Gut microbiota plays multiple important roles in intestinal and physiological homeostasis, and using fecal microbiota transplantation (FMT) to reprogram gut microbiota has demonstrated promise for redressing intestinal and physiological disorders. This study tested the alterations in reprogramming efficiency caused by different gut preparation procedures and explored the associated underlying mechanisms. We prepared the guts of mice for FMT by administering one of the three most-clinically used pretreatments [antibiotics, bowel cleansing (BC) solution, or no pretreatment], and we found that preparing the gut with antibiotics induced a more efficient modification of the gut bacterial community than was induced by either of the other two pretreatment types. The increased efficiency of antibiotic treatment appeared to occur via increasing the xenomicrobiota colonization. Further analysis demonstrated that antibiotic treatment of mice induced intestinal microbiota disruption, mostly by expelling antibiotic-sensitive bacteria, while the indigenous microbiota was maintained after treatment with a BC solution or in the absence of pretreatment. The amount of antibiotic-resistant bacteria increased shortly after antibiotics usage but subsequently decreased after FMT administration. Together, these results suggest that FMT relied on the available niches in the intestinal mucosa and that preparing the gut with antibiotics facilitated xenomicrobiota colonization in the intestinal mucosa, which thus enhanced the overall gut microbiota reprogramming efficiency.

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The community structure of colonised bacteria in the gastrointestinal tracts (GITs) of pre-weaned calves is affected by extrinsic factors, such as the genetics and diet of the calves; however, the dietary impact is not fully understood and warrants further research. Our study revealed that a total of 6, 5, 2 and 10 bacterial genera showed biologically significant differences in the GITs of pre-weaned calves fed four waste-milk diets: acidified waste milk, pasteurised waste milk, untreated bulk milk, and untreated waste milk, respectively. Specifically, generic biomarkers were observed in the rumen (e.g., Bifidobacterium, Parabacteroides, Fibrobacter, Clostridium, etc.), caecum (e.g., Faecalibacterium, Oxalobacter, Odoribacter, etc.) and colon (e.g., Megamonas, Comamonas, Stenotrophomonas, etc.) but not in the faeces. In addition, the predicted metabolic pathways showed that the expression of genes related to metabolic diseases was increased in the calves fed untreated waste milk, which indicated that untreated waste milk is not a suitable liquid diet for pre-weaned calves. This is the first study to demonstrate how different types of waste milk fed to pre-weaned calves affect the community structure of colonised bacteria, and the results may provide insights for the intentional adjustment of diets and gastrointestinal bacterial communities.

Abstract• The key message N addition decreased soil inorganic P availability, microbial biomass P, and acid phosphatase activity in the larch plantation. Soil inorganic P availability decreased after N addition due to the changes in both microbial properties and plant uptake.• Context Soil phosphorus (P) availability is considered an important factor in influencing the biomass production of plants. Sustained inputs of nitrogen (N) through atmospheric deposition or N fertilizers, particularly in temperate forests, may change the composition and availability of P and thus affect long-term forest productivity.• Aims The objective of this study was to assess soil P availability, P fractions, and microbial properties including microbial biomass P and acid phosphatase activity after 9 consecutive years of N addition in a larch (Larix gmelinii) plantation, northeastern China.• Methods From 2003 to 2011, NH 4 NO 3 was added to replicate plots (three 20 m×30 m plots) in the larch plantation each year at a rate of 100 kg N ha. Soil samples from 0-10-cm and 10-20-cm depths were collected in N addition plots and control (no N addition) plots.• Results N addition significantly decreased soil NaHCO 3 -Pi (Pi is inorganic P), microbial biomass P, and acid phosphatase activity but increased the NaOH-Pi concentration. N addition appeared to induce a decrease in soil inorganic P availability by changing pH and P uptake by trees. In addition, N addition significantly decreased the NaOH-Po (Po is organic P) concentration, possibly because of increased P mineralization. However, the total P and other P fractions were unaffected by N fertilization.• Conclusion Our results suggested that N addition enhanced P uptake by trees, whereas it reduced soil inorganic P availability as well as microbial biomass and activity related to soil P cycling in the larch plantation.Keywords Larch plantation . Microbial biomass P . Phosphorus availability . Phosphatase activity IntroductionNitrogen (N) is generally believed to be the one nutrient limiting primary productivity in a wide variety of terrestrial ecosystems (LeBauer and Treseder 2008), particularly in Handling Editor: Andreas BOLTE Contribution of the co-authors Kai Yang-designed and ran the experiment, analyzed the data, and wrote the manuscript. Jiaojun Zhu-supervised the experiment design and data analysis and wrote the manuscript. Jiacun Gu-sample analysis and gave the help in running the experiment. Lizhong Yu-sample analysis and gave the help in running the experiment. Zhengquan Wang-designed the experiment and gave the suggestions to the composition of manuscript.Electronic supplementary material The online version of this article