Table 1.

Intestinal microbiota alternation during anticancer treatment in clinical studies

Study year (ref)	Number of patients	Anticancer treatment	Bacteria-detecting techniques	Samples	Bacteria Alteration
Rajagopala et al., 2019 [40]	32 pediatric and adolescent acute lymphoblastic leukemia (ALL) patients	Chemotherapy	qPCR and 16S rRNA gene sequencing	Feces	Relative abundance:
					Phylum level:
					Firmicutes↓; Bacteroidetes↑
					Genus level: Bacteroides↑
					Alistipes↓; Parabacteroides↑
					Lachnospiraceae-UCG-005↑
					Faecalibacterium↓
					Pseudobutyrivibrio↓
					Lachnoclostridium↑; Fusicatenibacter↓
Wang el at., 2019 [2]	Eighteen patients with stage II-IV cervical cancer (CCa)	Pelvic radiotherapy DT: 50.4 Gy in 28 fractions	DNA extraction; 16S rRNA gene sequencing and bioinformatics	Feces	Relative abundance:
					Phylum level: Bacteroidetes↑
					Proteobacteria↑ Firmicutes↓
					Class level: Gammaproteobacteria↑
					Order level: Enterobacteriales↑
					Oceanospirillales↑
					Family level: Enterobacteriaceae↑
					Phyllobacteriaceae↑
					Beijerinckiaceae↑
					Ruminococcaceae↓; Bacteroidaceae↓
					Genus level: Serratia↑
					Bacteroides↑ Prevotella↑
					Megamonas↑, Novosphingobium↑
					Prevotella↑
Montassier et al., 2015 [9]	28 patients with non-Hodgkin lymphoma	5 consecutive chemotherapy days: high-dose carmustine (bis-chloroethylnitrosourea), etoposide, aracytine and melphalan	16S rRNA gene sequencing and 454 high-throughput pyrosequencing	Feces	Relative abundance:
					Phylum level:
					Firmicutes↓; Actinobacteria↓
					Proteobacteria↑
					Family level: Enterococcaceae↑
					Enterobacteriaceae↑
					Genus level: Ruminococcus↓
					Oscillospira↓, Blautia↓
					Lachnospira↓, Roseburia↓
					Dorea↓, Coprococcus↓
					Anaerostipes↓, Clostridium↓
					Collinsella↓; Adlercreutzia↓
					Bifidobacterium↓; Citrobacter↑
					Klebsiella↑, Enterococcus↑
					Megasphaera↑, Parabacteroides↑
Wang et al., 2015 [8]	8 females with cervical cancer, 1 female with anal cancer and 2 males with colorectal cancer	Conventional radiotherapy at a dosage of 1.8-2.0 Gy/day, five times a week during the 5-week period (a cumulative dosage of 44-50 Gy)	454 high-throughput pyrosequencing	Feces	Relative abundant:
					Phylum level:
					Firmicutes/Bacteroidetes ratio↓
					Family level:
					Lachnospiraceae↓
					Genus level: Faecalibacterium↓,
					Oscillibacter↓, Roseburia↓,
					Streptococcus↓; Clostridium↑
					Bacteroides↑
Stringer et al., 2013 [42]	11 patients with colorectal cancer; 2 with breast cancer; 1 with melanoma, and 2 healthy individuals	Different chemotherapy treatment protocols with or without concomitant antibiotics	qPCR	Feces	Relative abudance:
					Genus level: Lactobacillus↓,
					Bacteroides↓, Bifidobacterium↓,
					Enterococcus↓, Staphylococcus↑
					Species level: Escherichia coli↑
Nam et al., 2013 [41]	9 gynecological cancer patients	Pelvic radiotherapy DT: 50.4 Gy in 28 fractions	454 high-throughput pyrosequencing	Feces	Relative abundant:
					Phylum level:
					Firmicutes↓, Fusobacterium↑
					Family level: Eubacteriaceae↓,
					Fusobacteriaceae↑; Streptococcacea↑

*↑, increase; ↓, decrease.