Characteristics of O/W emulsion gels stabilized by soy protein-xanthan gum complex for plant-based processed meat products.

The aim of the present study is to characterize the mechanical properties of O/W emulsion gels stabilized through soy protein isolate (SPI)-xanthan gum (XG) complex and to elucidate their practical usefulness in plant-based processed meat products. O/W emulsions prepared by mixing aqueous solutions of SPI-XG complexes, which was formed via electrostatic interactions under acidic conditions (pH 4.0), with plant oil were gelled in the presence of several hydrocolloids. Effects of hydrocolloid composition, oil type and load, and oil droplet size on the mechanical properties of the emulsion gels were investigated by dynamic viscoelasticity measurements, and fluorescence microscopy was performed for observation of the oil droplet dispersion. Results indicated that methylcellulose should be required to provide the gels with heat resistance and that the type of oil used should affect dynamic storage modulus (G') of the gels particularly at lower temperatures. It was also found that increased oil load should decrease the gel's resistance to deformation, making the gel structure brittle, and that oil drop size should affect G' and dynamic loss modulus (G") at lower strains. Food application tests indicated that the emulsion gels used had a great impact on the mechanical properties of plant-based meat patties. These findings would contribute to the utilization of the emulsion gels as a lipid portion in plant-based processed meat products, leading to the progress of industrial practice.

Gut Microbiota-Derived Short-Chain Fatty Acids Promote Prostate Cancer Growth via IGF1 Signaling.

Excessive intake of animal fat and resultant obesity are major risk factors for prostate cancer. Because the composition of the gut microbiota is known to change with dietary composition and body type, we used prostate-specific Pten knockout mice as a prostate cancer model to investigate whether there is a gut microbiota-mediated connection between animal fat intake and prostate cancer. Oral administration of an antibiotic mixture (Abx) in prostate cancer-bearing mice fed a high-fat diet containing a large proportion of lard drastically altered the composition of the gut microbiota including Rikenellaceae and Clostridiales, inhibited prostate cancer cell proliferation, and reduced prostate Igf1 expression and circulating insulin-like growth factor-1 (IGF1) levels. In prostate cancer tissue, MAPK and PI3K activities, both downstream of the IGF1 receptor, were suppressed by Abx administration. IGF1 directly promoted the proliferation of prostate cancer cell lines DU145 and 22Rv1 in vitro. Abx administration also reduced fecal levels of short-chain fatty acids (SCFA) produced by intestinal bacteria. Supplementation with SCFAs promoted tumor growth by increasing IGF1 levels. In humans, IGF1 was found to be highly expressed in prostate cancer tissue from obese patients. In conclusion, IGF1 production stimulated by SCFAs from gut microbes influences the growth of prostate cancer via activating local prostate MAPK and PI3K signaling, indicating the existence of a gut microbiota-IGF1-prostate axis. Disrupting this axis by modulating the gut microbiota may aid in prostate cancer prevention and treatment. SIGNIFICANCE: These results suggest that intestinal bacteria, acting through short-chain fatty acids, regulate systemic and local prostate IGF1 in the host, which can promote proliferation of prostate cancer cells.