The Effects of Low-Nickel Diet Combined with Oral Administration of Selected Probiotics on Patients with Systemic Nickel Allergy Syndrome (SNAS) and Gut Dysbiosis
Department of Life, Health & Environmental Sciences, University of L’Aquila, Via Pompeo Spennati, Building Rita Levi Montalcini, Coppito, 67100 L’Aquila, Italy
PoliSmail, Specialistic Unit Allergic & Immunological Pathologies, Via Clemente Rebora, 1, 73100 Lecce, Italy
Pegaso Online University, Centro Direzionale Isola F2, 80132 Naples, Italy
Authors to whom correspondence should be addressed.
These authors contributed equally to this work.
Nutrients 2020, 12(4), 1040; https://doi.org/10.3390/nu12041040
Received: 10 March 2020 / Revised: 6 April 2020 / Accepted: 8 April 2020 / Published: 9 April 2020
(This article belongs to the Section Prebiotics and Probiotics)
Background: Nickel (Ni) oral consumption may elicit systemic reactions in patients affected by systemic nickel allergy syndrome (SNAS), including gastrointestinal symptoms, which in turn are associated with gut dysbiosis. We evaluated the effects of a low-Ni diet alone or in combination with the oral consumption of appropriate probiotics on Ni-sensitivity and urinary dysbiosis markers in SNAS patients. Methods: n = 51 patients with SNAS and concomitant intestinal dysbiosis were enrolled in the study. According to the urinary indican/skatole levels, quantified through a colorimetric and a high-performance liquid chromatographic method, respectively, patients were assigned to a dysbiosis type/grade and followed a low-Ni diet for three months. Along with the diet, 22 patients also consumed probiotics based on the dysbiosis type. In particular, a Lactobacilli- or Bifidobacteria-containing formulation was administered to patients with fermentative or putrefactive dysbiosis, respectively, while a broad-spectrum probiotic formulation containing both Lactobacilli and Bifidobacteria was administered to patients with mixed dysbiosis. After three months, patients were invited to repeat the Ni-stimulation and the dysbiosis tests. Results: The fermentative dysbiosis group represented the largest group followed by the mixed dysbiosis group, while only two patients had putrefactive dysbiosis. Overall, at three months of treatment in general (diet alone with or without probiotics), the Ni-sensitivity and dysbiosis levels were strongly ameliorated. The association of a low-Ni diet with a specific probiotic oral supplementation was significantly more effective in decreasing dysbiosis levels or reaching eubiosis than with diet alone. Conclusion: Our results, while confirming the benefits of a low-Ni diet in SNAS patients, strongly support that appropriate adjuvant treatment with probiotics significantly helps to improve intestinal dysbiosis or restore a healthy microbiota.