Looking into key bacterial proteins involved in gut dysbiosis

Table 1 Summary of primary key proteins

Classification	Name	Function	Ref.
Enzyme	DegP	Inhibiting EHEC biofilms.	[11]
Enzyme	Llp1, Llp2	Inhibiting biofilm formation of pathogen.	[12]
Enzyme	Protease of S. boulardii	Digesting both C. difficile toxin A and its receptor binding sites.	[15]
Enzyme	Lon protease	Degrading the oncogene c-MYC.	[19]
Secreted protein	P9	Inducing the secretion of GLP-1. Inducing the secretion of IL-6 in macrophages.	[21,22]
Secreted protein	Peptide B7	Reducing CCR2 expression on all APCs from health people.	[25]
Secreted protein	MAM	Inhibiting the NF-κB pathway and several cell immune responses. Inducing expression of TGF β.	[26-28]
Surface layer protein	MIMP	Inducing the secretion of anti- inflammatory cytokines and inhibiting inflammatory cytokines. Enhancing the intestinal barrier.	[29]
Enzyme	OGA	Hydrolysing O-GlcNAcylated NF-κB-p65 and IKKβ to inhibit NF-κB signaling.	[30]
Bacteriocins	PediocinPA-1/AcHnisin Z	Reducing colonization of VRE in vivo.	[38]
	Microcin	limiting the expansion of pathogens.	[39,40]
Bacteriocins	Enterocins	Inhibiting a wide spectrum of Gram-positive bacteria. Inhibiting the growth of cancer cells.	[42,43]
Bacteriocins	Bacteriocin A, B	Degrading pathogenic biofilm and having antibacterial potential.	[36]
Bacteriocins	Nisin A	Changing the integrity of the cancer cell membrane.	[44]
Secreted protein	P8	Inducing host cell growth arrest at the G2 phase.	[46,47]
Ribosomal proteins	HPRP-A1; HPRP-A2	Resisting infection. Arresting the cancer cells cycle at the G0/G1 phase and G2/M phase.	[48-53]
Innermembrane protein	Pre-FadA	Binding host epithelial cells.	[54]
Secreted protein	m-FadA	Inducing the invasion of host cells.	[54]
Outer membrane protein	Fap2	Leading to colonization of Fn. Facilitating tumor immunity evasion. Binding to and activating TIGIT. Inducing host lymphocyte apoptosis.	[55-57]
Secreted proteins	OMVs of Fn	Inducing the colonization of host epithelial cells.	[58-60]
Cell envelope-associated multiprotein systems	Sus-like systems	Inducing the colonization of host epithelial cells.	[64]
Pili	SpaCBA	Inducing the adhesion of mucus.	[66,67]
Secreted proteins	EVs	Inducing the expression of the TJ protein-encoding genes and regulating the intestinal barrier. Inducing the expression of PPARα and PPARγ genes and ANGPTL4 gene. Inhibiting blood lipase lipoproteins in the bloodstream.	[71,72]
Secreted proteins	TcpC OMVs of EcN	Enhancing epithelial barrier.	[77-81]

EcN: Escherichia coli Nissle 1917; EVs: Extracellular vesicles; OMVs: Outer membrane vesicles.

Table 2 Summary of secondary key proteins

Classification	Name	Function	Ref.
Flagellin		Inducing the secretion of proinflammatory cytokines.	[87]
Flagellin		Recuiting flagellin specific CD4+ T-cells.	[85]
Flagellin		Inducing the secretion of flagellin antibodies.	[88,89]
Flagellin		Inducing the secretion of AMPs.	[90]
Flagellin		Inducing the secretion of human β-defensin 2.	[91]
Flagellin		Inducing the expression of lncRNA (HIF1A-AS2) and suppressing NF-kB signaling pathway activation.	[92]
Outer membrane protein	OmpC, OmpW	Adhesion and invasion of the CD-associated Escherichia coli in intestinal epithelial cells. Cross-reactive bacterial proteins.	[95-97]
Outer membrane protein	FomA	Inducing upregulation of CD86, MHC II, and primary B cells. Inducing secretion of antigen-specific antibody IgA and IgG.	[99,100]
Bacterial division protein	FtsZ	Cross-reacting with TBB-5 and mediating the secretion of p-ANCA.	[102,103]
Bacterial heat shock protein	GroEL	Cross-reacting with Hsp60 and inducing antibodies.	[110,111]

p-ANCA: Perinuclear antineutrophil cytoplasmic antibody.