Evaluation Of Microencapsulated Probiotics In Vitro Characteristics And Animal Application

The Saccharomyces boulardii and Enterococcus faecium were pre-encapsulated by the method of emulsion and internal gelation. The vitro characteristics and beneficial on animal of the microencapsulated bacteria were evaluated in this paper. And this study provided a theoretical reference and parameter for livestock production.Experiment 1 was performed to study the vitro characteristics of the microencapsulated probiotics and preparation.The morphological structures of the prepared microcapsules were observed with biological microscope and scanning electron microscope. The diameter distribution of microcapsules were measured by laser granularity analyzer. Compared with unencapsulated probiotics, the resistance of the microencapsulated bacteria to the storage, high temperature, simulated gastric and intestinal conditions were evaluated. The results showed that: These beads were highly spherical over the entire range of agitation rate and loaded with S. boulardii and E. faecalis. The diameter of freshly prepared beads followed a normal distribution. The resistance of probiotics, especially E. faecalis to the high temperature at 110℃ and 130℃ were significantly increased(P<0.05) by the microencapsulation. There were 57.76% and 46.73% increasing in the survived rate of microencapsulated S. boulardii and E. faecalis respectively compared with those of free ones when the probiotics were treated in the simulated gastric conditions for 180 minutes. And 26.89% and 19.27% increasing in survived rate were found by the microencapsulation to the S. boulardii and E. faecalis respectively in the simulated intestinal conditions for 180 minutes. The survival rates of microencapsulated S. boulardii and E. faecalis were 34.63% and 19.46% higher(P<0.05) respectively than those of free un-encapsulated bacteria in five months storage.These results suggest that, microcapsulations prepared by the emulsion and internal gelation can be an effective way for protecting probiotic microbes.Experiment 2 was performed to study the effects of microencapsulated S. boulardii on growth performance, immunity function and cecal microflora in broiler chickens.Seven hundred 1-d-old male Arbor Acres broilers were randomly allotted into seven dietary treatments. Each group included five replicate pens with 20 broilers per pen. The dietary treatments used in this study were as follows:(1) basal diet(CON);(2) basal diet containing 100 mg/kg aureomycin(ANT);(3) basal diet containing unencapsulated S. boulardii at a dose of 1×108 cfu·kg-1 of feed(P1);(4) basal diet containing unencapsulated S. boulardii at a dose of 1×1010 cfu·kg-1 of feed(P2);(5) basal diet containing 0.01% empty microcapsules(CAP);(6) basal diet containing microencapsulated S. boulardii at a dose of 1×108 cfu·kg-1 of feed(CAPP1); and(7) basal diet containing microencapsulated S. boulardii at a dose of 1×1010 cfu·kg-1 of feed(CAPP2). Samples were collected for analysis on d 21 and d 42. The results showed that:(1) Compared with unencapsulated S. boulardii, ADG were greater and F:G were lower of encapsulated S. boulardii in the starter, grower and whole phase. And ADG in CAPP1 were significantly(P<0.05) greater than P2.(2) The content of CAT in CAPP2 were significantly(P<0.05) greater compared with unencapsulated S. boulardii on d 21.(3) Compared with P1, the content of CD4 were significantly(P<0.05) greater and TNF-? was significantly(P<0.05) lower in the starter phase; IL-6 in CAPP1 and CAPP2 were significantly(P<0.05) greater in the grower phase.(4) Compared with P1, the villus height of jejunum in CAPP1 were significantly(P<0.05) greater. And the villus height of jejunum and ileum in CAPP1 were significantly(P<0.05) greater than unencapsulated S. boulardii.(5) The Shannon were significantly(P<0.05) greater in CAPP1 and CAPP2 than in CON. In the starter phase, the number of Bacteroidetes was significantly(P<0.05) enriched in ANT on d 21, while the number of Lactobacillus was significantly(P<0.05) enriched in CAPP1 on d 42.Experiment 3 was performed to study the effects of microencapsulated E. faecalis on growth performance, immunity function and cecal microflora in broiler chickens.Six hundred 1-d-old male Arbor Acres broilers were randomly allotted into six dietary treatments. Each group included five replicate pens with 20 broilers per pen. The dietary treatments used in this study were as follows:(1) basal diet(CON);(2) basal diet containing 100 mg/kg aureomycin(ANT);(3) basal diet containing unencapsulated E. faecalis at a dose of 1 × 109 cfu kg-1 of feed(P1);(4) basal diet containing unencapsulated E. faecalis at a dose of 1 × 1011 cfu kg-1 of feed(P2);(5) basal diet containing microencapsulated E. faecalis at a dose of 1 × 109 cfu kg-1 of feed(CAPP1); and(6) basal diet containing microencapsulated E. faecalis at a dose of 1 × 1011 cfu kg-1 of feed(CAPP2). Samples were collected for analysis on d 21 and d 42. The results showed that:(1) In the starter and phase. ADG in encapsulated E. faecalis groups were significantly(P<0.05) greater than P1, F:G in CAPP2 groups were significantly(P<0.05) lower than P1.(2) The content of T-AOC in CAPP2 were significantly(P<0.05) greater than unencapsulated S. boulardii on d 21. The content of MDA in CAPP2 was significantly(P<0.05) decresed than in unencapsulated S. boulardii on d 21 and d 42.(3) In the starter phase, the content of TNF-? in CAPP1 and CAPP2 were significantly(P<0.05) greater than P2. In the grower phase, IL-2 in CAPP1 and CAPP2 were significantly(P<0.05) greater than P1 and P2. IL-6 in CAPP1 was significantly(P<0.05) greater than P1.(4) In the starter phase, the villus height of duodenum in CAPP2 were significantly(P<0.05) greater than P1 and P2, VH/CD of jejunum in CAPP1 and CAPP2 were significantly(P<0.05) greater than P1.(5) In the grower phase, the content of Firmicutes and in Lactobacillus CAPP1 and CAPP2 were significantly(P<0.05) greater compared with the other groups. By studying the effects of microencapsulated bacteria on growth performance, antioxidant, immune function, intestinal morphology and cecal microflora in broiler chickens, the results shows that microencapsulated probiotics can improve the benefit.Experiment 4 was performed to study the effects of the microencapsulated E. faecalis and S. boulardii on inhibition of colitis function in mice.Seventy two male 8-wk-old C57BL/6 mice were randomly allotted into sixty dietary treatments. Each group included 12 mice. The dietary treatments used in this study were as follows: CON, DSS, unencapsulated E. faecalis, microencapsulated E. faecalis, unencapsulated S. boulardii, microencapsulated S. boulardii. The serum, colon and colonic mucosa were collected for analysis on d 7. The results showed that:(1) The colour, spirit alive and movement of mice in CON group were normal and the mice in DSS group were not well than probiotic groups. The body weight and activity of MPO in DSS group were significantly(P<0.05) lower than CON. The content of IL-6 and TNF-α in probiotic groups were significantly(P<0.05) lower than DSS group. The Occludin and Claudin-1 protein expression in microencapsulated S. boulardii. and unencapsulated S. boulardii groups was significantly(P<0.05) greater than DSS group. It is concluded that, E. faecalis and S. boulardii can reduce the content of IL-6 and TNF-α, and increase the expression of Occludin and Claudin-1 in mice. Microencapsulated pribiotics have better results.