Table 1:
Examples of gut microbiota phyla and taxa, along with an analysis of their role in the functioning of the human organism based on (Almonajjed et al. 2025; Mamieva et al. 2022)
| Phylum | Taxa | Role |
|---|---|---|
| Firmicutes | Enterococcus, Ruminococcus, Clostridium, Lactobacillus, Faecalibacterium, Roseburia, Eubacterium | metabolism of amino acids, carbohydrates and lipids, the transformation of BAs and the biosynthesis of cholesterol, the synthesis of vitamins (K2, B1, B2, B6, B7, B9 and B12) support the integrity of the intestinal epithelial barrier and protection against enteric infections |
| Bacteroidetes | Bacteroides, Prevotella | immunomodulation, appetite regulation |
| Actinobacteria | Bifidobacterium, Corynebacterium | vitamin synthesis, BAs metabolism, protection against infections |
| Proteobacteria | Shigella, Escherichia, Desulfovibrio | amino-acids metabolism |
Table 2:
Differences in gut microbiota qualitative-quantitative composition in depending on subtype of irritable bowel syndrome.
| Subtype | Changes in gut microbiota | Ref. | |
|---|---|---|---|
| increase | decrease | ||
| IBS-D | Enterobacteriaceae, Proteobacteria, Firmicutes, Clostridiales, Bacteroides, Lactobacillus, Prevotella, Escherichia coli, Pseudomonas aeruginosa, Dorea | Actinobacteria, Bacteroidetes, Ruminococcaceae, Methanobacteriaceae, Parasuterella, Lactobacillus, Bifidobacterium, Prevotella, Enterococcus, Faecalibacterium, Lachnospira, Turicibacter, Weisella, Oxolobacter, Oceanobacillus, Collinsella aerofaciens | Cheng et al. 2024; Chong et al. 2019; Surdea-Blaga et al. 2024 |
| IBS-C | Bacteroides, Clostridiales, Christensenellaceae, Veilonella, Akkermansia, Methanobrevibacter, Pseudomonas aeruginosa, Methanobrevibacter smithii | Bacteroides, Methanobrevibacter, Bifidobacterium catenulatum, Prevotella | Cheng et al. 2024; Chong et al. 2019; Surdea-Blaga et al. 2024 |
| IBS-M | - | Faecalibacterium prausnitzii | Cheng et al. 2024 |
| IBS-U | Pseudomonas aeruginosa | - | |
Table 3:
Prebiotics, probiotics, synbiotics and postbiotics used in alleviating symptoms of irritable bowel syndrome
| Biotics in prophilaxis or therapeutic approach | Potential use for the prevention and treatment | Therapeutic activity | Ref. |
|---|---|---|---|
| Probiotics | Beneficial bacteria strains that can be administered orally as a dietary supplement | The reduction on gut inflammation, increase the level of beneficial bacteria (Lactobacillus spp., Bifidobacterium spp.), inhibition of growth of pathogenic bacteria, modulation of both anti- and pro-inflammatory cytokines, participation in production of SCFAs, production of neurotransmitters, improve symptoms in IBS (e.g. abdominal pain, bloating), tighten gut barrier, regulation of GBA, improve gut barrier integrity and mucus production, reduction of intestinal permeability, improve patient’s quality of life and mood, influence on the both innate and adaptive immunity, with interaction occurring with epithelial cells, dendritic cells, macrophages and lymphocytes through pattern-recognition receptors, helping regulate Tcell balance (especially boosting Treg. to reduce inflammation), prevention antibioticassociated diarrhea, necrotizing enterocolitis, pouchitis, and traveler’s diarrhea, in vitro and animal studies indicate improved burn wound healing with Saccharomyces cerevisiae, and prevention or reduction of eczema through mechanisms involving the GBA | Cheng et al. 2024; Aggeletopoulou and Triantos 2024; Almonajjed et al. 2025; Shaikh et al. 2023; Martyniak et al. 2021; Luzzi et al. 2024; Qiao et al. 2025; Maftei et al. 2023; Campaniello et al. 2023; Rijkers et al. 2011; Ranjha et al. 2021; Fuochi and Furneri 2023 |
| Prebiotics |
| Promotion of growth of beneficial bacteria, improve symptoms in irritable bowel syndrome, production of SCFAs (including byturate, propionate and acetate), regulation of gut motility, improve intestinal barrier function, reduction of inflammatory processess, anti-oxidative activity, regulation of cholesterol and lipids synthesis | Aggeletopoulou and Triantos 2024; Almonajjed et al. 2025; Shaikh et al. 2023; Chong et al. 2019; Martyniak et al. 2021; Luzzi et al. 2024 |
| Synbiotics |
| Improve probiotics survival in gastrointestinal tract, reduction of symptoms in IBS (bloating, abdominal pain), increase a bowel movement frequency, reduction of levels of pro-inflammatory cytokine (IL-8, TNF-α) and increase of levels of anti-inflammatory cytokines (IL-10), improve intestinal barrier integrity and gut motility | Almonajjed et al. 2025; Shaikh et al. 2023; Chong et al. 2019; Martyniak et al. 2021; Luzzi et al. 2024 |
| Postbiotics |
| It is assumed that improve symptoms in IBS (particularly in IBS-D) and reduce inflammatory activity | Almonajjed et al. 2025; Martyniak et al. 2021 |