Diarrhea is a word-widely severe disease coupled with gastrointestinal dysfunction, especially in cattle causing huge economic losses. However, the effects of currently implemented measures are still not enough to prevent diarrhea. Previously we found that dropped short-chain fatty acids in diarrhea yaks, and butyrate is commonly known to be related to the epithelial barrier function and intestinal inflammation. However, it is still unknown whether sodium acetate/sodium butyrate could alleviate diarrhea in animals. The present study is carried out to explore the potential effects of sodium acetate/sodium butyrate on lipopolysaccharide-induced diarrhea in mice. Fifty ICR mice were randomly divided into control (C), LPS-induced (L), and sodium acetate/sodium butyrate (D, B, A)-treated groups. Serum and intestine samples were collected to examine inflammatory cytokines, antioxidant levels, relative gene expressions via real-time PCR assay, and gut microbiota changes through high-throughput sequencing. Results indicated that LPS decreased the villus height (p < 0.0001), increased the crypt depth (p < 0.05), and lowered the villus height to crypt depth ratio (p < 0.0001), while sodium acetate/sodium butyrate supplementation caused a significant increase in the villus height (p < 0.001), decrease in the crypt depth (p < 0.01), and increase in the villus height to crypt depth ratio (p < 0.001), especially. In mice treated with LPS, it was found that the serum level of IL-1β, TNF-α (p < 0.001), and MDA (p < 0.01) was significantly higher; however, sodium acetate/sodium butyrate supplementation significantly reduced IL-1β (p < 0.001), TNF-α (p < 0.01), and MDA (p < 0.01), respectively. A total of 19 genera were detected among mouse groups; LPS challenge decreased the abundance of Lactobacillus, unidentified F16, unidentified_S24-7, Adlercreutzia, Ruminococcus, unclassified Pseudomonadales, [Ruminococcus], Acetobacter, cc 1, Rhodococcus, unclassified Comamonadaceae, Faecalibacterium, and Cupriavidus, while increased Shigella, Rhodococcus, unclassified Comamonadaceae, and unclassified Pseudomonadales in group L. Interestingly, sodium acetate/sodium butyrate supplementation increased Lactobacillus, unidentified F16, Adlercreutzia, Ruminococcus, [Ruminococcus], unidentified F16, cc 115, Acetobacter, Faecalibacterium, and Cupriavidus, while decreased Shigella, unclassified Enterobacteriaceae, unclassified Pseudomonadales, Rhodococcus, and unclassified Comamonadaceae. LPS treatment upregulated the expressions of ZO-1 (p < 0.01) and NLRP3 (p < 0.0001) genes in mice; however, sodium acetate/sodium butyrate solution supplementation downregulated the expressions of ZO-1 (p < 0.05) and NLRP3 (p < 0.05) genes in treated mice. Also, the LPS challenge clearly downregulated the expression of Occludin (p < 0.001), Claudin (p < 0.0001), and Caspase-1 (p < 0.0001) genes, while sodium acetate/sodium butyrate solution supplementation upregulated those gene expressions in treated groups. The present study revealed that sodium acetate/sodium butyrate supplementation alleviated LPS-induced diarrhea in mice via enriching beneficial bacterium and decreasing pathogens, which could regulate oxidative damages and inflammatory responses via NLRP3/Caspase-1 signaling. The current results may give insights into the prevention and treatment of diarrhea.

The occurrence of diarrhea in Tibetan piglets is highly notable, but the microorganisms responsible are yet unclear. Its high incidence results in serious economic losses for the Tibetan pig industry. Moreover, the dynamic balance of intestinal microflora plays a crucial role in maintaining host health, as it is a prime cause of diarrhea. Therefore, the present study was performed to analyze the characteristics of bacterial microbiota structure in healthy, diarrheal and treated weaned piglets in Tibet autonomous region for providing a theoretical basis to prevent and control diarrhea. The study was based on the V3–V4 region of the 16S rRNA gene and gut microbiota functions following the metagenome analysis of fresh fecal samples (n = 5) from different groups. The Shannon and Simpson indices differed substantially between diarrheal and treated groups (p < 0.05). According to our findings, the beta diversities, especially between healthy and diarrheal groups, were found different. Firmicutes, Bacteroidetes and Proteobacteria were the dominant phyla in three groups. Furthermore, the abundance of Fusobacteria in the diarrheal group was higher than the other groups. The dominant genera in the diarrheal group were Fusobacterium, Butyricimonas, Sutterella, Peptostreptococcus, and Pasteurella. Moreover, Lactobacillus, Megasphaera and Clavibacter were distinctly less abundant in this group. It is noteworthy that the specific decrease in the abundance of pathogenic bacteria after antibiotic treatment in piglets was noticed, while the level of Lactobacillus was evidently increased. In conclusion, fecal microbial composition and structure variations were discovered across the three groups. Also, the ecological balance of the intestinal microflora was disrupted in diarrheal piglets. It might be caused by a reduction in the relative number of beneficial bacteria and an increase in the abundance of pathogenic bacteria. In the context of advocating for non-resistant feeding, we suspect that the addition of probiotics to feed may prevent early-weaning diarrhea in piglets. Moreover, our findings might help for preventing diarrhea in weaned Tibetan piglets with a better understanding of microbial population dynamics.

Due to the high crude fiber content, straw of various crops is difficult to become a high quality forage resource. The degradation of cellulose in nature mainly depends on the cellulase secreted by microbes, which degrade cellulose into small molecular substances through chemical action, and the microbes that secrete cellulase mainly include some bacteria, fungi and actinomycetes, etc. The large and diverse microbial population contained in the mammalian gastrointestinal tract plays an important role in nutrient digestion. At present, many cellulose-degrading strains have been screened and obtained from animal digestive system and feces, such as Bacillus subtilis from the feces of Panda, Bacillus amyloliquefaciens from the cecum of goose. In this study, the fungal diversity was analysed in the fresh faeces of Tibetan sheep, Tibetan gazelle and Tibetan antelope in Qiangtang, Tibet. Results showed that the structure and species of gut fungi are different in three animals, which may be related to the different physiological functions among different animals, e.g., Tibetan antelope and Tibetan gazelle have stronger tolerance to rough feeding than Tibetan sheep. This study will lay a foundation for cellulose-degrading fungal development and provides technical support for improving rough feeding tolerance of Tibetan sheep.