Advances in intestinal microecology: the microbiome, prebiotics, and probiotics

Targeting the human microbiome and its metabolite TMAO in cardiovascular prevention and therapy

The human gut microbiota is the most important active part of the intestinal micro-ecosystem. Lifestyle modification, drug intake and nutrition have an impact on the composition of the gut microbiota and its metabolites. This review focuses on the effects of changes in the gut microbiota as well as the important metabolite Trimethylamine-N-oxide (TMAO). Furthermore, relevant therapeutic options to target the human microbiome in patients with cardiovascular disease are presented.

Diversity, compositional and functional differences between gut microbiota of children and adults

The gut microbiota has been shown to play diverse roles in human health and disease although the underlying mechanisms have not yet been fully elucidated. Large cohort studies can provide further understanding into inter-individual differences, with more precise characterization of the pathways by which the gut microbiota influences human physiology and disease processes. Here, we aimed to profile the stool microbiome of children and adults from two population-based cohort studies, comprising 2,111 children in the age-range of 9 to 12 years (the Generation R Study) and 1,427 adult individuals in the range of 46 to 88 years of age (the Rotterdam Study). For the two cohorts, 16S rRNA gene profile datasets derived from the Dutch population were generated. The comparison of the two cohorts showed that children had significantly lower gut microbiome diversity. Furthermore, we observed higher relative abundances of genus Bacteroides in children and higher relative abundances of genus Blautia in adults. Predicted functional metagenome analysis showed an overrepresentation of the glycan degradation pathways, riboflavin (vitamin B2), pyridoxine (vitamin B6) and folate (vitamin B9) biosynthesis pathways in children. In contrast, the gut microbiome of adults showed higher abundances of carbohydrate metabolism pathways, beta-lactam resistance, thiamine (vitamin B1) and pantothenic (vitamin B5) biosynthesis pathways. A predominance of catabolic pathways in children (valine, leucine and isoleucine degradation) as compared to biosynthetic pathways in adults (valine, leucine and isoleucine biosynthesis) suggests a functional microbiome switch to the latter in adult individuals. Overall, we identified compositional and functional differences in gut microbiome between children and adults in a population-based setting. These microbiome profiles can serve as reference for future studies on specific human disease susceptibility in childhood, adulthood and specific diseased populations.

Influence of Chongcao Yigan Capsule on function of intestinal flora and chemoprevention for patients with chronic hepatitis B-induced liver fibrosis

OBJECTIVE

Hapatitis B visus (CHB)-induced fibrosis is a precancerous condition of liver. To explore the influence of Chongcao Preparation (Chongcao Yigan Capsule) on the function of intestinal flora and chemoprevention for patients with CHB-induced liver fibrosis.

METHODS

A total of 136 patients with CHB-induced liver fibrosis were randomly divided into control group treated with lamivudine (LAM) and research group added with Chongcao Yigan Capsule for totally 48 weeks. The changes of intestinal flora, secretory immunoglobin A (SIgA), serum albumin (ALB), prealbumin (PALB), IgA and IgG at different time points in both groups were observed.

RESULTS

Before treatment, there was no significant difference between two groups in each index (P>0.05). After treatment, the intestinal flora were evidently optimized in research group than treatment before (P<0.05 or P<0.01), and were apparently better than those in control group (P<0.05 or P<0.01); SIgA was obviously increased and ALB, PALB, IgA and IgG were markedly improved in research group than treatment before (P<0.05 or P<0.01), and were significantly better than those in control group (P<0.05 or P<0.01).

CONCLUSIONS

Chongcao Yigan Capsule could regulate the intestinal flora, increase SIgA, serum ALB and PALB concentrations and significantly improve serum IgA and IgG as well as strengthen the immunological function and autologous repair capacity of patients with CHB-induced liver fibrosis.

Intestinal microbiota in healthy U.S. young children and adults--a high throughput microarray analysis

It is generally believed that the infant's microbiota is established during the first 1–2 years of life. However, there is scarce data on its characterization and its comparison to the adult-like microbiota in consecutive years.

Aim

To characterize and compare the intestinal microbiota in healthy young children (1–4 years) and healthy adults from the North Carolina region in the U.S. using high-throughput bacterial phylogenetic microarray analysis.

Methods

Detailed characterization and comparison of the intestinal microbiota of healthy children aged 1–4 years old (n = 28) and healthy adults of 21–60 years (n = 23) was carried out using the Human Intestinal Tract Chip (HITChip) phylogenetic microarray targeting the V1 and V6 regions of 16S rRNA and quantitative PCR.

Results

The HITChip microarray data indicate that Actinobacteria, Bacilli, Clostridium cluster IV and Bacteroidetes are the predominant phylum-like groups that exhibit differences between young children and adults. The phylum-like group Clostridium cluster XIVa was equally predominant in young children and adults and is thus considered to be established at an early age. The genus-like level show significant 3.6 fold (higher or lower) differences in the abundance of 26 genera between young children and adults. Young U.S. children have a significantly 3.5-fold higher abundance of Bifidobacterium species than the adults from the same location. However, the microbiota of young children is less diverse than that of adults.

Conclusions

We show that the establishment of an adult-like intestinal microbiota occurs at a later age than previously reported. Characterizing the microbiota and its development in the early years of life may help identify ‘windows of opportunity’ for interventional strategies that may promote health and prevent or mitigate disease processes.