The unique composition of Indian gut microbiome, gene catalogue, and associated fecal metabolome deciphered using multi-omics approaches

BACKGROUND

Metagenomic studies carried out in the past decade have led to an enhanced understanding of the gut microbiome in human health; however, the Indian gut microbiome has not been well explored. We analyzed the gut microbiome of 110 healthy individuals from two distinct locations (North-Central and Southern) in India using multi-omics approaches, including 16S rRNA gene amplicon sequencing, whole-genome shotgun metagenomic sequencing, and metabolomic profiling of fecal and serum samples.

RESULTS

The gene catalogue established in this study emphasizes the uniqueness of the Indian gut microbiome in comparison to other populations. The gut microbiome of the cohort from North-Central India, which was primarily consuming a plant-based diet, was found to be associated with Prevotella and also showed an enrichment of branched chain amino acid (BCAA) and lipopolysaccharide biosynthesis pathways. In contrast, the gut microbiome of the cohort from Southern India, which was consuming an omnivorous diet, showed associations with Bacteroides, Ruminococcus, and Faecalibacterium and had an enrichment of short chain fatty acid biosynthesis pathway and BCAA transporters. This corroborated well with the metabolomics results, which showed higher concentration of BCAAs in the serum metabolome of the North-Central cohort and an association with Prevotella. In contrast, the concentration of BCAAs was found to be higher in the fecal metabolome of the Southern-India cohort and showed a positive correlation with the higher abundance of BCAA transporters.

CONCLUSIONS

The study reveals the unique composition of the Indian gut microbiome, establishes the Indian gut microbial gene catalogue, and compares it with the gut microbiome of other populations. The functional associations revealed using metagenomic and metabolomic approaches provide novel insights on the gut-microbe-metabolic axis, which will be useful for future epidemiological and translational researches.

Demographic, clinical, biochemical, radiological and etiological characteristics of malignant pleural effusions from Eastern India

CONTEXT

There are very limited data regarding clinical, radiological and etiological aspects of malignant pleural effusion (MPE) from Eastern India.

AIMS

To review natural history, clinical features, radiological features and etiology of MPEs.

SETTING AND DESIGN

Hospital based cross-sectional descriptive study.

MATERIALS AND METHODS

We had reviewed166 diagnosed cases of MPEsregarding demography; clinical, radiological and biochemical characteristics, diagnostic modalities and etiologies.

RESULTS

Out of 166 patients, 72.89% were males and 27.11% were females. Mean age of presentation among males was 64.3 ± 12.7 and among females was 52.5 ± 14.8. Most common presenting symptom was dry cough (87.9%) and most common presenting sign was clubbing (54.5%). Massive effusion was found in 45.78% of cases. Pleural fluid macroscopic appearance was haemorrhagic in 54.82% of cases. Mean adenosine deaminase activity in MPE was 24.05 U/L. Mean pleural fluid/serum protein ratio was 0.65, mean pleural fluid/serum lactate dehydrogenase ratio was 1.01. Most of the cases (84.94%) were diagnosed by pleural fluid cytology for malignant cells. Primary cancer was diagnosed in 136 (81.93%) cases; among which 121 (88.97%) cases were lung cancers, among which adenocarcinoma (52.89%) was the most common histology.

CONCLUSIONS

Pleural fluid cytologies for malignant cells are usually sufficient to diagnose MPE in nearly 85% of cases and in remaining cases if thoracoscopyis not available, blind pleural biopsy can be helpful. The most common primary in cases of MPE is lung cancer with adenocarcinoma being the commonest culprit.