| In nature,many plants contain high levels of secondary compounds,which are resistant to feeding by herbivorous mammals.Tannin are a polyphenolic secondary compounds in plants which combine with proteins to form tannin-protein complexes,thus affecting the digestion of food and the effective absorption of protein.However,animals can break down tannins in different ways.Rodents in Murine intestines have microorganisms that can specifically degrade tannins,so that proteins in foods with high tannin content can be absorbed,thereby improving the food utilization rate.Tamias sibiricus and Apodemus peninsulae perfer to eating Quercus mongolica with high tannins.However,the intestinal microbial basis of their adaptation to high tannin foods remains unclear.In view of this,the paper adopted T.sibiricus and A.peninsulae as the experimental materials.The 16 S rDNA technique was used to analyze the diversity and difference of intestinal microbial structure and composition under different conditions.The differences in physiological metabolism between the two rodent species were used to elucidate the intestinal microbial basis that how they adapt to high tannin foods.The main findings were as follows:(1)In the natural conditions,there was a significant difference in the OUT value of intestinal flora between T.sibiricus and A.peninsulae.There were significant differences in the level of species and family,but no significant differences in the level of kingdom,phylum,class,order and genus.There was a significant difference in the Chao1 index of the intestinal flora between T.sibiricus and A.peninsulae,but there was no significant difference between the observed species,the Shannon index and the Simpson index.The composition and colony structure of T.sibiricus and A.peninsulae were quite different.(2)After long-term feeding of Q.mongolica acorns,the OUT values of the intestinal flora of T.sibiricus and A.peninsulae were significantly different.There was no significant changes in the community structure of T.sibiricus.Similarly,there was no significant effects on the community structure and composition of the intestinal flora of A.peninsulae.The tolerance and adaptability of A.peninsulae to foods with high tannin content was greater than that of T.sibiricus.(3)The intestinal microbes of the C.arakawai were mainly Lactococcus,Serratia and Pseudomonas that show degradation activity of tannins.After feeding on larvae of C.arakawai,the body weight of T.sibiricus was significantly higher than that of the control.The dry mass of consumed acorns by T.sibiricus receiving sterilized larvae was significantly higher than that of the control group.The excretion of feces by T.sibiricus receiving sterilized and unsterilized larvae was significantly higher than that of the control group.However,feeding on C.arakawai had no significant effects on the body weight,dry mass of consumed acorns and fecal excretion of the A.peninsulae.The fecal nitrogen content of T.sibiricus receiving unsterilized larvae was lower than those receiving sterilized larvae and the control group.After feeding C.arakawai,there was a significant effect on fecal nitrogen content of A.peninsulae.The dry matter digestibility of T.sibiricus receiving sterilized and unsterilized larvae was significantly greater than that in control group.Our results showed that T.sibiricus,A.peninsulae and C.arakawai shared 136 OTUs,whereas they shared 143 OTUs after feeding larvae of C.arakawai.Firmicute was dominat in A.peninsulae even after 30 days of feeding larvae of C.arakawai.Whether eating C.arakawai or not showed no effects on the intestinal flora parameters of A.peninsulae at the level of genus,but there was significant changes in the gut microbiota of T.sibiricus.The relative abundance of intestinal flora in the three groups of T.sibiricus was significantly different.There was no significant difference in the composition of intestinal flora between T.sibiricus receiving sterilized larvae and the control group,but there was significant difference in the composition of intestinal flora between T.sibiricus receiving unsterilized and sterilized larvae.There was no significant difference in biology community structure among the three groups of T.sibiricus.Similarly,there was no significant difference in the composition of the flora or the community structure among the three groups of A.peninsulae.(4)The mice(M.musculus)transplanted with A.peninsulae faeces and the mice gavaged with neomycin had an increasing body weight,while the body weight of mice that were transplanted with T.sibiricus faeces or gavaged with saline decreased continuously.There was a difference in the intestinal flora between the mice transplanted with A.peninsulae and those with T.sibiricus faeces,and the community structure between mice gavaged with neomycin and saline was similar.The intestinal flora composition of the four groups of mice was significantly altered by fecal transplantation. |
PDF Full Text Request