Persistent low prevalence of Western digestive diseases in Africa: confounding aetiological factors

Diet, ageing and genetic factors in the pathogenesis of diverticular disease

“…Animal models of DD hint at a role for the colonic microflora in the disease process, especially when one considers the differences in microflora composition between high and low risk populations [60,102] . A direct comparison of the fecal and colonic mucosal flora between cases and controls might simply reveal differences associated with the altered luminal environment; a better approach would be to characterize the microflora of volunteers prior to any prospective study.…”

“…The average Kenyan diet whilst being relatively high in fiber is also considered, for much of the population, to be total energy, macro and micronutrient deficient [59] . Similarly, the diet of poor urban South Africans may also be deficient in total energy and some macro and micronutrients, but in contrast to the Kenyan diet it is low in dietary fiber with an increasing emphasis on fat [60] . The point is that modern (and by inference non-traditional) African diets are highly variable; there is also evidence of a shift towards a western dietary pattern with corresponding clinical observations suggesting that DD prevalence may actually be on the rise [61] .…”

Fiber, FODMAPs, flora, flatulence, and the functional bowel disorders

“…10 Even Segal and Walker, two of the early proponents for the high-fiber diet, have recently acknowledged that reduced dietary fiber intake has not resulted in increased colonic diseases in Africans. 11 In fact they have now recognized the importance of the "quality of the intestinal bacteria", and the impact that this has on the fermentation of malabsorbed carbohydrates. 12 In their recent paper they have assembled measurements for various classes of immunoglobulins, and other markers of immune activation, that support a high level of exposure to gastrointestinal infections in childhood.…”

“…12 In their recent paper they have assembled measurements for various classes of immunoglobulins, and other markers of immune activation, that support a high level of exposure to gastrointestinal infections in childhood. 11 Their new hypothesis is that it is this early priming that gives the African a more robust gut microflora, better able to withstand the insults in adult life. The corollary is also that if we expect fiber and oligosaccharides that are promoted as prebiotics to enhance the proliferation of 'good bacteria', we have to start feeding these substrates to our gut in the early years of life.…”

“…7,9 Clinical trials have demonstrated a survival advantage of approximately 2-3 months with sorafenib among patients with advanced-stage HCC. 10,11 The outcomes of these trials in Asian and Western countries, however, were noticeably different in terms of overall survival, time to progression, and adverse events. Reasons for these differences are not fully understood, but may include differences in the severity of underlying disease, differing etiological factors, and/or cultural differences in relation to the reporting of adverse events.…”