B longum KACC 91563 induces apoptosis of mast cells specifically and alleviates food allergy symptoms. Accordingly, B longum KACC 91563 and family 5 extracellular solute-binding protein exhibit potential as therapeutic approaches for food allergies.

Muscle development and lipid accumulation in muscle critically affect meat quality of livestock. However, the genetic factors underlying myofiber-type specification and intramuscular fat (IMF) accumulation remain to be elucidated. Using two independent intercrosses between Western commercial breeds and Korean native pigs (KNPs) and a joint linkage-linkage disequilibrium analysis, we identified a 488.1-kb region on porcine chromosome 12 that affects both reddish meat color (a*) and IMF. In this critical region, only the MYH3 gene, encoding myosin heavy chain 3, was found to be preferentially overexpressed in the skeletal muscle of KNPs. Subsequently, MYH3-transgenic mice demonstrated that this gene controls both myofiber-type specification and adipogenesis in skeletal muscle. We discovered a structural variant in the promotor/regulatory region of MYH3 for which Q allele carriers exhibited significantly higher values of a* and IMF than q allele carriers. Furthermore, chromatin immunoprecipitation and cotransfection assays showed that the structural variant in the 5′-flanking region of MYH3 abrogated the binding of the myogenic regulatory factors (MYF5, MYOD, MYOG, and MRF4). The allele distribution of MYH3 among pig populations worldwide indicated that the MYH3 Q allele is of Asian origin and likely predates domestication. In conclusion, we identified a functional regulatory sequence variant in porcine MYH3 that provides novel insights into the genetic basis of the regulation of myofiber type ratios and associated changes in IMF in pigs. The MYH3 variant can play an important role in improving pork quality in current breeding programs.

Skeletal muscle is an heterogeneous tissue with various biochemical and physical properties of several fiber types. In this study, we carried out the comparative study of protein expression patterns in white and red muscles using two-dimensional gel electrophoresis (2-DE). From more than 500 protein spots detected on each 2-DE gel, we screened five proteins that were differentially expressed between white and red muscles. Using peptide mass fingerprint and tandem mass spectrometry analysis these proteins were identified as myoglobin, two slow-twitch isoforms of myosin light chain and two small heat shock proteins (HSP20 and HSP27). The protein levels of myoglobin, myosin light chain and HSP20 were higher in red muscle, whereas HSP27 was higher in white muscle. In addition, genes of the identified proteins were cloned and their mRNAs were examined. Positive correlations between protein content and their mRNA levels were observed in white and red muscle. These results may provide us with valuable information to understand the different expression profiling between white and red muscle at the protein level.