Pectin Intervention Study and Long-term Follow-up in Lipid Transfer Proteins Allergic Patients
NCT Number: NCT06558526
Acronym: PI23/00820
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Food Allergy
Interventions: DIETARY_SUPPLEMENT: Apple pectin (DE 57%)|DIETARY_SUPPLEMENT: Placebo
Sponsor: Fundación Pública Andaluza para la Investigación de Málaga en Biomedicina y Salud
Sex: ALL
Age: ADULT
Enrollment: 62
Study Design: Allocation: RANDOMIZED|Intervention Model: PARALLEL|Masking: TRIPLE (PARTICIPANT, INVESTIGATOR, OUTCOMES_ASSESSOR)|Primary Purpose: TREATMENT
Start Date: 2024-08
Completion Date: 2026-07

Summary:
Pectins are dietary fibers that have shown a health effect on patients with food allergy, as they are capable of modifying the composition of gastrointestinal microbiota, and producing an immunomodulatory effect. Preliminary results by the investigators show that the intervention for 2 months with pectins produces an increase in tolerance to peach, and changes in the microbiota compared to the group of patients treated with placebo. In this project, the investigators aim to study these clinical effects and the involved mechanisms. Moreover, the long-term effect (clinical reactivity to nsLTP and immunomodulatory effect) of the dietary intervention will be prospectively evaluated 6 months after the intervention.

Primary Outcome Measures: Clinical efficacy of a six-month dietary intervention with pectins in patients with food allergy to peach and peanut due to sensitization to nsLTP., Clinical efficacy will be defined as an increase in oral tolerance to peach and/or peanut determined through the DBPCFCs performed pre- and post- dietary intervention, compared to the Placebo., 15 months
Secondary Outcome Measures: Correlation between the induced changes in oral tolerance to peach and/or peanut and the reactivity in skin prick test (SPT)., Changes in oral tolerance to peach and/or peanut (see Primary outcome). Reactivity in SPT to Pru p 3 and peanut will be defined by the size of the papule area (mm2) measured pre- and post- dietary intervention., 15 months|Changes in Pru p 3 and Ara h 9 (nsLTP of peach and peanut, respectively) specific immunoglobulin production (IgE and IgG4) induced by the pectin dietary intervention., Results will be expresses as kUA/L., 15 months|Changes in Pru p 3 and Ara h 9-specific basophil activation induced by the pectin dietary intervention, Results will be presented as the percentage of activated basophils (CD63+CD203c+CCR3+) and basophil allergen threshold sensitivity (CD-Sens)., 15 months|Maturational changes in Pru p 3 and Ara h 9-specific dendritics cells induced by the pectin dietary intervention., Results will be expressed as maturation index (MI)., 15 months|Pru p 3 and Ara h 9-specific proliferative response of different lymphocytes cell subpopulations after the pectin dietary intervention., The specific proliferation responses of different lymphocytes subpopulations will be measured: Th1, Th2, Th9, and Plasma-cells/IgE+, T regulatory cells (Treg), Treg/IL10+ and B regulatory cells/ IL10+. The results will be expressed as fold change of proliferation index (PI)., 15 months|Changes on gastrointestinal microbiota induced by the pectin dietary intervention., Analysis of bacteria composition: relative abundance (%) and alpha-, beta diversity as Jensen Shannon divergence (JSD) (PChao1 vs PChao2)., 15 months|Changes on feces metabolome induced by the pectin dietary intervention., Metabolomic profile from feces samples will be analyzed using a combination of untargeted mass spectrometry techniques: liquid chromatography-mass spectrometry (LC-ESI-QTOF-MS) and capillary electrophoresis-mass spectrometry (CE-TOF-MS). Results will be expressed as μg/g., 15 months|Changes on serum metabolome induced by the pectin dietary intervention., Metabolomic profile from serum samples will be analyzed by a combination of liquid chromatography-mass spectrometry (LC-MS) and gas chromatography coupled to mass spectrometry (GC-MS). Results will be expressed as μg/mL., 15 months|Pectin dietary intervention long-term clinical efficacy., Peach and peanut oral tolerance after 6 months of completing the dietary intervention with the active (pectin) will be determine through DBPCFCs., 12 months|Pectin dietary intervention long-term effect on the immunological profile., Determination and analysis of Pru p 3 and Ara h 9-specific IgE and IgG4 production, basophil activation, dendritic cell maturation and proliferative response of different lymphocytes cell subpopulations, after 6 months of completing the dietary intervention with the active (pectin). Each determination will be performed and measured as same as for the related previous outcomes mentioned., 12 months|Pectin dietary intervention long-term effect on the gastrointestinal microbiota., Analysis of gastrointestinal microbiota composition after 6 months of completing the dietary intervention with the active (pectin). Relative abundance (%) and alpha-, beta diversity as Jensen Shannon divergence (JSD) (PChao1 vs PChao2)., 12 months|Pectin dietary intervention long-term effect on feces metabolome., Analysis by a combination of mass spectrometry techniques after 6 months of completing the dietary intervention with the active (pectin). Results will be expressed as μg/g., 12 months|Pectin dietary intervention long-term effect on serum metabolome., Analysis by a combination of mass spectrometry techniques after 6 months of completing the dietary intervention with the active (pectin). Results will be expressed as μg/mL., 12 months