Gut Liver.  2021 Mar;15(2):243-252. 10.5009/gnl19354.

Characteristics of the Gut Microbiome of Healthy Young Male Soldiers in South Korea: The Effects of Smoking

• Yoon H
• Lee DH
• Lee JH
• Kwon JE
• Shin CM
• Yang SJ
• Park SH
• Lee JH
• Kang SW
• Lee JS
• Kim BY

• KMID: 2513697
• DOI: http://doi.org/10.5009/gnl19354

Abstract

Background/Aims
South Korean soldiers are exposed to similar environmental factors. In this study, we sought to evaluate the gut microbiome of healthy young male soldiers (HYMS) and to identify the primary factors influencing the microbiome composition.
Methods
We prospectively collected stool from 100 HYMS and performed next-generation sequencing of the 16S rRNA genes of fecal bacteria. Clinical data, including data relating to the diet, smoking, drinking, and exercise, were collected.
Results
The relative abundances of the bacterial phyla Firmicutes, Actinobacteria, Bacteroidetes, and Proteobacteria were 72.3%, 14.5%, 8.9%, and 4.0%, respectively. Fifteen species, most of which belonged to Firmicutes (87%), were detected in all examined subjects. Using cluster analysis, we found that the subjects could be divided into the two enterotypes based on the gut microbiome bacterial composition. Compared with enterotype 2 subjects, subjects classified as enterotype 1 tended to be characterized by higher frequencies of potentially harmful lifestyle habits (current smoker: 55.6% vs 36.6%, p=0.222; heavy drinker: 16.7% vs 3.7%, p=0.120; insufficient physical activity: 27.8% vs 14.6%, p=0.318). We identified a significant difference in the microbiome compositions of current and noncurrent smokers (p=0.008); the former differed from the latter mainly in a relatively lower abundance of Bifidobacterium species and a higher abundance of Negativicutes.
Conclusions
A high abundance of Actinobacteria and low abundance of BacteroidetesBifidobacterium and higher abundance of Negativicutes

Keyword

Microbiota; Health; Smokers; Military personnel