目的探讨慢性功能性便秘患者与健康对照组之间肠道菌群的差异。方法选取便秘组和健康对照组共计20人,留取新鲜粪便样本,冰块运送至实验室并存放于-80度冰箱。采用16S r RNA测序技术检测V4区鉴定菌群。结果发现两组人群的菌群丰富度差异...目的探讨慢性功能性便秘患者与健康对照组之间肠道菌群的差异。方法选取便秘组和健康对照组共计20人,留取新鲜粪便样本,冰块运送至实验室并存放于-80度冰箱。采用16S r RNA测序技术检测V4区鉴定菌群。结果发现两组人群的菌群丰富度差异有统计学意义(P<0.05),菌群多样性差异无统计学意义。便秘患者与健康对照组之间的肠道细菌组成在门和属水平差异均存在显著统计学意义(P<0.05)。在门水平,便秘患者肠道中放线菌门(Actinobacteria)丰度显著增加(Z=-3.10,P<0.05),而变形菌门(Proteobacteria)丰度显著降低(Z=-2.42,P<0.05),在属水平发现20个菌属差异存在统计学意义(P<0.05)。其中,Coprobacillus(Z=-2.10,P<0.05)、Hungatella(Z=-2.31,P<0.05)、Holdemanella(Z=-2.32,P<0.05)、Anaerostipes(Z=-3.78,P<0.01)、Bacteroidales_S24-7_group_norank(Z=-2.15,P<0.05)、Bacteroides(Z=-3.78,P<0.01)、Blautia(Z=-3.78,P<0.05)、Collinsella(Z=-3.02,P<0.05)、Dorea(Z=-2.95,P<0.05)、[Eubacterium]_ruminantium_group(Z=-2.70,P<0.05)、Erysipelotrichaceae_UCG-003(Z=-3.10,P<0.05)、Ruminococcaceae_uncultured(Z=-2.50,P<0.05)、Parabacteroides(Z=-2.87,P<0.05)菌属在便秘患者的肠道中丰度明显增多,而Megasphaera(Z=-2.31,P<0.05)、Paraprevotella(Z=-2.94,P<0.05)、Prevotella_2(Z=-3.10,P<0.05)、Prevotella_9(Z=-3.68,P<0.01)、Enterococcus(Z=-2.27,P<0.05)、Catenibacterium(Z=-2.48,P<0.05)、Clostridium_sensu_stricto_1(Z=-2.50,P<0.05)菌属在健康对照组的肠道中丰度明显增多。结论慢性功能性便秘患者的肠道菌群与健康人群的菌群存在较大差异,通过改变肠道菌群可能成为治疗慢性功能性便秘的新策略。展开更多
Aims Theories based on resource additions indicate that plant species richness is mainly determined by the number of limiting resources.However,the individual effects of various limiting resources on species richness ...Aims Theories based on resource additions indicate that plant species richness is mainly determined by the number of limiting resources.However,the individual effects of various limiting resources on species richness and aboveground net primary productivity(ANPP)are less well understood.Here,we analyzed potential linkages between additions of limiting resources,species loss and ANPP increase and further explored the underlying mechanisms.Methods Resources(N,P,K and water)were added in a completely randomized block design to alpine meadow plots in the Qinghai-Tibetan Plateau.Plant aboveground biomass,species composition,mean plant height and light availability were measured in each plot.Regression and analysis of variance were used to analyze the responses of these measures to the different resource-addition treatments.Important Findings Species richness decreased with increasing number of added limiting resources,suggesting that plant diversity was apparently determined by the number of limiting resources.Nitrogen was the most important limiting resource affecting species richness,whereas Pand K alone had negligible effects.The largest reduction in species richness occurred when all three elements were added in combination.Water played a different role compared with the other limiting resources.Species richness increased when water was added to the treatments with N and P or with N,P and K.The decreases in species richness after resource additions were paralleled by increases in ANPP and decreases in light penetration into the plant canopy,suggesting that increased light competitionwas responsible for the negative effects of resource additions on plant species richness.展开更多
Alpine Kobresia meadows are major vegetation types on the Qinghai-Tibetan Plateau. There is growing concern over their relationships among biodiversity, productivity and environments. Despite the im-portance of specie...Alpine Kobresia meadows are major vegetation types on the Qinghai-Tibetan Plateau. There is growing concern over their relationships among biodiversity, productivity and environments. Despite the im-portance of species composition, species richness, the type of different growth forms, and plant bio-mass structure for Kobresia meadow ecosystems, few studies have been focused on the relationship between biomass and environmental gradient in the Kobresia meadow plant communities, particularly in relation to soil moisture and edaphic gradients. We measured the plant species composition, her-baceous litter, aboveground and belowground biomass in three Kobresia meadow plant communities in Haibei Alpine Meadow Ecosystem Research Station from 2001 to 2004. Community differences in plant species composition were reflected in biomass distribution. The total biomass showed a de-crease from 13196.96±719.69 g/m2 in the sedge-dominated K. tibetica swamp to 2869.58±147.52 g/m2 in the forb and sedge dominated K. pygmaea meadow, and to 2153.08±141.95 g/m2 in the forbs and grasses dominated K. humilis along with the increase of altitude. The vertical distribution of below-ground biomass is distinct in the three meadow communities, and the belowground biomass at the depth of 0-10 cm in K. tibetica swamp meadow was significantly higher than that in K. humilis and K. pygmaea meadows (P<0.01). The herbaceous litter in K. tibetica swamp was significantly higher than those in K. pygnaeca and K. humilis meadows. The effects of plant litter are enhanced when ground water and soil moisture levels are raised. The relative importance of litter and vegetation may vary with soil water availability. In the K. tibetica swamp, total biomass was negatively correlated to species richness (P<0.05); aboveground biomass was positively correlated to soil organic matter, soil moisture, and plant cover (P<0.05); belowground biomass was positively correlated with soil moisture (P<0.05). However, in the K. pygnaeca and K. humilis meadow communities, abo展开更多
文摘目的探讨慢性功能性便秘患者与健康对照组之间肠道菌群的差异。方法选取便秘组和健康对照组共计20人,留取新鲜粪便样本,冰块运送至实验室并存放于-80度冰箱。采用16S r RNA测序技术检测V4区鉴定菌群。结果发现两组人群的菌群丰富度差异有统计学意义(P<0.05),菌群多样性差异无统计学意义。便秘患者与健康对照组之间的肠道细菌组成在门和属水平差异均存在显著统计学意义(P<0.05)。在门水平,便秘患者肠道中放线菌门(Actinobacteria)丰度显著增加(Z=-3.10,P<0.05),而变形菌门(Proteobacteria)丰度显著降低(Z=-2.42,P<0.05),在属水平发现20个菌属差异存在统计学意义(P<0.05)。其中,Coprobacillus(Z=-2.10,P<0.05)、Hungatella(Z=-2.31,P<0.05)、Holdemanella(Z=-2.32,P<0.05)、Anaerostipes(Z=-3.78,P<0.01)、Bacteroidales_S24-7_group_norank(Z=-2.15,P<0.05)、Bacteroides(Z=-3.78,P<0.01)、Blautia(Z=-3.78,P<0.05)、Collinsella(Z=-3.02,P<0.05)、Dorea(Z=-2.95,P<0.05)、[Eubacterium]_ruminantium_group(Z=-2.70,P<0.05)、Erysipelotrichaceae_UCG-003(Z=-3.10,P<0.05)、Ruminococcaceae_uncultured(Z=-2.50,P<0.05)、Parabacteroides(Z=-2.87,P<0.05)菌属在便秘患者的肠道中丰度明显增多,而Megasphaera(Z=-2.31,P<0.05)、Paraprevotella(Z=-2.94,P<0.05)、Prevotella_2(Z=-3.10,P<0.05)、Prevotella_9(Z=-3.68,P<0.01)、Enterococcus(Z=-2.27,P<0.05)、Catenibacterium(Z=-2.48,P<0.05)、Clostridium_sensu_stricto_1(Z=-2.50,P<0.05)菌属在健康对照组的肠道中丰度明显增多。结论慢性功能性便秘患者的肠道菌群与健康人群的菌群存在较大差异,通过改变肠道菌群可能成为治疗慢性功能性便秘的新策略。
基金National Natural Science Foundation of China(30970465)Research Station of Alpine Meadow and Wetland Ecosystems of Lanzhou University.
文摘Aims Theories based on resource additions indicate that plant species richness is mainly determined by the number of limiting resources.However,the individual effects of various limiting resources on species richness and aboveground net primary productivity(ANPP)are less well understood.Here,we analyzed potential linkages between additions of limiting resources,species loss and ANPP increase and further explored the underlying mechanisms.Methods Resources(N,P,K and water)were added in a completely randomized block design to alpine meadow plots in the Qinghai-Tibetan Plateau.Plant aboveground biomass,species composition,mean plant height and light availability were measured in each plot.Regression and analysis of variance were used to analyze the responses of these measures to the different resource-addition treatments.Important Findings Species richness decreased with increasing number of added limiting resources,suggesting that plant diversity was apparently determined by the number of limiting resources.Nitrogen was the most important limiting resource affecting species richness,whereas Pand K alone had negligible effects.The largest reduction in species richness occurred when all three elements were added in combination.Water played a different role compared with the other limiting resources.Species richness increased when water was added to the treatments with N and P or with N,P and K.The decreases in species richness after resource additions were paralleled by increases in ANPP and decreases in light penetration into the plant canopy,suggesting that increased light competitionwas responsible for the negative effects of resource additions on plant species richness.
基金Supported by the Hundred Talents Programs of the Chinese Academy of Sciencesthe National Natural Science Important Foundation of China (Grant No. 30730069)
文摘Alpine Kobresia meadows are major vegetation types on the Qinghai-Tibetan Plateau. There is growing concern over their relationships among biodiversity, productivity and environments. Despite the im-portance of species composition, species richness, the type of different growth forms, and plant bio-mass structure for Kobresia meadow ecosystems, few studies have been focused on the relationship between biomass and environmental gradient in the Kobresia meadow plant communities, particularly in relation to soil moisture and edaphic gradients. We measured the plant species composition, her-baceous litter, aboveground and belowground biomass in three Kobresia meadow plant communities in Haibei Alpine Meadow Ecosystem Research Station from 2001 to 2004. Community differences in plant species composition were reflected in biomass distribution. The total biomass showed a de-crease from 13196.96±719.69 g/m2 in the sedge-dominated K. tibetica swamp to 2869.58±147.52 g/m2 in the forb and sedge dominated K. pygmaea meadow, and to 2153.08±141.95 g/m2 in the forbs and grasses dominated K. humilis along with the increase of altitude. The vertical distribution of below-ground biomass is distinct in the three meadow communities, and the belowground biomass at the depth of 0-10 cm in K. tibetica swamp meadow was significantly higher than that in K. humilis and K. pygmaea meadows (P<0.01). The herbaceous litter in K. tibetica swamp was significantly higher than those in K. pygnaeca and K. humilis meadows. The effects of plant litter are enhanced when ground water and soil moisture levels are raised. The relative importance of litter and vegetation may vary with soil water availability. In the K. tibetica swamp, total biomass was negatively correlated to species richness (P<0.05); aboveground biomass was positively correlated to soil organic matter, soil moisture, and plant cover (P<0.05); belowground biomass was positively correlated with soil moisture (P<0.05). However, in the K. pygnaeca and K. humilis meadow communities, abo
