooligosaccharide inhibits infection of SARS-CoV-2 in vitro.

AIMS: The discovery of antiviral substances to respond to COVID-19 is a global issue, including the field of drug development based on natural materials. Here, we showed that chitosan-based substances have natural antiviral properties against SARS-CoV-2 in vitro. METHODS AND RESULTS: The molecular weight of chitosan-based substances was measured by the gel permeation chromatography analysis. In MTT assay, the chitosan-based substances have low cytotoxicity to Vero cells. The antiviral effect of these substances was confirmed by quantitative viral RNA targeting the RdRp and E genes and plaque assay. Among the substances tested, low molecular weight chitooligosaccharide decreased the fluorescence intensity of SARS-CoV-2 nucleocapsid protein of the virus-infected cells in a dose-dependent manner. CONCLUSIONS: In conclusion, the chitooligosaccharide, a candidate for natural treatment, has antiviral effects against the SARS-CoV-2 virus in vitro. SIGNIFICANCE AND IMPACT OF STUDY: In this study, it was suggested for the first time that chitosan-based substances such as chitooligosaccharide can have an antiviral effect on SARS-CoV-2 in vitro.

The Korean Medication Algorithm Project for Bipolar Disorder (KMAP-BP): Changes in preferred treatment strategies and medications over 16 years and five editions.

OBJECTIVES: The Korean Medication Algorithm Project for Bipolar Disorder (KMAP-BP) is based on expert consensus and has been revised five times since 2002. This study evaluated the changes in treatment strategies advocated by the KMAP-BP over time. METHODS: The five editions of the KMAP-BP were reviewed, and the recommendations of the KMAP-BP were compared with those of other bipolar disorder (BP) treatment guidelines. RESULTS: The most preferred option for the initial treatment of mania was a combination of a mood stabilizer (MS) and an atypical antipsychotic (AAP). Either MS or AAP monotherapy was also considered a first-line strategy for mania, but not for all types of episodes, including mixed/psychotic mania. In general, although lithium and valproic acid were commonly recommended, valproic acid has been increasingly preferred for all phases of BP. The most notable changes over time included the increasing preference for AAPs for all phases of BP, and lamotrigine for the depressive and maintenance phases. The use of antidepressants for BP has gradually decreased, but still represents a first-line option for severe and psychotic depression. CONCLUSIONS: In general, the recommended strategies of the KMAP-BP were similar to those of other guidelines, but differed in terms of the emphasis on rapid effectiveness, which is often desirable in actual clinical situations. The major limitation of the KMAP-BP is that it is a consensus-based rather than an evidence-based tool. Nevertheless, it may confer advantages in actual clinical practice.

Gender and age differences in the association between work stress and incident depressive symptoms among Korean employees: a cohort study.

PURPOSE: The aim of this study was to identify gender- and age-specific occupational stress associated with depressive symptoms among Korean employees. METHODS: Data of 73,014 employees aged 18 and above who had undergone comprehensive health examinations at Kangbuk Samsung Hospital Health Screening Center, South Korea, in January 2012 and who were followed up until December 2017 were collected, and 63,959 (participation rate: 87.59%, men: 50,413, women: 13,546) were finally analyzed. A Cox proportional hazards model was used to estimate the hazard ratios and 95% confidence intervals of the relationship between occupational stress and depressive symptoms. In light of gender and age differences in the association between occupational stress and depressive symptoms, interaction and stratification by gender and age groups were tested. RESULTS: During 238,630 person-years of follow-up, case-level depressive symptoms developed in 4227 participants (an incident rate of 1.8%). There were gender differences in the relationship between job stress and incident depressive symptoms. For men, high job demand, job insecurity, lack of reward, and discomfort in their organizational climate were associated with incident depressive symptoms in all age groups. Insufficient job control was associated with the development of depressive symptoms only in midlife and organizational injustice only in early adulthood. For women, the results for high job demand, organizational injustice, and discomfort in an organizational climate were associated with the onset of depressive symptoms from early adulthood to the midlife decade. CONCLUSION: The results suggest gender and age differences in the relationship between occupational stress and incident depressive symptoms.

Brazing Characteristics and Bonding Strength of Pure Titanium Joints Brazed with Low-Melting Temperature Zi-17Ti-22Ni Filler Metal.

The brazing characteristics and bonding strengths of pure titanium joints are evaluated for joints brazed with Zr-17Ti-22Ni filler. Vacuum brazing was conducted at temperatures between the melting temperatures of the filler metals and the beta-transition temperature of pure titanium at 3 MPa of pressure for 5 min. Fracturing of the pure titanium joint brazed at 1,093 K occurred before yielding during the tensile tests owing to the presence of a serious segregation region containing harder and more brittle [Ti, Zr]2Ni intermetallic compounds. In contrast, in pure titanium joints brazed at and above 1,113 K, fracturing occurred at the base metal. The yield strengths of the samples brazed at 1,113 K-1,133 K were estimated to be in the range of 320-350 MPa and the ultimate tensile strengths likewise ranged from 350 to 380 MPa. The strength of pure titanium brazed at 1,153 K decreased rapidly. The results of this study show that the optimum temperature to ensure good performance after the brazing of pure titanium with Zr-17Ti-22Ni as a filler metal ranges from 1,113 K to 1,133 K.

Evaluation of the Hot Workability of Commercially Pure Ti Using Hot Torsion Tests.

Optimum processing conditions were obtained by evaluating the hot working behavior of commercially pure Ti using hot torsion tests. Hot torsion tests were conducted at temperatures ranging from 800 °C-1000 °C and strain rates ranging from 0.1-10 s-1. The flow curves show that the peak stress increases as the temperature decreases and the strain rate increases. The optimum processing conditions were derived by comparing the processing and activation energy maps. The microstructure was characterized based on various regions of the processing map. The activation energy for plastic deformation was obtained using the constitutive equation. The activation energy differs depending on the constituent phases.

Microstructural and Mechanical Characteristics of A356 Alloys as a Function of Mn Content and Cast Thickness.

In this study, the changes in the microstructural characteristics and mechanical properties of A356 alloys as a function of Mn content and cast thickness were evaluated using structural analysis and tensile tests. Five different A356+x%Mn alloys were prepared by casting in molds of different thicknesses followed by solid solution treatment at 813 K for 195 min and aging treatment at 423 K for 120 min. It was confirmed that the secondary dendrite arm spacing (SDAS) increased with increasing thickness of the cast sample, whilst, for a given thickness, the addition of small amounts of Mn resulted in a decrease of the SDAS. Mn contents of 0.05-0.15% resulted in ~7-9% improvements in the spheroid ratio of the primary Si particles compared to that of the commercial A356 alloy. Further, the spheroid ratio of the primary Si particles obtained in the thin cast samples were higher than that obtained in the thick cast samples. In particular, the addition of small amounts of Mn was also effective in suppressing the formation of the needle-like beta Al-Fe-Si intermetallic compound. The yield and tensile strengths of the thinner cast samples were higher than those of the thicker cast samples. Finally, Mn contents of 0.05-0.15% resulted in enhanced yield and tensile strengths, but Mn content ≥0.1% resulted in decreased elongation.

Resilience as a Protective Factor for Depressive Mood and Anxiety among Korean Employees.

BACKGROUND: This study aimed to investigate resilience as a protective factor for depressive mood and anxiety among Korean employees. METHODS: Participants were employees of eight private and local government organizations in Korea, aged 19 to 65 years. A self-report questionnaire that included items on resilience, job stress, levels of depression and anxiety, and socio-demographic factors, was administered to 1,079 Korean employees, with 1,076 valid responses. We performed hierarchical linear regression analyses with the levels of depression and anxiety scores as dependent variables. RESULTS: Being women and having a high level of job stress were associated with greater depressive mood and anxiety. In contrast, resilience was negatively related to depressive mood and anxiety, after adjusting for demographic variables and the level of job stress. Among the five factors for resilience, "support" and "hardiness" were protective factors for depressive mood and anxiety after adjusting for demographic variables and the level of job stress. CONCLUSION: Based on the results of the current study, we suggest that focusing on the resilience of employees, especially on "support" and "hardiness," factors as well as developing and engaging in interventions that increase resilience in the workplace, can protect against depressive mood and anxiety, especially for those with high levels of job stress.

Impaired facial expression recognition in patients with social anxiety disorder: a case-control study.

INTRODUCTION: The aim of this study was to investigate whether social anxiety disorder (SAD) patients have low emotion recognition accuracy, take longer for emotion recognition and tended to interpret a stimulus more negatively than controls. METHODS: Fifty-six SAD patients and 56 healthy controls were participated in this study. We evaluated facial emotion recognition using a computer program in which participants chose one of seven emotions as displayed in each of 55 photographs of faces. We compared the accuracy and reaction times of the patients and controls. We further analysed which emotions were selected in the incorrect answers. RESULTS: SAD patients showed delayed reaction times for all emotions except anger and lower accuracy for fear, surprise, neutrality and happiness compared to controls. After applying Bonferroni correction, only delayed reaction time for surprise and happiness were remain significant. Neutrality was not mistaken for a negative emotion at a higher rate by SAD patients than by controls. CONCLUSION: This result suggests that the alterations of reaction time and accuracy of emotion recognition of SAD patients, especially in emotions with positive valence, play a more important role than negative bias in the cognitive aspects of SAD.

Binge eating is associated with trait anxiety in Korean adolescent girls: a cross sectional study.

BACKGROUND: Binge eating occurs more frequently in women than in men, and is known to be related to psychological factors such as stress, depression, and anxiety. This study examined the relationship between binge eating and depression, trait anxiety, and perceived stress in Korean adolescents. METHODS: Four hundred girls (aged 17-18 years) from two high schools located in Seoul completed self-report questionnaires. In total, 327 participants returned reliable responses, and were included in the final study. Binge eating was measured using the Bulimic Inventory Test Edinburgh. The questionnaire also included the Perceived Stress Scale (PSS), Trait Anxiety (TA) of State-Trait Anxiety Inventory, Anxiety Sensitivity Inventory (ASI), and Beck Depression Inventory (BDI). RESULTS: The binge-eating group had higher BMI than the control group. The binge-eating group showed higher scores than control on the PSS, BDI, ASI, and TA. The TA was most highly correlated with binge eating. From logistic regression analysis, TA was revealed to be the only factor that raised the risk of binge eating, whereas PSS, BDI, and ASI showed no statistical significance. CONCLUSION: Although binge eating was correlated with perceived stress, depression, and trait anxiety, when their influences were controlled, only binge eating appeared to be associated with trait anxiety.

What Kind of Stress Is Associated with Depression, Anxiety and Suicidal Ideation in Korean Employees?

Various types of stress affect mental health in the form of mood disorders, anxiety disorders, and suicidal ideation. Recently, the increasing suicide rate in the working-age population has become a major mental health concern in Korea. Thus, we investigated what kind of stress influence depression, anxiety, and suicidal ideation in Korean employees. The study participants were 189,965 employees who attended health screenings and responded to the Center for Epidemiologic Study-Depression Scale, the Beck Anxiety Inventory, and a questionnaire on the major causes of stress and suicidal ideation. We investigated the major causes of stress by gender and age categories and used binary logistic regression to determine the impact of the causes of stress on depression, anxiety and suicidal ideation. Of several stress causes, work-related stress was the most prevalent, regardless of age category and gender, followed by interpersonal relationships. However, interpersonal relationships and financial problems were the predominant causes of stress related to depression or suicidal ideation. This research suggests that despite the fact that work is the most common cause of stress for Korean employees, stress related to life problems other than work has a greater influence on the mental health of Korean employees.

Treatment modalities for patients with gambling disorder.

BACKGROUND: Gambling disorder (GD) is defined as persistent and recurrent problematic gambling behavior leading to clinically significant impairment or distress. The prevalence of GD has been shown to be 1.2-7.1% in the general population. GD can severely impact on personal and vocational wellbeing as well as lead to financial problems, and has been known to be difficult to treat. This review describes the available pharmacotherapy/psychosocial treatments for GD patients, and summarizes data on the effectiveness of these GD treatments. METHODS: This review refers to newly as well as previously published studies and guidelines. RESULTS: The description of pharmacotherapy mainly focuses on opioid receptor antagonists, selective serotonin reuptake inhibitors, and mood stabilizers. Psychosocial treatments/strategies mainly include cognitive behavioral therapy, motivational interviewing, and Gamblers Anonymous. We also introduce relatively novel treatment modalities. CONCLUSIONS: This review can help clinicians to decide treatment plans for their GD patients. In addition, it can be used as a reference for designing future research.

Current prescription pattern of maintenance treatments for bipolar patients in Korea: A focus on the transition from acute treatments.

AIMS: We examined prescription patterns in maintenance treatment for recovered bipolar patients and compared these with acute treatments. METHODS: Using retrospective methods, the bipolar patients in clinical recovery (Clinical Global Impression Bipolar Version score ≤ 2 for 6 months) after acute episode were selected. We reviewed differences between prescription patterns at remission and after a maintenance period of at least 6 months. RESULTS: A total of 340 bipolar disorder patients were selected. During the maintenance period, more than half of the patients (192, 56.5%) took a mood stabilizer (MS) + antipsychotic (AP) combination. Among the MS, valproate (149, 43.8%) was most prescribed, and lithium (98, 28.8%) was second, but as patients moved into maintenance treatment, lithium use decreased, and the use of lamotrigine (86, 25.3%) increased. Preferred AP were quetiapine (125, 36.8%), aripiprazole (67, 19.7%), risperidone (48, 14.1%), and olanzapine (39, 11.5%). The use of olanzapine in maintenance was greatly decreased compared with that during acute treatment (67, 19.7%). Most patients did not take an antidepressant (AD), but the proportion using one or more AD was increased during maintenance (17.9% to 30.3%), and bupropion (28, 8.2%) was the preferred AD. Doses were decreased in all drugs, but lamotrigine was maintained at a dose of 133.2 ± 68.5 mg/day. CONCLUSIONS: The most common prescription combination for bipolar maintenance treatment was MS + AP. The use of AP was decreased, whereas the use of AD in combination with MS and/or AP was increased. The doses of MS and AP were generally decreased during the maintenance periods, with the exception of lamotrigine.

Pharmacotherapy and group cognitive behavioral therapy enhance follow-up treatment duration in gambling disorder patients.

BACKGROUND: Longer treatment duration is important for the successful treatment of gambling disorder (GD). This retrospective study investigated the factors and interventions that might enhance treatment duration in GD patients in South Korea. METHODS: A total of 758 outpatients with a primary diagnosis of GD, who were treated in a clinical practice from 2002 to 2011, were assessed by retrospective chart review. We compared the treatment duration according to pharmacotherapy and group cognitive behavioral therapy (CBT). RESULTS: Pharmacotherapy contributed to a longer duration of treatment maintenance, despite the patients' gambling severity (p < 0.001). Participation in group CBT (p < 0.001) and antidepressants (p = 0.009) were associated with a longer treatment duration after adjusting for age, depression, and gambling severity. The treatment maintenance duration was the longest in those receiving combined antidepressant pharmacotherapy and group CBT (F = 35.79, p < 0.001). CONCLUSIONS: Group CBT and antidepressants seem to enhance treatment follow-up duration in GD patients. Additional studies are needed to advance GD prevention and treatment strategies.

Transenteral bowel preparation for colonoscopy is more comfortable than the traditional method with no inferiority in efficacy.

BACKGROUND: Transenteral (TE) administration of a bowel cleanser prior to colonoscopy avoids the discomfort associated with drinking a large volume of unpalatable cleanser. AIM: To explore patient comfort, preference for future colonoscopy, the efficacy and adverse events associated with TE bowel preparation. METHODS: Bowel preparation is traditionally practised using polyethylene glycol (PEG) + ascorbic acid (ASC), which was the treatment used in the control group (peroral group; PO group). In the study group (TE group), PEG + ASC were administered directly to the third portion of the duodenum through a scope immediately after completing upper gastrointestinal endoscopy. RESULTS: A higher proportion of subjects in the TE group graded their degree of comfort as very or rather comfortable (28.4 % in the PO group, 65.1 % in the TE group; p = 0.000) and had greater preference for future colonoscopy (69.6 % in the PO group, 82.5 % in the TE group; p = 0.030), compared with the PO group. The TE group had non-inferiority in efficacy compared with the PO group (non-inferiority margin -15 %; lower limit of 95 % confidence interval for difference between success rates -6.4 %, when using the Aronchick Scale, and -7.1 % when using the Ottawa Scale). Nausea or vomiting were more prevalent during preparation in the PO group (46.1 vs. 17.5 %; p = 0.000), and dizziness was more common in the TE group (0 vs. 12.6 %; p = 0.000). CONCLUSIONS: TE preparation was found to be more comfortable than the traditional peroral method and not inferior in efficacy. The adverse events rate was acceptable.

Clinical symptoms associated with suicidality in patients with panic disorder.

BACKGROUND: Patients with panic disorder have higher rates of suicide than the general population. Among panic disorder subjects, early onset, female gender, alcohol abuse, and mood disorder increase the risk of suicidality. However, less is known about the unique relationships between discrete DSM-IV panic symptoms and higher suicidality. Therefore, in the current study we examined the panic symptom profile that is associated with higher suicidality in a sample of outpatients with panic disorder. METHODS: This cross-sectional study included 427 patients diagnosed with current panic disorder on the basis of the DSM-IV-TR. In order to assess the contribution of the clinical variables, a univariate logistic regression was carried out examining the relationships between the demographic variables, suicidality from the suicide module of the Korean version of the MINI International Neuropsychiatric Interview Plus, and DSM-IV panic symptoms. Additionally, a multivariate logistic regression was performed to identify specific panic symptoms that were significant risk factors for suicidality among patients with current panic disorder. RESULTS: We found that 74 (17.33%) panic disorder patients experienced high suicidality. Univariate analyses showed that high suicidality was significantly associated with a younger age (OR = 13.66; 95% CI 2.68-69.70), comorbid depressive disorders (OR = 4.57; 95% CI 2.57-8.11), and the following panic symptoms: palpitations (OR = 2.20; 95% CI 0.90-5.35), trembling (OR = 0.61; 95% CI 0.362-1.18), nausea or abdominal distress (OR = 1.77; 95% CI 0.96-3.27), fear of losing control or going crazy (OR = 2.18; 95% CI 1.12-4.23), and paresthesia (OR = 1.57; 95% CI 0.83-2.98). Multivariate logistic regression analyses demonstrated that specific panic symptoms, such as palpitations (adjusted OR = 2.69; 95% CI 1.08-6.73) and fear of losing control or going crazy (adjusted OR = 2.28; 95% CI 1.21-4.31), were related to suicidality after controlling for confounding factors. CONCLUSION: Some panic symptoms (e.g. palpitations and fear of losing control or going crazy) are associated with a risk of suicidality among patients with panic disorder. A priori identification of high-risk suicidal subjects could lead to effective treatment strategies for panic disorder.

Deformation Behavior and Microstructure of 6061 Aluminum Alloy Processed by Severe Plastic Deformation Using Biaxial Alternate Forging.

The deformation behavior and microstructure of 6061 aluminum alloy processed by severe plastic deformation (SPD) using biaxial alternate forging that can evaluate the forming limit and mechanical properties of alloys, simultaneously, were investigated in this study. A finite element (FE) analysis on the biaxial alternating forging process, considering the strain-hardening coefficient and forging pass of the material, was conducted. When the strain-hardening coefficient is 0, an average effective strain of 440% was found within a diameter of 4 mm in the core of the workpiece after eight passes, while it was 300% at the same pass number when the strain-hardening coefficient was 0.2. The average effective strain estimated from the FE analysis was about 264% after eight passes of forging, which is considered to be a level of SPD that significantly exceeds the elongation of the raw material. As a result of the tensile test according to the forging pass, after two passes, the strength of the material could be gradually improved without significant degradation of elongation. Even though a large strain of 264% was found after eight passes were applied, deformed grains and twins with no recrystallized structure in optical microstructures with different forging passes were found.

Association between intra-individual variability and prefrontal cortex activity measured by functional Near Infrared Spectroscopy (fNIRS) in children with ADHD.

This study uses fNIRS to determine whether there is a difference in the relationship between intra-individual variability and frontal lobe activity between ADHD patients and typically developing children. A total of 28 subjects (14 in ADHD patient group and 14 in control group) participated in this study. The subjects were tested for K-SADS and intelligence, and then the frontal lobe activity of the subjects was measured by continuous performance test, using functional near-infrared spectroscopy (NIRSIT). Processing speed index was significantly lower in the ADHD patient group than in the control group (p = .04). The CPT test results showed a positive correlation in the activity of the right dorsolateral prefrontal region in the patient group, but not at a statistically significant level. In the control group, activity showed a significant level of negative correlation with commission and hit reaction time standard deviation (p = .023; p = .063 respectively). In contrary to ADHD patient group, activation of the right dorsolateral prefrontal area was significantly correlated with reduction of intra-individual variability. This result showing that the relationship between activation of the right dorsolateral prefrontal area of the ADHD patient group and intra-individual variability shows a different pattern from typically developing children.

Examining the links between burnout and suicidal ideation in diverse occupations.

Introduction: It is uncertain whether burnout is associated with suicidal ideation among workers not in health care services. The aim of this study was to identify how burnout and suicidal ideation are linked among employees in various occupations and whether depression affects this link. Methods: This cross-sectional study collected data from 12,083 participants aged 19-65 years from 25 companies and public institutions who underwent workplace mental health screening. Burnout and depression were assessed using both the Oldenburg Burnout Inventory and the Center for Epidemiologic Studies Depression Scale. Suicidal ideation was assessed by a self-rated questionnaire from the Korea National Health and Nutrition Examination Survey. Results: Exhaustion but not the cynicism dimension of burnout was associated with increased odds of suicidal ideation after adjustment for depression and other covariates (odds ratio [OR] = 1.47, 95% CI = 1.26-1.72). The association of exhaustion with suicidal ideation was significant in both depressed (OR = 1.36, 95% CI = 1.14-1.61) and not depressed (OR = 1.77, 95% CI = 1.13-2.76) participants. In exhausted participants, insufficient job control, an unfavorable occupational climate, low educational level, and depression were associated with increased odds of suicidal ideation. Conclusion: Exhaustion is linked with risk of suicidal ideation in employees not in health care service, regardless of depression status. Exhausted employees, particularly those having poor job resources, should be recognized as an at-risk group.

Characteristics of Korean Employees Without Depression but Having Suicidal Ideation.

OBJECTIVE: The aim of this study was to identify the factors related to suicidal ideation targeting the risk group showing suicidal ideation despite the absence of depression in Korean workers. METHODS: The data of 14,425 participants who were employees aged of 18 to 75 years who attended a mental health checkup program at the Workplace Mental Health Institute, Kangbuk Samsung Hospital from June 2015 to October 2019 were analyzed. A self-report questionnaire consisting of sociodemographic factors, suicidal ideation, job stress, levels of depression and anxiety, and resilience was administered. A Hierarchical logistic regression model was used with suicidal ideation as dependent variable. Separate analyses were conducted according to depressive symptoms using the 20-item Center for Epidemiological Studies Depression (CES-D) scale. RESULTS: Being women, older, and having low resilience, more perceived stress, more severe anxiety and less sleeping hours were associated with suicidal ideation in no-depression group (CES-D <16). In the subcategories of job stress, lack of reward was significantly associated with suicidal ideation in no-depression group. CONCLUSION: This study identified the characteristics of a group that has no depression but has suicidal ideation in Korean workers. Among job stress items, lack of reward is a clear characteristic to be considered with caution in this group.

N-Acetylglucosamine and its dimer ameliorate inflammation in murine colitis by strengthening the gut barrier function.

Ulcerative colitis (UC) is a chronic gastrointestinal disease whose incidence is increasing rapidly worldwide. Anti-inflammatory medications, including 5-aminosalicylic acid (5-ASA), corticosteroids, and immunosuppressants, are used for its treatment; however, new alternatives would be required due to the serious side effects of some of these medications. N-Acetylglucosamine (NAG) is an amino sugar composed of mucin that is secreted by intestinal epithelial cells. It is also used to promote the growth of intestinal bacteria. The current study aimed to determine the efficacy of NAG against dextran sulfate sodium (DSS)-induced chronic colitis and elucidate its mechanism of action. Mice were randomly divided into control, DSS, 0.1% sulfasalazine, 0.1% NAG, 0.3% NAG, and 0.3% NAG-dimer (NAG-D) groups, and results showed that colitis-induced body weight loss, disease activity, colonic tissue damage, colon length shortening, and the loss of mucin-secreting area were significantly improved in the NAG-D group. The intestinal permeability indicator, serum CD 14 level, and expression of the tight junction protein, occludin, were both improved in the 0.3% NAG group. Inflammatory biomarkers, including GATA3, IFN-γ, p-IκBα, COX2, TGF-ß1, and Smad7, were significantly lower in the 0.3% NAG and NAG-D groups than in the DSS group. The intestinal microbial composition was most significantly altered in the 0.3% NAG group, showing decreased ratios of pathogenic bacteria, such as Betaproteobacteria, especially Burkholderiales. The results overall suggested that NAG or NAG-D supplementation can alleviate inflammation by strengthening the intestinal barrier function and maintaining gut microbiota homeostasis in a DSS-induced colitis mouse model.