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- Effects of whey peptide extract on the growth of probiotics and gut microbiotaPublication . Yu, Ya-Ju; Amorim, Manuela; Marques, Cláudia; Calhau, Conceição; Pintado, M. E.Whey peptide extract with molecular weight below 1 kDa was investigated in microplate assay, and viable cells, as well as metabolic activity were determined to evaluate augmented growth of probiotic bacteria (Lactobacillus acidophilus and Bifidobacterium animalis). Results illustrated that whey peptide extract 1% (w/v) has the capacity to stimulate the proliferation of both probiotic bacteria tested, further supported by the faster generation of metabolic products. The effect of whey peptide extract on the modulation of gut microbiota was also examined inWistar rats fed either with a standard or a high-fat diet, assessed via 16S ribosomal RNA expression of gut microbiota by quantitative PCR. Relative abundance of Lactobacillus spp., Bifidobacterium spp. and Bacteroidetes was significantly increased by whey peptide extract in rats fed with a standard diet. These results highlight an additional unexploited positive effect of whey peptide extract on gut microbiota modulation.
- Fermentation of bioactive solid lipid nanoparticles by human gut microfloraPublication . Madureira, Ana Raquel; Campos, Débora; Gullon, Beatriz; Marques, Cláudia; Rodríguez-Alcalá, Luís M.; Calhau, Conceição; Alonso, Jose Luis; Sarmento, Bruno; Gomes, Ana M.; Pintado, M. E.Solid lipid nanoparticles (SLNs) can be used for oral delivery of phenolic compounds in order to protect them from the harsh conditions of digestion and improve their bioavailability in the intestinal epithelium. Recently, the production and characterization of SLNs loaded with rosmarinic acid (RA) and herbal extracts was performed for future use as functional food ingredients. Diet components have been shown to have a huge impact on gut microbiota viability and metabolic activity. Hence, SLNs loaded with RA, sage and savoury extracts have been evaluated for their effect on intestinal microbiota growth and the metabolic products generated. Fermentations in anaerobic batch cultures using volunteer human faeces were performed during 24 h. Dynamic bacterial population changes were analysed using PCR-real time, as well as the generation of fatty acids and the quantification of phenolic compounds by analytical methods. Solid lipid nanoparticles released phenolic compounds at non-inhibitory bacterial growth concentrations. Released herbal extract phenolic compounds showed a beneficial effect on gut microbiota growth (e.g. bifidogenic effects) and were used as substrates. Acetate, formate, lactate and butyrate were produced in higher concentrations. The released phenolic compounds also induced PUFA and trans fatty acids metabolic activity, the production of saturated fatty acids, as well of potential beneficial conjugated linoleic acid isomers. Solid lipid nanoparticles modulate gut microbiota and metabolic activities.
- Safety profile of solid lipid nanoparticles loaded with rosmarinic acid for oral use: in vitro and animal approachesPublication . Reis, Flávio; Madureira, Ana Raquel; Nunes, Sara; Campos, Débora; Fernandes, João; Marques, Cláudia; Zuzarte, Monica; Gullón, Beatriz; Rodríguez-Alcalá, Luis M.; Calhau, Conceição; Sarmento, Bruno; Gomes, Ana M.; Pintado, M. E.Rosmarinic acid (RA) possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe) delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL) were evaluated for cell (lymphocytes) viability, necrosis and apoptosis, and antioxidant/prooxidant effects upon DNA. Wistar rats were orally treated for 14 days with vehicle (control) and with Witepsol or Carnauba nanoparticles loaded with RA at 1 and 10 mg/kg body weight/d. Blood, urine, feces, and several tissues were collected for analysis. Free and loaded RA, at 0.15 mg/mL, presented a safe profile, while genotoxic potential was found for the higher dose (1.5 mg/mL), mainly by necrosis. Our data suggest that both types of nanoparticles are safe when loaded with moderate concentrations of RA, without in vitro genotoxicity and cytotoxicity and with an in vivo safety profile in rats orally treated, thus opening new avenues for use in nutraceutical applications.