Smoking habits and previous appendectomy have emerged in many epidemiological studies as two of the main environmental factors that have been shown to be associated with IBD. Diet, exercise patterns, and occupational exposures are other examples of possible confounders which are often not considered in these studies, but may vary between individuals and especially between industrialized and non-industrialized nations.4 Furthermore, though urban living conditions, which have also been associated with chronic inflammatory diseases22, are often included into regression models, the definitions of urban vs. rural may be inconsistent from one country to another and may not be reflective of actual hygienic conditions, potential exposures, and disease risks. This could lead to misclassification bias and could create confusion within the results. Additionally, it is very plausible that the mechanism by which these organisms affect the human immune system may differ significantly based on the specific species. This would mean that studies in one helminth should not be seen as evidence for or against another type of helminthic therapy; however, due to limited availability of peer-reviewed publications on the topic, it is important to consider all of the work that has been done. Finally, it is still possible that certain individuals are genetically predisposed to develop the chronic inflammatory diseases and that helminth infection is being confused with the geographical spread of these
Smoking habits and previous appendectomy have emerged in many epidemiological studies as two of the main environmental factors that have been shown to be associated with IBD. Diet, exercise patterns, and occupational exposures are other examples of possible confounders which are often not considered in these studies, but may vary between individuals and especially between industrialized and non-industrialized nations.4 Furthermore, though urban living conditions, which have also been associated with chronic inflammatory diseases22, are often included into regression models, the definitions of urban vs. rural may be inconsistent from one country to another and may not be reflective of actual hygienic conditions, potential exposures, and disease risks. This could lead to misclassification bias and could create confusion within the results. Additionally, it is very plausible that the mechanism by which these organisms affect the human immune system may differ significantly based on the specific species. This would mean that studies in one helminth should not be seen as evidence for or against another type of helminthic therapy; however, due to limited availability of peer-reviewed publications on the topic, it is important to consider all of the work that has been done. Finally, it is still possible that certain individuals are genetically predisposed to develop the chronic inflammatory diseases and that helminth infection is being confused with the geographical spread of these