Project description:Ulcerative colitis (UC) is a chronic inflammatory disease of the colon, associated with gut microbiota dysbiosis. While global studies have explored this link, region-specific microbial profiles remain underreported. This pilot study aimed to characterize and compare, for the first time, the gut microbiota of Lebanese UC patients and healthy controls using 16S rRNA gene sequencing (V3–V4 region). Fecal samples from 11 UC patients and 11 healthy individuals were analyzed. Alpha and beta diversity metrics were computed, and gut microbial composition was assessed across taxonomic levels. Statistical comparisons used Mann-Whitney and Fisher’s exact tests. UC patients showed significantly reduced microbial diversity based on Faith’s Phylogenetic Diversity and Shannon index (p < 0.05), though evenness was unaffected. Beta diversity also revealed significant group-level dissimilarities (p < 0.05). At the phylum level, Bacteroidota was elevated in UC, while Bacillota and Actinomycetota were reduced. Genera such as Ruminococcus, Fusicatenibacter, Mediterraneibacter, Eubacterium, and Coprococcus were depleted in UC. Faecalibacterium, commonly reduced in UC, showed no significant difference. This first analysis of gut microbiota in Lebanese UC patients reveals a distinct microbial signature that partially diverges from global trends, supporting the need for region-specific microbiome studies and personalized microbiota-targeted therapies.
2025-11-27 | GSE303706 | GEO
Project description:studies of microbial diversity
| PRJNA970525 | ENA
Project description:studies of microbial diversity
Project description:Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be a two-step process catalysed by chemolithoautotrophic microorganisms oxidizing either ammonia or nitrite. No known nitrifier carries out both steps, although complete nitrification should be energetically advantageous. This functional separation has puzzled microbiologists for a century. Here we report on the discovery and cultivation of a completely nitrifying bacterium from the genus Nitrospira, a globally distributed group of nitrite oxidizers. The genome of this chemolithoautotrophic organism encodes the pathways both for ammonia and nitrite oxidation, which are concomitantly activated during growth by ammonia oxidation to nitrate. Genes affiliated with the phylogenetically distinct ammonia monooxygenase and hydroxylamine dehydrogenase genes of Nitrospira are present in many environments and were retrieved on Nitrospira contigs in new metagenomes from engineered systems. These findings fundamentally change our picture of nitrification and point to completely nitrifying Nitrospira as key components of nitrogen-cycling microbial communities.