Clinical and nutritional significance of intestinal bacterial overgrowth

Symbiosis, in which two very different creatures live together in constant and largely harmonious relationship, is always interesting not least when it concerns our own insides or outsides. The microflora of our two surfaces exposed to the elements skin and gut have received over the years a good deal of attention. Each probe by microbiologists has quickly revealed situations bristling with giant problems of classification of multiple species, themselves apparently held together by interdependencies and feedback controls which have proved peculiarly intractable to elucidation. Not surprisingly, the steam has tended to run out of these investigations and beyond the readily ascertainable facts that the microflora of the skin and gut are different from one another, complex in their make-up, broadly similar at the same site in different individuals, and normally maintained within extraordinarily fine limits, we know very little about the details. But while the professional microbiologists (with rare exceptions) have been wringing their hands, clinicians have become convinced that disturbances of the bowel flora underly some of their patients' disorders, and as befits men of action, have set out to discover why. As might be expected, a minimum of study has shown that pathological states do little to alleviate the complexity which exists normally. Nevertheless a number of conditions have been shown to improve on antibacterial therapy a finding not unreasonably interpreted as indicating bacterial participation and changes in the bowel flora have been shown to accompany some disorders of nutrition.