Table 2.
Potential modulators of the Microbiome-Gut-Brain Axis targeting toll-like receptors are summarized.
| Modulator | Impact on Microbiome-Gut-Brain Axis | Target | Refs. |
|---|---|---|---|
| Prebiotics | |||
| Galacto oligosaccharides | Villus surface enhancement in the small intestine | TLR1-TLR13 | [110, 134] |
| Fructo oligosaccharides | Raised expression of BDNF in the hippocampus | TLR2, TLR4 | [110, 135] |
| Short-chain fatty acids (SCFA) | Colonic epithelium probity maintenance | TLR4 | [110, 136] |
| Probiotics | |||
| L.rhamnosus | GABA-A receptor modulation | TLR1, TLR2, TLR6 | [110,137] |
| Lactobacillus reuteri | Increased frequency of evacuation and enhanced bowel movement | TLR1, TLR2, TLR6 | [113, 138] |
| Lactobacillus casei shirota | Diminishing bloating of viscera and pain and improvement in the consistency of the stool | TLR1, TLR2, TLR6 | [114, 139] |
| Dietary supplements | |||
| Docosahexaenoic acid (DHA) | Improvement in the neuronal mitochondrial dysfunctioning by diminishing the oxidative stress | TLR2, TLR4 | [111, 140, 141] |
| Panax Notoginseng | Repression of the microglial stimulation and limiting the release of TNF-α and IL-6 release | TLR4 | [142] |
| Sylimarine | Neuroprotective effect and antioxidant (salvaging the free radicals) | TLR4 | [143] |