Typical indigenous bacteria in the cecum of ddY mice fed a casein-beef tallow diet or whole-egg diet.

With the aim to prove the existence of food ingredient-susceptible indigenous bacteria (SIBs) in the gut, the gut microbiota of ddY mice fed a diet containing 20% milk casein and 17% beef tallow (CT diet) or 40% whole-egg powder (Egg diet) for 14 days were analyzed by 16S ribosomal RNA gene (V4) amplicon sequencing. At the genus level, abundance levels of Desulfovibrionaceae sp., Oscillospira, and Bacteroides were high in mice fed the CT diet. At the operational taxonomic unit level, Bacteroides acidifaciens- and Bacteroides caecimuris-like bacteria were highly abundant in mice fed the CT diet. Faecalibaculum rodentium- and Allobaculum stercoricanis-like bacteria were highly abundant in the mice fed the Egg diet. These sets of taxa were assumed to be estimates of casein-tallow SIBs and egg SIBs, respectively, in the gut microbiome. Among the SIBs, B. caecimuris and F. rodentium could be isolated using blood and liver agar. PRACTICAL APPLICATIONS: B. caecimuris and F. rodentium are regarded as casein-tallow and/or egg SIBs in mice. It is possible to demonstrate functionality with orally administered food ingredients. Isolation and application of human or livestock SIB is considered promising for the development of new probiotics and functional foods.

Effects of Lactobacillus plantarum Uruma-SU4 fermented green loofah on plasma lipid levels and gut microbiome of high-fat diet fed mice.

To clarify the effect of loofah Luffa cylindrica and fermented loofah on hyperlipidemia, the in vitro bile acid lowering capacity and blood lipid levels of ddY mice fed high-fat diet supplemented with loofah were determined. Furthermore, the caecal microbiomes patterns were analysed using 16S rDNA amplicon sequencing with a next generation sequencer (MiSeq) system. Green loofah was homogenized and autoclaved (LH), and subsequently fermented with Lactobacillus plantarum Uruma-SU4 (FL). In vitro bile acid (taurocholic, glycocholic and deoxycholic acids (DCA)) lowering capacity was significantly high in FL. The levels of plasma triacylglyceride in mice which were fed a high-fat diet containing 17% beef tallow was lowered by 5% dried FL (FLD) and was unaffected by dried LH (LHD). Caecal Lactobacillus johnsonii and Clostridium disporicum known as predominant lactic acid bacteria in mice gut and urso-DCA producer, respectively, were increased by FLD. On the other hand, Flintibacter butyricus was lowered by both LHD and FLD. These results suggest that if green loofah cannot be consumed as a fresh vegetable, lactic acid fermentation may be useful in generating effective nutritional supplements and functional foods.

Effects of fermented green-loofah and green-papaya on nitric oxide secretion from murine macrophage raw 264.7 cells.

To clarify the effect of lactic acid bacteria (LAB) fermentation on the immunomodulation capacity of green-loofah and green-papaya, aqueous suspensions prepared from the fresh and dry-powdered vegetables were fermented by Lactococcus lactis subsp. lactis Uruma-SU1 and Lactobacillus plantarum Uruma-SU4. Fermented and non-fermented suspensions were added to murine macrophage RAW264.7 culture with and without Escherichia coli O111 lipopolysaccharide (LPS). In the absence of LPS, nitric oxide (NO) secretion was elevated significantly in LAB fermented suspensions compared to that in non-fermented suspensions. NO production in fermented suspensions was observed even at low sample concentrations, but it was attenuated in the centrifuged supernatant. With LPS treatment, inhibition of NO secretion was shown with the high concentration of the non-fermented and also fermented samples. These results suggest that fermented green-loofah and green-papaya suspensions can play both immunostimulatory and anti-inflammatory roles at low and high doses, respectively.

Lactobacillus plantarum AN1 cells increase caecal L. reuteri in an ICR mouse model of dextran sodium sulphate-induced inflammatory bowel disease.

To clarify the different effects of live and heat-killed probiotics on inflammatory bowel disease (IBD), the anti-inflammatory and protective effects of Lactobacillus plantarum AN1 cells isolated from the fermented fish aji-narezushi on murine macrophage RAW264.7 cells and in ICR mice with dextran sodium sulphate (DSS)-induced IBD were determined. L. plantarum AN1 cells showed anti-inflammatory activities in vitro, indicated by secretion of nitric oxide (NO) from RAW264.7 cells in the presence and absence of Escherichia coli 0111 lipopolysaccharide (LPS). L. plantarum AN1 cells also protected RAW264.7 cells against hydrogen peroxide toxicity. There was no difference between these effects in heat-killed and ultraviolet irradiation-killed cells. In the murine IBD model, both live and heat-killed L. plantarum AN1 cells via drinking water tended to ameliorate atrophy of colon length, mucosal tissue damage, and spleen enlargement. Amplicon sequencing of 16S rDNA (V4) revealed that both live and heat-killed AN1 cells increased abundance of indigenous lactic acid bacteria, particularly Lactobacillus reuteri. The results suggest that increased indigenous lactic acid bacterial abundance and feeding with L. plantarum AN1 cells synergistically improve effects against IBD.

Effect of Lactobacillus plantarum Tennozu-SU2 on Salmonella Typhimurium Infection in Human Enterocyte-Like HT-29-Luc Cells and BALB/c Mice.

The probiotic properties and inhibitory effect on Salmonella Typhimurium adhesion on human enterocyte-like HT-29-Luc cells of three Lactobacillus plantarum strains isolated from fermented fish, beach sand and a coastal plant were determined. Compared with the type strain L. plantarum NBRC 15891T, which was isolated from pickled cabbage, L. plantarum Tennozu-SU2 isolated from the acorn of a coastal tree showed high autoaggregation in de Man, Rogosa and Sharpe (MRS) broth and an antagonistic effect against S. Typhimurium in brain heart infusion (BHI) broth. Furthermore, heat-killed L. plantarum Tennozu-SU2 cells inhibited S. Typhimurium adhesion on HT-29-Luc cells. Both live and heat-killed L. plantarum Tennozu-SU2 cells showed an inhibitory effect on gut colonisation in BALB/c mice, as assessed by viable Salmonella count in faecal samples and by invasion into liver and spleen tissues. The properties shown in this study suggest that L. plantarum Tennozu-SU2 is useful as a starter and probiotic bacteria in functional food material.