Individual-Level Health Care Costs Attributable to Noncommunicable Diseases: A Longitudinal Study Based on the Older Adults in China.

Noncommunicable chronic diseases among the elderly population represent a significant economic burden in China. However, previous disease-related health cost studies lacked representation of older adults and comparability of the burden of multiple chronic diseases. The objective of this study was to determine the fraction of health care costs attributable to the 6 most prevalent chronic diseases and comorbidities in the sample of older adults. This study employed data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), with 3 waves in 2011, 2014, and 2018, and included 18 349 observations in total. Outpatient costs, inpatient costs, and total health care costs were included in this study. Based on a 2-part random effects model, the effect of chronic disease on health service utilization was first explored by constructing a dummy variable for whether or not to utilize health care, followed by estimation of attributable costs in the population with health care utilization. Among the older adults in the sample, hypertension, heart disease, cataracts, arthritis, stroke or Cerebrovascular disease (CVD) and chronic lung disease are the 6 most prevalent chronic conditions. The costs attributable to the 6 chronic diseases mentioned above were 36.00% of outpatient costs, 55.92% of inpatient costs, and 45.05% of total health care costs for older adults. Of these, heart disease, stroke or CVD, and chronic lung disease accounted for 22.11%, 13.24%, and 10.56% of total health care costs, respectively. Moreover, the proportion of health care costs attributable to chronic diseases was higher for older adults who were male, lived in urban areas, and had a lower level of education. The proportion of health care costs attributable to chronic diseases is substantial among older adults in China. Health care costs associated with chronic diseases can be decreased with well-targeted interventions and comprehensive access to health services.

Study of the impact of digitization on the carbon emission intensity of agricultural production in China.

The digital economy is an important engine for China's economic and social development, accelerating the development of agricultural digitization and promoting the integration of agricultural digitization. Low-carbon production is an inevitable trend in China's current economic development. The article takes 30 provinces (cities and districts) in China as research objects, constructing and measuring indicators of digitization level and carbon emission intensity of agricultural production from 2006 to 2018. It classifies agricultural production into planting and animal husbandry and uses a basic regression model to study their dynamic relationships. A mediating effect model is used to explore the specific mechanism path of the digital economy affecting carbon emission intensity, and a regional heterogeneity analysis is conducted. The study found that: (1) The level of digitalization can significantly reduce the carbon intensity of agricultural production; (2) Digitalization can reduce China's carbon intensity by promoting the level of agricultural technological inputs, the level of human capital and the urbanization rate. (3) There are regional and sectoral differences in the impact of digitization on the carbon intensity of agricultural production. The impact on the plantation sector is greater than that on the livestock sector, and the carbon reduction effect is slightly greater in the central and western regions than in the eastern regions.

Chinese Consumer Assessment of Australian Sheep Meat Using a Traditional Hotpot Cooking Method.

Hotpot is a widely popular cooking method for sheepmeat in China. This study measured the sensory responses of 720 untrained Chinese consumers to Australian sheepmeat cooked using a hotpot technique with methods based on Meat Standards Australia protocols. Shoulder and leg cuts of 108 lambs and 109 yearlings were scored on tenderness, juiciness, flavour and overall liking with linear mixed effects models used to analyse the influence of muscle type and animal factors on these scores. On average, shoulder cuts were more palatable than legs cuts for all sensory traits (p < 0.01) and lambs compared to yearlings (p < 0.05). Intramuscular fat and muscularity were identified as strong drivers of eating quality (p < 0.05), with greater palatability for both cuts as intramuscular fat increased (range 2.5 to 7.5%), and muscularity decreased (as measured through loin weight adjusted for hot carcase weight). Consumers were unable to detect differences between animal sire type and sex in sheepmeat hotpot. These findings suggest shoulder and leg cuts performed comparatively well in hotpot compared to previously tested sheepmeat cooking methods and emphasise the importance of balanced selection for quality and yield traits to ensure that consumer satisfaction is maintained.

A hybrid interpretable deep structure based on adaptive neuro-fuzzy inference system, decision tree, and K-means for intrusion detection.

For generating an interpretable deep architecture for identifying deep intrusion patterns, this study proposes an approach that combines ANFIS (Adaptive Network-based Fuzzy Inference System) and DT (Decision Tree) for interpreting the deep pattern of intrusion detection. Meanwhile, for improving the efficiency of training and predicting, Pearson Correlation analysis, standard deviation, and a new adaptive K-means are used to select attributes and make fuzzy interval decisions. The proposed algorithm was trained, validated, and tested on the NSL-KDD (National security lab-knowledge discovery and data mining) dataset. Using 22 attributes that highly related to the target, the performance of the proposed method achieves a 99.86% detection rate and 0.14% false alarm rate on the KDDTrain+ dataset, a 77.46% detection rate on the KDDTest+ dataset, which is better than many classifiers. Besides, the interpretable model can help us demonstrate the complex and overlapped pattern of intrusions and analyze the pattern of various intrusions.

Dynamic Changes and Regional Differences of Net Carbon Sequestration of Food Crops in the Yangtze River Economic Belt of China.

The carbon sequestration of food crops is of great significance to slow down agricultural greenhouse gas emissions in agricultural production and management. This paper analyzes the dynamic change and regional differences of net carbon sequestration of food crops from temporal and spatial perspectives for the case study area of the Yangtze River economic belt (YREB) in China. We use the calculation formula of carbon sequestration and carbon emission to calculate the net carbon sequestration in the Yangtze River economic belt. On this basis, we analyze the dynamic trend and regional differences of net carbon sequestration in the Yangtze River economic belt. Furthermore, we use the Gini coefficient to measure the quantitative gap of net carbon sequestration of grain crops in different regions of the Yangtze River economic belt. The results show that: (1) from 2000-2018, the net carbon sequestration of food crops keeps rising within the studied area, while the carbon emission shows a fluctuating downward trend; (2) remarkable regional differences in the net carbon sequestration of food crops have occurred, and most provinces (cities) show an upward trend for the studied area; (3) the unequitable distribution of net carbon sequestration of food crops is clearly displayed in the upper, middle, and lower reaches of the studied area. Moreover, the most uneven place is located on the lower reaches, and the least uneven place is in the upper reaches. These findings are important points of reference for reducing the carbon emissions of the agricultural industry in the Yangtze River economic belt of China and in China more generally.

EasyNAT MTC assay: A simple, rapid, and low-cost cross-priming amplification method for the detection of mycobacterium tuberculosis suitable for point-of-care testing.

More sensitive, rapid, and affordable diagnostic tools for pulmonary tuberculosis (PTB) are urgently needed. This study aimed to assess the performance of EasyNAT MTC (abbreviation: EasyNAT) (Ustar Biotechnologies, China), a novel isothermal amplification method with a turnaround time of less than two hours that requires a few manual steps to process the sputum. Sputum samples from 249 patients with suspected PTB were subjected to smear, culture, Xpert MTB/RIF (Cepheid, USA) and EasyNAT assay testing. Of the 169 PTB patients, EasyNAT detected more PTB patients than Xpert (72.19% vs. 61.54%, P < 0.05, χ2 = 4.326). Both the Xpert assay and EasyNAT assay detected almost all the culture-positive sputa successfully, but EasyNAT yielded more positive results among the smear-negative and culture-negative PTB cases (44.59% (33/74) vs. 22.97% (17/74), P < 0.01, χ2 = 7.732). Although the specificity of EasyNAT was lower in contrast to Xpert [95.00% (76/80) vs. 98.75% (79/80)], the difference was not significant (P = 0.363, χ2 = 0.826). EasyNAT could be used as an initial test for PTB diagnosis due to its simplicity, rapid turnaround time, high sensitivity, and low cost.

The human gut microbiome and health inequities.

Individuals who are minoritized as a result of race, sexual identity, gender, or socioeconomic status experience a higher prevalence of many diseases. Understanding the biological processes that cause and maintain these socially driven health inequities is essential for addressing them. The gut microbiome is strongly shaped by host environments and affects host metabolic, immune, and neuroendocrine functions, making it an important pathway by which differences in experiences caused by social, political, and economic forces could contribute to health inequities. Nevertheless, few studies have directly integrated the gut microbiome into investigations of health inequities. Here, we argue that accounting for host-gut microbe interactions will improve understanding and management of health inequities, and that health policy must begin to consider the microbiome as an important pathway linking environments to population health.

A highway crash risk assessment method based on traffic safety state division.

In order to quantitatively analyze the influence of different traffic conditions on highway crash risk, a method of crash risk assessment based on traffic safety state division is proposed in this paper. Firstly, the highway crash data and corresponding traffic data of upstream and downstream are extracted and processed by using the matched case-control method to exclude the influence of other factors on the model. Secondly, considering the weight of traffic volume, speed and occupancy, a multi-parameter fusion cluster method is applied to divide traffic safety state. In addition, the quantitative relationship between different traffic states and highway crash risk is analyzed by using Bayesian conditional logistic regression model. Finally, the results of case study show that different traffic safety conditions are in different crash risk levels. The highway traffic management department can improve the safety risk management level by focusing on the prevention and control of high-risk traffic safety conditions.

Assessment of intracranial pressure with ultrasonographic retrobulbar optic nerve sheath diameter measurement.

BACKGROUND: Ultrasonograpic retrobulbar optic nerve sheath diameter (ONSD) measurement is considered to be an alternative noninvasive method to estimate intracranial pressure,but the further validation is urgently needed. The aim of the current study was to investigate the association of the ultrasonographic ONSD and intracranial pressure (ICP) in patients. METHODS: One hundred and ten patients whose intracranial pressure measured via lumbar puncture were enrolled in the study. Their retrobulbar ONSD with B-scan ultrasound was determined just before lumber puncture. The correlation between the ICP and the body mass index (BMI), ONSD or age was established respectively with the Pearson correlation coefficient analysis. The discriminant analysis was used to obtain a discriminant formula for predicting ICP with the ONSD、BMI、gender and age. Another 20 patients were recruited for further validation the efficiency of this discriminant equation. RESULTS: The mean ICP was 215.3 ± 81.2 mmH2O. ONSD was 5.70 ± 0.80 mm in the right eye and 5.80 ± 0.77 mm in the left eye. A significant correlation was found between ICP and BMI (r = 0.554, p < 0.001), the mean ONSD (r = 0.61, P < 0.001), but not with age (r = -0.131, p = 0.174) and gender (r = 0.03, p = 0.753). Using receiver operating characteristic (ROC) curve analysis, the critical value for the risk mean-ONSD was 5.6 mm from the ROC curve, with the sensitivity of 86.2% and specificity of 73.1%. With 200 mmH2O as the cutoff point for a high or low ICP, stepwise discriminant was applied, the sensitivity and specificity of ONSD predicting ICP was 84.5%-85.7% and 86.5%-92.3%. CONCLUSIONS: Ophthalmic ultrasound measurement of ONSD may be a good surrogate of invasive ICP measurement. This non-invasive method may be an alternative approach to predict the ICP value of patients whose ICP measurement via lumbar puncture are in high risk. The discriminant formula, which incorporated the factor of BMI, had similar sensitivity and higher specificity than the ROC curve.

Bayesian hierarchical model for analyzing multiresponse longitudinal pharmacokinetic data.

Traditional Chinese medicine (TCM) is a very complex mixture containing many different ingredients. Thus, statistical analysis of traditional Chinese medicine data becomes challenging, as one needs to handle the association among the observed data across different time points and across different ingredients of the multivariate response. This paper builds a 3-stage Bayesian hierarchical model for analyzing multivariate response pharmacokinetic data. Usually, the dimensionality of the parameter space is very huge, which leads to the parameter-estimation difficulty. So we take the hybrid Markov chain Monte Carlo algorithms to obtain the posterior Bayesian estimation of corresponding parameters in our model. Both simulation study and real-data analysis show that our theoretical model and Markov chain Monte Carlo algorithms perform well, and especially the correlation among different ingredients can be calculated very accurately.

Assessment of the efficacy of drug transdermal delivery by electro-phonophoresis in treating tuberculous lymphadenitis.

Electro-phonophoresis (EP) has been used in various clinical fields. The objective of present study is to evaluate the skin permeability of isoniazid (INH) and rifampicin (RIF) in patients with tuberculous lymphadenitis with the aid of EP to validate the clinical applications of this transdermal delivery system for the treatment of superficial extrapulmonary tuberculosis. INH and RIF solutions were delivered transdermally, with or without EP, in the surrounding tissue of the lesion for 0.5 h. Local pyogenic fluids or necrotic tissue samples from the infection sites in patients were collected at 1 h after dosing. Drug concentrations in samples were evaluated by high performance liquid chromatography. The median INH and RIF intra-lesional concentrations were 0.365 (interquartile range [IQR] 0.185-1.775) µg/mL and 1.231 (IQR 0.304-1.836) µg/mL in oral group; 2.964 (IQR 0.193-7.325) µg/mL and 2.646 (IQR 1.211-3.753) µg/mL in INH- and RIF-transdermal plus EP group. Drug concentrations in the local sites of patients receiving INH or RIF through EP transdermal delivery were statistically higher than those observed in patients only taking INH and RIF orally. However, this enhancement was not observed in the transdermal delivery of INH or RIF without EP in contrast to the oral administrations of drugs. EP can effectively enhance the skin permeability of INH and RIF in patients with tuberculous lymphadenitis. The increase in drug concentrations in the lesions could help eradication of the germs; shorten the treatment course and increase the cure rate of patients with tuberculous lymphadenitis.

The impact of hyperglycemia and obesity on hospitalization costs and clinical outcome in general surgery patients.

BACKGROUND: The impact of obesity on clinical outcomes and hospitalization costs in general surgery patients with and without diabetes (DM) is unknown. MATERIALS AND METHODS: We reviewed medical records of 2451 patients who underwent gastrointestinal surgery at two university hospitals. Hyperglycemia was defined as BG ≥140 mg/dl. Overweight was defined by body mass index (BMI) between 25-29.9 kg/m(2) and obesity as a BMI ≥30 kg/m(2). Hospital cost was calculated using cost-charge ratios from Centers for Medicare and Medicaid Services. Hospital complications included a composite of major cardiovascular events, pneumonia, bacteremia, acute kidney injury (AKI), respiratory failure, and death. RESULTS: Hyperglycemia was present in 1575 patients (74.8%). Compared to patients with normoglycemia, those with DM and non-DM with hyperglycemia had higher number of complications (8.9% vs. 35.8% vs. 30.0%, p<0.0001), longer hospital stay (5 days vs. 9 days vs. 9 days, p<0.0001), more readmissions within 30 days (9.3% vs. 18.8% vs. 17.2%, p<0.0001), and higher hospitalization costs ($20,273 vs. $79,545 vs. $72,675, p<0.0001). In contrast, compared to normal-weight subjects, overweight and obesity were not associated with increased hospitalization costs ($58,313 vs. $58,173 vs. $66,633, p=0.74) or risk of complications, except for AKI (11.9% vs. 14.8% vs. 20.5%, p<0.0001). Multivariate analysis revealed that DM (OR=4.4, 95% CI=2.8,7.0) or perioperative hyperglycemia (OR=4.1, 95% CI=2.7-6.2) were independently associated with increased risk of complications. CONCLUSION: Hyperglycemia but not increasing BMI, in patients with and without diabetes undergoing gastrointestinal surgery was associated with a higher number of complications and hospitalization costs.

Differences in systemic oxidative stress based on race and the metabolic syndrome: the Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) study.

BACKGROUND: Classification schema such as metabolic syndrome may underestimate cardiovascular disease (CVD) risk in African Americans, despite a higher burden of CVD in African Americans. Oxidative stress results from an imbalance of prooxidants and antioxidants and leads to endothelial dysfunction that promotes vascular inflammation and atherosclerosis. Aminothiol markers of oxidative stress are associated with CVD risk factors and metabolic syndrome; however, little is known about racial differences in levels of oxidative stress. We sought to investigate whether oxidative stress would be higher in African Americans compared to whites independently of traditional risk factor burden. METHODS: We assessed oxidative stress in a biracial, community-based cohort. In 620 subjects (59% female, 52% African American) in the Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) study, we measured plasma levels of glutathione, an intracellular antioxidant, and its redox potential as a ratio of reduced and oxidized glutathione (E(h) glutathione). RESULTS: African Americans had lower glutathione levels (P<0.001) compared to whites. There was a trend toward more oxidized E(h) glutathione (P = 0.07) in African Americans; however, this did not reach statistical significance. After adjustment for demographics and CVD risk factors, African-American race remained a significant correlate of lower glutathione levels (P<0.001) and a more oxidized E(h) glutathione (P = 0.04). After further adjustment for high-sensitivity C-reactive protein (hsCRP), glutathione remained significantly lower in African Americans (P = 0.001). African Americans with or without metabolic syndrome had lower glutathione levels compared to whites with or without metabolic syndrome, respectively (both P ≤ 0.001), and African Americans without metabolic syndrome had a more oxidized E(h) glutathione compared to whites without metabolic syndrome (P = 0.003). CONCLUSIONS: African Americans have higher levels of oxidative stress than whites, even after adjustment for differences in CVD risk factors and inflammation. Racial differences in oxidative stress may play a key role in understanding observed racial disparities in CVD.

Mental comorbidity and quality of diabetes care under Medicaid: a 50-state analysis.

BACKGROUND: Patients with comorbid medical and mental conditions are at risk for poor quality of care. With the anticipated expansion of Medicaid under health reform, it is particularly important to develop national estimates of the magnitude and correlates of quality deficits related to mental comorbidity among Medicaid enrollees. METHODS: For all 657,628 fee-for-service Medicaid enrollees with diabetes during 2003 to 2004, the study compared Healthcare Effectiveness Data and Information Set (HEDIS) diabetes performance measures (hemoglobin A1C, eye examinations, low density lipoproteins screening, and treatment for nephropathy) and admissions for ambulatory care-sensitive conditions (ACSCs) between persons with and without mental comorbidity. Nested hierarchical models included individual, county, and state-level measures. RESULTS: A total of 17.8% of the diabetic sample had a comorbid mental condition. In adjusted models, presence of a mental condition was associated with a 0.83 (0.82-0.85) odds of obtaining 2 or more HEDIS indicators, and a 1.32 (1.29-1.34) increase in odds of one or more ACSC hospitalization. Among those with diabetes and mental comorbidities, living in a county with a shortage of primary care physicians was associated with reduced performance on HEDIS measures; living in a state with higher Medicaid reimbursement fees and department of mental health expenses per client were associated both with higher quality on HEDIS measures and lower (better) rates of ACSC hospitalizations. CONCLUSIONS: Among persons with diabetes treated in the Medicaid system, mental comorbidity is an important risk factor for both underuse and overuse of medical care. Modifiable county and state-level factors may mitigate these quality deficits.

Association between depression and inflammation--differences by race and sex: the META-Health study.

OBJECTIVE: To test whether the association between depression and inflammation differs by race and sex. Depressive symptoms have been associated with higher levels of C-reactive protein (CRP). However, few studies have examined this association in samples including a significant number of African Americans, or examined whether the association differs by race and sex. METHODS: Depressive symptoms and CRP were assessed in 512 African American and white participants, age 30 to 65 years, as part of the community-based Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) Study. Depression was determined by responses to the Beck Depression Inventory II (BDI-II). Multivariable linear regression models were used to adjust for demographic and metabolic risk factors. RESULTS: African American men had higher total BDI-II scores than white men (p = .03), whereas there was no difference in women. There was a significant race-sex-depression interaction in predicting CRP levels (p = .02). White women with mild to severe depressive symptoms had higher levels of CRP compared with those with minimal to no depressive symptoms (p < .05). There were no differences in levels of CRP by severity of depressive symptoms in white men or African Americans of either sex. Higher BDI-II scores were related to higher CRP levels in white women after adjusting for age and level of education (ß = 0.227, p = .006). However, the association was eliminated after further adjustment for metabolic risk factors (ß = 0.077, p = .35). CONCLUSIONS: Although depressive symptoms are associated with inflammation, the association varies by race and sex.

Budget impact and sustainability of medical care management for persons with serious mental illnesses.

OBJECTIVE: The authors assessed the 2-year outcomes, costs, and financial sustainability of a medical care management intervention for community mental health settings. METHOD: A total of 407 psychiatric outpatients with serious mental illnesses were randomly assigned to usual care or to a medical care manager who provided care coordination and education. Two-year follow-up chart reviews and interviews assessed quality and outcomes of care, as well as costs from both the health system and managerial perspectives. RESULTS: Sustained improvements were observed in the intervention group in quality of primary care preventive services, quality of cardiometabolic care, and mental health-related quality of life. From a health system perspective, by year 2, the mean per-patient total costs for the intervention group were $932 (95% CI=-1,973 to 102) less than for the usual care group, with a 92.3% probability that the program was associated with lower costs than usual care. From the community mental health center perspective, the program would break even (i.e., revenues would cover setup costs) if 58% or more of clients had Medicaid or another form of insurance. Given that only 40.5% of clients in this study had Medicaid, the program was not sustainable after grant funding ended. CONCLUSIONS: The positive long-term outcomes and favorable cost profile provide evidence of the potential value of this model. However, the discrepancy between health system and managerial cost perspectives limited the program's financial sustainability. With anticipated insurance expansions under health reform, there is likely to be a stronger business case for safety net organizations considering implementing evidence-based interventions such as the one examined in this study.

Assessment of the modulating effects of fructo-oligosaccharides on fecal microbiota using human flora-associated piglets.

We first used human flora-associated (HFA) piglets, a significantly improved model for research on human gut microbiota, to study the effects of short-chain fructo-oligosaccharides (scFOS) on the gut bacterial populations. Ten neonatal HFA piglets were assigned to receive basal diets alone or supplemented with scFOS (0.5 g/kg body weight/day) from 1 to 37 days after birth (DAB). The impact of scFOS on the fecal bacterial populations of the piglets before (12 DAB), during (17 DAB), and after (25 and 37 DAB) weaning were monitored by PCR-denaturing gradient gel electrophoresis and real-time quantitative PCR. The Bifidobacterium genus was stimulated consistently, except during weaning, confirming the bifidogenic property of scFOS. At 12 DAB, the Clostridium leptum subgroup was decreased and two unknown Bacteroides-related species were increased; at 25 DAB, the C. leptum subgroup and Subdoligranulum variabile-like species were elevated, whereas one unknown Faecalibacterium-related species was suppressed; and at 37 DAB, the Bacteroides genus was decreased. The results showed that effects of scFOS on non-bifidobacteria varied at different developmental stages of the animals, warranting further investigation into the host-development-related effects of prebiotics on the gut microbiota and the host physiology using the HFA piglets as a model for humans.

Predictors of incident heart failure in a large insured population: a one million person-year follow-up study.

BACKGROUND: Studies on the incidence and predictors of heart failure (HF) are often restricted to elderly persons or identify only inpatient cases. METHODS AND RESULTS: We determined the incidence and predictors of new HF diagnosed in either outpatient or inpatient settings, among 359 947 women and men (age ≥18 years) insured by Kaiser Permanente Georgia at any time during calendar years 2000 to 2005. Subjects were free of HF at baseline, and incident HF was identified with ICD-9 codes (1 inpatient or 2 outpatient HF visits). We developed multivariable Cox models to assess the association of antecedent factors (coronary heart disease, hypertension, diabetes mellitus, atrial fibrillation, and valvular heart disease) with incident HF. Separate models were created for each sex and for newly diagnosed HF in outpatient or inpatient settings. There were 4001 incident HF cases (50% women and 48% in subjects <65 years old), during 1 015 794 person-years of follow-up. The incidence rate of HF was greater in men than in women (4.24 versus 3.68 per 1000 person-years) but was stable across the study interval in both sexes. Two thirds of incident HF cases from this population occurred in outpatients. These 5 antecedent factors and age yielded excellent discrimination for incident HF in both outpatients and inpatients and in both sexes (C >0.85 in all models). CONCLUSIONS: Common modifiable risk factors accurately discriminate women and men at risk for HF diagnosed in either outpatient or inpatient settings. Approximately two thirds of new HF cases in our insured population were diagnosed in outpatients; more research is needed to characterize these subjects and their prognosis.

Structural shifts of gut microbiota as surrogate endpoints for monitoring host health changes induced by carcinogen exposure.

This study monitored structural shifts of gut microbiota of rats developing precancerous mucosal lesions induced by carcinogen 1,2-dimethyl hydrazine (DMH) treatment using PCR-denaturing gradient gel electrophoresis (DGGE) and 454 pyrosequencing on the 16S rRNA gene V3 region. Partial least square discriminant analysis of DGGE fingerprints showed that the gut microbiota structure of treated animals was similar to that of the controls 1 and 3 weeks after DMH treatments, but significantly different 7 weeks after DMH treatments, when a large number of aberrant crypt foci (ACF) developed in their colons. Martens' uncertainty test, followed by anova test (P<0.05) identified Ruminococcus-like and Allobaculum-like bacteria as key variables for discrimination of DMH-treated rats from controls. Real-time PCR confirmed the significant increase of the Ruminococcus obeum and the Allobaculum-like bacteria in DMH-treated rats. UniFrac analysis based on V3 pyrosequencing further validated that the gut microbiota structures of treated and control animals were similar at an early stage, but segregated after ACF formation. Thirteen operational taxonomic units including Ruminococcus-like and Allobaculum-like bacteria were identified as key variables for the discrimination of DMH-treated rats from controls. Dynamic analysis of gut microbiota may become a noninvasive strategy for monitoring host health changes induced by carcinogen exposure.