The Microbiota–Gut–Brain Axis: Gut Microbiota Modulates Conspecific Aggression in Diversely Selected Laying Hens

Abstract

The gut microbiota plays an important role in regulating brain function, influencing psychological and emotional stability. The correlations between conspecific aggression, gut microbiota, and physiological homeostasis were further studied in inbred laying chicken lines, 63 and 72, which were diversely selected for Marek’s disease, and they also behave differently in aggression. Ten sixty-week-old hens from each line were sampled for blood, brain, and cecal content. Neurotransmitters, cytokines, corticosterone, and heterophil/lymphocyte ratios were determined. Cecal microbiota compositions were determined by bacterial 16s rRNA sequencing, and functional predictions were performed. Our data showed that the central serotonin and tryptophan levels were higher in line 63 compared to line 72 (p < 0.05). Plasma corticosterone, heterophil/lymphocyte ratios, and central norepinephrine were lower in line 63 (p < 0.05). The level of tumor necrosis factor α tended to be higher in line 63. Faecalibacterium, Oscillibacter, Butyricicoccus, and Bacteriodes were enriched in line 63 birds, while Clostridiales vadin BB60, Alistipes, Mollicutes RF39 were dominated in line 72. From the predicted bacterial functional genes, the kynurenine pathway was upregulated in line 72. These results suggested a functional linkage of the line differences in serotonergic activity, stress response, innate immunity, and gut microbiota populations.

Effects of Alhagi camelorum Fisch polysaccharide from different regions on growth performance and gastrointestinal microbiota of sheep lambs

“…Firmicutes can decompose polysaccharides and produce short-chain fatty acids such as propionic acid, butyric acid and acetic acid ( Cockburn and Koropatkin, 2016 ). Tenericutes have been reported to promote gastrointestinal health and inhibit intestinal inflammation ( Hu et al, 2022a ). On the other hand, Proteobacteria and Actinobacteria harbor many pathogenic microorganisms.…”

Probiotic Fermentation of Kelp Enzymatic Hydrolysate Promoted its Anti‐Aging Activity in D‐Galactose‐Induced Aging Mice by Modulating Gut Microbiota

“…The bidirectional relationship between gut microbiota and the brain is an established fact, and the concept of the gut microbiotagut-brain axis has been proposed. [ 41,42] The gut microbiota can directly or indirectly affect aging and associated diseases. [43] SC-FAs can improve intestinal barrier functioning, and they are significant metabolites of gut microbiota.…”

The Impact of Early-Life Cecal Microbiota Transplantation on Social Stress and Injurious Behaviors in Egg-Laying Chickens

“…IL-8, as a chemoattractant cytokine, attracts and activates neutrophils in inflammatory regions via regulating the innate immune system. In addition, line differences in social stress and stress-induced aggressive behaviors have been observed; line 7 2 chickens have higher heterophil-to-lymphocyte (H/L) ratios (a stress indicator) with more aggressive pecks and longer durations of fights than those of line 6 3 chickens [ 102 , 104 , 112 ]. The differences in behaviors could be related to the line differences in serotonergic activities [ 105 ].…”