Differences in the gut microbiota between Gurkhas and soldiers of British origin

Study information

Needs review

study design

cross-sectional observational, not case-control

Citation

PMID PubMed identifier for scientific articles.

38113233

DOI Digital object identifier for electronic documents.

https://doi.org/10.1371/journal.pone.0292645

URI Uniform resource identifier for web resources.

Authors

Troth TD, McInnes RS, Dunn SJ, Mirza J, Whittaker AH, Goodchild SA, Loman NJ, Harding SV, van Schaik W

Journal

PloS one

Year

2023

Previous work indicated that the incidence of travellers' diarrhoea (TD) is higher in soldiers of British origin, when compared to soldiers of Nepalese descent (Gurkhas). We hypothesise that the composition of the gut microbiota may be a contributing factor in the risk of developing TD in soldiers of British origin. This study aimed to characterise the gut microbial composition of Gurkha and non-Gurkha soldiers of the British Army. Recruitment of 38 soldiers (n = 22 Gurkhas, n = 16 non-Gurkhas) and subsequent stool collection, enabled shotgun metagenomic sequencing-based analysis of the gut microbiota. The microbiota of Gurkhas had significantly (P < 0.05) lower diversity, for both Shannon and Simpson diversity indices, using species level markers than the gut microbiota of non-Gurkha soldiers. Non-metric Multidimensional Scaling (NMDS) of the Bray-Curtis distance matrix revealed a significant difference in the composition of the gut microbiota between Gurkhas and non-Gurkha soldiers, at both the species level (P = 0.0178) and the genus level (P = 0.0483). We found three genera and eight species that were significantly enriched in the non-Gurkha group and one genus (Haemophilus) and one species (Haemophilus parainfluenzae) which were enriched in the Gurkha group. The difference in the microbiota composition between Gurkha soldiers and soldiers of British origin may contribute to higher colonization resistance against diarrhoeal pathogens in the former group. Our findings may enable further studies into interventions that modulate the gut microbiota of soldiers to prevent TD during deployment.

Experiment 1

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Curated date: 2025/09/22

Curator: SheikhAlMamun

Revision editor(s): SheikhAlMamun

Subjects

Location of subjects: United Kingdom

Host species Species from which microbiome was sampled. Contact us to have more species added.: Homo sapiens

Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology: Feces Cow dung,Cow pat,Droppings,Dung,Excrement,Excreta,Faeces,Fecal material,Fecal matter,Fewmet,Frass,Guano,Matières fécales@fr,Merde@fr,Ordure,Partie de la merde@fr,Piece of shit,Porción de mierda@es,Portion of dung,Portion of excrement,Portion of faeces,Portion of fecal material,Portion of fecal matter,Portion of feces,Portion of guano,Portion of scat,Portionem cacas,Scat,Spoor,Spraint,Stool,Teil der fäkalien@de,Feces,feces

Group 0 name Corresponds to the control (unexposed) group for case-control studies: British soldiers

Group 1 name Corresponds to the case (exposed) group for case-control studies: Gurkhas

Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: This field could be left blank or potentially used to describe factors related to the differences observed, if any are known and being controlled for, although the core "condition" is the origin (Gurkhas vs. British soldiers).

Group 0 sample size Number of subjects in the control (unexposed) group: 22

Group 1 sample size Number of subjects in the case (exposed) group: 16

Antibiotics exclusion Number of days without antibiotics usage (if applicable) and other antibiotics-related criteria used to exclude participants (if any): 3 months

Lab analysis

Sequencing type: 16S

16S variable region One or more hypervariable region(s) of the bacterial 16S gene: V1-V4

Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance: Illumina

Statistical Analysis

Data transformation Data transformation applied to microbial abundance measurements prior to differential abundance testing (if any).: relative abundances

Statistical test: MaAsLin2

Significance threshold p-value or FDR threshold used for differential abundance testing (if any): 0.05

MHT correction Have statistical tests be corrected for multiple hypothesis testing (MHT)?: Yes

LDA Score above Threshold for the linear discriminant analysis (LDA) score for studies using the popular LEfSe tool: 3

Alpha Diversity

Pielou Quantifies how equal the community is numerically: decreased

Shannon Estimator of species richness and species evenness: more weight on species richness: decreased

Chao1 Abundance-based estimator of species richness: unchanged

Simpson Estimator of species richness and species evenness: more weight on species evenness: decreased

Inverse Simpson Modification of Simpsons index D as 1/D to obtain high values in datasets of high diversity and vice versa: decreased

Richness Number of species: decreased

Faith Phylogenetic diversity, takes into account phylogenetic distance of all taxa identified in a sample: unchanged

Signature 1

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Source: Figure 1

Description: British soldiers' gut microbiota included 41 unique genera over 1% abundance. The most common were Bacteroides, Blautia, Dorea, Eubacterium, and Roseburia, present in all samples, while Anaerotruncus was least common, found in just one sample.

Abundance in Group 1: increased abundance in Gurkhas

NCBI	Quality Control	Links
Lachnospira
Lactobacillus
Megamonas
Oscillibacter
Prevotella
Roseburia
Ruminococcus
Streptococcus
ParasutterelaParasutterela
ParabacteroidsParabacteroids
Blautia
Dorea
Eubacterium

Revision editor(s): SheikhAlMamun

Signature 2

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Mark reviewed

Your review change was submitted

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Curated date: 2025/09/22

Curator: SheikhAlMamun

Revision editor(s): SheikhAlMamun

Source: Figure 1

Description: British soldiers' gut microbiota included 41 unique genera over 1% abundance. The most common were Bacteroides, Blautia, Dorea, Eubacterium, and Roseburia, present in all samples, while Anaerotruncus was least common, found in just one sample.

Abundance in Group 1: increased abundance in Gurkhas