Effects of commercial apple varieties on human gut microbiota composition and metabolic output using an in vitro colonic model

Apples are a rich source of polyphenols and fiber. A major proportion of apple polyphenols escape absorption in the small intestine and together with non-digestible polysaccharides reach the colon, where they can serve as substrates for bacterial fermentation. Animal studies suggest a synergistic interaction between apple polyphenols and the soluble fiber pectin; however, the effects of whole apples on human gut microbiota are less extensively studied. Three commercial apple varieties-Renetta Canada, Golden Delicious and Pink Lady-were digested and fermented in vitro using a batch culture colonic model (pH 5.5-6.0, 37 °C) inoculated with feces from three healthy donors. Inulin and cellulose were used as a readily and a poorly fermentable plant fiber, respectively. Fecal microbiota composition was measured by 16S rRNA gene Illumina MiSeq sequencing (V3-V4 region) and Fluorescence in Situ Hybridization. Short chain fatty acids (SCFAs) and polyphenol microbial metabolites were determined. The three apple varieties significantly changed bacterial diversity, increased Actinobacteria relative abundance, acetate, propionate and total SCFAs (p < 0.05). Renetta Canada and Golden Delicious significantly decreased Bacteroidetes abundance and increased Proteobacteria proportion and bifidobacteria population (p < 0.05). Renetta Canada also increased Faecalibacterium prausnitzii, butyrate levels and polyphenol microbial metabolites (p < 0.05). Together, these data suggest that apples, particularly Renetta Canada, can induce substantial changes in microbiota composition and metabolic activity in vitro, which could be associated with potential benefits to human health. Human intervention studies are necessary to confirm these data and potential beneficial effects

Identification of Ixodes ricinus blood meals using an automated protocol with high resolution melting analysis (HRMA) reveals the importance of domestic dogs as larval tick hosts in Italian alpine forests

Background In Europe, Ixodes ricinus L. is the main vector of a variety of zoonotic pathogens, acquired through blood meals taken once per stage from a vertebrate host. Defining the main tick hosts in a given area is important for planning public health interventions; however, until recently, no robust molecular methods existed for blood meal identification from questing ticks. Here we improved the time- and cost-effectiveness of an HRMA protocol for blood meal analysis and used it to identify blood meal sources of sheep tick larvae from Italian alpine forests. Methods Nine hundred questing nymphs were collected using blanket-dragging in 18 extensive forests and 12 forest patches close to rural villages in the Province of Trento. Total DNA was either extracted manually, with the QIAamp DNA Investigator kit, or automatically using the KingFisher™ Flex Magnetic Particle Processors (KingFisher Cell and Tissue DNA Kit). Host DNA was amplified with six independent host group real-time PCR reactions and identified by means of HRMA. Statistical analyses were performed in R to assess the variables important for achieving successful identification and to compare host use in the two types of forest. Results Automating DNA extraction improved time- and cost-effectiveness of the HRMA protocol, but identification success fell to 22.4% (KingFisher™) from 55.1% (QIAamp), with larval hosts identified in 215 of 848 questing nymphs; 23 mixed blood meals were noted. However, the list of hosts targeted by our primer sets was extended, improving the potential of the method. Host identification to species or genus level was possible for 137 and 102 blood meals, respectively. The most common hosts were Rodentia (28.9%) and, unexpectedly, Carnivora (28.4%), with domestic dogs accounting for 21.3% of all larval blood meals. Overall, Cetartiodactyla species fed 17.2% of larvae. Passeriformes (14.6%) fed a significantly higher proportion of larvae in forest patches (22.3%) than in extensive forest (9.6%), while Soricomorpha (10.9%) were more important hosts in extensive forest (15.2%) than in forest patches (4.3%). Conclusions The HRMA protocol for blood meal analysis is a valuable tool in the study of feeding ecology of sheep ticks, especially with the cost- and time- reductions introduced here. To our knowledge, we show for the first time that domestic dogs are important larval hosts in the Alps, which may have possible implications for tick-borne disease cycles in urbanized area

Impact of ageing and a synbiotic on the immune response to seasonal influenza vaccination; a randomised controlled trial

Background & Aims Ageing increases risk of respiratory infections and impairs the response to influenza vaccination. Pre- and probiotics offer an opportunity to modulate anti-viral defenses and the response to vaccination via alteration of the gut microbiota. This study investigated the effect of a novel probiotic, Bifidobacterium longum bv. infantis CCUG 52486, combined with a prebiotic, gluco-oligosaccharide, on the B and T cell response to seasonal influenza vaccination in young and older subjects. Methods In a double-blind, randomized controlled trial, 58 young (18-35y) and 54 older (60-85y) subjects were supplemented with the synbiotic for 8 weeks. At 4 weeks they were administered with a seasonal influenza vaccine. B and T cell phenotype and responsiveness to in vitro re-stimulation with the vaccine were assessed at baseline, 4, 6 and 8 weeks. Results B and T cell profiles differed markedly between young and older subjects. Vaccination increased numbers of memory, IgA+ memory, IgG+ memory and total IgG+ B cells in young subjects, but failed to do so in older subjects and did not significantly alter T cell subsets. Seroconversion to the H1N1 subunit in the older subjects was associated with higher post-vaccination numbers of plasma B cells, but seroconversion was less consistently associated with T cell phenotype. B and T cell subsets from both young and older subjects demonstrated a strong antigen-specific recall challenge, and although not influenced by age, responsiveness to the recall challenge was associated with seroconversion. In older subjects, CMV seropositivity was associated with a significantly lower recall response to the vaccine, but the synbiotic did not affect the responsiveness of B or T cells to re-stimulation with influenza vaccine. Conclusions Antigen-specific B and T cell activation following an in vitro recall challenge with the influenza vaccine was influenced by CMV seropositivity, but not by a synbiotic

Result of Brett Survey in Finger Lakes Pinot Noir

Brettanomyces bruxellensis has been associated with wines which exhibit off-flavors and odors described as "burnt plastic," "wet wool," "horse sweat," and "barn yard." The yeast can grow in wines at very low cell densities and can withstand the combined stresses of acetic acid, free SO2, tartaric acid and ethanol. Brettanomyces bruxellensis tends to overproduce acetic acid and convert fruity phenolic compounds into undesirable aromas such as 4-ethylphenol and 4-ethylguiacol which give wine burnt plastic, Bandaid (R), plastic, and barnyard aromas (Chatonnet et al., 1992, 1997; Licker, 1998; Arvik, 2002). These products are malodorous by themselves, but small concentration of "bretty" aroma compounds may increase the wine's aroma complexity if they are kept at concentrations near the odor threshold. Some winemakers are convinced that any amount of Brettanomyces is bad for a winery. Others like the character that some B. bruxellensis strains may give an under-ripe, simple fruity wine. Because there is evidence for the global presence of "Brett" (Fugelsang, 1997), the issue has become more of an immediate priority for wine researchers. We have isolated Brettanomyces from several NY wines as well as from bottled wines from other parts of the USA and Europe (Arvik, 2002). A wide overview on the "Brett" phenomenon was presented at the 31st Annual NY Wine Industry Workshop (Arvik and Henick-Kling, 2002). In this research a survey on Brettanomyces bruxellensis occurrence in the 28 samples of Finger Lake Pinot Noir has been accomplished. The wines were produced in the wineries member to the Pinot Noir Alliance that supported the project submitted in 2002, as well. Moreover, more information about factors affecting B. bruxellensis wine-altering activity will be added to our database. The results were also compared to the survey previously performed on Cabernet Franc (Arvik and Henick-Kling in progress)

Brettanomyces Bruxellensis in New York State Wines: A Global Issue

Recent work in our laboratory to identify strains of Brettanomyces bruxellensis in New York State has focused on red wines from the Finger Lakes region and Long Island. Most isolates were from barrel samples and were therefore unfiltered blends of several separate environments. Two isolates were from finished wines in bottle, one of which was not filtered as a matter of style