Achieve remission if you reduce the number of these bacteria in your small intestine!

Section	Note
Section 1. Bacteria presumable psoriagenic and Table 1	Based on the work (Peslyak & Korotky 2021).
Section 2. Table 2. Gram(-) TLR4-active gastrointestinal bacteria (enhancing the effect of psoriagenic).	Based on the work (Peslyak & Korotky 2021, Peslyak 2026).
Section 3. Table 3. Dependence of psoriasis severity on the concentration of bacteria in the small intestinal microbiome (conditionally).	From the work (Peslyak 2026)
Section 4. Table 4. The main goals when adjusting the small intestinal microbiome.
Bibliography	.

Section 1.
Table 1 lists all bacteria presumable psoriagenic.
These are all species of Streptococcus, most species of Leuconostoc, Weissella and Oenococcus, as well as some species of Lactococcus. PsB is also found among several species of other genera (in particular, Enterococcus faecalis. All PsB have a peptidoglycan (the basis of their cell wall) containing interpeptide bridges of the (L-Ala)-(L-Ala) and/or (L-Ser)-(L-Ala) types. This peptidoglycan is similar to the peptidoglycan of the pathogenic bacterium Streptococcus pyogenes.

Within the framework of the YN–model of psoriasis pathogenesis, it is assumed that the antigen that causes an inadequate reaction of the cutaneous immune system originates from fragments of the interpeptide bridges of this particular peptidoglycan.

Formation of these bridges in peptidoglycans is caused by the presence of enzymes such as murM and murN.
murM is an enzyme that ensures the attachment of serine/alanine (the first amino acid starting from Lys) in the formation of an interpeptide bridge in peptidoglycan. In the absence of this enzyme, there will be almost no bridges. What exactly is attached (serine or alanine) depends on the allele of the murM gene.
murN is an enzyme that ensures the attachment of alanine (the second amino acid starting from Lys) in the formation of an interpeptide bridge in a peptidoglycan. In the absence of this enzyme, the bridge will be one amino acid long. In different bacteria, the formation of interpeptide bridges is provided by different murMN genes (Peslyak & Korotky 2021).

The KEGG database identifies all bacterial species (among those included in this database) that have genes that ensure the secretion of both enzymes, i.e. both murM and murN.

Table 1. PsB – Gram+ bacteria presumable psoriagenic

Genus/species	Characteristics, source of income, note	Presence GI microbiome (%)
Commensals and opportunistic pathogens***
Enterococcus faecalis	The colon microbiome is the main source of entry into the small intestine. Correlation between E. faecalis and psoriasis (Ely 2018, Ramírez-Boscá 2015, Memariani 2025, Zhou 2022, Gumayunova 2016).	The small intestine is a conditional pathogen (less than 1%). Colon – commensal (at least 1%) (Krawczyk 2021).
Eubacterium sulci	Oral microbiome and URP.	Conditional pathogen
.	.	.
Lactococcus sp.	Some types are used in the production of fermented dairy products.	Less than 1%. Probably by consuming fermented dairy products or poorly cooked foods.
Lactococcus carnosus	Beef steaks (raw)
Lactococcus formosensis	Fermented broccoli sprouts
Lactococcus garvieae	Pathogen to fish, animals, and (very rarely) to humans.
Lactococcus petauri	Pathogen for some animals
Lactococcus piscium	Pathogen for fish. It is used in the preservation of seafood.
Lactococcus raffinolactis	It ferments raffinose in milk and is used in the production of fermented dairy products.
.	.	.
Leuconostoc sp.	A genus of lactic acid bacteria that are used in the fermentation of products (dairy, meat, vegetable).	. . . . Less than 1%. Probably by consuming fermented or poorly cooked foods. .
Leuconostoc carnosum	Chilled meat
Leuconostoc citreum	Food Production
Leuconostoc garlicum	Garlic (on the surface)
Leuconostoc gasicomitatum	Poultry meat
Leuconostoc gelidum	Chilled meat
Leuconostoc kimchii	Production (fermentation) of kimchi (Chinese cabbage)
Leuconostoc koreense	Production (fermentation) of kimchi (Chinese cabbage)
Leuconostoc lactis	Dairy Production
Leuconostoc mesenteroides	Production of food products (dairy, meat)
Leuconostoc pseudomesenteroides	Vegetable or soy fermentation
.	.	.
Oenococcus sp.	Malolactic fermentation, the formation of diacetyl – a component of wines and cider.	Less than 1%. Probably (transitory) when consuming wine/cider.
Oenococcus oeni	Wine, cider
Oenococcus sicerae	Cider
.	.	.
Streptococcus sp.	Oral microbiome (always includes streptococci of non-pathogenic species) or dairy products. . Correlation between streptococci and psoriasis (Peslyak 2021, Sitton 2024).	Small Intestine: Commensals, Conditional Pathogens – up to 20% (Leite 2024). Colon: Commensals – less than 1%. Except for pathogenic species (Str. pyogenes, Str. agalactiae and Str. pneumoniae, etc.), which are normally absent.
.	.	.
Weissella sp.	Fermented foods (kimchi, pickled vegetables) or oral probiotics.	Less than 1%. Probably with the consumption of fermented foods or oral probiotics.
Weissella ceti	Fish microbiome
Weissella cibaria	Oral microbiome. Production of oral probiotics.
Weissella hellenica	Fermentation of meat and vegetables (Korean and Japanese products)
Weissella jogaejeotgali	Fermented fish products
Weissella koreensis	Fermented foods (kimchi, bread, seaweed).
Weissella paramesenteroides	Fermented products (dairy, meat, vegetable).
Weissella viridescens	Fermented foods
.
Unlikely for GI microbiome
Arthrobacter sp. PGP41	A bacterium that stimulates plant growth.	Extremely unlikely
Enterococcus silesiacus	Drinking water, animal gastrointestinal tract	Unlikely .
Furfurilactobacillus rossiae L1	Lactic acid bacterium	Unlikely .
Melissococcus plutonius	Insect pathogen (including honey bees)	Extremely unlikely
Pseudarthrobacter psychrotolerans	Root soil of herbaceous plants	Extremely unlikely
Pseudarthrobacter sulfonivorans	Root soil of herbaceous plants	Extremely unlikely
Weissella coleopterorum	Insect microbiome	Unlikely
Weissella diestrammenae	Insect microbiome	Unlikely
Weissella soli	Soil	Unlikely
Weissella tructae	Fish microbiome	Unlikely

Section 2.

Table 2. Gram(-)TLR4-active gastrointestinal bacteria
(enhancing the effect of psoriagenic).

Genus/species	Small intestine	Colon	Sources**
Commensals and opportunistic pathogens***
Alistipes	commensal, rare	Commensal	SP
Bacteroides*	commensal (more often distal)	Dominant Commensal	SP, FROM
Escherichia coli	commensal, but there are pathogenic strains		B, ST, SP
Klebsiella*	Conditional pathogen, commensal		B, ST, SP
Parabacteroides	commensal, rare	Commensal	SP
Proteus	Conditional pathogen		B
Pathogens and rare (transient) conditional pathogens for the small intestine
Aeromonas	Conditional pathogen, rare		B
Burkholderia*	Conditional pathogen, rare		OT
Campylobacter jejuni	Pathogen		D
Citrobacter*	Conditional pathogen, rare	Conditional pathogen, commensal	B, SP
Edwardsiella*	Pathogen		B
Enterobacter cloacae	Conditional pathogen, rare	Conditional pathogen, commensal	OT
Haemophilus*	Conditional pathogen, rare		B
Morganella	Conditional pathogen, rare	Conditional pathogen, commensal	B
Pantoea*	Conditional pathogen, rare		B
Providencia	Conditional pathogen, rare	Conditional pathogen, commensal	B
Pseudomonas aeruginosa	Conditional pathogen, rare		ST
Raoultella	Conditional pathogen, rare	Conditional pathogen, commensal	SP
Salmonella	Pathogen		B, ST
Serratia*	Conditional pathogen, rare	Conditional pathogen, commensal	B, ST
Shewanella	Conditional pathogen, rare		B
Shigella	Pathogen		B, SP
Vibrio	pathogen, but there are non-pathogenic species.		B

Notes. * – only some species. ** – B – have the LpxL and LpxM genes according to BioCyc, D – Di Lorenzo 2019, ST – Stephens 2020, SP – Spindler 2022, OT – other sources.

Commensal is safe and can be beneficial.
Conditional pathogen is safe, but can cause disease in case of overgrowth and/or weakened immunity.
Pathogen – causes disease.

.Section 3.

Table 3. Dependence of psoriasis severity on the concentration of bacteria in the small intestinal microbiome (conditionally).

Concentration of Psoriagenic bacteria	Concentration of Enhancing Bacteria
Concentration of Psoriagenic bacteria	normal (<= 10e3)	above normal (>10e3 and <= 10e5)	Significantly higher than normal (>10e5)
normal (<= 10e3)	no	Weak	Medium
above normal (>10e3 and <= 10e5)	Weak	Medium	medium-heavy
Significantly higher than normal (>10e5)	Medium	medium-heavy	severe, the possibility of psoriatic arthritis

.

Section 4. Table 4. The main goals when adjusting the small intestinal microbiome.

Goal 1. Pathogens.
Completely eliminate all detected pathogens (regardless of genus and species).

Goal 2. Psoriagenic bacteria (Table 1).
2.1. Reduce to a minimum (or better completely eliminate) the consumption of probiotics and fermented foods containing Enterococcus faecalis, Lactococcus sp., Leuconostoc sp., Oenococcus sp., Streptococcus sp., Weissella sp.

2.2. Bring concentration Streptococcus sp. to the norm (i.e. not higher than 10e3 CFU/ml). Completely eliminate Streptococcus sp. is impossible, because many species are commensal to the oral microbiome and constantly replenish the small intestinal microbiome (especially when stomach acid is low).

2.3. Reduce the concentration of other detected psogenic bacteria (except Streptococcus sp.) to a minimum (i.e. not higher than 10e3 CFU/ml), or completely eliminate.

Goal 3. Enhancing bacteria (Table 2).
Reduce the concentration of detected bacteria to a minimum (i.e., not higher than 10e3 CFU/ml), or eliminate completely.

Bibliography

Di Lorenzo F., De Castro C., Silipo A., Molinaro A. Lipopolysaccharide structures of Gram-negative populations in the gut microbiota and effects on host interactions. FEMS Microbiology Reviews, Volume 43, Issue 3, May 2019, Pages 257–272, doi: 10.1093/femsre/fuz002

Ely PH. Is psoriasis a bowel disease? Successful treatment with bile acids and bioflavonoids suggest it is. Clin Dermatol. 2018 May – Jun; 36(3):376-389. PMID 29908580. doi: 10.1016/j.clindermatol.2018.03.011

Gumayunova NG, Nesterov AS, Potaturkina-Nesterova NI. Small intestine bacterial overgrowth syndrome and psoriatic disease. Monograph. Ulyanovsk state university, 2016, 156 p. ISBN 9785888665923 (rus). elib.

Krawczyk B, Wityk P, Gałęcka M, Michalik M. The Many Faces of Enterococcus spp.-Commensal, Probiotic and Opportunistic Pathogen. Microorganisms. 2021 Sep 7; 9(9):1900. PMID 34576796. doi:10.3390/microorganisms9091900

Leite G., Rezaie A., Mathur R. at al. Defining Small Intestinal Bacterial Overgrowth by Culture and High Throughput Sequencing. Throughput Sequencing. Clin Gastroenterol Hepatol. 2024 Feb; 22(2):259-270 PMID 37315761.
doi: 10.1016/j.cgh.2023.06.001

Memariani M, Memariani H. New horizons in the treatment of psoriasis: Modulation of gut microbiome. Heliyon. 2025 Jan 3; 11(1):e41672 PMID 39866422. doi:10.1016/j.heliyon.2025.e41672

Peslyak M. SIBO – Detect and eliminate! MYPE, 2026. doi:10.5281/zenodo.19020687

Peslyak MY, Korotky NG. “Psoriasis as netopathy. Model of pathogenesis with unique netosis role.”, ApA “The Natural Alternative”, 2021, 73 p., ISBN 9785905504082, DOI: 10.5281/zenodo.4310085.

Ramírez-Boscá A, Navarro-López V, Martínez-Andrés A, Such J, Francés R, Horga de la Parte J, Asín-Llorca M. Identification of Bacterial DNA in the Peripheral Blood of Patients With Active Psoriasis. JAMA Dermatol. 2015 Jun; 151(6):670-1. PMID 25760018. doi:10.1001/jamadermatol.2014.5585

Sitton B, Walker T, Mital R, Varra V, Kaffenberger J. Antistreptococcal treatment of psoriasis: a systematic review. Arch Dermatol Res. 2024 Jun 8; 316(7):363. doi: 10.1007/s00403-024-03051-8. PMID: 38850287;

Spindler MP, Siu S, Mogno I. et al. Human gut microbiota stimulate defined innate immune responses that vary from phylum to strain. Cell Host Microbe. 2022 Oct 12; 30(10):1481-1498.e5. PMID 36099923. doi:10.1016/j.chom.2022.08.009.

Stephens M, von der Weid PY. Lipopolysaccharides modulate intestinal epithelial permeability and inflammation in a species-specific manner. Gut Microbes. 2020 May 3; 11(3):421-432. PMID 31203717. doi:10.1080/19490976.2019.1629235.

Zhou S., Yao Z. Roles of Infection in Psoriasis. International journal of molecular sciences. – 2022. – vol. 23. – 13. – p. 6955. PMID 35805960. doi:10.3390/ijms23136955

.Section 3. Table 3. Dependence of psoriasis severity on the concentration of bacteria in the small intestinal microbiome (conditionally).

.

Section 4.

Table 4. The main goals when adjusting the small intestinal microbiome.

.Section 3.

Table 3. Dependence of psoriasis severity on the concentration of bacteria in the small intestinal microbiome (conditionally).