Isomaltooligosaccharides Sustain the Growth of Prevotella Both In Vitro and in Animal Models.

The human digestive tract is colonized by trillions of bacterial cells that play important roles in human health and diseases. It is well known that dietary habits are associated with human microbiota enterotypes. However, the factors that determine the enterotype still remain elusive. In this study, it was first examined, via in vitro batch fermentation, how different carbohydrates affect the Bacteroides and Prevotella enterotypes. Among the 11 substrates (fructo-, galacto-, xylo-, manno-, and isomalto-oligosaccharides [IMO] and lactulose, raffinose, starch, inulin [INU], mannitol, and xylitol) tested, IMO, INU, and starch were found to sustain the growth of Prevotella through batch fermentation. The development of the Prevotella and Bacteroides enterotypes was further simulated in chemostats using fecal samples. IMO coupled with faster dilution rates and lower pH were required to sustain the growth of Prevotella copri in the chemostat based on 16S rRNA gene and metagenomic sequencing. Meanwhile, starch with relatively lower dilution rates and higher pH was required to support the development of the Bacteroides enterotype. Amylo-α-1,6-glucosidase, pectin, and xylan lyases were the carbohydrate-active enzymes associated with the Prevotella enterotype. The Bacteroides enterotype was associated with more diversified carbohydrate-active enzymes. Consistently, since honey contains high isomaltose content, mice fed IMO and honey displayed an increased relative abundance of Prevotella in the colon. In conclusion, both in vitro systems and a mouse model were used to demonstrate that IMO maintains the Prevotella enterotype. This result provides insight into the nutritional requirements underlying gut enterotype formation. IMPORTANCE The Prevotella enterotype type is a human traditional enterotype with high dietary fiber intake, which is related to healthy ageing and Parkinson's disease development. Manipulations of the dwelled gut microbes by dietary isomalto-oligosaccharides efficiently sustained Prevotella type enterotypes, indicating that it can be used in the improvement of elderly health by increasing the gut transit time.

Age-related changes of microbiota in midlife associated with reduced saccharolytic potential: an in vitro study.

BACKGROUND: Gut microbiota is critical in maintaining human health, of which diversity and abundance are subject to significantly reduce in seniors. Gut microbiota is reported to be stable across the long adulthood in general, but lack of careful examination, especially for the midlife people. RESULTS: To characterize the gut microbiota in midlife, we investigated the faecal microbiota between two groups of healthy people, young, 20-39 years old, n = 15; and midlife, 40-60 years old, n = 15. Metabolic responses of the microbiota were studied through in vitro batch fermentation model. Although no difference was observed in the diversity indices between the two age groups, a wide range taxonomic changes were found in the faecal microbiota. Furthermore, substantial Bifidobacterium reduction was also found in both faecal and fermented samples. The faecal SCFAs are similar in both groups, as well as starch fermentation broth. However, after inulin fermentation, the acetate concentration and inulin degradation rate decreased while the gas production increased in midlife group, suggesting a deficiency of saccharolytic potential in midlife, especially for non-digestible carbohydrate. CONCLUSIONS: Our data demonstrate that gut microbiota begins to change as early as in midlife. The reduction in Bifidobacterium dominates the change of the microbiota composition in midlife resulting in attenuated saccharolytic capacity of inulin, possibly leading to insufficient acetate production which might be associated with healthy problems in this transition period from young to elderly.

Effects of bifidobacteria-produced exopolysaccharides on human gut microbiota in vitro.

Exopolysaccharides (EPSs) are carbohydrate polymers that are synthesized and present on the surface of bifidobacteria. Due to their potential applications in diverse sectors, such as food, biotechnology, cosmetics, and medicine, EPSs synthesized by bifidobacteria have recently attracted more attention. EPS production not only has benefits in food and health but also has effects on probiotics in the microbial ecosystem. In this study, we investigated the interaction between bifidobacteria EPSs and human gut microbiota in vitro using thin-layer chromatography, 16S rDNA high-throughput sequencing, and gas chromatography. The results showed that human gut microbiota has the capacity to degrade EPSs, although the degradation rate was approximately 50% after fermenting for 48 h. On the other hand, EPSs regulate the human gut microbiota. Fermented samples in the VI_Bif group clustered together according to the bacterial community compared to the VI_Starch group, in which starch was added as a carbon source. The bifidobacteria EPS promoted the growth of phylum Deinococcus_Thermus, class Deinococci, order Deinococcales, and genus Coprococcus. EPSs also increased the production of propionic acid compared to the starch group. The detection results of Dionex ICS 5000 high-purity capillary ion chromatography system showed that EPSs had absorption peaks of fucose, rhamnose, galactose/acetyl glucosamine, glucose, and ribose, and the molecular proportion of these monosaccharides was approximately 2: 2: 440: 3: 53. The monosaccharide composition of this EPS appears to be more complex than previously reported for bifidobacteria EPS. Additional studies are needed to elucidate its structure and functions.

Protective effects of Yinhuapinggan granule on mice with influenza viral pneumonia.

Yinhuapinggan granule (YHPG), a Chinese medicine granule on the basis of Ma-Huang-Tang (Ephedra Decoction) and the clinical experience of Professor Wan Haitong, has been shown to inhibit the growth of influenza virus in vitro. The aim of this study was to investigate the protective effects of YHPG on mice with influenza viral pneumonia and its effects on regulating related inflammatory cytokines in influenza virus A-infected mice. ICR mice were inoculated intranasally with 15 LD50 viral dose of influenza virus A/PR/8/34 (H1N1) and treatments with YHPG (7.5, 15 and 30g/kg) were orally administrated daily for 5 consecutive days after challenge, respectively. The results showed that mortality rate, lung index, lung histopathological changes, IL-6 and TNF-α in serum were significantly attenuated in the treatment of YHPG (15 and 30g/kg) than those in the IFV control group, while the levels of IL-2 was significantly enhanced. Moreover, the RT-PCR results revealed that YHPG (15 and 30g/kg) significantly depressed the expressions of IL-1ß, IFN-γ and TNF-α mRNA in lung tissues. Furthermore, the immunohistochemical staining results also revealed that the expression of NF-κB p65 proteins was downregulated when treated with YHPG (15 and 30g/kg). These results showed YHPG has protective effects on IFV-infected mice, due to its ability of alleviation of lung damage, regulation of the cytokine production via inhibiting the NF-κB p65 activation, attenuation of systemic and pulmonary inflammatory responses.

[Effect of Yinghua Pinggan granule against influenza A/H1N1 virus in vivo].

To study the effect of Yinghua Pinggan granule (YHPG) against influenza A/H1N1 virus in vivo and on the immunologic function of infected mice. The intranasal influenza virus infection was adopted in ICR mouse to establish the influenza virus pneumonia model. At the 3rd and 7th day after the infection, the lung index and pathologic changes in lung tissues of mice were detected. Realtime PCR and flow cytometry were employed to observe the virus load in lung tissues and the levels of CD4+, CD8+, and CD4+/CD8+ in peripheral blood. The result showed that at the 3rd and 7th day after the infection, YHPG (15, 30 g x kg(-1)) can significant decrease in the lung index and virus load in lung tissues of mice infected with influenza virus, alleviate the pathologic changes in lung tissues, significantly increase the levels of CD4+ and CD4+/CD8+ ratio and reduce the levels of CD8+ in whole blood. This indicated that YHPG can inhibit the influenza virus replication, alleviate pulmonary damage and adjust the weak immunologic function of infected mice, with a certain therapeutic effect on mice infected by H1N1 virus in vivo.

[Transabdominal rectopexy with mesh repair for full-thickness rectal prolapse in adults].

OBJECTIVE: To investigate the efficacy of transabdominal rectopexy with mesh repair for adults with full-thickness rectal prolapse (II-III degree). METHODS: Between January 2005 and March 2009, 11 adult patients with full-thickness rectal prolapse (II-III degree) were treated by transabdominal rectopexy with mesh repair. Clinical data were analyzed retrospectively. RESULTS: Of the 11 cases of rectal prolapse, 7 cases were in II degree, 4 in III degree. Operative time ranged from 1.8 to 2.6 hours. Estimated blood loss during operation ranged from 50 to 300 ml. There was only one patient developed urinary retention postoperatively and no other complications were observed. After follow-up from 1 to 3 years, no recurrence was found. Patients had good anal function during the follow up. CONCLUSION: Transabdominal recopexy with mesh repair is a simple procedure with low recurrence rate.