Background Obesity is the cause of cardiovascular diseases and other diseases, leading to increased medical costs, and causing a great burden to individuals, families and society. The prevalence of ...obesity is increasing and has become a global health problem. There is growing evidence that gut microbiota plays an important role in obesity. In this article, we revealed the differences in the gut microbiota between 21 people with obesity and 21 control subjects, and predicted the functional potential changes by 16S rRNA sequencing of the fecal bacteria of the subjects. Methods The raw sequencing data of 21 healthy Beijing volunteers was downloaded from Microbial Genome Database System. Microbial 16S rRNA genes of 21 adults with obesity were sequenced on an Illumina MiSeq instrument and analyzed by using bioinformatics and statistical methods. Results The diversity of gut microbiota in people with obesity decreased significantly. There were significant differences in gut microbiota between the Obesity and Control group at different levels. At the phylum level, Firmicutes, Bacteroidetes, Actinobacteria and Fusobacteria are significantly different between the Obesity and Control group. In people with obesity, the ratio of Firmicutes/Bacteroidetes decreased significantly. At the genus level, there were significant differences among the 16 major genera, of which four genera Prevotella, Megamonas, Fusobacterium and Blautia increased significantly in people with obesity, while the remaining 12 genera, Faecalibacterium, Lachnospiracea_incertae_sedis, Gemmiger and Clostridium XlVa, etc. decreased significantly. At the species level, nine species including Bacteroides uniformis and Prevotella copri had significant differences. Compared with the control group, subjects with obesity were abnormalities in 57 pathways, mainly in Carbohydrate metabolism and Lipid metabolism. Conclusions Overall, our study revealed differences in the gut microbiota between people with obesity and control subjects, providing novel target for the treatment of individuals with obesity.
Liver cirrhosis is the pathologic end stage of chronic liver disease. Increasing evidence suggests that gut flora is implicated in the pathogenesis of liver cirrhosis complications. The aim of this ...study was to characterize the fecal microbial community in patients with liver cirrhosis in comparison with healthy individuals. We recruited 36 patients with liver cirrhosis and 24 healthy controls. The fecal microbial communities was analyzed by way of 454 pyrosequencing of the 16S ribosomal RNA V3 region followed by real‐time quantitative polymerase chain reaction. Community‐wide changes of fecal microbiota in liver cirrhosis were observed compared with healthy controls. The proportion of phylum Bacteroidetes was significantly reduced (P = 0.008), whereas Proteobacteria and Fusobacteria were highly enriched in the cirrhosis group (P = 0.001 and 0.002, respectively). Enterobacteriaceae (P = 0.001), Veillonellaceae (P = 0.046), and Streptococcaceae (P = 0.001) were prevalent in patients with cirrhosis at the family level. A positive correlation was observed between Child‐Turcotte‐Pugh (CTP) score and Streptococcaceae (R = 0.386, P = 0.02). Lachnospiraceae decreased significantly in patients with cirrhosis (P = 0.004) and correlated negatively with CTP score (R = −0.49, P = 0.002). Using partial least square discriminate analysis, we identified 149 operational taxonomic units (OTUs) as key phylotypes that responded to cirrhosis, most of which were Lachnospiraceae (65 OTUs), Streptococcaceae (23 OTUs), and Veillonellaceae (21 OTUs). Conclusion: Fecal microbial communities are distinct in patients with cirrhosis compared with healthy individuals. The prevalence of potentially pathogenic bacteria, such as Enterobacteriaceae and Streptococcaceae, with the reduction of beneficial populations such as Lachnospiraceae in patients with cirrhosis may affect prognosis. (HEPATOLOGY 2011;)
Milk microbiota has a great influence on the safety and quality of dairy products. However, few studies have investigated the variations of bacterial composition in raw milk. In this study, raw milk ...samples were collected in 12 successive months, and their bacterial compositions were determined by 16 S rRNA gene sequencing. The highest diversity of bacterial composition was detected in June, while the lowest was in December. Firmicutes, Proteobacteria and Actinobacteria were the most abundant phyla and exhibited a counter-balanced relationship. Pseudomonas, Lactococcus and Acinetobacter were the most prevalent genera (>1%), and a tiny core microbiota (Acinetobacter and Pseudomonas) was observed. Temperature and humidity were the determining factors for most variation in bacterial compositions at both the phylum and genus levels. Higher abundances of Pseudomonas, Propionibacterium and Flavobacterium were correlated with low temperature. Furthermore, Pseudomonas/Propionibacterium and Lactobacillus/Bifidobacterium were two pairs of genera that had synergistic effects. Associations between the microbiota and milk quality parameters were analyzed. The abundances of Propionibacterium and Pseudoalteromonas were negatively correlated to total bacterial count, which meant that they helped to maintain milk quality, while a series of environmental microorganisms contributed to the spoilage of raw milk.
In this study, we tested the feces of children with ASD and those of healthy children, and the overall changing of the gut fungal community was observed in ASD children compared with controls. ...However, there were no abundant fungi populations showed significant variations between the ASD and Control group both at phylum and class level. Among the 507 genera identified,
Saccharomyces
and
Aspergillus
showed significant differences between ASD (59.07%) and Control (40.36%), indicating that they may be involved in the abnormal gut fungal community structure of ASD. When analyzed at the species level, a decreased abundance in
Aspergillus versicolor
was observed while
Saccharomyces cerevisiae
was increased in children with ASD relative to controls. Overall, this study characterized the fungal microbiota profile of children with ASD and identified potential diagnostic species closely related to the immune response in ASD.
Eczema is frequently the first manifestation of an atopic diathesis and alteration in the diversity of gut microbiota has been reported in infants with eczema. To identify specific bacterial ...communities associated with eczema, we conducted a case-control study of 50 infants with eczema (cases) and 51 healthy infants (controls). We performed high-throughput sequencing for V3-V4 hypervariable regions of the 16S rRNA genes from the gut fecal material. A total of 12,386 OTUs (operational taxonomic units) at a 97% similarity level were obtained from the two groups, and we observed a difference in taxa abundance, but not the taxonomic composition, of gut microbiota between the two groups. We identified four genera enriched in healthy infants: Bifidobacterium, Megasphaera, Haemophilus and Streptococcus; and five genera enriched in infants with eczema: Escherichia/Shigella, Veillonella, Faecalibacterium, Lachnospiraceae incertae sedis and Clostridium XlVa. Several species, such as Faecalibacterium prausnitzii and Ruminococcus gnavus, that are known to be associated with atopy or inflammation, were found to be significantly enriched in infants with eczema. Higher abundance of Akkermansia muciniphila in eczematous infants might reduce the integrity of intestinal barrier function and therefore increase the risk of developing eczema. On the other hand, Bacteroides fragilis and Streptococcus salivarius, which are known for their anti-inflammatory properties, were less abundant in infants with eczema. The observed differences in genera and species between cases and controls in this study may provide insight into the link between the microbiome and eczema risk.
The human gut microbiota is a complex system that is essential to the health of the host. Increasing evidence suggests that the gut microbiota may play an important role in the pathogenesis of ...colorectal cancer (CRC). In this study, we used pyrosequencing of the 16S rRNA gene V3 region to characterize the fecal microbiota of 19 patients with CRC and 20 healthy control subjects. The results revealed striking differences in fecal microbial population patterns between these two groups. Partial least-squares discriminant analysis showed that 17 phylotypes closely related to Bacteroides were enriched in the gut microbiota of CRC patients, whereas nine operational taxonomic units, represented by the butyrate-producing genera Faecalibacterium and Roseburia, were significantly less abundant. A positive correlation was observed between the abundance of Bacteroides species and CRC disease status (R=0.462, P=0.046<0.5). In addition, 16 genera were significantly more abundant in CRC samples than in controls, including potentially pathogenic Fusobacterium and Campylobacter species at genus level. The dysbiosis of fecal microbiota, characterized by the enrichment of potential pathogens and the decrease in butyrate-producing members, may therefore represent a specific microbial signature of CRC. A greater understanding of the dynamics of the fecal microbiota may assist in the development of novel fecal microbiome-related diagnostic tools for CRC.
Oral microbiota dysbiosis is associated with the occurrence and progression of oral cancer. To investigate the association between the microbiota and risk of oral squamous cell carcinoma (OSCC), we ...identified the microbial composition of paired tumor (TT)/normal paracancerous tissues (NPT) and saliva (TS) samples in OSCC patients through 16S rRNA gene sequencing. A total of 22 phyla, 321 genera, and 869 species were identified in the oral samples. Paired comparisons revealed significant differences between TT, NPT, and TS groups, with the genus
Filifactor
significantly enriched in TT. The phylum Actinobacteria; genus
Veillonella
; and species
Granulicatella adiacens
,
Streptococcus sanguinis
, and
Veillonella rogosae
were significantly enriched in NPT, while the phylum Bacteroidetes; genera
Capnocytophaga
,
Haemophilus
, and
Prevotella
; and seven species, including
Capnocytophaga
sp.,
Haemophilus
sp., and
Neisseria
sp., were significantly enriched in TS. In TTs, the abundance of
Prevotella intermedia
was profoundly higher in the gingiva, while
Capnocytophaga gingivalis
and
Rothia mucilaginosa
were enriched in the lining mucosa and tongue. Increasing in abundance from the early tumor stage to the late stage,
Solobacterium moorei
in TT and
Campylobacter
sp.
strain HMT 044
in TS were positively correlated with OSCC development, suggesting that bacteria were selected by different microenvironments. The correlation between 11 microbial species and 17 pathway abundances was revealed, indicating the potential function of low-abundance bacteria. Overall, our analysis revealed that multiple oral bacterial taxa are associated with a subsequent risk of OSCC and may be used as biomarkers for risk prediction and intervention in oral cancers.
The microbiota profile of children changes with age. To investigate the differences in the gut microbiota profile of 1- and 4-year-old children, we collected fecal samples and sequenced the V3-V4 ...hypervariable region of the 16S rRNA gene via high-throughput DNA sequencing. From phylum to species level, the microbiota underwent significant changes with age. The abundance of phyla Proteobacteria and Actinobacteria declined with age, whereas phyla Firmicutes and Bacteroidetes increased with age and dominated the gut microbiota of 4-year-olds. The intestinal environment of children at age four is closer to maturity. Hence, the abundance of Bifidobacterium significantly decreased in the gut of 4-year-olds, whereas Akkermansia muciniphila increased from 0.14% in 1-year-olds to 4.25% in 4-year-olds. The functional change in gut microbiota is consistent with changes in infant food, as microbiota participating in amino acid and vitamin metabolism were enriched in 1-year-olds, whereas microbiota involved in lipid metabolism increased with age.
Algal toxins produced by microalgae, such as domoic acid (DA)
, have toxic effects on humans. However, toxicity tests using mice only yield lethal doses of algal toxins without providing insights ...into the mechanism of action on cells. In this study, a fast segmentation of microfluidic flow cytometry cell images based on the bidirectional background subtraction (BBS)
method was developed to get the visual evidence of apoptosis in both bright-field and fluorescence images. This approach enables mapping of changes in cell morphology and activity under algal toxins, allowing for fast (within 60 s) and automated biological detection. By combining microfluidics with flow cytometry, the intricate cellular-level reaction process can be observed in micro samples of 293 T cells and mouse spleen cells, offering potential for future in vitro experiments.
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