2.7 | Statistical analyses
All the data for enzymes activities and intestinal morphology were tested for normality and homogeneity of variances by using Shapiro-Wilk and Levene’s tests, respectively. Afterwards, one-way analysis of variance (ANOVA) was used to test for statistical differences on the data for enzymes activities and intestinal morphology among the four feeding habits. Tukey multiple comparisons test was used to compare for significant differences among the four feeding habits when ANOVA indicated statistical differences. The analysis of enzymes activities and intestinal morphology data was conducted by using SPSS 20.0 (SPSS, Inc., Chicago, IL, USA). Results with P ≤ 0.05 were considered significant different. The results obtained are expressed as mean ± standard error of the mean (SEM).
The differences in bacterial phylotype distribution was assessed by using principal component analysis (PCA). The alpha-diversity indices (the abundance coverage-based Estimator - ACE, Chao1, Shannon and Simpson indices) were generated by using Mothur v1.31.2 (http://www.mothur.org/wiki/Calculators). Abundance of microbiota was analyzed by using ACE and Chao1 indices while microbiota species diversity was assessed by using Shannon and Simpson indices. Linear discriminant analysis effect size (LEfSe) was analyzed by using the R statistical package (v3.1.1).