To clarify the effect of soy protein (SP) and fish meal (FM), compared to milk casein (MC), on the intestinal environment, we examined caecal environment of rats fed the test diets. Four-week-old rats were fed AIN-76-based diet containing 20 %, w/w MC, SP or FM for 16 days. Caecal organic acids were analysed by HPLC. Caecal putrefactive compounds (indole, phenol, H2S and ammonia) were analysed by colorimetric assays. Caecal microflora was determined by 16S rRNA gene-DGGE and pyrosequencing with bar-coded primers targeting the bacterial 16S rRNA gene. n-Butyric and lactic acid levels were high in rats fed SP and FM, respectively. Butyrate-producing bacteria, such as Oscillibacter, and lactate-producing bacteria, such as Lactobacillus, were detected in each diet group. Also, the putrefactive compound contents were high in rats fed SP and FM. In this study, both DGGE and pyrosequencing analyses were able to evaluate the dynamics of the intestinal microbiota. The results indicate that dietary proteins can alter the intestinal environment, affecting fermentation by the intestinal microbiota and the generation of putrefactive compounds.

Edible brown algae are used as major food material in Far East Asian countries, particularly in South Korea and Japan. They contain fermentable dietary fibers, alginic acid (uronic acid polymer) and laminaran (␤-1,3-glucan), that are fermented into organic acids by intestinal bacteria. To clarify the effect of edible algae on the intestinal environment, the cecal microbiotas of rats fed diets containing no dietary fiber (control) or 2% (wt/wt) sodium alginate or laminaran for 2 weeks were analyzed using FLX amplicon pyrosequencing with bar-coded primers targeting the bacterial 16S rRNA gene. The most abundant phylum in all groups was Firmicutes. Specifically, Allobaculum was dominant in all diet groups. In addition, Bacteroides capillosus (37.1%) was abundant in the alginate group, while Clostridium ramosum (3.14%) and Parabacteroides distasonis (1.36%) were only detected in the laminaran group. Furthermore, rats fed alginate showed simplified microbiota phylotypes compared with others. With respect to cecal chemical compounds, laminaran increased cecal organic acid levels, particularly propionic acid. Alginate increased total cecal organic acids. Cecal putrefactive compounds, such as indole, H 2 S, and phenol, were decreased by both alginate and laminaran. These results indicate that edible brown algae can alter the intestinal environment, with fermentation by intestinal microbiota.

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Significance and Impact of the Study: Lactobacillus plantarum AN6 was isolated from aji-narezushi. Cholesterol-lowering activity of AN6 was higher than ones of the type strain. Cell surface of AN6 was rough. FT-IR analysis indicated that the content of cell wall polysaccharides of AN6 is higher than ones in the type strain. These results indicate that AN6 can be used as a new profitable starter and probiotic. AbstractAji-narezushi is a traditional lactic acid-fermented fish. In this study, we screened for lactose-utilizing, acidophilic, bile-resistant and cholesterollowering lactic acid bacteria (LAB) from aji-narezushi for use as starter strains for fermented foods, as well as for use as probiotics. Of the 301 LAB isolates, 277 fermented lactose, and among these, 171 grew in de Man, Rogosa and Sharpe broth adjusted to pH 3Á5. Thirty-four of the isolates were grown in a broth containing 3% (w/v) bile. All of the isolates were lactobacilli. Seven isolates that demonstrated cholesterol-lowering activity in ethanolic solution were selected. All of the isolates were identified as Lactobacillus plantarum. Lactobacillus plantarum AN6 showed the highest cholesterol-lowering activity. AN6 was more resistant to acid, salt and bile than the type strain NBRC15891T . One-half of the cholesterol-lowering effect remained after boiling AN6 for 10 min. The Fourier transform infrared (FT-IR) analysis indicated that the content of cell wall polysaccharides in AN6 is higher than ones in the type strain. These results indicate that Lact. plantarum AN6 can be used as a profitable starter organism and probiotic.

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