Bacteria
anaerobic bacteria, especially Propionibacterium acnes: Lower back pain
Bartonella: Major depressive disorder, Panic disorder
Borrelia: Anorexia nervosa, ADHD, Bipolar disorder, Obsessive–compulsive disorder, Panic disorder, Rheumatoid arthritis, Sarcoidosis, Schizophrenia
Borrelia burgdorferi: Dementia, Major depressive disorder
Campylobacter jejuni: Guillain–Barré syndrome
Chlamydia pneumoniae: Adult-onset asthma, Alzheimer's disease, Atherosclerosis, Chronic fatigue syndrome (myalgic encephalomyelitis), Chronic obstructive pulmonary disease (which includes both chronic bronchitis and emphysema), Coronary heart disease, Lung cancer, Metabolic syndrome, Multiple sclerosis, Myocardial infarction (heart attack) , Stroke, Tourette syndrome
Chlamydia trachomatis: Schizophrenia, Tourette syndrome
Clostridia bacteria species: Autism
Coxiella burnetii: Chronic fatigue syndrome (myalgic encephalomyelitis)
enteroaggregative Escherichia coli: Irritable bowel syndrome
Firmicutes bacteria (such as Clostridium, Staphylococcus, Streptococcus, and Helicobacter pylori): Obesity
Fusobacterium nucleatum: Colorectal cancer
Helicobacter pylori: Alzheimer's disease, Anxiety disorder, Autoimmune thyroid disease, Colorectal cancer, Metabolic syndrome, Pancreatic cancer, Psoriasis, Sarcoidosis, Stomach cancer, Stroke
Mycobacteria species: Sarcoidosis
Mycobacterium avium subspecies paratuberculosis: Crohn's disease, Irritable bowel syndrome
Mycobacterium tuberculosis: Autoimmune diseases, Stroke
Mycoplasma pneumoniae: Stroke, Tourette syndrome
Rickettsia species bacteria: Thromboangiitis obliterans
Salmonella typhi: Gallbladder cancer
Streptococcus: Anorexia nervosa, ADHD, Obsessive–compulsive disorder, Tourette syndrome
Streptococcus bovis: Colorectal cancer
Fungi
Histoplasma: Stroke
Parasites
Schistosoma helminths: Bladder cancer
Schistosoma japonicum helminths: Colorectal cancer, Liver cancer -- Hepatocellular carcinoma
Taenia solium helminths (pork tapeworm): Dementia
Blastocystis hominis protozoan: Irritable bowel syndrome
Dientamoeba fragilis protozoan: Anorexia, Irritable bowel syndrome (HIV)
Giardia lamblia protozoan: Irritable bowel syndrome
Toxoplasma gondii protozoan: Alzheimer's disease, Depression, Parkinson's disease, Tourette syndrome
Virii
adenovirus 36: Obesity
BK virus: Adrenal tumor, Brain tumor -- Glioblastoma multiforme, Prostate cancer
bornavirus: Bipolar disorder, Dementia, Major depressive disorder, Schizophrenia
cytomegalovirus: Anxiety disorder, Autism, Autoimmune diseases, Brain tumor -- Glioblastoma multiforme, Dementia, Depression, Diabetes mellitus type 2, Guillain–Barré syndrome, Lupus, Metabolic syndrome, Myocardial infarction (heart attack)
enteroviruses such as Coxsackie B virus: Autoimmune diseases, Carcinoid tumors, Chronic fatigue syndrome (myalgic encephalomyelitis), Diabetes mellitus type 2, Dilated cardiomyopathy, Guillain–Barré syndrome, Myocardial infarction (heart attack) , Schizophrenia
enterovirus 71: ADHD
echovirus (an enterovirus): Amyotrophic lateral sclerosis
viral species from the enterovirus genus (echovirus 4, Coxsackie B virus, Coxsackie B1 virus): Crohn's disease (disease-associated mutations in either NOD2 or ATG16L1 genes), Diabetes mellitus type 1
Epstein-Barr virus: Autoimmune diseases, Autoimmune thyroid disease, Breast cancer, Chronic obstructive pulmonary disease (which includes both chronic bronchitis and emphysema), Hodgkin's lymphoma, Lupus, Multiple sclerosis, Nasopharyngeal carcinoma, Seasonal affective disorder
hepatitis B virus: Liver cancer -- Hepatocellular carcinoma, Pancreatic cancer, Vasculitis
hepatitis C virus: Diabetes mellitus type 2, Hodgkin's lymphoma, Liver cancer -- Hepatocellular carcinoma, Vasculitis
herpes simplex virus 1: Alzheimer's disease, Bipolar disorder (level of cognitive impairment), Coronary heart disease, Dementia, Metabolic syndrome
herpes simplex virus 2: Dementia
HIV: ADHD, Autoimmune diseases, Dementia, Hodgkin's lymphoma, Kaposi's Sarcoma, Non-Hodgkin lymphoma, Vasculitis
human herpesvirus: Epilepsy
human herpesvirus 6: ADHD, Multiple sclerosis, Chronic fatigue syndrome (myalgic encephalomyelitis)
human herpesvirus 7: Chronic fatigue syndrome (myalgic encephalomyelitis)
Kaposi's sarcoma herpesvirus: Kaposi's Sarcoma
human papillomaviruses: Anal cancer, Breast cancer, Cervical cancer, Colorectal cancer, Lung cancer, Oropharyngeal cancer, Skin neoplasm, Squamous cell carcinoma
human parechovirus: Diabetes mellitus type 1
human respiratory syncytial virus: Asthma
human T-cell leukemia virus-1: Leukemia -- Adult T-cell leukemia
influenza A: ADHD, Parkinson's disease
JC virus: Brain tumor -- Glioblastoma multiforme, Colorectal cancer
Ljungan virus: Diabetes mellitus type 2
Merkel cell polyomavirus: Lung cancer
mouse mammary tumor virus: Breast cancer
mumps virus: Ovarian cancer
the norovirus CR6 strain (only in combination with a variant of the Crohn’s susceptibility gene ATG16L1, and chemical toxic damage to the gut): Crohn's disease (murine)
parvovirus B19: Autoimmune diseases, Chronic fatigue syndrome (myalgic encephalomyelitis), Lupus, Rheumatoid arthritis, Vasculitis
retrovirus activity (it is not known whether this retrovirus activity arises from a human endogenous retrovirus, or from an exogenous retrovirus): Amyotrophic lateral sclerosis
rhinovirus: Asthma
rubella virus: Autism
simian virus 40: Adrenal tumor, Brain tumor -- Glioblastoma multiforme, Non-Hodgkin lymphoma, Thyroid cancer, Mesothelioma
varicella zoster virus: Multiple sclerosis, Stroke
West Nile virus: Dementia, Depression
xenotropic murine leukemia virus-related virus (XMRV): Prostate cancer