Dietary soybean protein ameliorates high-fat diet-induced obesity by modifying the gut microbiota-dependent biotransformation of bile acids.

The consumption of soybean protein has well-known favorable metabolic effects (e.g., reduced body weight, body fat, hyperglycemia, insulin resistance, hepatic steatosis, and lipogenesis). These effects of soy protein have been linked to modulation by the gut microbiota; however, the dynamic interplay among these factors remains unclear. Accordingly, we examined the metabolic phenotype, intestinal BA pool, and the gut microbiome of male C57BL/6 mice that were randomized to receive either a regular high-fat diet (HFD) or HFD that contained soybean protein isolate (SPI) in place of dairy protein. The intake of SPI significantly reduced the HFD-induced weight gain and adipose tissue mass accumulation and attenuated hepatic steatosis. Along with an enhancement in the secretion of intestinal Glucagon-like peptide-1 (GLP-1), an enlarged cecal BA pool with an elevated secondary/primary BA ratio was observed in the mice that consumed SPI, while fecal BA excretion remained unaltered. SPI also elicited dramatic changes in the gut microbiome, characterized by an expansion of taxa that may be involved in the biotransformation of BAs. The observed effects were abolished in germ-free (GF) mice, indicating that they were dependent on the microbiota. These findings collectively indicate that the metabolic benefits of SPI under the HFD regime may arise from a microbiota-driven increase in BA transformation and increase in GLP-1 secretion.

Characterization of Paecilomycescinnamomeus from the camellia whitefly, Aleurocanthus camelliae (Hemiptera: Aleyrodidae), infesting tea in Japan.

The whitefly, Aleurocanthus camelliae Kanmiya and Kasai (Hemiptera: Aleyrodidae), is an invasive species in Japan that was first discovered in 2004 on tea in Kyoto. Soon after its arrival epizootics of an entomopathogenic fungus were observed in populations of the whitefly in many tea-growing regions. Here we identify this fungus as Paecilomyces cinnamomeus (Petch) Samson and W. Gams (Hypocreales: Clavicipitaceae) based on morphological characteristics and molecular analyses. This is the first record of P. cinnamomeus in Japan and also the first time it has been recorded from the genus Aleurocanthus. A isolate of P. cinnamomeus caused greater than 50% and 90% infection in whitefly nymphs at 1×10(6) and 1×10(7)conidia/ml respectively, while the commercial mycoinsecticides Preferd® (Isaria fumosorosea) and Mycotal® (Lecanicillium muscarium) caused <10% infection at their recommended field rates (5×10(6) and 9×10(6)conidia/ml, respectively), suggesting that P. cinnamomeus may be more useful as a control agent than the currently available mycoinsecticides. Optimum and upper limit temperatures for in vitro growth of P. cinnamomeus isolates were 22.5-25°C and 32.5°C, respectively. At field rates, the fungicide thiophanate-methyl caused some inhibition of in vitro growth of P. cinnamomeus isolates, and the bactericide copper oxychloride and the insecticides tolfenpyrad and methidathion were strongly inhibitory. The findings obtained in this study will be useful in the development of microbial control programs using P. cinnamomeus against A. camelliae.