Fecal virus transplantation has more moderate effect than fecal microbiota transplantation on changing gut microbial structure in broiler chickens

Growing evidence of fecal microbiota transplantation (FMT) and fecal virus transplantation (FVT) provides a possibility to regulate animal health, whereas little is known about the impact of the 2 methods. This study aimed to investigate the effects of gut microbes on jejunal function in healthy broiler chickens, with the objective of establishing a theoretical basis for the application of FMT and FVT. Cecal feces from 28-day-old AA broilers were collected to prepare gavage juice for FMT and FVT. FMT for Group FM, FVT for group FV and PBS gavage for group CON, continuously treated for 6 days start at 5-day-old chicks. Samples were collected at d 11 and d 21. The results showed that the treatment d 2 and the overall fecal score in treatment groups were significantly lower than CON group (P< 0.05). The jejunum morphology showed that FMT increased crypt depth, decreased villus height, V/C (P< 0.05) and FVT increased villus height (P< 0.05) at d 11. At d 21, villus height and crypt depth significantly higher (P< 0.05) in group FM and group FV. The expression of Claudin1, Occludin, ZO2, and Muc2in the FV group was significantly increased (P< 0.05) at 11-day-old. FMT increased the secretion of sIgA at 11-day-old, and this influence lasted up to 21-day-old (P< 0.05). At 11-day-old, the expression of b0+ATof basic amino acid transport carrier and chymotrypsin activity (P< 0.05) had a significant correlation. At 21 d of age, FVT significantly increased the expression of PepT1and SGLT1(P< 0.05). At 11-day-old, FM group showed significantly higher faith pd index (P= 0.004) and Shannon index (P= 0.037), and separated from FV and CON according to PCoA. Among differentiating bacteria, Bacteroidessignificantly enriched (P< 0.05) in group FM, which positively correlated with the expression of ZO2, Muc2, Occludin,and Claudin1; R_Ruminococcus, L_Ruminococcus, Butyricicoccusssignificantly enriched (P< 0.05) in group CON, which significantly higher than processing groups, R_Ruminococcusand L_Ruminococcusnegatively correlated with the expression of Occludin(P< 0.05), and R_Ruminococcus, Butyricicoccusnegatively correlated with the expression of Claudin1(P< 0.05). At 21-day-old, PCoA based on Bray-Curtis shows that microbes taxa of 3 groups are isolated with each other and treatment groups were significant different with CON group based on Unweighted UniFrac and weighted UniFrac. The expression of PepT1was significantly negatively (P< 0.05) correlated with Ruminococcus, and the expression of sIgA was significantly negatively (P< 0.05) correlated with Parabacteroides. In conclusion, FMT regulated intestinal flora rapidly, while it had little effect on intestinal function and a higher potential damaging risk on jejunal. FVT regulated intestinal flora structure softer, improved tight junction expression, but the mechanism of action needs further exploration.