BACKGROUND: Previous studies have reported that gut microbiota, permeability, short-chain fatty acids (SCFAs), and inflammation are altered in Parkinson's disease (PD), but how these factors are linked and how they contribute to disease processes and symptoms remains uncertain. This study sought to compare and identify associations among these factors in PD patients and controls to elucidate their interrelations and links to clinical manifestations of PD. METHODS: Stool and plasma samples and clinical data were collected from 55 PD patients and 56 controls. Levels of stool SCFAs and stool and plasma inflammatory and permeability markers were compared between patients and controls and related to one another and to the gut microbiota. RESULTS: Calprotectin was increased and SCFAs decreased in stool in PD in a sex-dependent manner. Inflammatory markers in plasma and stool were neither intercorrelated nor strongly associated with SCFA levels. Age at PD onset was positively correlated with SCFAs and negatively correlated with CXCL8 and IL-1β in stool. Fecal zonulin correlated positively with fecal NGAL and negatively with PD motor and non-motor symptoms. Microbiota diversity and composition were linked to levels of SCFAs, inflammatory factors, and zonulin in stool. Certain relationships differed between patients and controls and by sex. CONCLUSIONS: Intestinal inflammatory responses and reductions in fecal SCFAs occur in PD, are related to the microbiota and to disease onset, and are not reflected in plasma inflammatory profiles. Some of these relationships are distinct in PD and are sex-dependent. This study revealed potential alterations in microbiota-host interactions and links between earlier PD onset and intestinal inflammatory responses and reduced SCFA levels, highlighting candidate molecules and pathways which may contribute to PD pathogenesis and clinical presentation and which warrant further investigation.
Experiment 1
Subjects
- Location of subjects
- Norway
- Host species Species from which microbiome was sampled. Contact us to have more species added.
- Homo sapiens
- Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology
- Feces Cow dung,Cow pat,Droppings,Dung,Excrement,Excreta,Faeces,Fecal material,Fecal matter,Fewmet,Frass,Guano,Matières fécales@fr,Merde@fr,Ordure,Partie de la merde@fr,Piece of shit,Porción de mierda@es,Portion of dung,Portion of excrement,Portion of faeces,Portion of fecal material,Portion of fecal matter,Portion of feces,Portion of guano,Portion of scat,Portionem cacas,Scat,Spoor,Spraint,Stool,Teil der fäkalien@de,Feces,feces
- Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology
- Parkinson's disease IDIOPATHIC PARKINSON DIS,Idiopathic Parkinson Disease,Idiopathic Parkinson's Disease,IDIOPATHIC PARKINSONS DIS,Idiopathic PD,LEWY BODY PARKINSON DIS,Lewy Body Parkinson Disease,Lewy Body Parkinson's Disease,Paralysis agitans,paralysis agitans,PARKINSON DIS,PARKINSON DIS IDIOPATHIC,Parkinson disease,Parkinson Disease, Idiopathic,Parkinson syndrome,Parkinson's,Parkinson's disease,Parkinson's disease (disorder),Parkinson's disease NOS,Parkinson's disease NOS (disorder),Parkinson's Disease, Idiopathic,Parkinson's Disease, Lewy Body,Parkinson's syndrome,Parkinsonian disorder,Parkinsonism, Primary,Parkinsons,PARKINSONS DIS,PARKINSONS DIS IDIOPATHIC,PARKINSONS DIS LEWY BODY,Parkinsons disease,Primary Parkinsonism,parkinson's disease
- Group 0 name Corresponds to the control (unexposed) group for case-control studies
- Healthy control
- Group 1 name Corresponds to the case (exposed) group for case-control studies
- Parkinson's disease patients
- Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
- Patients who have Parkinson's disease
- Group 0 sample size Number of subjects in the control (unexposed) group
- 56
- Group 1 sample size Number of subjects in the case (exposed) group
- 55
Lab analysis
- Sequencing type
- 16S
- 16S variable region One or more hypervariable region(s) of the bacterial 16S gene
- V3-V4
- Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance
- Illumina
Statistical Analysis
- Data transformation Data transformation applied to microbial abundance measurements prior to differential abundance testing (if any).
- raw counts
- Statistical test
- DESeq2
- MHT correction Have statistical tests be corrected for multiple hypothesis testing (MHT)?
- Yes
- Matched on Factors on which subjects have been matched on in a case-control study
- age, body mass index, sex
- Confounders controlled for Confounding factors that have been accounted for by stratification or model adjustment
- sex, Confounders controlled for: "rome III score" is not in the list (abnormal glucose tolerance, acetaldehyde, acute graft vs. host disease, acute lymphoblastic leukemia, acute myeloid leukemia, adenoma, age, AIDS, alcohol consumption measurement, alcohol drinking, ...) of allowed values.rome III score
Alpha Diversity
- Shannon Estimator of species richness and species evenness: more weight on species richness
- decreased
- Inverse Simpson Modification of Simpsons index D as 1/D to obtain high values in datasets of high diversity and vice versa
- increased