The Western Diet-Microbiome-Host Interaction and Its Role in Metabolic Disease.

The dietary pattern that characterizes the Western diet is strongly associated with obesity and related metabolic diseases, but biological mechanisms supporting these associations remain largely unknown. We argue that the Western diet promotes inflammation that arises from both structural and behavioral changes in the resident microbiome. The environment created in the gut by ultra-processed foods, a hallmark of the Western diet, is an evolutionarily unique selection ground for microbes that can promote diverse forms of inflammatory disease. Recognizing the importance of the microbiome in the development of diet-related disease has implications for future research, public dietary advice as well as food production practices. Research into food patterns suggests that whole foods are a common denominator of diets associated with a low level of diet-related disease. Hence, by studying how ultra-processing changes the properties of whole foods and how these foods affect the gut microbiome, more useful dietary guidelines can be made. Innovations in food production should be focusing on enabling health in the super-organism of man and microbe, and stronger regulation of potentially hazardous components of food products is warranted.

Microbe-microbe and host-microbe interactions drive microbiome dysbiosis and inflammatory processes.

An extensive microbiome comprised of bacteria, viruses, bacteriophages, and fungi is now understood to persist in nearly every human body site, including tissue and blood. The genomes of these microbes continually interact with the human genome in order to regulate host metabolism. Many components of this microbiome are capable of both commensal and pathogenic activity. They are additionally able to persist in both 'acute' and chronic forms. Inflammatory conditions historically studied separately (autoimmune, neurological and malignant) are now repeatedly tied to a common trend: imbalance or dysbiosis of these microbial ecosystems. Population-based studies of the microbiome can shed light on this dysbiosis. However, it is the collective activity of the microbiome that drives inflammatory processes via complex microbe-microbe and host-microbe interactions. Many microbes survive as polymicrobial entities in order to evade the immune response. Pathogens in these communities alter their gene expression in ways that promote community-wide virulence. Other microbes persist inside the cells of the immune system, where they directly interfere with host transcription, translation, and DNA repair mechanisms. The numerous proteins and metabolites expressed by these pathogens further dysregulate human gene expression in a manner that promotes imbalance and immunosuppression. Molecular mimicry, or homology between host and microbial proteins, complicates the nature of this interference. When taken together, these microbe-microbe and host-microbe interactions are capable of driving the large-scale failure of human metabolism characteristic of many different inflammatory conditions.

Immunostimulation in the treatment for chronic fatigue syndrome/myalgic encephalomyelitis.

Chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) has long been associated with the presence of infectious agents, but no single pathogen has been reliably identified in all patients with the disease. Recent studies using metagenomic techniques have demonstrated the presence of thousands of microbes in the human body that were previously undetected and unknown to science. More importantly, such species interact together by sharing genes and genetic function within communities. It follows that searching for a singular pathogen may greatly underestimate the microbial complexity potentially driving a complex disease like CFS/ME. Intracellular microbes alter the expression of human genes in order to facilitate their survival. We have put forth a model describing how multiple species-bacterial, viral, and fungal-can cumulatively dysregulate expression by the VDR nuclear receptor in order to survive and thus drive a disease process. Based on this model, we have developed an immunostimulatory therapy that is showing promise inducing both subjective and objective improvement in patients suffering from CFS/ME.

Immunostimulation in the era of the metagenome.

Microbes are increasingly being implicated in autoimmune disease. This calls for a re-evaluation of how these chronic inflammatory illnesses are routinely treated. The standard of care for autoimmune disease remains the use of medications that slow the immune response, while treatments aimed at eradicating microbes seek the exact opposite-stimulation of the innate immune response. Immunostimulation is complicated by a cascade of sequelae, including exacerbated inflammation, which occurs in response to microbial death. Over the past 8 years, we have collaborated with American and international clinical professionals to research a model-based treatment for inflammatory disease. This intervention, designed to stimulate the innate immune response, has required a reevaluation of disease progression and amelioration. Paramount is the inherent conflict between palliation and microbicidal efficacy. Increased microbicidal activity was experienced as immunopathology-a temporary worsening of symptoms. Further studies are needed, but they will require careful planning to manage this immunopathology.