Go With Your GUT

How the gastrointestinal tract affects -- and is affected by -- one's general health status.

The human cell is analogous to a complex industrial plant. It cannot operate properly with inadequate raw materials, malfunctioning metabolic machinery or in the presence of too many toxic compounds. It is critical our cells receive adequate nutrition, but how can our bodies benefit if nutrition is consumed but not delivered at the cellular level?

The gastrointestinal tract has three primary physiological functions: food digestion, nutrient absorption and eliminating toxins from the body. Failure of any one of these functions can lead to decreased energy production, increased energy needs and excess usage of body reserves, which serve as a buffer against the development of diseases.

For thousands of years, we have known nutrition is essential in maintaining good health. However, the role of the gastrointestinal tract as the site of origin and/or site of exacerbation of many diseases is a relatively new concept. About 100 years ago, Elie Metchnikoff conceived the notion that the development of many illnesses originated from a "toxic bowel." In his eagerness to cure, he went a little overboard by recommending a colectomy as treatment for many of his patients. Needless to say, this had limited success and the concept rapidly fell into disrepute. Nonetheless, Metchnikoff's concept stands as a major contribution in medical history.

Over the past 30 years, there has been renewed interest in the metabolic consequences resulting from disordered intestinal ecology (dysbiosis) and from increased intestinal permeability (leaky gut syndrome). These two concepts have revolutionized the way we look at the normal function and malfunction of the gastrointestinal tract, as well as the relationship between these concepts and the development of disease.

As we learn about dysbiosis and leaky gut syndrome, we discover they can exist separately or simultaneously and each can cause the development of the other. Additionally, they are particularly important because of their widespread presence in clinical situations. We will learn that the clinical management of dysbiosis and leaky gut syndrome is critical in controlling the manifestations of many underlying disease processes, as well as preventing potential diseases prior to the onset of clinical symptoms.

DYSBIOSIS

A complex ecological balance exists between the microflora in the gastrointestinal tract and its human host. When the host and microflora coexist in harmony, a healthy state of symbiosis results. When they live in dys-symbiosis (or "dysbiosis" for short), this disordered ecology often results in mal-homeostasis and--ultimately--clinical disease.

The gastrointestinal flora has been called an organ system within itself. There are more than 500 different bacterial species (99% of which are anaerobic) that collectively comprise more metabolic activity than any organ system in the human body.

A wide variety of important functions are normally provided by the microflora when the ecology is undisturbed and healthy. These normal functions include the metabolism of hormones, carcinogens and xenobiotics, the synthesis of vitamins K, [B.sub.5], [B.sub.6] and biotin, synthesis of short chain fatty acids (SCFA's) such as butyrate, crowding out of pathogenic flora, as well as the stimulation of the secretory immunoglobulin A antibody (SIgA) and intramural antibody systems.

The presence of abnormal microflora in the gastrointestinal tract can result in:

* deactivation of digestive enzymes that can lead to maldigestion and malnutrition consumption of vitamin [B.sub.12] and certain amino acids

* saturation of essential omega three and six fatty acids

* disruption of the intestinal lining, potentially causing leaky gut syndrome

* sensitization against translocated bacteria and their fragments that can lead to leaky gut syndrome and to autoimmune diseases

* development of yeast overgrowth syndromes

* development of irritable bowel syndrome and inflammatory bowel disease such as C. difficile enterocolitis

* deconjugation of bile acids and estrogen, potentially inducing bowel or breast cancer

The causes of dysbiosis are far more prevalent than generally recognized by most medical practitioners. Basically, any situation that can alter the physical, chemical or physiological integrity of the gastrointestinal tract can result in changes in the microflora make up. The microflora by itself, however, is rarely the instigator of dysbiosis. What happens that enables certain amounts of organisms to overgrow, thereby upsetting the previously existing ecological balance? What makes an organism pathogenic when it's normally commensal?

There are two factors that determine the pathogenicity of an organism. First, the virulence of the organism or its ability to overgrow and produce toxins that can injure the human host. The second factor, host resistance, is half-heartedly acknowledged by modern medicine, but generally not addressed adequately. In fact, it is widely believed the organism invading the tissues is the primary underlying problem and eradicating it is the solution. It is interesting that all organisms inhabiting the intestinal tract (including friendly bacteria such as acidophilus), under the right circumstances, can cause sepsis and death. Yet, in other circumstances--such as when patients are immunocompromised in cases of AIDS or cancer--modern medicine pays more attention to the fact that host defenses are weakened. In these situations, rather than focusing on augmenting host defenses, the goal seems to be killing organisms that might be potential pathogens. Indeed, it is seen as a war between man and germs.