The Gut Microbiome and Our Health


Perhaps the time-worn expression “having a gut feeling” holds more potency than any of us realized. Studies of the intestinal gut microbiome reveal how disturbances in its biodiversity can affect everything from obesity and autoimmune diseases to chronic depression. As a follow-up to our article the Mediterranean Diet and gut health, we will now delve deeper into the far-reaching effects of gut health and how certified personal trainers can counsel their clients in this area.

The Gut-Microbiome, Inflammation, and Obesity

Systemic chronic low-grade inflammation, often associated with obesity, renders an individual prone to cardiovascular diseases and type 2 diabetes. Past research honed in on unregulated adipose tissue or insulin resistance as the main culprits in inflammation. However, systemic inflammation involves a complexity only recently studied and still somewhat of a mystery.

Chronic inflammation often presents in individuals consuming a high-fat diet; scientists now posit whether this condition appears as a prelude to obesity-related metabolic disorders, not an end product since the gut microbiome appears substantially different in those living with autoimmune diseases, obesity, and other metabolic disorders.

Considering the human gastrointestinal system receives first exposure to everything we ingest, the supposition exists that as diet affects the gut microflora, systemic inflammation might result. The medical community feels that a promising step rests on the premise that restoring gut microbiota composition (by dietary intervention, prebiotics, and probiotics) could mitigate disease.

High-Fat Factor

To examine the relationship between food consumption and gut dysfunction, a study was conducted with two groups of subjects: one received a high-fat diet, the other continued to consume normal meals.  Data revealed that the higher fat diet aligned with significant changes in the gut microbiome, intestinal permeability, and systemic low-grade inflammation. Glucose tolerance also plummeted.

Armed now with the strong conviction that one’s gut microbiome plays a key role in the appearance of inflammation and altered metabolic pathways, future studies plan to assess whether probiotics might serve as an important tool in both the treatment and prevention of obesity and Type 2 diabetes.

Not All Calories are Created Equal

According to a study published in the journal Nature Communications, the human body appears to react differently to calories ingested from high-fiber whole foods vs. ultra-processed or “junk” foods. The latter get absorbed faster upon entering the upper GI tract, rendering fewer calories enter the gut microbiome at the end of the digestive tract.

Conversely, high-fiber foods can remain intact longer, sustaining the full journey to the large intestine. Here, the trillions of bacteria comprising the gut microbiome can begin to get busy.  Interestingly, the net result seems a reduction of caloric intake.

The study reveals that gut microbes exist in a perennial tug of war with the rest of the body for calories, said Karen D. Corbin, an investigator at the AdventHealth Translational Research Institute of Metabolism and Diabetes in Orlando and the lead author of the study.

She further adds, “On a Western diet that doesn’t feed the microbes very much, almost all the energy goes to us and very little goes to the microbes. We don’t give the microbes any opportunity to utilize the calories we ate because we use them all. We pull the rope all the way to one end.”

To minimize early absorption and to maximize the quantity of food ultimately reaching the microbes in the large intestine, choosing a diet comprised of whole foods rather than their processed counterparts keeps the gut microflora happy and in peak working order.

Such a meal plan advocates eating whole nuts over nut butter, steak instead of ground beef, and fresh whole fruits as opposed to processed juices. Such a plan ultimately leads to weight and body fat loss, a primary reason clients state for seeking out the expertise of personal trainers.

The Gut Microbiome and Organ Cross-Talk

Irritable Bowel Syndrome IBS Medical Concept

Upon closer inspection, scientists noted the presence of what they call “bi-directional cross-talk” between host microflora and the endocrine system, the point of origin for autoimmune dysfunction. The immune system participates in such cross-conversation.

The gut microbiome not only regulates systemic immunity; the immune system also contributes to the biodiversity of the microflora. This mutual communication between the microbiota and the immune system underscores how the human body’s health relies on “outside-in” and “inside-out” systems of checks and balances.

The ever-evolving studies on intestinal microflora now demonstrate that inflammation within the central nervous system also stems from our gut health.  Once again, bi-directional communication occurs, referred to as the “brain axis signaling pathways”.

A healthy gut landscape can transmit brain signals through connections involving neurogenesis, neural transmission, and behavioral control. Disruption to the indigenous gut microbiota renders these pathways dysregulated; the resulting altered permeability negatively affects the blood-brain barrier.

It seems feasible then to see how gut microflora has a powerful impact on mental health, most notably stress, depression, and anxiety disorders. As a prime example, over 20% of individuals living with chronic inflammatory bowel disease suffer from some manner of sleep disturbances and depression.

The “Inside-Outside” Scoop

Clients often open up to us about how they “do everything right” with regard to lifestyle and diet, yet still cannot achieve their goals. Educating them about the far-reaching effects of their gut microbiome could shed some light on their predicament. Trainers have the ability to guide clients, reminding them how healthy insides keep us fit and disease-free.



Cathleen Kronemer is an NFPT CEC writer and a member of the NFPT Certification Council Board. Cathleen is an AFAA-Certified Group Exercise Instructor, NSCA-Certified Personal Trainer, ACE-Certified Health Coach, former competitive bodybuilder and freelance writer. She is employed at the Jewish Community Center in St. Louis, MO. Cathleen has been involved in the fitness industry for over three decades. Feel free to contact her at [email protected]. She welcomes your feedback and your comments!
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