Background: Cellulolytic microorganisms are considered a key player in the degradation of feed fiber. These microorganisms can be isolated from various resources, such as animal gut, plant surfaces, soil and oceans. A new strain of Bacillus amyloliquefaciens, TL106, was isolated from faeces of a healthy Tibetan pigs. This strain can produce cellulase and shows strong antimicrobial activity in mice. Thus, in this study, to better understand the strain of B. amyloliquefaciens TL106 on degradation of cellulose, the genome of the strain TL106 was completely sequenced and analyzed. In addition, we also explored the cellulose degradation ability of strain TL106 in vitro. Results: TL106 was completely sequenced with the third generation high-throughput DNA sequencing. In vitro analysis with enzymatic hydrolysis identified the activity of cellulose degradation. TL106 consisted of one circular chromosome with 3,980,960 bp and one plasmid with 16,916 bp, the genome total length was 3.99 Mb and total of 4,130 genes were predicted. Several genes of cellulases and hemicellulase were blasted in Genbank, including β-glucosidase, endoglucanase, ß-glucanase and xylanase genes. Additionally, the activities of amylase (20.25 U/mL), cellulase (20.86 U/mL), xylanase (39.71 U/mL) and β-glucanase (36.13 U/mL) in the fermentation supernatant of strain TL106 were higher. In the study of degradation characteristics, we found that strain TL106 had a better degradation effect on crude fiber, neutral detergent fiber, acid detergent fiber, starch, arabinoxylan and β-glucan of wheat and highland barley . Conclusions: The genome of B. amyloliquefaciens TL106 contained several genes of cellulases and hemicellulases, can produce carbohydrate-active enzymes, amylase, cellulase, xylanase and β-glucanase. The supernatant of fermented had activities of strain TL106. It could degrade the fiber fraction and non-starch polysaccharides (arabinoxylans and β-glucan) of wheat and highland barley. The present study demonstrated that the degradation activity of TL106 to crude fiber which can potentially be applied as a feed additive to potentiate the digestion of plant feed by monogastric animals.

Diarrhea is a severe issue in calves that causes fertility problems and economic issues worldwide. Sodium acetate/sodium butyrate (SA/SB) alleviates diarrhea in mice; however, little information is available about the preventive effect of SA/SB on diarrheic yak calves living on the Tibet plateau. Yak calves (n = 19) of age ≥4 months and weight 37 ± 2 Kg were randomly divided into control (C, n = 10) and supplement groups (S, n = 9). Yaks belonging to the supplement group were given sodium butyrate (10 g/kg) and sodium acetate (5 g/kg) for 28 days, along with normal feed, seasonal grasses, pasture, and water. The blood and fecal samples from yak calves were collected for assessment of antioxidant capacity, inflammatory cytokines, microbiome, and short-chain fatty acids (SCFAs) concentration analysis. Results of this study revealed that a lower diarrhea rate, higher weight, and net weight gain were recorded in yaks belonging to group S supplemented with SA/SB. Similarly, increased antioxidant capacity with higher levels of T-AOC, SOD, and GSH-px and decreased inflammatory reactions by decreasing both TNF-α and IL-1β concentrations were recorded in yaks of group S. The concentration of SCFAs was significantly higher (p < 0.05) in yaks from group S than group C. Microbiome analysis revealed that 8 phyla and 54 genera were significantly different (p < 0.05) in both yak groups, with increased probiotics (Akkermansia, Oscillospira), SCFAs producing genera (Oscillospira, ASF356, Anaerosporobacter and Phascolarctobacterium), and decreased inflammatory related genus (Flavonifractor, Fournierella) and harmful bacteria (Oscillibacter, Achromobacter) in group S. In conclusion, the results demonstrated that SA and SB could decrease diarrhea rates in yak calves on the plateau via increasing antioxidant ability and SCFAs, while decreasing inflammatory responses in yaks by moderating gut microbiota. The current results provide new insights for the prevention and treatment of diarrhea in yaks.

Gut microbiota are the microbial organisms that play a pivotal role in intestinal health and during disease conditions. Keeping in view the characteristic functions of gut microbiota, in this study, Lactobacillus reuteri TPC32 (L. reuteri TPC32) was isolated and identified, and its whole genome was analyzed by the Illumina MiSeq sequencing platform. The results revealed that L. reuteri TPC32 had high resistance against acid and bile salts with fine in vitro antibacterial ability. Accordingly, a genome sequence of L. reuteri TPC32 has a total length of 2,214,495 base pairs with a guanine–cytosine content of 38.81%. Based on metabolic annotation, out of 2,212 protein-encoding genes, 118 and 101 were annotated to carbohydrate metabolism and metabolism of cofactors and vitamins, respectively. Similarly, drug-resistance and virulence genes were annotated using the comprehensive antibiotic research database (CARD) and the virulence factor database (VFDB), in which vatE and tetW drug-resistance genes were annotated in L. reuteri TPC32, while virulence genes are not annotated. The early prevention of L. reuteri TPC32 reduced the Salmonella typhimurium (S. Typhimurium) infection in mice. The results show that L. reuteri TPC32 could improve the serum IgM, decrease the intestinal cytokine secretion to relieve intestinal cytokine storm, reinforce the intestinal biochemical barrier function by elevating the sIgA expression, and strengthen the intestinal physical barrier function. Simultaneously, based on the 16S rRNA analysis, the L. reuteri TPC32 results affect the recovery of intestinal microbiota from disease conditions and promote the multiplication of beneficial bacteria. These results provide new insights into the biological functions and therapeutic potential of L. reuteri TPC32 for treating intestinal inflammation.

The systematic analysis of the synergistic mechanism between microbial fiber-degrading enzymes and short-chain fatty acids under high-fiber diet conditions is limited. In this study, we evaluated the effects of a high-fiber diet on the growth performance, nutrient digestibility, blood and serum metrics, cellulase/hemicellulase activity, and fecal microbial composition of growing Tibetan pigs. Forty Tibetan pigs were allocated to a control group (CON, the diet contains 5% crude fiber) or a high-fiber group (HF, the diet contains 10% crude fiber) based on crude fiber levels as a blocking factor. The pre-trial period was 7 d, and the formal trial lasted 28 d. CON group and HF group showed no effect on growth performance and nutrient apparent digestibility (p > 0.05). The HF group showed significantly higher fecal cellulase and hemicellulase activities than those of the CON group (p < 0.05). Additionally, the HF group showed significantly elevated levels of acetic, propionic, and butyric acids, as well as increased relative abundances of Fibrobacter and p-75-a5 in the feces (p < 0.05). The correlation analysis revealed that Fibrobacter exhibited significant positive correlations with acetic acid, butyric acid, cellulase, and hemicellulase, whereas p-75-a5 was significantly positively correlated with hemicellulase (p < 0.05). In conclusion, this study provides strong evidence that the efficient utilization of dietary fiber by Tibetan pigs results from highly specialized microbial mechanisms in their large intestine, as reflected by their fecal microbiota composition. Fibrobacter and p-75-a5 play a crucial role in enabling these pigs to utilize fiber effectively. Certain specific microbiota secrete a greater quantity of enzymes to facilitate the decomposition of dietary fiber, and this process ultimately leads to the generation of more metabolites.

Yak has ability to adapt the harsh environments like extremely cold, anoxic, strong ultraviolet rays and shortage of pasture. It is observed that the nutritional supply during the preweaning period is highly associated with the development of the gastrointestinal tract and immunity of animals. In this study, twenty-one male yak calves were divided into control group (DFC), starter feed group 1 (DFO), and starter feed group 2 (DFT) to study the growth of early weaning Chawula yak calves. Calves in group DFC were free-ranged, DFO group were fed with alfalfa (1.4 kg/head/day) and starter feed 1 (1.4 kg/head/day), and DFT group were fed with alfalfa ( 1.4 kg/head/day) and starter feed 2 ( 1.4 kg/head/day) for 6 weeks. The body weight of yak calves in DFT was significantly higher than that of control yaks in DFC (P < 0.05), and the net weight growth rate in DFO (P < 0.001) and DFT (P < 0.0001) were both obviously higher than that in the DFC group. The chest girth (bust) in group DFO (P < 0.05) and DFT (P < 0.05) were both markedly higher than that in the DFC group. The serum contents of T-AOC in DFC calves were markedly lower than DFO (P < 0.01) and DFT (P < 0.001) yaks. Also, T-AOC was obviously higher in DFT yaks than in DFO animals (P < 0.05). The levels of GSH-Px were significantly higher in DFO (P < 0.01) and DFT (P < 0.01) yaks than DFC yaks. High throughout sequencing achieved 391520, 356907 and 353763 filtered sequences in DFC, DFO and DFT yaks, and one phylum (Firmicutes B 370539) and thirty-seven genera (Phocaeicola A 858004, Cryptobacteroides, Evtepia, CAG-273, etc.) were identified as biomarkers in yak calves. We observed that starter feeds could promote the growth of early weaning Chawula yak calves by enhancing antioxidant capacity and regulating the gut microbiota.

The physiological parameters of Tibetan piglets have been found to be significantly influenced by environmental factors particularly during the weaning period and in the context of large fluctuations in ambient temperature in plateau regions. This study was designed to examine the effects of different ambient temperatures on gut microbiota diversity, serum antioxidant status, and growth performance of weaned Tibetan piglets. The study comprised of n = 40 weaned Tibetan piglets that were randomly allocated to five temperature-controlled groups with increase in temperature as BC4 (18 °C), BD4 (22-24 °C), BE4 (25-27 °C), BF4 (28-30 °C), and BG4 (31-33 °C). The growth performance was calculated by average daily weight gain (ADG) while serum antioxidant capacity was assessed through malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px) levels. Fecal samples were taken and through 16 S rRNA gene sequencing the gut microbiota profiling was checked. Microbial α- and β-diversity indices, community composition, and taxa-specific shifts were evaluated by temperature-dependent changes. Results indicated that moderate increase in ambient temperature (25 ~ 27 °C) significantly improved the growth performance with higher ADG in the BE4 group. The serum antioxidant markers SOD, T-AOC, and GSH-Px level were higher than MDA concentrations, indicating enhanced oxidative resistance. The beneficial bacterial taxa such as Paraprevotella, Limosilactobacillus, and Paralachnospira flourished and change the gut microbiota diversity and structure, whereas potentially harmful taxa (Bifidobacterium_388775 and Ligilactobacillus) were decreased at the moderate temperatures. The LEfSe and multiple t-tests determine the gut microbial ecology when temperature-dependent shifts in microbial composition indicate a regulatory effect of ambient temperature. It is concluded that the optimal growth performance and enhanced serum antioxidant capacity in weaned Tibetan piglets maintained by moderate raise of ambient temperature (25 ~ 27 °C) to support a balanced gut microbiota. These findings indicated that during the weaning period temperature played an important role in regulating oxidative status and gut microbial diversity.