The chicken gastrointestinal tract has a diverse microbial community. There is increasing evidence for how this gut microbiome affects specific molecular pathways and the overall physiology, nervous system and behavior of the chicken host organism due to a growing number of studies investigating conditions such as host diet, antibiotics, probiotics, and germ-free and germ-reduced models. Systems-level investigations have revealed a network of microbiome-related interactions between the gut and state of health and behavior in chickens and other animals. While some microbial symbionts are crucial for maintaining stability and normal host physiology, there can also be dysbiosis, disruptions to nutrient flow, and other outcomes of dysregulation and disease. Likewise, alteration of the gut microbiome is found for chickens exhibiting differences in feather pecking (FP) behavior and this alteration is suspected to be responsible for behavioral change. In chickens and other organisms, serotonin is a chief neuromodulator that links gut microbes to the host brain as microbes modulate the serotonin secreted by the host’s own intestinal enterochromaffin cells which can stimulate the central nervous system via the vagus nerve. A substantial part of the serotonergic network is conserved across birds and mammals. Broader investigations of multiple species and subsequent cross-comparisons may help to explore general functionality of this ancient system and its increasingly apparent central role in the gut-brain axis of vertebrates. Dysfunctional behavioral phenotypes from the serotonergic system moreover occur in both birds and mammals with, for example, FP in chickens and depression in humans. Recent studies of the intestine as a major site of serotonin synthesis have been identifying routes by which gut microbial metabolites regulate the chicken serotonergic system. This review in particular highlights the influence of gut microbial metabolite short chain fatty acids (SCFAs) on the serotonergic system. The role of SCFAs in physiological and brain disorders may be considerable because of their ability to cross intestinal as well as the blood-brain barriers, leading to influences on the serotonergic system via binding to receptors and epigenetic modulations. Examinations of these mechanisms may translate into a more general understanding of serotonergic system development within chickens and other avians.
The nexus of gut microbiota, diet, and health
The gut microbiome incorporates the ecological niche specific to the totality of the microorganisms in the human gut. Unique to every individual, the blueprint of the microbiome sets up at birth and functions as a human organ and plays a significant role in digestion, detoxification, fighting pathogens, modulating the immune system, and improving health. The gut microbiota and associated health implications are influenced by factors such as birth and age, diseases, use of antibiotics and food components (e.g., complex carbohydrates and dietary fibers, plant proteins, unsaturated fatty acids, and functional compounds of natural origin such as flavones, flavonoids, polyphenols, and antioxidants). Toward this end, diet and the gut microbiome interact and govern each other’s fate. Herein, gut dysbiosis, the alteration of natural state and composition of the gut microbiome, and the gut microflora diversity modulated by food constituents and associated health effects have been discussed. The gut microbiota composition and related metabolites are influenced by the diet which in turn modulates human health. The outcome is deemed to aid in developing personalized diet recommendations (based on the unique gut microbiome) toward improving human health. Keywords: gut microbiome, gut microbiota, gut dysbiosis, short-chain fatty acids, metabolites, health modulation
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- Award ID(s):
- 1849206
- NSF-PAR ID:
- 10335993
- Date Published:
- Journal Name:
- Functional Food Science
- Volume:
- 2
- Issue:
- 2
- ISSN:
- 2767-3146
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.31989/ffs.v2i2.885
