Agricultural Risk Factors Influence Microbial Ecology in Honghu Lake

Agricultural activities, including stock-farming, planting industry, and fish aquaculture,can affect the physicochemical and biological characters of freshwater lakes. However, the effects of pollution producing by agricultural activities on microbial ecosystem of lakes remain unclear.Hence, in this work, we selected Honghu Lake as a typical lake that is influenced by agriculture activities. We collected water and sediment samples from 18 sites, which span a wide range of areas from impacted and less-impacted areas. We performed a geospatial analysis on the composition of microbial communities associated with physicochemical properties and antibiotic pollution of samples. The co-occurrence networks of water and sediment were also built and analyzed. Our results showed that the microbial communities of impacted and less-impacted samples of water were largely driven by the concentrations of TN, TP, NO_3^--N, and NO_2^--N, while those of sediment were affected by the concentrations of Sed-OM and Sed-TN. Antibiotics have also played important roles in shaping these microbial communities: the concentrations of oxytetracycline and tetracycline clearly reflected the variance in taxonomic diversity and predicted functional diversity between impacted and less-impacted sites in water and sediment samples, respectively. Furthermore, for samples from both water and sediment, large differences of network topology structures between impacted and less-impacted were also observed. Our results provide compelling evidence that the microbial community can be used as a sentinel of eutrophication and antibiotics pollution risk associated with agricultural activity; and that proper monitoring of this environment is vital to maintain a sustainable environment in Honghu Lake.

Micro-coevolution of host genetics with gut microbiome in three Chinese ethnic groups

Understanding the micro-coevolution of the human gut microbiome with host genetics is challenging but essential in both evolutionary and medical studies.To gain insight into the interactions between host genetic variation and the gut microbiome,we analyzed both the human genome and gut microbiome collected from a cohort of 190 students in the same boarding college and representing 3 ethnic groups,Uyghur,Kazakh,and Han Chinese.We found that differences in gut microbiome were greater between genetically distinct ethnic groups than those genetically closely related ones in taxonomic composition,functional composition,enterotype stratification,and microbiome genetic differentiation.We also observed considerable correlations between host genetic variants and the abundance of a subset of gut microbial species.Notably,interactions between gut microbiome species and host genetic variants might have coordinated effects on specific human phenotypes.Bacteroides ovatus,previously reported to modulate intestinal immunity,is significantly correlated with the host genetic variant rs12899811(meta-P=5.55×10^(-5)),which regulates the VPS33B expression in the colon,acting as a tumor suppressor of colorectal cancer.These results advance our understanding of the micro-coevolution of the human gut microbiome and their interactive effects with host genetic variation on phenotypic diversity.