A summary of sampling information.

<p>A summary of sampling information.</p

Box plots showing fecal bacterial composition of different ethnic groups.

<p>Bacterial amounts are expressed in Log 16S rRNA copy number per gram of fecal sample. Boxes show the median, 25^th and 75^th percentiles. The lower and upper adjacent hinges show the minimum and maximum values. The significant difference between sample pair was evaluated by pairwise Mann-Whitney test with Bonferroni correction. A corrected p-value <0.05, 0.01 and 0.001 are denoted by ‘*’, ‘**’, and ‘***’, respectively. The obtained p-values are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093631#pone.0093631.s005" target="_blank">Table S3</a>.</p

Characterization of Fecal Microbiota across Seven Chinese Ethnic Groups by Quantitative Polymerase Chain Reaction

<div><p>The human gut microbiota consists of complex microbial communities, which possibly play crucial roles in physiological functioning and health maintenance. China has evolved into a multicultural society consisting of the major ethnic group, Han, and 55 official ethnic minority groups. Nowadays, these minority groups inhabit in different Chinese provinces and some of them still keep their unique culture and lifestyle. Currently, only limited data are available on the gut microbiota of these Chinese ethnic groups. In this study, 10 major fecal bacterial groups of 314 healthy individuals from 7 Chinese ethnic origins were enumerated by quantitative polymerase chain reaction. Our data confirmed that the selected bacterial groups were common to all 7 surveyed ethnicities, but the amount of the individual bacterial groups varied to different degree. By principal component and canonical variate analyses of the 314 individuals or the 91 Han subjects, no distinct group clustering pattern was observed. Nevertheless, weak differences were noted between the Han and Zhuang from other ethnic minority groups, and between the Heilongjiang Hans from those of the other provinces. Thus, our results suggest that the ethnic origin may contribute to shaping the human gut microbiota.</p></div

Variation of the fecal bacterial composition across the 7 ethnic groups.

<p>A. PCA score plot of the first two principal components with the proportion of variance explained by each component printed next to the axes labels. B. MANOVA score plot using the first 9 principal components. Individuals are classified according to their corresponding ethnic group and lifestyle. The first two canonical variables are plotted. Each individual is represented by one dot and the color label corresponds to the ethnic origin and lifestyle. C. Dendrogram constructed based on the distance metrics of different ethnic groups. ‘*’ and ‘***’ indicate p<0.05, 0.001, respectively.</p

Bacterial strains used for construction of standard curves, efficiency and coefficient of determination of qPCR.

<p>Bacterial strains used for construction of standard curves, efficiency and coefficient of determination of qPCR.</p

Pairs of Han subgroups showing significant difference in bacterial quantity.

<p>Remark: Pairwise Mann-Whitney test was performed to evaluate the sample difference.</p

qPCR primer information and predicted product size.

<p>qPCR primer information and predicted product size.</p

Box-plots of the <i>Firmicutes</i>/<i>Bacteroidetes</i> ratio of the 7 ethnic groups.

<p>Boxes show the median, 25^th and 75^th percentiles. The lower and upper adjacent hinges are 1.5× interquartile range (IQR) from the 1^st and 3^rd quartiles, respectively. ‘Suspected upper outliers’ >1.5 and >3 times of the IQR above the 3^rd quartile are symbolized with open and filled circles, respectively. No lower outlier was detected in any of the groups. The significant difference between sample pair was evaluated by pairwise Mann-Whitney test with Bonferroni correction. A corrected p-value <0.05 and 0.01 are denoted by ‘*’ and ‘**’, respectively. The obtained p-values are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0093631#pone.0093631.s007" target="_blank">Table S5</a>.</p