While Parkinson’s disease (PD) has traditionally been considered a central nervous system disease, recent groundbreaking research argues that PD symptomology is influenced by gut microbiota alterations (dysbiosis).1 People with PD suffer from dysbiosis,2-6 and gut symptoms characteristic of dysbiosis, like constipation.7,8 Given this evidence, strategies that improve gut health in PD are warranted. One possible strategy is exercise. In non-PD populations, fitness status is linked to gut health,9-13 and exercise which increases fitness status improves the gut.14-19 It is now known that exercise improves motor symptoms in PD,20-23 but the gut may be a moderator of these improvements. However, no study has taken the crucial first step to link fitness with motor and gut symptoms in PD. In addition, there is a need to determine whether norms for fitness status 24 indicate PD symptom severity to provide clinicians with a benchmark by which they can improve the fitness of people with PD. PURPOSE: We aimed to 1) associate fitness, motor symptoms, and constipation and 2) determine the influence of aerobic fitness norms on motor symptoms and constipation in 19 people with PD. METHODS: Constipation was measured via the ROME-IV survey (summing nine symptom questions). Fitness was defined as estimated oxygen consumption (VO2) via a 6-minute walk test (6MW). Normative classifications were used to determine whether participants met (HI) or did not meet aerobic fitness status (LO).25 Motor symptoms were assessed via the Unified Parkinson’s Disease Rating Scale III (UPDRS-III). A linear regression was used to associate VO2 peak, UPDRS-III, and constipation. A MANOVA was used to compare symptoms between HI and LO groups. RESULTS: VO2 peak was inversely associated with constipation (t= 2.67, p=.018, effect size = -.48, 95% CI= -.86 to -.10) and UPDRS-III scores (t= -2.35, p= .033, effect size= -.48, 95% CI= -.92 to -.04). The HI group had lower constipation (p=.018) and UPDRS-III scores (p=.03) than the LO group. DISCUSSION: Not only is there a link between aerobic fitness, motor function, and constipation in people with PD, but there seems to be aerobic fitness benchmarks (i.e., HI vs. LO) that clinicians can use to improve the fitness status of their patients. In doing so, this can not only lead to improvements in motor function, but also improved gut health in people with PD.


1. McCann H, Cartwright H, Halliday GM. Neuropathology of alpha-synuclein propagation and braak hypothesis. Mov Disord. 2016;31(2):152-160.

2. Aho VTE, Pereira PAB, Voutilainen S, et al. Gut microbiota in Parkinson's disease: Temporal stability and relations to disease progression. EBioMedicine. 2019;44:691-707.

3. Scheperjans F, Aho V, Pereira PA, et al. Gut microbiota are related to Parkinson's disease and clinical phenotype. Mov Disord. 2015;30(3):350-358.

4. Heintz-Buschart A, Pandey U, Wicke T, et al. The nasal and gut microbiome in Parkinson's disease and idiopathic rapid eye movement sleep behavior disorder. Mov Disord. 2018;33(1):88-98.

5. Cilia R, Piatti M, Cereda E, et al. Does Gut Microbiota Influence the Course of Parkinson's Disease? A 3-Year Prospective Exploratory Study in de novo Patients. J Parkinsons Dis. 2021;11(1):159-170.

6. Ren T, Gao Y, Qiu Y, et al. Gut Microbiota Altered in Mild Cognitive Impairment Compared With Normal Cognition in Sporadic Parkinson's Disease. Front Neurol. 2020;11:137.

7. Fasano A, Visanji NP, Liu LW, Lang AE, Pfeiffer RF. Gastrointestinal dysfunction in Parkinson's disease. Lancet Neurol. 2015;14(6):625-639.

8. Adams-Carr KL, Bestwick JP, Shribman S, Lees A, Schrag A, Noyce AJ. Constipation preceding Parkinson's disease: a systematic review and meta-analysis. J Neurol Neurosurg Psychiatry. 2016;87(7):710-716.

9. Clarke SF, Murphy EF, O'Sullivan O, et al. Exercise and associated dietary extremes impact on gut microbial diversity. Gut. 2014;63(12):1913-1920.

10. Durk RP, Castillo E, Marquez-Magana L, et al. Gut Microbiota Composition Is Related to Cardiorespiratory Fitness in Healthy Young Adults. Int J Sport Nutr Exerc Metab. 2019;29(3):249-253.

11. Yang Y, Shi Y, Wiklund P, et al. The Association between Cardiorespiratory Fitness and Gut Microbiota Composition in Premenopausal Women. Nutrients. 2017;9(8).

12. Estaki M, Pither J, Baumeister P, et al. Cardiorespiratory fitness as a predictor of intestinal microbial diversity and distinct metagenomic functions. Microbiome. 2016;4(1):42.

13. Barton W, Penney NC, Cronin O, et al. The microbiome of professional athletes differs from that of more sedentary subjects in composition and particularly at the functional metabolic level. Gut. 2018;67(4):625-633.

14. Cronin O, Barton W, Skuse P, et al. A Prospective Metagenomic and Metabolomic Analysis of the Impact of Exercise and/or Whey Protein Supplementation on the Gut Microbiome of Sedentary Adults. mSystems. 2018;3(3).

15. Resende AS, Leite GSF, Lancha Junior AH. Changes in the Gut Bacteria Composition of Healthy Men with the Same Nutritional Profile Undergoing 10-Week Aerobic Exercise Training: A Randomized Controlled Trial. Nutrients. 2021;13(8).

16. Louis S, Tappu RM, Damms-Machado A, Huson DH, Bischoff SC. Characterization of the Gut Microbial Community of Obese Patients Following a Weight-Loss Intervention Using Whole Metagenome Shotgun Sequencing. PLoS One. 2016;11(2):e0149564.

17. Kang SS, Jeraldo PR, Kurti A, et al. Diet and exercise orthogonally alter the gut microbiome and reveal independent associations with anxiety and cognition. Mol Neurodegener. 2014;9:36.

18. Campbell SC, Wisniewski PJ, Noji M, et al. The Effect of Diet and Exercise on Intestinal Integrity and Microbial Diversity in Mice. PLoS One. 2016;11(3):e0150502.

19. Allen JM, Mailing LJ, Cohrs J, et al. Exercise training-induced modification of the gut microbiota persists after microbiota colonization and attenuates the response to chemically-induced colitis in gnotobiotic mice. Gut Microbes. 2018;9(2):115-130.

20. Uhrbrand A, Stenager E, Pedersen MS, Dalgas U. Parkinson's disease and intensive exercise therapy--a systematic review and meta-analysis of randomized controlled trials. J Neurol Sci. 2015;353(1-2):9-19.

21. Li Y, Song H, Shen L, Wang Y. The efficacy and safety of moderate aerobic exercise for patients with Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials. Ann Palliat Med. 2021;10(3):2638-2649.

22. Fisher BE, Wu AD, Salem GJ, et al. The effect of exercise training in improving motor performance and corticomotor excitability in people with early Parkinson's disease. Arch Phys Med Rehabil. 2008;89(7):1221-1229.

23. Tabak R, Aquije G, Fisher BE. Aerobic exercise to improve executive function in Parkinson disease: a case series. J Neurol Phys Ther. 2013;37(2):58-64.

24. Rikli RE, Jones CJ. Senior fitness test manual. Champaign, IL: Human Kinetics; 2001.

25. Enright PL, Sherrill DL. Reference equations for the six-minute walk in healthy adults. Am J Respir Crit Care Med. 1998;158(5 Pt 1):1384-1387.



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