Changes in the intestinal microbiota of healthy adults induced by brown yogurt and relationships of bacterial taxa with specific components.

Yogurt consumption shows a wide range of effects on the gut microbial composition, and correlation of components in yogurt with the changes of gut microbia remains largely uncharacterized. We aimed to determine the effect of brown yogurt (SSN) on the composition of the gut microbiota and to explore the effects of the major components. We performed a randomized study of 70 healthy adults to compare the effects of SSN and standard probiotic-containing yogurt (YJD) during a 28-day intervention and a 10-day follow-up period. The results showed that the SSN group showed significant increases in the butyrate-producer Akkermansia muciniphila, Ruminococcus, and Veillonella (p < 0.05), whereas the YJD group showed increases in the butyrate-producer Megasphaera, Anaerostipes, and Eubacterium. There were reductions in the potential pathogens Haemophilus parainfluenzae and Gemmiger formicilis in both groups (p < 0.05). The SSN group had more Faecalibacterium prausnitzii, Prevotella copri, Bifidobacterium and B. longum than the YJD group (p < 0.001), but fewer Bacteroides, unspecified Clostridiales and Coprococcus eutactus (p < 0.01). These differences might be at least in part explained by the higher concentrations of monosaccharide, palmitoleic acid, and glutamine synthetase adenyltransferase in the SSN product (p < 0.05), which were positively associated with F. prausnitzii (p ≤ 0.001) and B. longum (p < 0.05), and negatively associated with C. eutactus (p < 0.01). The single strain of starter culture and lower content of polyunsaturated fatty acids (PUFA) in the SSN product were also related to the different changes of gut microbia, and the taxa F. prausnitzii, Bifidobacterium and B. longum were negatively associated with starter culture and PUFA (p < 0.01). These findings suggested that SSN is rich in prebiotic components and might be beneficial for healthy adults. Furthermore, bacterial taxa with potential health benefits could be encouraged through improving the formulation and technology used to produce the dairy products.

Influence of Kluyveromyces marxianus on proteins, peptides, and amino acids in Lactobacillus-fermented milk.

With increasing application of yeast in fermented milk, in order to study the effect of yeast on milk protein during the fermentation process, the effects of the presence of Kluyveromyces marxianus in milk fermented by Streptococcus thermophilus and Lactobacillus bulgaricus were investigated. After fermentation, the amino acid, protein, and peptide contents were analyzed by ultra-performance liquid chromatography, two-dimensional gel electrophoresis, and liquid chromatography-mass spectrometry, respectively. After the addition of K. marxianus for fermentation, 25 protein spots changed significantly. These were mostly caseins and bovine serum proteins, and the content of total free amino acids increased by 16.30%; ten types of bioactive peptides were identified. Furthermore, the number of peptide types in milk fermented by K. marxianus increased significantly compared with milk fermented by Lactobacillus. K. marxianus is considered to promote proteometabolism in milk when added with Lactobacillus, generate flavor compounds, and improve the digestion and absorption character of milk.

Performance of remote target pointing hand movements in a 3D environment.

In this study, we investigated and modeled the performance of target pointing hand movements in a hand free, touchless 3D environment. The targets had different positions, sizes and distances. Performance measurements included total movement time and movement trajectories. The total movement time consisted of a "primary submovement time" and a "secondary submovement time". Results indicated that the total movement time for targets with depth in the upper part of the spherical framework (3.10s) was shorter than for targets without depth (3.79s). The time for targets without depth in the lower part of the spherical framework (2.94s) was shorter than for targets with depth (3.57s). Within a 3D perspective display, the perception of distance and size depends on its depth position. Our results confirmed the adequacy of the 3D information in the display by showing the longest total movement time was observed for the reach of the "forward" target (3.94s). Fitts' model explained the total movement time (for targets without depth r(2)=.72; for targets with depth r(2)=.72). This study showed that participants navigated the 3D space naturally and could move the cursor using both sequential a axis moving strategy and a straight line moving strategy. Real-life applications of the proposed method include interface design for 3D perspective displays and hand movements in 3D environments.