An aging global population poses substantial challenges to society [1]. Centenarians are a model for healthy aging because they have reached the extreme limit of life by escaping, surviving, or delaying chronic diseases [2]. The genetics of centenarians have been extensively examined [3], but less is known about their gut microbiotas. Recently, Biagi et al.[4] characterized the gut microbiota in Italian centenarians and semi-supercentenarians. Here, we compare the gut microbiota of Chinese long-living people with younger age groups, and with the results from the Italian population [4], to identify gut-microbial signatures of healthy aging.

Rex rabbit is an important small herbivore for fur and meat production. However, little is known about the gut microbiota in rex rabbit, especially regarding their relationship with different fecal types and growth of the hosts. We characterized the microbiota of both hard and soft feces from rex rabbits with high and low body weight by using the Illumina MiSeq platform targeting the V4 region of the 16S rDNA. High weight rex rabbits possess distinctive microbiota in hard feces, but not in soft feces, from the low weight group. We detected the overrepresentation of several genera such as YS2/Cyanobacteria, and Bacteroidales and underrepresentation of genera such as Anaeroplasma spp. and Clostridiaceae in high weight hard feces. Between fecal types, several bacterial taxa such as Ruminococcaceae, and Akkermansia spp. were enriched in soft feces. PICRUSt analysis revealed that metabolic pathways such as “stilbenoid, diarylheptanoid, gingerol biosynthesis” were enriched in high weight rabbits, and pathways related to “xenobiotics biodegradation” and “various types of N-glycan biosynthesis” were overrepresented in rabbit soft feces. Our study provides foundation to generate hypothesis aiming to test the roles that different bacterial taxa play in the growth and caecotrophy of rex rabbits.

The intestinal microbiome is critically important in shaping a variety of host physiological responses. However, it remains elusive on how gut microbiota impacts overall growth and more specifically, adipogenesis. Using the pig as an animal model, we compared the differences in bacterial community structure throughout the intestinal tract in two breeds (Landrace and Jinhua) of pigs with distinct phenotypes. The Landrace is a commercial purebred and the Jinhua is a Chinese indigenous, slow-growing breed with high propensity for fat deposition. Using 16S rRNA gene sequencing, we revealed that the bacterial communities are more diverse in the duodenum, jejunum, and cecum of Jinhua pigs than in those of Landrace pigs, whereas the ileal and colonic microbiota show a similar complexity between the two breeds. Furthermore, a number of bacterial taxa differentially exist in Jinhua and Landrace pigs throughout the entire intestinal tract, with the jejunal and ileal microbiome showing the greatest contrast. Functional prediction of the bacterial community suggested increased fatty acid biosynthesis in Jinghua pigs, which could partially explain their adiposity phenotype. Further studies are warranted to experimentally verify the relative contribution of each enriched bacterial species and their effect on adipogenesis and animal growth.

Rumen microbial communities play important roles in feed conversion and the physiological development of the ruminants. Despite its significance, little is known about the rumen microbial communities at different life stages after birth. In this study, we characterized the rumen bacterial and the archaeal communities in 11 different age groups (7, 15, 30, 60, 90, 120, 150, 180, 360, 540 and 720 days old) of a crossbred F1 goats (n = 5 for each group) by using an Illumina MiSeq platform targeting the V3-V4 region of the 16S rRNA gene. We found that the bacterial communities were mainly composed of Bacteroidetes, Firmicutes, and Proteobacteria across all age groups. The relative abundance of Firmicutes was stable across all age groups. While changes in relative abundance were observed in Bacteroidetes and Proteobacteria, these two phyla reached a stable stage after weaning (day 90). Euryarchaeota (82%) and Thaumarchaeota (15%) were the dominant phyla of Archaea. Crenarchaeota was also observed, although at a very low relative abundance (0.68% at most). A clear age-related pattern was observed in the diversity of bacterial community with 59 OTUs associated with age. In contrast, no age-related OTU was observed in archaea. In conclusion, our results suggested that from 7 days to 2 years, the ruminal microbial community of our experimental goats underwent significant changes in response to the shift in age and diet.