Table 1.
Microbes and their associated conditions in relation to cognition and neuroinflammation.
| Microbe | Type | Associated Condition(s) | Cognitive/Neuroinflammatory Impact | References |
|---|---|---|---|---|
| Porphyromonas gingivalis | Bacteria | Periodontitis | Linked to neuroinflammation and cognitive decline, found in AD brains | [66] |
| Chlamydia pneumoniae | Bacteria | Respiratory infections | Associated with neuroinflammation, found in AD brains | [78] |
| Helicobacter pylori | Bacteria | Gastritis, peptic ulcers | Linked to cognitive impairment, possibly through systemic inflammation | [79] |
| Borrelia burgdorferi | Bacteria | Lyme disease | Cognitive deficits in “Lyme brain,” linked to neuroinflammation | [95] |
| Streptococcus pneumoniae | Bacteria | Pneumonia and meningitis | Cognitive impairment | [97] |
| Mycobacterium tuberculosis | Bacteria | Tuberculous meningitis | Cognitive impairment associated with elevated cytokine levels | [99] |
| Neisseria meningitidis | Bacteria | Meningococcal meningitis | Cognitive deficits in survivors, including memory and attention issues | [41] |
| Candida spp. | Fungi | Systemic candidiasis | Linked to neuroinflammation and cognitive dysfunction in AD | [90] |
| Aspergillus spp. | Fungi | Invasive aspergillosis (cerebral aspergillosis | Cognitive disturbances linked to CNS involvement | [100] |
| Histoplasma capsulatum | Fungi | CNS histoplasmosis | Neuroinflammation and cognitive impairment, especially in endemic regions | [140] |
| Plasmodium falciparum | Parasite | Cerebral malaria | Causes significant cognitive impairment due to brain inflammation | [102] |
| Toxoplasma gondii | Parasite | Toxoplasmosis | Chronic infection linked to cognitive decline and psychiatric disorders | [104,141] |
| Trypanosoma brucei | Parasite | African trypanosomiasis (sleeping sickness) | Linked to neuroinflammation | [107,152] |
| Herpes simplex virus (HSV) | Virus | Herpes simplex encephalitis | Acute neuroinflammation leading to cognitive deficits | [142] |
| Human immunodeficiency virus (HIV | Virus | HIV-associated neurocognitive disorder (HAND) | Chronic neuroinflammation and cognitive impairment | [143] |
| Cytomegalovirus (CMV) | Virus | CMV infection, CMV encephalitis | Increases tau phosphorylation, cognitive impairment and increased risk of AD | [110] |
| Varicella-zoster virus (VZV) | Virus | VZV encephalitis | Neuroinflammation and cognitive impairment | [144] |