Table 1.

Changes in gut microbiota in patients with cancer-causing viral infections.

Infection	Study Population	Study Characteristics	Observed Microbial Changes	Reference
Pulmonary Tuberculosis	31 healthy controls vs. 46 patients from China	Patients with active Mycobacterium tuberculosis infection; gut microbial signatures using shotgun sequencing	Depletion of SCFA producing microbes (Roseburia inulinivorans, R. hominis, R. intestinalis, Eubacterium rectale, and Coprococcus comes, Bifidobacterium adolescentis and B. longum, Ruminococcus obeum, and Akkermansia muciniphila); lower microbial metabolic functions related to SCFA production; decrease in alpha diversity.	[128]
Hepatitis B virus (HBV)	30 Asymptomatic HBV carriers, 31 chronic hepatitis B, 31 decompensated HBV cirrhosis, and 32 health controls from China	16S rRNA sequencing of fecal microbiota and qPCR-based analysis of bacterial virulence genes	Depletion of Lactobacillus, Pediococcus, Leuconostoc, and Weissella in symptomatic patients; variation in F. prausnitzii, E. faecalis, and Enterobacteriaceae in asymptomatic carriers; lower Bifidobacteria-to-Enterobacteriaceae ratio in subjects with infections; lower abundance of Clostridium clusters XI and XIVab in decompensated HBV cirrhotic patients.	[129]
Urinary tract infection	168 kidney transplant patients, with 30% developing Enterobacteriaceae bacteremia within 6-mo of transplantation from USA	16S rRNA sequencing; fecal samples	Increased abundance of Faecalibacterium and Romboutsia, and lower Lactobacillus; decreased microbial diversity.	[130]
Human immunodeficiency virus (HIV)	31 HIV patients (18 with antiretroviral treatment) vs. 27 healthy controls from France	16S rRNA sequencing; fecal samples	Lower microbial diversity in HIV patients; Lower Clostridia, Subdoligranulum, Ruminococcus, Blautia, Faecalibacterium, Bifidobacterium, and increased gamma-proteobacteria, Enterococcus in HIV patients; systemic inflammatory markers were inversely correlated with R. bromii and F. prausnitzii, whereas associated with E. coli, Enterobacter aerogenes, E. faecalis and E. faecium.	[131]
Human papillomavirus (HPV)	345 women having infection with 27 different HPV types Sweden	16S rRNA sequencing; vaginal fluid samples	Prevalence of Lactobacillus crispatus and L. iners; infected subjects had higher microbial diversity; abundance of Sneathia, Prevotella, and Megasphaera were associated with HPV infection.	[132]
Hepatitis C virus (HCV)	166 HCV infected patients vs. 23 healthy subjects from Japan	16S rRNA sequencing from fecal samples	Less abundance of Lachnospiraceae and Ruminococcaceae in the patients; a decrease of Streptococcus salivarius and increase of Lactobacillus spp. with disease progression.	[62]
Chlamydia trachomatis	42 infected and 35 non-infected subjects from Malaysia	16S rRNA sequencing; endocervical swab samples	Lower abundance of Tenericutes and Proteobacteria, and increased abundance of Delftia, Streptococcus, Pseudomonas, Cloacibacterium, Prevotella, Veillonella, Megasphaera, Ureaplasma, and Ralstonia in infected subjects	[133]
Opisthorchis viverrini	30 infected and 26 non-infected subjects from Russia; all 54 were diagnosed with cholelithiasis	16S rRNA sequencing of samples from gall bladder	Increased abundance of Spirochaetes, Planctomycetes, Synergistetes, Verrucomicrobia, and Saccharibacteria (TM7) in infected patients; detection of Veillonella dispar, Paracoccus aminovorans, Parabacteroides distasonis, Sphingomonas changbaiensis, Cellulosimicrobium sp., Phycicoccus spp. only in infected patients, whereas Flectobacillus sp., Xanthobacter sp., Burkholderia sp., Streptomyces sp., Jeotgalicoccus psychrophilus, and Treponema socranskii present only in un-infected subjects.	[134]
Urogenital schistosomiasis	116 pre-school children with infection from UK	16S rRNA sequencing from fecal samples	The most abundant genera were Prevotella, Bacteroides, Alistipes, Eubacterium, Faecalibacterium, Clostridium, Roseburia; Pseudomonas, Azospirillum, Stenotrophomonas, Derxia, and Thalassospira were associated with infection.	[135]
Kaposi’s sarcoma (KS)-associated herpesvirus	29 subjects from USA with pathology-confirmed KS who were serologically positive for KS-associated herpesvirusand HIV infection	16S rRNA gene sequencing of samples from an oral swab	Lower microbial diversity and observed species and distinctly altered microbial taxonomic signatures in subjects with oral KS without any oral cell-associated HIV infection; the abundance of Aggregibacter and Lautropia were higher, but Corynebacterium and Shuttleworthia were lower in subjects with no oral KS.	[136]