Effect of pine bark extract and its phenolic compounds on selected pathogenic and probiotic bacterial strains.

Introduction: Inflammatory bowel disease (IBD) comprises a heterogeneous group of chronic diseases as ulcerative colitis (UC) and Crohn's disease (CD). IBD is the result of a dysregulation of intestinal homeostasis with a host's loss of tolerance toward normal enteric microflora. Plant-based extracts as phenolic compounds can play a role by modulating the intestinal inflammation response. Methods: The in vitro antimicrobial activity of French maritime pine bark extract (PBE) and its phenolic constituents has been investigated in this study. Furthermore, the ability of PBE and phenolic compounds (caffeic acid, chlorogenic acid, ferulic acid, gallic acid and taxifolin) to modulate the microbiota has been assessed. Results: Phenolic compounds and PBE showed a great inhibitory effect on the pathogens growth at the highest concentration assessed (1.25 mg/mL). The growth of E. sakazakii and E. faecalis were affected by the effect of caffeic acid and ferulic acid. Taxifolin showed a very strong activity against Listeria sp. (with a reduction ~98%). Gallic acid revealed antibacterial effect on S. aureus at different concentrations. The inhibitory effect of PBE was highly significant on the growth of E. coli O157:H7. PBE, caffeic acid and chlorogenic acid seem to provide the greatest beneficial effect on the probiotic bacteria. However, the highest concentrations of taxifolin may have impaired the growth of beneficial microbiota. Conclusion: Present findings could be of interest for considering PBE and/or its phenolic constituents as protectors against gastrointestinal disturbances which lead to ulcerative colitis and Crohn's disease.

In vitro prebiotic activity of rhLf and galactooligosaccharideson infant intestinal microbiota / Actividad prebiótica in vitro de lactoferrina y galactooligosácridossobre la microbiota intestinal infantil

Objective: human lactoferrin (Lf) and human milk oligosaccharides possess a wide range of functions. So, the present study focusses on the role of Lf and/or galactooligosaccharides (GOS) in the modulation of gut microbiota composition.Methods: recombinant human lactoferrin (rhLf) was added to the first infant formula (0.10, 0.15, 0.20 %) alone or in combination with GOS (1 %) in vessels of a small-scale batch culture fermentation model. Short-chain fatty acids (SCFAs), microbial population groups, and pH were monitored through fermentation for 24 hours. Results: insignificant changes were observed in pH values and acetic acid accumulated during fermentation. Propionic acid content has been insignificantly increased while butyric acid has been insignificantly decreased. Moreover, increments in all bacterial groups except for Bacteroides were observed through the fermentation process. Lactobacillus and Bifidobacterium showed an increase in relation to initial time over thefermentation process, demonstrating the prebiotic effect of lactoferrin and GOS. After 24 hours of fermentation, all tested ingredients showed significant similarities in Enterococcus for controls except for 0.20 % rhLf + 1 % GOS, which provoked a diminution of Enterococci growth. Conclusion: despite the importance of the batch culture fermentation technique in uncovering the prebiotic activity of food ingredients, it is not useful for detecting the prebiotic nature of Lf due to its nature as a protein. Thus, Lf maybe shows its prebiotic activity on the gut microbiota through other mechanisms.(AU)

Objetivo: la lactoferrina humana (Lf) y los oligosacáridos de leche materna presentan un amplio rango de funciones. El presente estudio se centra en el papel de la Lf y/o galactooligosácridos (GOS) en la modulación de la composición de la microbiota intestinal. Métodos: se añadió lactoferrina humana recombinante (rhLf) a fórmula infantil (0,10, 0,15, 0,20 %), sola o en combinación con GOS (1 %) en botes de fermentación colónica. A lo largo de 24 horas de fermentación, se monitorizaron ácidos grasos de cadena corta, grupos de poblaciones microbianas y pH. Resultados: se observaron pequeños cambios en valores de pH y cantidad de ácido acético durante la fermentación. El contenido de ácido propiónico aumentó ligeramente, mientras que el butírico sufrió un ligero descenso. Todos los grupos bacterianos estudiados incrementaron, excepto los Bacteroides, durante la fermentación. Lactobacillus and Bifidobacterium mostraron un incremento respecto al valor inicial, demostrando el efecto prebiótico de la lactoferrina y los GOS. A las 24 horas de fermentación, todos los ingredientes estudiados mostraron similitud al control en cuanto a Enterococcus, excepto para 0,20 % rhLf + 1 % GOS, donde disminuyó el crecimiento de los enterococos. Conclusión: a pesar de la importancia de los estudios de fermentación in vitro para descubrir potenciales ingredientes prebióticos, no fue útil en el caso de lactoferrina debido a su naturaleza proteica. Por tanto, la lactoferrina podría mostrar su actividad prebiótica en la microbiota intestinal a través de otros mecanismos.(AU)

[Anti-inflammatory effect of milk whey from different species after in vitro digestion]. / Efecto antiinflamatorio del suero de leche de diferentes especies tras una digestión in vitro.

Introduction: Introduction: there is a close relationship between obesity, gut health and immune system. A low-grade of inflammation, which could precede obesity, may have implications for the development of metabolic syndrome and insulin resistance. Objective: analyzing the anti-inflammatory capacity of several types of whey (cow, sheep, goat and a mixture of them). Methods: an in vitro model of intestinal inflammation employing a cell co-culture (Caco-2 and RAW 264.7) was performed after an in vitro digestion and fermentation (simulating mouth-to-colon conditions). Inflammatory markers such as IL-8 and TNF-α, as well as the transepithelial electrical resistance (TEER) of Caco-2 monolayer, were determined. Results: digested and fermented whey had a protective effect on cell permeability, being lower in the case of fermented goat whey and mixture. The anti-inflammatory activity of whey was greater the more digestion progressed. Fermented whey showed the greatest anti-inflammatory effect, inhibiting IL-8 and TNF-α secretion, probably due to its composition (protein degradation products such as peptides and amino acids, and SCFA). However, fermented goat whey did not show this degree of inhibition, perhaps due to its low SCFA concentration. Conclusion: milk whey, especially after being fermented in the colon, can be useful nutritional strategy to preserve the intestinal barrier and mitigate the low-grade of inflammation that characterizes metabolic disorders and obesity.

Introducción: Introducción: existe una estrecha relación entre obesidad, salud intestinal y sistema inmune. Un bajo grado de inflamación, que precedería a la obesidad, puede tener implicaciones en el desarrollo de síndrome metabólico y resistencia a la insulina. Objetivo: analizar el poder antiinflamatorio de varios tipos de lactosuero (vaca, oveja, cabra y mezcla de los anteriores). Metodología: se utilizó un modelo in vitro de inflamación intestinal, empleando un cocultivo celular (Caco-2 y RAW 264.7). Para ello, se realizó una digestión y fermentación in vitro (simulando las condiciones de boca a colon). Se estudiaron IL-8 y TNF-α como marcadores inflamatorios y la resistencia eléctrica transepitelial celular (RETE) de la monocapa celular Caco-2. Resultados: el suero digerido y fermentado tuvo un efecto protector sobre la permeabilidad celular que fue menor en el caso de lactosuero fermentado de cabra y mezcla. La actividad antiinflamatoria del suero fue mayor cuanto más progresaba la digestión. El lactosuero fermentado mostró el mayor efecto antiinflamatorio, inhibiendo la secreción de IL-8 y TNF-α, probablemente debido a su composición (productos de degradación proteica como péptidos y aminoácidos, y ácidos grasos de cadena corta [AGCC]). Sin embargo, el suero fermentado de cabra no mostró ese grado de inhibición, quizás debido a su baja concentración en AGCC. Conclusión: el lactosuero, sobre todo tras ser fermentado en colon, puede ser una estrategia nutricional útil para preservar la barrera intestinal y mitigar el bajo grado de inflamación que caracteriza a desordenes metabólicos y a la obesidad.

In vitro prebiotic activity of rhLf and galactooligosaccharides on infant intestinal microbiota.

Introduction: Objective: human lactoferrin (Lf) and human milk oligosaccharides possess a wide range of functions. So, the present study focusses on the role of Lf and/or galactooligosaccharides (GOS) in the modulation of gut microbiota composition. Methods: recombinant human lactoferrin (rhLf) was added to the first infant formula (0.10, 0.15, 0.20 %) alone or in combination with GOS (1 %) in vessels of a small-scale batch culture fermentation model. Short-chain fatty acids (SCFAs), microbial population groups, and pH were monitored through fermentation for 24 hours. Results: insignificant changes were observed in pH values and acetic acid accumulated during fermentation. Propionic acid content has been insignificantly increased while butyric acid has been insignificantly decreased. Moreover, increments in all bacterial groups except for Bacteroides were observed through the fermentation process. Lactobacillus and Bifidobacterium showed an increase in relation to initial time over the fermentation process, demonstrating the prebiotic effect of lactoferrin and GOS. After 24 hours of fermentation, all tested ingredients showed significant similarities in Enterococcus for controls except for 0.20 % rhLf + 1 % GOS, which provoked a diminution of Enterococci growth. Conclusion: despite the importance of the batch culture fermentation technique in uncovering the prebiotic activity of food ingredients, it is not useful for detecting the prebiotic nature of Lf due to its nature as a protein. Thus, Lf maybe shows its prebiotic activity on the gut microbiota through other mechanisms.

Introducción: Objetivo: la lactoferrina humana (Lf) y los oligosacáridos de leche materna presentan un amplio rango de funciones. El presente estudio se centra en el papel de la Lf y/o galactooligosácridos (GOS) en la modulación de la composición de la microbiota intestinal. Métodos: se añadió lactoferrina humana recombinante (rhLf) a fórmula infantil (0,10, 0,15, 0,20 %), sola o en combinación con GOS (1 %) en botes de fermentación colónica. A lo largo de 24 horas de fermentación, se monitorizaron ácidos grasos de cadena corta, grupos de poblaciones microbianas y pH. Resultados: se observaron pequeños cambios en valores de pH y cantidad de ácido acético durante la fermentación. El contenido de ácido propiónico aumentó ligeramente, mientras que el butírico sufrió un ligero descenso. Todos los grupos bacterianos estudiados incrementaron, excepto los Bacteroides, durante la fermentación. Lactobacillus and Bifidobacterium mostraron un incremento respecto al valor inicial, demostrando el efecto prebiótico de la lactoferrina y los GOS. A las 24 horas de fermentación, todos los ingredientes estudiados mostraron similitud al control en cuanto a Enterococcus, excepto para 0,20 % rhLf + 1 % GOS, donde disminuyó el crecimiento de los enterococos. Conclusión: a pesar de la importancia de los estudios de fermentación in vitro para descubrir potenciales ingredientes prebióticos, no fue útil en el caso de lactoferrina debido a su naturaleza proteica. Por tanto, la lactoferrina podría mostrar su actividad prebiótica en la microbiota intestinal a través de otros mecanismos.

In vitro digestion effect on CCK and GLP-1 release and antioxidant capacity of some plant-based milk substitutes.

Recently, plant-based milk substitutes, as an emerging industry, are receiving more attention. Despite that, these dairy alternatives have not been adequately studied for their functional properties. Thus, the current research was devoted to study the satiety potential through in vitro secretion of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), and the antioxidant capacity of these dairy alternatives after in vitro digestion. The enteroendocrine cell line, STC-1, was used to measure satiety hormones release (CCK and GLP-1) by enzyme-linked immunoassay (ELISA). Also, total phenolic and flavonoid contents and antioxidant capacity (using oxygen radical absorbance capacity [ORAC], ferric reducing antioxidant power [FRAP], and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid [ABTS] assays) were measured before and after in vitro digestion. The results demonstrated that CCK secretion was significantly (p < 0.05) higher for cow's milk (350.64 pg ml-1 ) as compared to plant-based milk substitutes. Among the plant-based milk substitutes, tiger nut milk showed the highest CCK stimulant (228.96 pg ml-1 ), followed by hazelnut milk (220.04 pg ml-1 ). Concerning GLP-1 release, the data exhibited that spelt milk was the food with the highest induction of GLP-1 hormone secretion, followed by cow's milk (910.17 and 876.59 pg ml-1 , respectively), but without any significant differences between them. total phenolic content (TPC) values strongly increased after in vitro digestion, cow's milk and soymilk being the samples with the highest TPC values after in vitro digestion (165.76 and 153.71 mg GAE/100 ml, respectively). In line with TPC values, soymilk had the highest ORAC, ABTS, and FRAP values after in vitro digestion (25.41, 8.17, and 2.51 µmol TE/ml, respectively). Thus, these dairy alternatives could be an adequate substitute for cow's milk, according to its satiety and antioxidant capacity. PRACTICAL APPLICATION: The first study deals with the efficacy of plant-based milk substitutes as satiating foods. Spelt milk was the highest stimulant for GLP-1 secretion. Tiger nut milk showed the highest CCK stimulant, followed by hazelnut milk. TPC and total antioxidant capacity increased after digestion.

Bioaccessibility and antioxidant activity of PCL-microencapsulated olive leaves polyphenols and its application in yogurt.

Polycaprolactone (PCL)was used via double emulsion/solvent evaporation technique for the encapsulation of polyphenols olive leaves (OLs) extracts. In this study, the PCL-microcapsules loaded with OLs polyphenols extract powder were characterized by scanning electron microscopy and fourier transform infrared spectrometry analysis. Their total phenolic (TPC), total flavonoid (TFC) contents, and antioxidant activities (DPPH, FRAP, and ABTS), and polyphenols stability were measured after oral, gastric, and intestinal steps of in vitro digestion. PCL-microcapsules were utilized in formulating novel functional yogurt containing 0, 25, 50, and 75 mg of TPC estimated as mg GAE (added as PCL-microcapsules) per 100g yogurt. All yogurt samples were evaluated for their pH, acidity, syneresis, viscosity, and color during storage. In vitro digestion significantly affected the phenolic composition in non-encapsulated extract whereas it had a lower impact on encapsulated phenolics. Higher protection was provided for encapsulated OLs extract and their higher release was observed at the intestinal phase. Unlike the undigested OLs extract, which had a TPC of 490 mg GAE/100 g, lower values of TPC (136 and 289 mg GAE/100 g) were obtained for non-encapsulated and encapsulated OLs extract, respectively, in the intestinal fluids. Yogurt with PCL-microcapsules had lower viscosity, syneresis, and color parameters, compared to control yogurt. Thus, OLs represent a valuable and cheap source of polyphenols that can be successfully applied in microencapsulated form, in formulating functional yogurt.

Screening ultrafiltration membranes to separate lactose and protein from sheep whey: application of simplified model.

Several studies demonstrated that protein from whey milk could be a new strategy to reduce energy intake and increase satiety. Sheep whey has high protein content, but it is also rich in lactose. The aim of this study was to screening different ultrafiltration membranes to separate protein and lactose from sheep whey in one step. Protein was recovered in the concentrate feed, and lactose passed through three membranes and was recovered in the permeate feed. Membranes with different chemical composition and molecular weight cut-offs were assayed, and the influence of operating pressure and lactose concentration feed in the permeate flux and lactose rejection coefficients were studied. Lactose separation was not affected by pressure in GR60PP or GR90PP, and 85% and 80%, respectively of the lactose was separated into permeate feed. When the feed concentration increased, lactose separation remained stable in all three membranes, being GR60PP the most efficient, as 90% of the disaccharides were separated. In all cases 100% of the protein was recovered. Finally, the Spiegler-Kedem-Katchalsky model perfectly fitted the results obtained about lactose rejection coefficients.

Effect of in Vitro Gastrointestinal Digestion on Encapsulated and Nonencapsulated Phenolic Compounds of Carob (Ceratonia siliqua L.) Pulp Extracts and Their Antioxidant Capacity.

To determine the effect of in vitro gastrointestinal digestion on the release and antioxidant capacity of encapsulated and nonencapsulated phenolics carob pulp extracts, unripe and ripe carob pulp extracts were microencapsulated with polycaprolactone via double emulsion/solvent evaporation technique. Microcapsules' characterization was performed using scanning electron microscopy and Fourier transform infrared spectrometry analysis. Total phenolics and flavonoids content and antioxidant activities (ORAC, DPPH, and FRAP) were evaluated after each digestion step. The release of phenolic acids and flavonoids was measured along the digestion process by HPLC-MS/MS analysis. The most important phenolics and flavonoids content as well as antioxidant activities were observed after gastric and intestinal phases for nonencapsulated and encapsulated extracts, respectively. The microencapsulation of carob polyphenols showed a protective effect against pH changes and enzymatic activities along digestion, thereby promoting a controlled release and targeted delivery of the encapsulated compound, which contributed to an increase in its bioaccessibility in the gut.