Gut microbes and integrative neuroscience

April 22, 2014 | James Kohl

Diverse Microbes in Hunter-Gatherers’ Guts

Modern hunter-gatherers have more diverse microbiota in their guts than do urban Europeans, but lack a few notable species. By Kerry Grens | April 16, 2014

Excerpt: Genetic diversity, rather than particular species, might be a more important criterion to determine the health of a microbiome, the authors proposed in a press release. “These findings illustrate a need to reevaluate the standards by which we consider [gut microbiota] ‘healthy’ or ‘unhealthy’, as they are clearly context dependent,” the authors wrote in their report.

My comment:  Diversity and function of the avian gut microbiota “With a broader knowledge of avian hosts, we may be able to compare and contrast solutions of terrestrial vertebrate hosts to various physiological challenges, perhaps gaining insight into the evolution of the intestinal microbiota in a broader sense.”

The avian-to-mammalian vertebrate link exemplifies how nutrient acquisition enables the pheromone-controlled physiology of reproduction associated with species-specific mate choice. (The pheromones are species-specific because the gut microbes that metabolize the nutrients are species-specific.) This exemplifies how ecological variation leads to ecological adaptation outside the context of evolution, no matter what aspect of evolution others think they are examining. For example, consciousness is an ecological adaptation, but most theorists place it into the context of something that has somehow evolved.

The evolutionary and genetic origins of consciousness in the Cambrian Period over 500 million years ago

My comment (1 of 8): In the context of olfactory associative consciousness, others may be interested in this excerpt “…we reason it was spontaneous binding between congruent olfactory and visual information [25] that formed a multimodal saliency map where the visual object with added olfactory presence gained increased perceptual saliency.” — from the Oct 2013 publication of “Olfaction spontaneously highlights visual saliency map.”

In the context of adaptive evolution, all of the conserved molecular mechanisms have their origins in the de novo creation of olfactory receptor genes that allow chemical stimuli to epigenetically alter the thermodynamics of intercellular signaling that leads to stochastic gene expression and the organism-level thermoregulation required for nutrient-dependent pheromone-controlled reproduction via a direct link from the epigenetic ‘landscape’ to the physical landscape of DNA.

Loss of olfactory acuity and specificity in neurodegenerative diseases like Alzheimers (and perhaps all others) indicates that no other sensory input is more important to consciousness than is olfaction — a fact that seems to be overlooked here. In addition, gonadotropin releasing hormone (GnRH) is the molecule that controls the nutrient-dependent physiology of reproduction in all vertebrates that have adaptively evolved during the past 400 million years, since substitution of achiral glycine constrained ligand-receptor binding — with downstream effects on every other adaptively evolved neuronal system in the vertebrate brain.

Constraints on adaptive evolution begin with glucose uptake and pheromones that epigenetically effect the pulsatile secretion of GnRH. Pulses transmit much more information than can be transferred linearly, which attests to the central important of food odors and pheromones in the context of olfactory associative consciousness. When age-related loss of olfactory acuity and specificity leads to conditions where loved ones become unrecognizable, how can consciousness be attributed to any other sensory input other than olfactory/pheromonal input in the context of adaptive evolution? It is obvious to me that vertebrate perceptual saliency is an extension of invertebrate perceptual saliency that is more clearly nutrient-dependent and pheromone-controlled, since invertebrates could not have otherwise adaptively evolved. Same with vertebrates; the molecular mechanisms are conserved!

[However, these are the conserved molecular mechanisms that lead from ecological variation to ecological adaptations. Have I erred by referring to them in terms of adaptive evolution, since no experimental evidence suggests that consciousness evolved? Or did I use the term adaptive evolution because reviewers reject the use of terms like ecological adaptations.]

The microbiota–gut–brain axis: neurobehavioral correlates, health and sociality

My comment: When I saw the citation to Kohl (2012), I thought of my work and how it could have been placed into the context of this article. See for example:

Kohl, J.V. (2012) Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2: 17338.

However, from a broader perspective, the link from microbial metabolism of nutrients to species-specific pheromones that control the physiology of reproduction, and thus control adaptive evolution [ecological adaptation] in species from microbes to man, may be more important. See for example:

Kohl, J.V. (2013) Nutrient-dependent/pheromone-controlled adaptive evolution: a model. Socioaffective Neuroscience & Psychology, 3: 20553.

See also: “From Fertilization to Adult Sexual Behavior

In our 1996 Hormones and Behavior Review article, our section on the molecular epigenetics of what are obviously nutrient-dependent alternative splicings predicted that the alternative splicings, which link the epigenetic “landscape” to the physical landscape of DNA would be controlled by species-specific pheromones.

These authors bring that concept forward to human chemical communication albeit without integrating the evolutionary continuum of ecological, social, neurogenic, and socio-cognitive niche construction that is nutrient-dependent and pheromone-controlled in the context of adaptive evolution [ecological adaptation]. Are theories about birds the problem?

Others have also failed to incorporate what is now known about pheromones in birds, which is probably because they continue to be misrepresented as primarily visual and auditory creatures. However, we know now that “Bird odour predicts reproductive success.”

Thus, perhaps

1) Kohl, K. D. (2012). Diversity and function of the avian gut microbiota.


2) Kohl, J.V. (2012) Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors.

will be considered in the future in the context of Frontiers in Integrative Neuroscience, which would extend integrative neuroscience to socioaffective neuroscience and psychology.



James Vaughn Kohl

James Vaughn Kohl

James Vaughn Kohl was the first to accurately conceptualize human pheromones, and began presenting his findings to the scientific community in 1992. He continues to present to, and publish for, diverse scientific and lay audiences, while constantly monitoring the scientific presses for new information that is relevant to the development of his initial and ongoing conceptualization of human pheromones.