Bacterial diversity index calculated from the DGGE banding patterns (Fig. 1A).

<p>N (negative control, basal diet); P (positive control, diet supplemented with neomycin); L, M, H (diets supplemented with probiotics 0.5×10⁹, 1.0×10⁹ and 2.5×10⁹ CFU/kg feed, respectively);</p><p>*1/D, the reciprocal of Simpson diversity index.</p><p>Bacterial diversity index calculated from the DGGE banding patterns (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116635#pone.0116635.g001" target="_blank">Fig. 1A</a>).</p

Dietary <i>Enterococcus faecalis</i> LAB31 Improves Growth Performance, Reduces Diarrhea, and Increases Fecal <i>Lactobacillus</i> Number of Weaned Piglets

<div><p>Lactic acid bacteria (LAB) have been shown to enhance performance of weaned piglets. However, few studies have reported the addition of LAB <i>Enterococcus faecalis</i> as alternatives to growth promoting antibiotics for weaned piglets. This study evaluated the effects of dietary <i>E. faecalis</i> LAB31 on the growth performance, diarrhea incidence, blood parameters, fecal bacterial and <i>Lactobacillus</i> communities in weaned piglets. A total of 360 piglets weaned at 26 ± 2 days of age were randomly allotted to 5 groups (20 pens, with 4 pens for each group) for a trial of 28 days: group N (negative control, without antibiotics or probiotics); group P (Neomycin sulfate, 100 mg/kg feed); groups L, M and H (supplemented with <i>E. faecalis</i> LAB31 0.5×10⁹, 1.0×10⁹, and 2.5×10⁹ CFU/kg feed, respectively). Average daily gain and feed conversion efficiency were found to be higher in group H than in group N, and showed significant differences between group H and group P (<i>P₀</i> < 0.05). Furthermore, groups H and P had a lower diarrhea index than the other three groups (<i>P₀</i> < 0.05). Denaturing gradient gel electrophoresis (DGGE) showed that the application of probiotics to the diet changed the bacterial community, with a higher bacterial diversity in group M than in the other four groups. Real-time PCR revealed that the relative number of <i>Lactobacillus</i> increased by addition of probiotics, and was higher in group H than in group N (<i>P₀</i> < 0.05). However, group-specific PCR-DGGE showed no obvious difference among the five groups in <i>Lactobacillus</i> composition and diversity. Therefore, the dietary addition of <i>E. faecalis</i> LAB31 can improve growth performance, reduce diarrhea, and increase the relative number of <i>Lactobacillus</i> in feces of weaned piglets.</p></div

Bacterial community of weaned piglets fed with neomycin or <i>E. faecalis</i>.

<p>(A) DGGE profiles of the V6~V8 regions of the 16S rDNA gene fragments from the samples. The denaturant gradient range is from 42% to 58%. The major difference bands are numbered. Lane S (Standard ladder, which are PCR products generated from different bacterial 16S rDNA genes with primers 968F-GC and 1401R); N (negative control, basal diet); P (positive control, diet supplemented with neomycin); L, M, H (diets supplemented with probiotics 0.5×10⁹, 1.0×10⁹ and 2.5×10⁹ CFU/kg feed, respectively); (B) UPGMA cluster analysis of Dice similarity indices from DGGE profiles.</p

Identification of band fragments in DGGE gels (Fig. 1A).

<p>* Bands are numbered according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116635#pone.0116635.g001" target="_blank">Fig. 1A</a>.</p><p>^◆Identity represents the sequence identity (%) compared with that in the GenBank database.</p><p>Identification of band fragments in DGGE gels (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116635#pone.0116635.g001" target="_blank">Fig. 1A</a>).</p

<i>Lactobacillus</i> community of weaned piglets fed with neomycin or <i>E. faecalis</i>.

<p>(A) DGGE profiles of V3 region of the 16S rDNA gene fragments with the primes Lac1 and Lac2-GC. The denaturant gradient range is from 41% to 60%. Lanes N (negative control, basal diet); P (positive control, diet supplemented with neomycin); L, M, H (diets supplemented with probiotics 0.5×10⁹, 1.0×10⁹ and 2.5×10⁹ CFU/kg feed, respectively); (B) UPGMA cluster analysis of Dice similarity indices from DGGE profiles.</p

<i>Lactobacillus</i> diversity index calculated from the DGGE banding patterns (Fig. 2A).

<p>N (negative control, basal diet); P (positive control, diet supplemented with neomycin); L, M, H (diets supplemented with probiotics 0.5×10⁹, 1.0×10⁹ and 2.5×10⁹ CFU/kg feed, respectively);</p><p>*1/D, the reciprocal of Simpson diversity index.</p><p><i>Lactobacillus</i> diversity index calculated from the DGGE banding patterns (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116635#pone.0116635.g002" target="_blank">Fig. 2A</a>).</p