Research Note: Increase of bad bacteria and decrease of good bacteria in the gut of layers with vs. without hepatic steatosis

Abstract

Fatty liver hemorrhagic syndrome ( FLHS ), usually occurring in hens in the late laying period, can lower egg yield and even cause death. Similar to nonalcoholic fatty liver disease in humans, FLHS may begin with simple hepatic steatosis. It is known that gut microbiota is important to the development of nonalcoholic fatty liver disease, but the relationship between FLHS and gut bacteria remains unclear. In this study, bacteria compositions in the ileum and cecum were determined by 16S rDNA sequencing analysis in the groups of hens with vs. without hepatic steatosis (average liver fat contents were 0.34 mmol/g protein or 2.6% vs. 0.84 mmol/g protein or 6.0%). These hens were in the 2 tails of the liver fat content distribution with each tail accounting for 10% of the test population containing 90 66-wk-old healthy Rhode Island Red laying hens raised under routine feeding regimen. The results showed that liver weight but not the weights of the body, heart and abdominal fat were significantly different between the groups. Moreover, bacterial diversity was not significantly different between the groups, but bacterial diversity in the cecum was higher than that in the ileum. Proteobacteria was the most dominant phylum in the ileum, whereas Proteobacteria, Firmicutes, and Bacteroidetes were the most dominant phyla in the cecum. Some bacteria were common to the ileum and cecum, but some were unique. Furthermore, some bacteria were significantly different in abundance between the groups, that is the group without hepatic steatosis had more bacteria inhibiting host energy absorption or benefiting intestinal health, whereas the group with hepatic steatosis had more conditionally pathogenic or harmful bacteria. In conclusion, hepatic steatosis in laying hens is associated with intestinal bacterial composition (bacterial abundance) but not bacterial diversity. The identified common and unique bacteria are related to the functional characteristics of the ileum and cecum. The decrease of beneficial bacteria and the increase of harmful bacteria in the intestine of laying hens may increase FLHS incidence by promoting hepatic steatosis.

Caecal microbiota could effectively increase chicken growth performance by regulating fat metabolism

“…Further findings indicated that the higher ratio of Firmicutes and Bacteroidetes can induce fat deposition (Ley et al ., 2006 ; Compare et al ., 2016 ; Koliada et al ., 2017 ; Indiani et al ., 2018 ). In addition, recent studies described Sphingomonas as an abundant bacterium in the gut microbiota of chicken (Chen et al ., 2018a ; Li et al ., 2020b ). Another study reported that sphingolipids from Sphingomonas could control different cellular processes, that is migration, apoptosis and proliferation (Bryan et al ., 2016 ).…”

“…For instance, Sphingomonas synthesized sphingosine, which later with fatty acids derivatives formed sphingomyelin, thus reduced fat deposition in the chicken liver. These findings suggested that the abundance of Sphingomonas genus was significantly correlated with hepatic fat metabolism (Li et al ., 2020b ). Microbacterium and Sphingomonas related to lipid metabolism were significantly observed across all chicken embryonic stages, which suggested a significant contribution in the development of gut microbiota for chicken growth (Akinyemi et al ., 2020 ).…”

Effects of Dietary Ferulic Acid on the Intestinal Microbiota and the Associated Changes on the Growth Performance, Serum Cytokine Profile, and Intestinal Morphology in Ducks

“…Similar results were reported previously regarding to those bacteria. Though phylum Proteobacteria included several pathogens, they could degrade the nutrients in the diet and provide suitable environmental support for symbiotic bacteria, and eventually promoted the growth of layers ( Li et al, 2020 ). Shi et al (2019) stated that species in order Oscillospirales , such as Oscillospira , were butyrate producers and negatively related to the F/G ratio in broilers under heat stress.…”

Effect of Dietary Methylsulfonylmethane Supplementation on Growth Performance, Hair Quality, Fecal Microbiota, and Metabolome in Ragdoll Kittens

“…For instance, Sphingomonas was shown to synthesize sphingosine and later formed sphingomyelin with fatty acids derivatives, thus reducing fat deposition in the chicken liver. These findings suggested that the abundance of the Sphingomonas genus was significantly correlated with hepatic fat metabolism ( Li et al, 2020 ). Thus, our results showed that MSM had no negative impact on the gut microbes of kittens.…”