Effects of Short-Chain Fatty Acid Modulation on Potentially Diarrhea-Causing Pathogens in Yaks Through Metagenomic Sequencing

Abstract

Short-chain fatty acids (SCFA) are principal nutrient substrates of intestinal epithelial cells that regulate the epithelial barrier in yaks. Until now, metagenomics sequencing has not been reported in diarrheal yaks. Scarce information is available regarding the levels of fecal SCFA and diarrhea in yaks. So, our study aims to identify the potential pathogens that cause the emerging diarrhea and explore the potential relationship of short-chain fatty acids in this issue. We estimated diarrhea rate in yaks after collecting an equal number of fecal samples from affected animals. Metagenomics sequencing and quantitative analysis of SCFA were performed, which revealed 15%–25% and 5%–10% prevalence of diarrhea in yak’s calves and adults, respectively. Violin box plot also showed a higher degree of dispersion in gene abundance distribution of diarrheal yaks, as compared to normal yaks. We found 366,163 significant differential abundance genes in diarrheal yaks, with 141,305 upregulated and 224,858 downregulated genes compared with normal yaks via DESeq analysis. Metagenomics binning analysis indicated the higher significance of bin 33 (Bacteroidales) (p < 0.05) in diarrheal animals, while bin 10 (p < 0.0001), bin 30 (Clostridiales) (p < 0.05), bin 51 (Lactobacillales) (p < 0.05), bin 8 (Lachnospiraceae) (p < 0.05), and bin 47 (Bacteria) (p < 0.05) were significantly higher in normal yaks. At different levels, a significant difference in phylum (n = 4), class (n = 8), oder (n = 8), family (n = 16), genus (n = 17), and species (n = 30) was noticed, respectively. Compared with healthy yaks, acetic acid (p < 0.01), propionic acid (p < 0.01), butyric acid (p < 0.01), isobutyric acid (p < 0.01), isovaleric acid (p < 0.05), and caproic acid (p < 0.01) were all observed significantly at a lower rate in diarrheal yaks. In conclusion, besides the increased Staphylococcus aureus, Babesia ovata, Anaplasma phagocytophilum, Bacteroides fluxus, viruses, Klebsiella pneumonia, and inflammation-related bacteria, the decrease of SCFA caused by the imbalance of intestinal microbiota was potentially observed in diarrheal yaks.

Sodium acetate/sodium butyrate alleviates lipopolysaccharide-induced diarrhea in mice via regulating the gut microbiota, inflammatory cytokines, antioxidant levels, and NLRP3/Caspase-1 signaling

“…In our previous study, we found a significant decrease in concentrations of SCFAs, especially acetic acid and butyric acid in yaks ( Li et al, 2022 ). We hypothesized that sodium acetate/sodium butyrate supplementation could alleviate diarrhea in animals, similar to how Lactobacillus plantarum alleviated diarrhea in a previous study by balancing gut microbiota and regulating SCFAs ( Yue et al, 2020 ).…”

“…Diarrhea is a severe disease coupled with gastrointestinal dysfunction that has a global impact on fertility rate, milk production, and immunity in livestock ( Coura et al, 2015 ; Li et al, 2022 ). Nowadays diarrhea in dairy cows and yak is very serious.…”

“…It has a high incidence rate, especially neonatal calf diarrhea is found usually with high morbidity and mortality, causing considerable economic damage to the industry due to the heavy treatment expenses and impairments in the growth of animal ( Coura et al, 2015 ; Schmoeller et al, 2021 ). Despite measures such as improved hygiene and scientific feeding management with the use of extensive drugs, this disease, i.e., diarrhea, remains serious ( Li et al, 2022 ). The imbalance in gut microbiota was commonly recognized as the primary cause of diarrhea ( Schmoeller et al, 2021 ), and many studies found changed intestine microbiota in diarrhea of cattle ( Chuang et al, 2022 ; Coelho et al, 2022 ; Li et al, 2022 ; Liu J. et al, 2022 ).…”

“…Despite measures such as improved hygiene and scientific feeding management with the use of extensive drugs, this disease, i.e., diarrhea, remains serious ( Li et al, 2022 ). The imbalance in gut microbiota was commonly recognized as the primary cause of diarrhea ( Schmoeller et al, 2021 ), and many studies found changed intestine microbiota in diarrhea of cattle ( Chuang et al, 2022 ; Coelho et al, 2022 ; Li et al, 2022 ; Liu J. et al, 2022 ).…”

Effects of Microencapsulated Sodium Butyrate, Probiotics and Short Chain Fructooligosaccharides in Patients with Irritable Bowel Syndrome: A Study Protocol of a Randomized Double-Blind Placebo-Controlled Trial

“…Butyrate constitutes a key source of energy for enterocytes and has a trophic effect on the colon epithelium, supporting the restoration of the disrupted structural and functional integrity of the epithelial barrier [ 17 ]. Butyrate may also affect the composition of intestinal microbiota by inhibiting the proliferation of pathogens and fostering desirable strains [ 18 ]. Moreover, butyrate beneficially affects several inflammatory cytokines and myeloperoxidase activity via inhibition of nuclear factor kappa B [ 19 ].…”