Dry alginate beads for fecal microbiota transplantation: From model strains to fecal samples.

Clostridioides difficile infection (CDI) is a critical nosocomial infection with more than 124,000 cases per year in Europe and a mortality rate of 15-17 %. The standard of care (SoC) is antibiotic treatment. Unfortunately, the relapse rate is high (∼35 %) and SoC is significantly less effective against recurrent infection (rCDI). Fecal microbiota transplantation (FMT) is a recommended treatment against rCDI from the second recurrence episode and has an efficacy of 90 %. The formulation of diluted donor stool deserves innovation because its actual administration routes deserve optimization (naso-duodenal/jejunal tubes, colonoscopy, enema or several voluminous oral capsules). Encapsulation of model bacteria strains in gel beads were first investigated. Then, the encapsulation method was applied to diluted stools. Robust spherical gel beads were obtained. The mean particle size was around 2 mm. A high loading of viable microorganisms was obtained for model strains and fecal samples. For plate-counting, values ranged from 1015 to 1017 CFU/g for single and mixed model strains, and 106 to 108 CFU/g for fecal samples. This corresponded to a viability of 30 % to 60 % as assessed by flow cytometry. This novel formulation is promising as the technology is applicable to both model strains and bacteria contained in the gut microbiota.

Stability of N-Acetylcysteine (NAC) in Standardized Pediatric Parenteral Nutrition and Evaluation of N,N-Diacetylcystine (DAC) Formation.

The ESPGHAN/ESPEN/ESPR-Guidelines on pediatric parenteral nutrition (PPN) recommend the administration of the semiessential amino acid (AA) cysteine to preterm neonates due to their biochemical immaturity resulting in an inability to sufficiently synthetize endogenous cysteine. The soluble precursor N-acetylcysteine (NAC) is easily converted into bioavailable cysteine. Its dimer N,N-diacetylcystine (DAC) is almost unconvertable to cysteine when given intravenously resulting in a diminished bioavailability of cysteine. This study aims to understand the triggers and oxidation process of NAC to DAC to evaluate possibilities of reducing DAC formation in standardized PPN. Therefore, different air volumes (21% O2) were injected into the AA compartment of a standardized dual-chamber PPN. O2 concentrations were measured in the AA solution and the headspaces of the primary and secondary packaging. NAC and DAC concentrations were analyzed simultaneously. The analysis showed that O2 is principally delivered from the primary headspace. NAC oxidation exclusively delivers DAC, depending on the O2 amount in the solution and the headspaces. The reaction of NAC to DAC being containable by limiting the O2 concentration, the primary headspace must be minimized during manufacturing, and oxygen absorbers must be added into the secondary packaging for a long-term storage of semipermeable containers.

Long-term physico-chemical stability of standard parenteral nutritions for neonates.

BACKGROUND & AIMS: Two ready-to-use parenteral nutritions (PN) have been developed, for the first days of life of the premature newborn, along with syringes of lipid emulsion with or without vitamins. Long-term physico-chemical stability for storage in wards was assessed. METHODS: Physico-chemical stability of PN: visual inspection, particle size, pH, osmolarity measurement, amino acids, glucose, and electrolytes dosages. Physico-chemical stability of lipid emulsion: visual inspection, globule size, peroxide level and vitamins A, E, and C dosages. Stability was studied for 12 weeks on refrigerated (2-8 °C) and room temperature (30 ± 2 °C) samples. RESULTS: No precipitation was detected in any PN. A brown coloration was observed in PN stored for four weeks at room temperature but not in the refrigerator. Concentrations of all the nutrients remained constant over the 12 week-study period. Phase separation of the lipid emulsion occurred after three weeks, but particle size complied with the USP limits for 12 weeks. Peroxide content increased only in the samples without vitamins at room temperature. Vitamins remained stable for one week under refrigeration. CONCLUSION: The PN did not present a detectable change of the tested properties when refrigerated for 12 weeks. The lipid emulsion with vitamins is stable for one week when refrigerated.