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NCT Number: NCT05227170

Impact of Lp299v on Vascular Function in Patients With PASC

Emerging data show that SARS-CoV-2 infection causes gut microbiome changes strongly associated with Post-Acute Sequelae of SARS-CoV-2 (PASC). The investigators and others have established that an orally ingested probiotic (Lactobacillus plantarum 299v, Lp299v) reduces circulating levels of cell-free mitochondrial DNA (cf-mtDNA), decreases toll-like receptor 9 (TLR9) activation [and downstream interleukin (IL-6)], and improves micro- and macrovascular (brachial artery) endothelial dysfunction [as measured by flow-mediated dilation (FMD%)] in humans. Recently published data also report impaired brachial FMD% and increased vascular stiffness post-SARS-CoV-2 infection. Based on these data, the investigators hypothesize that supplementation with Lp299v will attenuate SARS-CoV-2 associated endothelial dysfunction by reducing cf-mtDNA, TLR9 activation, and inflammation.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

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Key information

Age range

18 year–89 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Medical College of Wisconsin

Milwaukee, Wisconsin, 53226, United States

About this study

The intestinal immune system plays a critical role in systemic immunity, and its interaction with the systemic immune system plays a crucial role in determining the severity and outcomes of common pulmonary infections. SARS-CoV-2 infection alters the composition and metabolism of the gut microbiome. Greater losses of beneficial species in the human gut microbiome of SARS-CoV-2 patients are associated with severe disease and greater systemic inflammation. These pathological alterations are observed at least 6 months post-infection and are associated with greater residual systemic inflammation and PASC symptoms.

Six weeks of Lp299v supplementation in otherwise healthy smokers reduces circulating levels of the pro-inflammatory IL-6 and reduces monocyte adhesion to endothelial cells. IL-6 is elevated in patients with PASC and strongly correlates with TLR9 activation in disease states with high circulating cf-mtDNA levels. We published trial data showing once daily Lp299v supplementation (20 billion colony forming units/day) in men with coronary artery disease (CAD) improves endothelium-dependent vasodilation in the brachial artery and NO-dependent vasodilation of resistance arterioles from CAD patients. Further, preliminary data suggest Lp299v reduces circulating levels of cf-mtDNA (Fig. 2B). We also published data showing that 6 weeks of Lp299v has a significant anti-inflammatory effect on PBMC gene transcription, with gene ontology analyses indicating Lp299v supplementation inhibits TLR9 activation (z-score -3.48, P<0.0000000023). Combining the evidence that Lp299v reduces (1) circulating cf-mtDNA; (2) TLR9 activation; and (3) IL-6 levels while improving micro- and macrovascular endothelial function make Lp299v an excellent candidate to test as an intervention to improve vascular function in PASC patients.

Therefore, we will recruit subjects ages ≥18-89 who carry a clinical diagnosis of PASC and are within a window of 30-180-day post-acute symptom resolution into an 8-week, double-blind, randomized, placebo-controlled clinical trial of Lp299v supplementation. Measurements of micro- and macrovascular function, systemic inflammation, and stool microbiota composition will be made.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Ages 18 to 89 years
  • 30-180 days post-COVID-19 diagnosis
  • PASC diagnosed based on symptom report/expert physician judgement

Exclusion criteria

  • Antibiotics within four weeks of enrollment
  • History of chronic diseases (renal insufficiency, liver dysfunction, cancer requiring systemic treatment within 3 years of enrollment)
  • History of cognitive impairment/inability to follow study procedures
  • Short gut syndrome, inflammatory bowel disease, or an ileostomy.
  • Subjects currently taking Vitamin K antagonists such as coumadin or warfarin
  • Pregnant at the time of screening
  • Unstable coronary artery disease (new symptoms or event within 30 days of enrollment)
  • Daily alcohol use (may interfere with Lp299v's action)

Treatment and study plan

Lactobacillus Plantarum 299v Freeze Dried Capsule

Other

The intervention is a probiotic lactobacillus that is contained in food products in the US

Freeze Dried Potato Starch Capsule

Other

The intervention is potato starch that is freeze dried designed to mimic the lp299v capsule.

Primary outcomes

  1. Brachial Artery Flow Mediated Dilation (FMD%)

    Time frame: 8 weeks

    This is a measurement of endothelial function in the brachial artery

Secondary outcomes

  1. Nitroglycerin-Mediated Vasodilation of the brachial artery (NMD)

    Time frame: 8 weeks

    Measurement of vascular smooth muscle reactivity

  2. Hyperemic Flow Velocity

    Time frame: 8 weeks

    Measurement of microvascular endothelial function

  3. Carotid-Femoral Pulse Wave Velocity (cfPWV)

    Time frame: 8 weeks

    Measurement of vascular stiffness

  4. Percentage of Laser Doppler Signal

    Time frame: 8 weeks

    Measurement of skin microvascular function

  5. interleukin-6

    Time frame: 8 weeks

    circulating inflammatory marker

  6. Stool microbiota alpha diversity

    Time frame: 8 weeks

    Diversity of bacterial species in the individual microbiome

  7. Stool microbiota beta diversity

    Time frame: 8 weeks

    Differences in bacterial composition between intervention arms

  8. Cell-Free Mitochondrial DNA (cf-mtDNA)

    Time frame: 8 weeks

    Level of circulating cf-mtDNA in the plasma

  9. Brachial Artery Resting Diameter

    Time frame: 8 weeks

    resting diameter of the brachial artery - representative of resting vascular tone

  10. Myeloid Cell Population phenotypes

    Time frame: 8 weeks

    Quantification and identification of mononuclear cell and neutrophil types

Sponsors and collaborators

Lead sponsor

Medical College of Wisconsin

Other

Registry information

Important dates

Study start
2022
Primary completion
2025
Study completion
2026
First posted
Feb 7, 2022
Registry last updated
May 1, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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