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Ghosh, T.

Publications and source records attributed to Ghosh, T..

2 recordsLinked to original sources

Gut microbiome recovery after antibiotic usage is mediated by specific bacterial species

Dysbiosis in the gut microbiome due to antibiotic usage can persist for extended periods of time, impacting host health and increasing the risk for pathogen colonization. The specific factors associated with variability in gut microbiome recovery remain unknown. Using data from 4 different cohorts in 3 continents comprising >500 microbiome profiles from 117 subjects, we identified 20 bacterial species exhibiting robust association with gut microbiome recovery post antibiotic therapy. Functional and growth analysis showed that microbiome recovery is supported by enrichment in carbohydrate degradation and energy production capabilities. Association rule mining on 782 microbiome profiles from the MEDUSA database enabled reconstruction of the gut microbial food-web, identifying many recovery-associated bacteria (RABs) as primary colonizing species, with the ability to use both host and diet-derived energy sources, and to break down complex carbohydrates to support the growth of other bacteria. Experiments in a mouse model recapitulated the ability of RABs (Bacteroides thetaiotamicron and Bifidobacterium adolescentis) to promote microbiome recovery with synergistic effects, providing a two orders of magnitude boost to microbial abundance in early time-points and faster maturation of microbial diversity. The identification of specific microbial factors promoting microbiome recovery opens up opportunities for rationally fine-tuning pre- and probiotic formulations that prevent pathogen colonization and promote gut health.

genomics

Sporosarcina pasteurii can form nanoscale crystals on cell surface

Using a semi-solid 0.5% agar column, we study the phenomenon of microbially induced mineral (calcium carbonate) by the bacteria Sporosarcina pasteurii. Our platform allows for in-situ visualization of the phenomena, and we found clear evidence of bacterial cell surface facilitating formation of nanoscale crystals. Moreover, in the bulk agar we found the presence of microspheres, which seem to arise from an aggregation of nanoscale crystals with needle like morphology. Extensive chemical characterization confirmed that the crystals to be calcium carbonate, and two different polymorphs (calcite and vaterite) were identified.

biophysics