. 2021 Mar 23;28(4):1029–1041. doi: 10.1111/odi.13843

TABLE 2.

General overview of studies investigating gut dysbiosis in relation to oral bacteria

Author	Study design	Aims	Subjects	Periodontitis definition	Periodontal assessment	Tissue sampled	Laboratory analysis	Key findings
Lourenςo et al., 2018	Case–control study	To characterize the gut microbiome of individuals with different periodontal conditions	7 PH, 14 G, 23 CP	PD: > 10% of teeth with PD and CAL ≥ 5 mm with BOP G: > 10% of sites with BOP and/or GI, no PD or CAL > 3 mm, although PD	Full‐mouth protocol: PPD, CAL, BoP, GI	Stool samples	Illumina MiSeq Sequencing	Lower alpha diversity in the gut microbiome of individuals with CP Firmicutes, Proteobacteria, Verrucomicrobia and Euryarchaeota increased, whereas Bacteroidetes decreased in patients with PD compared to PH Prevotella, Comamonadaceae and Lactobacillales detected in higher numbers in G, while Bacteroidales predominant in PH Mogibacteriaceae, Ruminococcaceae and Prevotella able to discriminate individuals with PD from PH
Dinakaran et al., 2019	Comparative study	To determine whether diseased full‐thickness colon specimens contain specific oral and gut pathogens	13 CD, 13 UC	NA	NA	Colonic mucosa specimens	16S rRNA sequencing (Illumina)	Proportion of non‐detrimental bacteria in CD or UC colon samples was altered compared to adjacent healthy colon specimens Microbiome of CD and UC diseased specimens is dominated by putative oral pathogens such as Streptococcus, Staphylococcus, Peptostreptococcus, Fusobacterium, Prevotella, Porphyromonas, Veilonella and Eubacterium
Strauss et al., 2011	Cross‐sectional	To determine whether F. nucleatum was associated with IBD patients and showed an increased capacity for invasion	17 CD, 4 UC, 1 IC, 34 HC (32 colon cancer screening, 2 IBS)	NA	NA	Colonic mucosa specimens	Fusobacterium‐selective agar plates (JVN plates): genomic DNA extracted from each isolate and used as template in a PCR	Fusobacterium spp. isolated from 63.6% of IBD patients versus 26.5% of HC The most recovered species was F. nucleatum, found in 50% of diseased patients and 17.6% of HC F. nucleatum from inflamed tissue of CD patients showed a significantly increased ability to invade Caco−2 cells in comparison with strains isolated from healthy tissue of both IBD and HC

Author

Study design

Aims

Subjects

Periodontitis definition

Periodontal assessment

Tissue sampled

Laboratory analysis

Key findings

Lourenςo et al., 2018

Case–control study

To characterize the gut microbiome of individuals with different periodontal conditions

7 PH,

14 G,

23 CP

PD: > 10% of teeth with PD and CAL ≥ 5 mm with BOP

G: > 10% of sites with BOP and/or GI, no PD or CAL > 3 mm, although PD

Full‐mouth protocol: PPD, CAL, BoP, GI

Stool samples

Illumina MiSeq Sequencing

Lower alpha diversity in the gut microbiome of individuals with CP

Firmicutes, Proteobacteria, Verrucomicrobia and Euryarchaeota increased, whereas Bacteroidetes decreased in patients with PD compared to PH

Prevotella, Comamonadaceae and Lactobacillales detected in higher numbers in G, while Bacteroidales predominant in PH

Mogibacteriaceae, Ruminococcaceae and Prevotella able to discriminate individuals with PD from PH

Dinakaran et al., 2019

Comparative study

To determine whether diseased full‐thickness colon specimens contain specific oral and gut pathogens

13 CD, 13 UC

Colonic mucosa specimens

16S rRNA sequencing (Illumina)

Proportion of non‐detrimental bacteria in CD or UC colon samples was altered compared to adjacent healthy colon specimens

Microbiome of CD and UC diseased specimens is dominated by putative oral pathogens such as Streptococcus, Staphylococcus, Peptostreptococcus, Fusobacterium, Prevotella, Porphyromonas, Veilonella and Eubacterium

Strauss et al., 2011

Cross‐sectional

To determine whether F. nucleatum was associated with IBD patients and showed an increased capacity for invasion

17 CD, 4 UC, 1 IC, 34 HC (32 colon cancer screening, 2 IBS)

Colonic mucosa specimens

Fusobacterium‐selective agar plates (JVN plates): genomic DNA extracted from each isolate and used as template in a PCR

Fusobacterium spp. isolated from 63.6% of IBD patients versus 26.5% of HC

The most recovered species was F. nucleatum, found in 50% of diseased patients and 17.6% of HC

F. nucleatum from inflamed tissue of CD patients showed a significantly increased ability to invade Caco−2 cells in comparison with strains isolated from healthy tissue of both IBD and HC

Abbreviations: CD: Crohn's disease; CP: chronic periodontitis; CPITN: community periodontal index of treatment needs; G: gingivitis; GCF: gingival crevicular fluid; GI: gingival index; HC: healthy controls; IBD: inflammatory bowel diseases; IBS: irritable bowel syndrome; IC: indeterminate colitis; PBS: papilla bleeding score; PCR: polymerase chain reaction; PD: periodontitis; PH: periodontal health; PI: plaque index; PPD: probing pocket depth; SoP: suppuration; UC: ulcerative colitis; VPI: visible plaque index.