Effects of urbanization and lifestyle habits on the intestinal microbiota of adolescents in eastern China

Introduction

Owing to urbanization, living habits have changed widely, leading to alterations in the intestinal microbiota of urban residents. However, there are few studies on the characteristics of intestinal microbiota of adolescents living in different urbanized areas in China.

Methods

A total of 302 fecal samples collected from adolescent students in eastern China were examined. 16S rRNA high-throughput sequencing was used to identify the fecal microbiota. These data were combined with questionnaire survey results to investigate the effect of urbanization on the intestinal microbiota of adolescents in eastern China. Moreover, the role of lifestyle habits in this relationship was also evaluated.

Results

The results revealed significant differences in the structure of the intestinal microbiota among adolescents living in regions with different levels of urbanization. Adolescents living in urban regions had a significantly higher proportion of Bacteroides (p <  0.001, FDR = 0.004), whereas those living in towns and rural regions had higher proportions of Bifidobacterium (p < 0.001, FDR < 0.001) and Prevotella (p  < 0.05, FDR = 0.019). The diversity of the intestinal microbiota was higher in urban residents than in adolescents living in towns and rural regions (p  <  0.05). In addition, the differences in intestinal microbiota across individuals living in cities, towns, and rural regions were related to dietary preferences, flavor preferences, and sleep and exercise durations. Adolescents who ate more meat had more Dorea (LDA = 3.622, p = 0.04), while the abundance of Escherichia-Shigella is higher among adolescents who ate more condiments (LDA = 4.285, p = 0.02). The abundance of Dialister was significantly increased in adolescents with longer sleep durations (LDA = 4.066, p = 0.03). Adolescents who exercised for a long duration had more Faecalibacterium than those who exercised for a shorter duration (LDA = 4.303, p = 0.04).

Discussion

Our research has preliminarily demonstrated that there were differences in the composition of Gut microbiome in stool samples of adolescents living in different urbanized areas, and provide a scientific basis for the maintenance of a healthy intentional microbota in adolescences.

Risk of SARS-CoV-2 infection among contacts of individuals with COVID-19 in Hangzhou, China

Objectives

This study determined the rate of secondary infection among contacts of individuals with confirmed coronavirus disease 2019 (COVID-19) in Hangzhou according to the type of contacts, the intensity of contacts, and their relationship with the index patient.

Study design

This is a retrospective cohort study.

Methods

The analysis used the data of 2994 contacts of 144 individuals with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The contacts were categorized according to the information source, type of contact, location, intensity of contact, and relationship with the index patient.

Results

The incidence of infection differed significantly according to contact type. Of the contacts, 186 (6.2%) developed symptoms, and 71 (2.4%) had confirmed SARS-CoV-2 infection. The main symptoms were cough and fever. Compared with those who had brief contact with the index case, those who had dined with the index case had 2.6 times higher risk of acquiring infection; those who had shared transport with, had visited, or had contact with the index case in a medical institution had 3.6 times higher risk of acquiring infection; and household contacts had 41.7 times higher risk of acquiring infection. Family members had 31.6 times higher risk of acquiring infection than healthcare providers or other patients exposed to an index case.

Conclusions

The form and frequency of contact are the main factors affecting the risk of infection among contacts of individuals with COVID-19. Centralized isolation and observation of close contacts of individuals with confirmed SARS-CoV-2 infection, in addition to population-based control measures, can reduce the risk of secondary infections and curb the spread of the infection.

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The incidence of infection differed significantly according to contact type.

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Contact form and frequency are important to the risk of COVID-19.

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Centralized isolation and observation of contacts curbed the spread of the infection.

[Analysis of epidemiologic and etiology of hepatitis E in Hangzhou, 2004-2011]

OBJECTIVE

To comprehend the epidemiologic of hepatitis E and genetic characteristics of hepatitis E virus (HEV) in Hangzhou from 2004 to 2011.

METHODS

Using China information system for disease control and prevention, the incidence of hepatitis E from 2004 to 2011 in Hangzhou city, and the basic information of patients were collected. In 2011, 65 hepatitis E laboratory confirmed cases were selected by random number table sampling method from the hospitals designated infectious diseases in Hangzhou city, and acquisition of the 60 blood specimens and stool specimens of 18 copies. One city and two surrounding counties were selected by cluster random sampling method in the context of Hangzhou city, and the pig slaughters and farmers were selected as the sampling point, and acquisition of pig gallbladder specimens of 52 copies, and 30 stool samples of scatter-feed pigs, 15 stool specimens of scatter-feed rabbits. HEV was tested in samples, gene extraction and analysis of gene sequence were conducted which were compared with gene bank HEV gene sequence, and a phylogenetic tree was formed. The epidemic characteristics of hepatitis E of Hangzhou city from 2004 to 2011 were described. The difference of incidence of hepatitis E was analyzed between years and sexes in Hangzhou city.

RESULTS

There were reported a total of 3 490 cases of hepatitis E in Hangzhou from 2004 to 2011, and 3 cases of death; The average annual incidence rate was 5.79/100 000 (3 490/60 276 338). There was the overall upward trend in incidence between different years (χ² = 52.38, P < 0.01) , which the highest was 8.10/100 000 (705/8 700 373) in 2011, and the lowest incidence rate was 4.19/100 000 in 2005. The incidence of males (8.12/100 000 (2 474/30 450 990) ) was significantly higher than that of the females (3.46/100 000 (1 016/29 384 491) ) (χ² = 558.45, P < 0.05). 78 specimens of blood and stool were collected, including 16 positive samples, with positive rate 21%. There were a total of 97 specimens of pig gallbladder, pig manure and rabbit stool, including 2 positive rabbit stool samples, with positive rate of 2%. HEV genes isolated from Hangzhou were mainly type IV, with homology of 91.8% to 100%; compared with human type IV strains, the homology of nucleotide was 84.6%-96.7%; compared with type IV strain of pig genome sequence alignment, homology was 82.6%-95.2%.

CONCLUSION

Hepatitis E's incidence showed an increasing trend year by year in Hangzhou. HEV of type IV was dominant, and HEV strains in the human and swine were highly homologous.

[Effects of chromium and fish oil on insulin resistance and leptin resistance in obese developing rats]

In order to study the effects of chromium and fish oil on insulin resistance and leptin resistance in obese rats, 50 rats were divided randomly into five groups: basal diet group was fed on normal diet, other four groups were fed on high fat diet. In addition to high fat diet, chromium group fed chromium (3 mg/kg BW), fish oil group fish oil(5 ml/kg BW) and chromium + fish oil group fed chromium(3 mg/kg BW) plus fish oil(5 ml/kg BW). Blood samples were collected in the following five weeks from tail each week to determine blood sugar, insulin and leptin. The results showed that blood sugar, insulin and leptin in fish oil group and chromium group were lower than those in high fat diet control group. Chromium and fish oil improved the insulin resistance and leptin resistance.