Constipation is a forerunner to Parkinson's disease (PD) diagnosis, worsening thereafter. We explore the relationship of intestinal barrier dysfunction to constipation and whether intestinal fungal load is an aggravating factor. Fungal load was quantified by real-time PCR, using ITS1F-ITS2 primer set, on microbial DNA extract from stool in 68 participants with PD, 102 without. Fungal load was 60% higher per decade after age 60 years, with no PD status interaction with age. After age adjustment, it was associated inversely with dietary renal acid load. It was unrelated to the presence of constipation or barrier dysfunction. Neither consumption of antimicrobials nor of other targeted exogenous substances was associated. Enzyme-linked immunosorbent assays measured barrier dysfunction markers, faecal alpha-1 antitrypsin (AAT), zonulin and serum intestinal fatty acid-binding protein (I-FABP). Barrier dysfunction was associated with constipation and slower radiographic colonic transit. Functional constipation was 28% more frequent with a doubling of AAT concentration. More colonic-transit test markers were retained in the transverse colon, the higher the AAT and zonulin concentrations, anatomically spotlighting abnormality for the entire colon. In contrast, the concentration of the small intestinal barrier marker I-FABP was associated with looser stool consistency, which is consistent with secondary microbial overgrowth. By showing a relationship of intestinal barrier dysfunction to constipation, this study supports the hypothesis that dysfunction may be consequential. Dysfunction may be a necessary, but not sufficient, precursor to PD, in allowing inflammaging. Since ageing is the clearest risk for PD, a gut pathogen escalating in abundance from the sixth decade, integral to fungal load, and whose reproduction and virulence is favoured by alkalinity, tallies.

Epidemiological and eradication trial evidence indicates that Helicobacter pylori, a major causative factor in peptic ulcer and gastric cancer, is a driver of the hypokinesia of Parkinson’s disease (PD). Psychological (cognitive impairment, depression and anxiety) and gastrointestinal (peptic ulceration and constipation) PD features can precede the symptomatic onset of motor features by decades. We hypothesise that the non-H. pylori Helicobacters (NHPH), which have farm, companion and wild animals as their main hosts, can have a role in PD aetiopathogenesis. In those occupationally at risk of NHPH infection, we address whether there is increased mortality with PD, or depression or suicide. Our systematic review gave evidence that occupational exposure to animals/their products is associated with excess mortality with PD. Indeed, whilst livestock farming increased the risk, crop farming decreased it. Moreover, excess mortality from non-Hodgkin lymphoma in livestock farmers is compatible with NHPH being causal. Our scoping review showed that farmers, veterinarians and abattoir workers have an increased risk of depression and suicide; whether their depression is associated with being down the pathway to PD and/or the presence of Helicobacter infection needs investigation. Regarding Helicobacter species specificity, the link between the presence of NHPH in gastric biopsy and PD was described using a ureA polymerase chain reaction (PCR) assay, targeting the most-commonly named NHPH, H. suis. We describe its redesign and optimisation as a probe-based PCR, confirming the exclusion of H. pylori but not H. suis specificity (additionally identifying 6 species of a 22-NHPH-species panel). The exploration of the zoonotic hypothesis requires a non-invasive pan-Helicobacter PCR screen, allowing the detection and molecular grouping of Helicobacter species.

ABSTRACT Background Gut‐brain axis is widely implicated in the pathophysiology of Parkinson's disease (PD). We take an integrated approach to considering the gut as a target for disease‐modifying intervention, using continuous measurements of disease facets irrespective of diagnostic divide. Methods We characterised 77 participants with diagnosed‐PD, 113 without, by dietary/exogenous substance intake, faecal metabolome, intestinal inflammation, serum cytokines/chemokines, clinical phenotype including colonic transit time. Complete‐linkage hierarchical cluster analysis of metabolites discriminant for PD‐status was performed. Results Longer colonic transit was linked to deficits in faecal short‐chain‐fatty acids outside PD, to a ‘tryptophan‐containing metabolite cluster’ overall. Phenotypic cluster analysis aggregated colonic transit with brady/hypokinesia, tremor, sleep disorder and dysosmia, each individually associated with tryptophan‐cluster deficit. Overall, a faster pulse was associated with deficits in a metabolite cluster including benzoic acid and an imidazole‐ring compound (anti‐fungals) and vitamin B3 (anti‐inflammatory) and with higher serum CCL20 (chemotactic for lymphocytes/dendritic cells towards mucosal epithelium). The faster pulse in PD was irrespective of postural hypotension. The benzoic acid‐cluster deficit was linked to (well‐recognised) lower caffeine and alcohol intakes, tryptophan‐cluster deficit to higher maltose intake. Free‐sugar intake was increased in PD, maltose intake being 63% higher (p = .001). Faecal calprotectin was 44% (95% CI 5%, 98%) greater in PD [p = .001, adjusted for proton‐pump inhibitors (p = .001)], with 16% of PD‐probands exceeding a cut‐point for clinically significant inflammation compatible with inflammatory bowel disease. Higher maltose intake was associated with exceeding this calprotectin cut‐point. Conclusions Emerging picture is of (i) clinical phenotype being described by deficits in microbial metabolites essential to gut health; (ii) intestinal inflammation; (iii) a systemic inflammatory response syndrome.

We question whether bradyphrenia, slowing of cognitive processing not explained by depression or a global cognitive assessment, is a nosological entity in idiopathic parkinsonism (IP). The time taken to break contact of an index finger with a touch-sensitive plate was measured, with and without a warning in the alerting signal as to which side the imperative would indicate, in 77 people diagnosed with IP and in 124 people without an IP diagnosis. The ability to utilise a warning, measured by the difference between loge-transformed reaction times (unwarned minus warned), was termed ‘cognitive efficiency’. It was approximately normally distributed. A questionnaire on self- and partner perception of proband’s bradyphrenia was applied. A multivariable model showed that those prescribed levodopa were less cognitively efficient (mean −5.2 (CI −9.5, −1.0)% per 300 mg/day, p = 0.02), but those prescribed the anti-muscarinic trihexyphenidyl were more efficient (14.7 (0.2, 31.3)% per 4 mg/day, p < 0.05) and those prescribed monoamine oxidase-B inhibitor (MAOBI) tended to be more efficient (8.3 (0.0, 17.4)%, p = 0.07). The variance in efficiency was greater within IP (F-test, p = 0.01 adjusted for any demographic covariates: coefficient of variation, with and without IP, 0.68 and 0.46, respectively), but not so after adjustment for anti-parkinsonian medication (p = 0.13: coefficient of variation 0.62). The within-participant follow-up time, a median of 4.8 (interquartile range 3.1, 5.5) years (101 participants), did not influence efficiency, irrespective of IP status. Perception of bradyphrenia did not usefully predict efficiency. We conclude that both bradyphrenia and ‘tachyphrenia’ in IP appear to have iatrogenic components, of clinically important size, related to the dose of antiparkinsonian medication. Levodopa is the most commonly prescribed first-line medication: co-prescribing a MAOBI may circumvent its associated bradyphrenia. The previously reported greater efficiency associated with (low-dose) anti-muscarinic was confirmed.

Neuroimmunology and Neuroinflammation is an open access journal, with focuses on neuroimmunology and neuroinflammation research, and coverage extending to other basic and clinical studies related to neuroscience.

Interest in an aetiopathogenic role for Helicobacter in neuropsychiatric diseases started with idiopathic parkinsonism (IP), where the cardinal signs can be assessed objectively. This systematic review, using an EMBASE database search, addresses Oxford Centre for Evidence-Based Medicine based questions on the inter-relationship of Helicobacter and IP, the benefits of eradicating Helicobacter in IP and the outcome of not treating. The search strategy was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines: 21 of 204 articles met the inclusion criteria. The results show that the assumption that any benefit of Helicobacter eradication results from improved levodopa bioavailability is unjustified. The inter-relationship between Helicobacter and IP is well-established. H. pylori virulence markers (associated with autoimmunity and immune tolerance) influence the risk, severity and progression of IP. The birth cohort effect for virulence marker antibodies, seen in controls, is obliterated in IP, suggesting causality. Successful H. pylori eradication in IP is disease-modifying (even in anti-parkinsonian treatment-naïve patients) but not preventive. Hypokinesia regresses with eradication and overall motor severity lessens. Eradication may influence gastrointestinal microbiota adversely, unlocking the next stage in the natural history, the development of rigidity. Failed eradication worsens hypokinesia, as does the presence/persistence of H. pylori at molecular level only. Adequate prognostic assessment of the consequences of not treating Helicobacter, for IP, is prevented by a short follow-up. We conclude that Helicobacter is a pathophysiological driver of IP.

Depression is associated with constipation within and outside Parkinson’s disease (PD). Since inefficient cognitive-processing (bradyphrenia) features in PD and an enterokinetic agent improved cognitive performance in healthy individuals, bradyphrenia may be associated with constipation. We aim to define the archetypical bowel function of PD, and its association with cognition, mood, and motor features within and outside PD. We assessed colonic transit time (oral radio-opaque markers over 6 days), bowel function and psychometric questionnaires and measures of PD facets, including bradyphrenia, in 58 participants with diagnosed PD, and 71 without (controls). The best abdominal X-ray (day 7) predictors of PD status were total retained marker count and transverse colon segmental delay. However, Rome functional constipation status complemented segmental delay better, giving good specificity (85%) but low sensitivity (56%). Transverse colon marker count appeared to be age-associated only in PD. In PD, those correctly classified by bowel dysfunction had higher depression scores (p = 0.02) and longer cognitive-processing times than the misclassified (p = 0.05). Controls misclassified as PD by bowel dysfunction had higher depression and anxiety scores than the correctly classified (p = 0.002 and 0.003, respectively), but not slower cognitive processing. Measures of motor features were independent of sub-classification by bowel function in PD and in controls. In conclusion, constipation in PD has distinct localized pathophysiology, and is associated with bradyphrenia.

Helicobacter pylori has been implicated in the pathogenesis of Parkinson's disease (PD). Its eradication, in a randomized placebo-controlled trial, improved PD hypokinesia. Helicobacter species zoonosis might explain excess mortality from PD and non-Hodgkin lymphoma in livestock, but not arable, farmers. Indeed, Helicobacter is causally-associated with gastric lymphoma. We have previously shown that the relative-frequency, H. suis to H. pylori, was 10-times greater in 60 PD-patients than in 256 controls. We now go on to evaluate the pathological significance of H. suis, detected in gastric-biopsy DNA-extracts by ureA-based species-specific qPCR, validated by amplicon sequencing. The methodology had been cross-validated by a carR-based PCR. The pathological significance is put in context of H. pylori detection [urea-breath-test (UBT) with biopsy-culture, and, if negative, PCR], and the potential reservoir in pigs. Here, we explore, in these 60 PD-patients, associations of H. suis status with all-cause-mortality, and with orthostatic cardiovascular and blood profiling. H. suis had been detected in 19 of the 60 PD-patients on one or more occasion, only two (with co-existent H. pylori) being UBT positive. We found that the hazard-of-death (age-at-diagnosis- and gender-adjusted) was 12 (95% CI 1,103) times greater (likelihood-ratio test, P = 0.005) with H. suis-positivity (6/19) than with negativity (2/40: one lost to follow-up). UBT-values did not influence the hazard. H. suis-positivity was associated with lower standing mean-arterial-pressure [6 (1, 11) mmHg], H. pylori-positivity having no effect. The lower total lymphocyte count with H. pylori-positivity [-8 (-1, -14) %] was not seen with H. suis, where T-cell counts were higher [24 (2, 52) %]. Regarding the potential zoonotic reservoir in the UK, Helicobacter-like-organism frequency was determined in freshly-slaughtered pigs, nature ascertained by sequencing. Organisms immunostaining for Helicobacter, with corkscrew morphology typical of non-H. pylori Helicobacter, were seen in 47% of 111 pig-antra. We conclude that H. suis is associated with all-cause-mortality in PD and has a potential zoonotic reservoir.

Levodopa is widely used, but rarely is the topic of tolerance raised. Escalating requirement and ‘on/off’ fluctuations are often ascribed to disease progression, rather than admitted to be iatrogenic. The risk should be discussed before introduction, since ‘weaning off’ levodopa is difficult and usually unsuccessful. Dependence on the mood elevation and relief of anxiety might add to the difficulty. Tolerance develops rapidly, especially after infusion or oral sustained release formulation. It is, in part, pharmacokinetic, being associated with the accumulation of the long t1⁄2 metabolite, 3-O-methyldopa. Therefore, effective use of catechol-O-methyl transferase inhibition should reduce tolerance.

Aim To estimate whether laxatives prescribed for constipation in Parkinson's disease (PD) could moderate rigidity. Constipation predates diagnosis of PD by decades. Deposition of misfolded protein may begin in the gut, driven by dysbiosis. Successive antimicrobial exposures are associated with cumulative increase in rigidity, and rigidity has biological gradients on circulating leukocyte‐subset counts. Methods Retrospective service evaluation, in a gut/brain axis clinic, yielded an interrupted time series, relating maintenance laxative and other medication to rigidity, in consecutive outpatients identified by inclusion and exclusion criteria. Objective assessment of rigidity was used to bring greater sensitivity to change, validated against subjective gold standard (UPDRS). Results There were 1493 measurements of torque required to extend (flexor rigidity) and flex (extensor rigidity) the forearm in 79 PD patients over 374 person‐years. Both were strongly associated with UPDRS (P < 0.001 and P = 0.008, respectively). Before exhibition of laxative, flexor rigidity increased by 6% (95% CI 1, 10) per year, plateauing at −2% (−4, 1) per year after, with no shift at initiation. Change in slope was significant (P = 0.002), and manifest in those naïve to antiparkinsonian medication. The change was replicated for individual laxative classes (bulk, osmotic, enterokinetic). There was no temporal change in extensor rigidity. Limited experience with a quanylate cyclase‐C receptor agonist (17 patients, 6 person‐years) indicated a large and significant step down in flexor and extensor rigidity, of 19% (1, 34) and 16% (6, 24) respectively (P = 0.04 and <0.001). Conclusions Maintenance laxative usage was associated with apparent stemming of the temporal increase in rigidity in PD, adding to indicative evidence of a continuing role of gastrointestinal dysbiosis in pathogenesis.

We seek an aetiopathogenic model for the spectrum of Parkinson's disease (PD), functional bowel disease, depression and cognitive impairment. The adopted concept is that systemic immuno-inflammatory processes mediate neuro-inflammation. The model would be based on phenotype, exposome (including gastrointestinal microbiome), milieu (immuno-inflammatory and metabolome), human genetics and their interactions. It would enable a patient's position, to be understood in terms of drivers, perpetuators and mediators, and a future position, with and without intervention, predicted. Even the cardinal facets of PD may have different drivers: halting one may allow escape down subordinate pathways. Peptic ulceration is prodromal to PD. In our randomised placebo-controlled trial, hypokinesia improved over the year following biopsy-proven Helicobacter pylori eradication and rigidity worsened. This was independent of any (stable, long t½) antiparkinsonian medication. There are pointers to an autoimmune process: for example, surveillance-confirmed hypokinesia effect was indication specific. During surveillance, successive antimicrobial courses, other than for Helicobacter, were associated with cumulative increase in rigidity. Exhibiting laxatives appeared to stem the overall temporal increase, despite antiparkinsonian medication, in rigidity. Thus, intestinal dysbiosis may be a major source of bystander neuronal damage. There are biological gradients of objective measures of PD facets on circulating inflammatory markers and leucocyte subset counts. Moreover, lactulose hydrogen breath test positivity for small-intestinal bacterial overgrowth (present in two thirds of PD patients) is associated with the same subsets: higher natural killer and total CD4+ counts and lower neutrophils. With greater aetiopathogenic understanding, relatively low cost and on-the-shelf medication could have a major impact. A new generation of animal models, based on the gut microbiome, is envisaged.

Helicobacter suis is a very fastidious microorganism associated with gastritis, gastric ulcers, and mucosa‐associated lymphoid tissue lymphoma in humans. In vitro isolation of this agent from human patients has so far been unsuccessful.

BackgroundFollowing Helicobacter pylori eradication in a placebo‐controlled trial, the hypokinesia of idiopathic parkinsonism improved but flexor rigidity worsened.MethodsWe surveyed the effect of all antimicrobial prescriptions in 66 patients with idiopathic parkinsonism over a median of 1.9 (interquartile range 0.4, 3.5) years. Initial Helicobacter screening was followed (where positive) by gastric biopsy. Serial lactulose hydrogen breath tests (364 tests) for small intestinal bacterial overgrowth monitored the need to encourage fluid intake and bulk/osmotic laxatives. We measured hypokinesia (401 assessments of mean stride length at free walking speed in 58 patients) and upper limb flexor rigidity (396 assessments in 49).ResultsFollowing successful H. pylori eradication (12 cases) but not failed (2), stride increased in entire group (including those receiving levodopa), core group (those receiving only longer‐t½ antiparkinsonian medication or untreated) and untreated (p = .001 each case). The effect was greater with less antiparkinsonian medication (19 (95% CI, 14, 25) cm/year in untreated). Flexor rigidity was unchanged. Following antimicrobials for other indications (75 courses), hypokinesia was unchanged. However, flexor rigidity increased cumulatively. It increased in core group only after a first course (by (10 (0, 20)%/year, p = .05)), but then in entire, core and untreated after a second course (18 (6, 31), 33 (19, 48) and 29 (12, 48)%/year respectively; p = .002, .001 and .001) and further still after a third (17 (2, 34), 23 (8, 41) and 38 (15, 65)%/year; p = .02, .003 and .001). Initially, 40/66 were lactulose hydrogen breath test positive. Odds for positivity fell with time (by 59 (46, 75)%/year, p = .001) and tended to be lower with Helicobacter positivity (28 (8, 104)%, p = .06), but were unrelated to other antimicrobial interventions.ConclusionsImproved hypokinesia following antimicrobials appeared unique to Helicobacter eradication. Rigidity increased following successive antimicrobial exposures for other indications, despite diminishing lactulose hydrogen breath test positivity.

Following Helicobacter pylori eradication in idiopathic parkinsonism (IP), hypokinesia improved but flexor-rigidity increased. Small intestinal bacterial-overgrowth (SIBO) is a candidate driver of the rigidity: hydrogen-breath-test-positivity is common in IP and case histories suggest that Helicobacter keeps SIBO at bay.

Helicobacter pylori eradication has a differential effect on the facets of idiopathic parkinsonism (IP): brady/hypokinesia improves, but rigidity worsens. Small intestinal bacterial overgrowth is common in IP and has been described as a sequel to Helicobacter eradication. The hyperhomocysteinaemia of IP is, in part, explained by serum vitamin B(12), but the concentration is not explained by Helicobacter status. Moreover, Helicobacter-associated gastric atrophy is uncommon in IP. However, overgrowth both increases B(12) utilization and provides a source of inflammation to drive homocysteine production. It is not a bystander event in IP: clouds of lysosomes are seen in duodenal enterocytes. Its candidature for causality of a rigidity-associated pathway is circumstantial: there are biological gradients of rigidity on natural killer and T-helper blood counts, both being higher with hydrogen breath test positivity for overgrowth.

BACKGROUND:We examine the effect of eradicating Helicobacter in idiopathic parkinsonism (IP). Marked deterioration, where eradication-therapy failed, prompted an interim report in the first 20 probands to reach de-blinding. The null-hypothesis, "eradication has no effect on principal outcome, mean stride length at free-walking speed," was rejected. We report on study completion in all 30 who had commenced post-treatment assessments.METHODS:This is a randomized, placebo-controlled, parallel-group efficacy study of eradicating biopsy-proven (culture and/or organism on histopathology) Helicobacter pylori infection on the time course of facets of IP, in probands taking no, or stable long-t(1/2), anti-parkinsonian medication. Persistent infection at de-blinding (scheduled 1-year post-treatment) led to open active eradication-treatment.RESULTS:Stride length improved (73 (95% CI 14-131) mm/year, p = .01) in favor of "successful" blinded active over placebo, irrespective of anti-parkinsonian medication, and despite worsening upper limb flexor rigidity (237 (57-416) Nm x 10(-3)/year, p = .01). This differential effect was echoed following open active, post-placebo. Gait did not deteriorate in year 2 and 3 post-eradication. Anti-nuclear antibody was present in all four proven (two by molecular microbiology only) eradication failures. In the remainder, it marked poorer response during the year after eradication therapy, possibly indicating residual "low-density" infection. We illustrate the importance of eradicating low-density infection, detected only by molecular microbiology, in a proband not receiving anti-parkinsonian medication. Stride length improved (424 (379-468) mm for 15 months post-eradication, p = .001), correction of deficit continuing to 3.4 years. Flexor rigidity increased before hydrogen-breath-test positivity for small intestinal bacterial overgrowth (208 (28-388) Nm x 10(-3), p = .02), increased further during (171 (67-274), p = .001) (15-31 months), and decreased (136 (6-267), p = .04) after restoration of negativity (32-41 months).CONCLUSION:Helicobacter is an arbiter of progression, independent of infection-load.